Oryza sativa L.) is the major source of daily caloric intake for more than 30% of the human population. However, the sustained productivity of this staple food crop is continuously threatened by various pathogens and herbivores. Breeding has been successful in utilizing various mechanisms of defense by gene pyramiding in elite cultivars, but the continuous resurgence of highly resistant races of pathogens and herbivores often overcomes the inherent capacity of host plant immunity. MicroRNAs (miRNAs) are endogenous, short, single-stranded, non-coding RNA molecules that regulate gene expression by sequence-specific cleavage of target mRNA or suppressing target mRNA translation. While miRNAs function as upstream regulators of plant growth, development, and host immunity, their direct effects on growth and development in the context of balancing defenses with agronomic potential have not been extensively discussed and explored as a more viable strategy in breeding for disease and pest resistant cultivars of rice with optimal agronomic potentials.Rice  in rice. Defense-related miRNAs such as Osa-miR156, Osa-miR159, Osa-miR162, Osa-miR396, Osa-530, Osa-miR1432, Osa-miR1871, and Osa-miR1873 are critical in fine-tuning and integrating immune responses with physiological processes that are necessary to the maintenance of grain yield. Recent research has shown that many defense-related miRNAs regulate complex and agronomically important traits.Using the available knowledge in rice and other model plants, this review examines the important roles of miRNAs in regulating host responses to various fungal, bacterial, and viral pathogens, and insect pests, in the context of gains and trade-offs to crop yield. Gains from R-gene-mediated resistance deployed in modern rice cultivars are often undermined by the rapid breakdown of resistance, negative pleiotropic effects, and linkage drags with undesirable traits. In stark contrast, several classes of miRNAs are known to efficiently balance the positive gains from host immunity without significant costs in terms of losses in agronomic potentials (i.e.Identification of novel immune-responsive miRNAs that orchestrate physiological processes critical to the full expression of agronomic potential will facilitate the stacking of optimal combinations of miRNA-encoding genes to develop high-yielding cultivars with durable resistance to disease and insect pests with minimal penalties to yield. Oryza sativa L.) is one of the major staple food crops that provide calories to more than one-third of the human population. Rice productivity is constantly challenged by the negative impacts of pathogens, insect herbivores, and other parasites. These biotic stresses, particularly pathogens, account for 20–30% of losses in global rice yields [The world population is increasing at an alarming rate, with projections of 10 billion by 2050 [Pathogens and their host plants continuously compete for dominance in a co-evolutionary battle. Plants have evolved multi-layered defense strategies against pathogen invasion , 4. HostHost-plant immunity is dependent on the successful activation of defense-related genes. Successful virulent pathogens often overcome the PTI by mediating effector-triggered susceptibility (ETS), which leads to disease development . In respMIR loci) by RNA polymerase II [hyponastic leaves 1 (HYL1) and serrate (SE) into double-stranded miRNA-miRNA* (*passenger strand of miRNA) duplex [MicroRNAs (miRNAs) are short (~ 22 nucleotides), endogenous, single-stranded, non-coding RNAs that form a characteristic stem-loop structure. Their function is to negatively regulate the expression of their target genes  at the post-transcriptional level. Importantly, microRNAs act as crucial modulators of various cellular and biological processes, including plant growth, development, reproduction, and responses to biotic and abiotic stresses –16. Planerase II . The lon) duplex , 19. The) duplex . The gui) duplex . ComplemIn the past few years, the rapid development of next-generation sequencing (NGS) technologies and powerful algorithms for the prediction and modelling of interactions at the genetic, genomic, and molecular levels opened new paths in miRNA discovery. Molecular genetic approaches like 5’RACE, degradome sequencing, stem-loop RT-PCR, reporter gene analysis, loss- or gain-of-function mutation experiments have led to the discovery and unraveling of the function of the large number of miRNAs . In riceMagnaporthe oryzae [•2−), hydroxyl radicals (OH·) and hydrogen peroxide (H2O2)  has been shown to play important roles in defense against fungal pathogens such as e oryzae . Patterne oryzae , 55. Whee oryzae , 57. In Osa-miR159, Osa-miR160, Osa-miR162a, Osa-miR166k, Osa-miR166h, Osa-miR398b, and Osa-miR7695 have been shown to function as positive regulators of defenses against the rice blast disease caused by fungus Magnaporthe oryzae [Osa-miR159a fine-tunes host plant growth and immunity by inhibiting its three target genes, OsGAMYB, OsGAMYBL, and OsZF. The OsGAMYB and OsGAMYBL are transcriptional regulators of gibberellic acid signaling, while OsZF is a C3HC4- domain-containing zinc finger protein involved in ubiquitin-protein transferase activity. Transgenic rice plants overexpressing a short tandem target mimic (STTM) to inhibit the Osa-miR159a showed enhanced host susceptibility to the disease. In contrast, the knock-down mutation of the target genes conferred resistance to M. oryzae.Several miRNAs, including e oryzae . For insOsa-miR159-GAMYB module orchestrates the reproductive developmental process by its direct role in the regulation of flower, pollen, and seed development [Osa-159a must be precisely spatiotemporally regulated to coordinate plant development and immunity. Similarly, leaf and seed development in rice has been shown to be regulated by Osa-miR160 via auxin signaling, which also acts as a positive regulator of rice immunity against M. oryzae. Transgenic plants overexpressing Osa-miR160 displayed significantly stronger resistance to blast disease. The Osa-miR160a enhances resistance to blast by suppressing the AUXIN RESPONSE FACTOR 16 (ARF16), which in turn silences the indole-3-acetic acid (IAA) signaling [miR166, which belongs to a highly conserved family of miRNA molecules. The miR166 targets the class III homeodomain-leucine zipper family (HD ZIP III) of transcription factors [miR166-family members, i.e., Osa-miR166k and Osa-miR166h, has been shown to cause stronger immunity against M. oryzae and Fusarium fujikuroi, through targeting of the ethylene insensitive 2 (EIN 2) gene via cross-regulation. This mechanism has been shown to occur without negative effects on plant growth [In addition, the elopment . It is aignaling . Diverse factors , 59. In t growth .2O2 in response to biotic and abiotic stresses. It has been shown that Osa-miR162a fine-tunes the host’s innate immunity against M. oryzae by targeting the Dicer-like 1 (OsDCL1) gene through the accumulation of intracellular H2O2 thereby facilitating cell death at the infection site. This mechanism also regulates other physiological processes that are critical to yield maintenance. Overexpression of Osa-miR162a showed enhanced resistance to M. oryzae by positively regulating many other defense-related genes [OsDCL1 showed developmental defects in rice at the seedling stage, including dwarfism, root and shoot abnormality, and wilting of leaves. All of these effects indicate that Osa-miR162a optimizes growth and immunity without any yield penalty. ROS homeostasis is regulated by several key enzymes, including superoxide dismutase (SOD). Consistent with earlier reports, elevated levels of cellular H2O2 has been observed with the suppression of the Cu/Zn superoxide dismutase (SOD) genes by the Osa-miR398b. This process positively regulates host immunity against blast by negatively regulating the components of ROS production and homeostasis [.Plants produce Hed genes . Growingeostasis .M. oryzae infection, higher activity of SOD is associated with accumulation of H2O2, which leads to enhanced resistance to blast [Osa-miR7695 has been shown to function as a positive regulator of rice immune response by mediating the trade-off between defense and iron homeostasis. Rice plants overexpressing Osa-miR7695 showed increased resistance to M. oryzae and stronger Fe accumulation at the site of infection. It was proposed that upon infection with M. oryzae, expression of Osa-miR7695 leads to the suppression of the target gene OsNramp 6 , which encodes an iron transporter [Upon to blast . ROS is nsporter , 60.Osa-miR156fhl-3p, Osa-miR164a, Osa-miR167d, Osa-miR169a, Osa-miR319, Osa-miR396, Osa-439a, Osa-miR444, Osa-miR530, Osa-miR1432, and Osa-miR1873 have been identified as negative regulators of rice innate immunity against M. oryzae. These miRNAs have been reported to control rice innate immunity by targeting critical transcription factors. The miR156 belongs to a conserved family that regulates plant growth, development, and yield by targeting the SQUAMOSA promoter-binding protein-like transcription factor 14 (SPL14) and WRKY45 transcription factor. In rice, overexpression of Osa-miR156fhl-3p in a target mimic mutant showed stronger resistance to blast by virtue of enhanced expression of the target genes SPL14 and WRKY45 transcription factors [OsNAC60 transcription factor is negatively regulated by the suppression of Osa-miR164a upon M. oryzae infection, which leads to the enhancement of defense responses [Osa-miR164a/OsNAC60 regulatory module has been shown to result in a susceptible phenotype. The Osa-miR164a has also been involved in controlling the sheath blight-causing fungus Rhizoctonia solani by activating the salicylic acid (SA) signaling pathway and expression of associated defense-related genes. Expression of Osa-miR169a has been shown to condition a strong resistance against M. oryzae by suppressing its target gene nuclear factor Y-A (NF-YA). Significant accumulation of Osa-miR169a has been documented in a susceptible genotype of rice with a somewhat decreased resistance level. Transgenic rice plants overexpressing Osa-miR169a have been shown to exhibit a higher level of susceptibility, which was associated with the downregulation of target genes and reduced accumulation of intracellular H2O2 [Osa-miR530 controls H2O2 production by regulating the expression of dihydrofolate reductase/thymidylate synthase (DHFR-TS). It is noted that DHFR-TS participates in the maintenance of redox balance by producing the nicotinamide adenine dinucleotide phosphate (NADPH) and ROS. Subsequently, ROS is converted into H2O2 by SOD. Perturbation of Osa-miR530 enhances resistance to blast disease through its effects on H2O2 accumulation. It is important to mention that blocking the Osa-miR530 also positively affects flowering and seed maturation [Osa-miR439a negatively affects immunity by inhibiting the expression of defense-related genes and H2O2 production Suppression of the Osa-miR439a using target mimic mutants has been shown to compromise susceptibility to M. oryzae by induction of H2O2 [The  factors . Expressesponses . Abolitituration . The Osa of H2O2 .Osa-miR319 modulates host immune response in the rice-M. oryzae interaction in a negative manner. Accumulation of Osa-miR319 has been observed in susceptible genotypes as indicated by the suppression of the target gene OsTCP21 upon M. oryzae infection. Blocking the conversion of a-linoleic acid (LnA) to hydroperoxy-octadecadienoic acid (HPODE) has been shown to inhibit the jasmonic acid (JA) signaling pathway [Osa-miR444b.2 has also been identified among the many negative regulators of rice immunity against M. oryzae. Overexpression of Osa-miR444b.2 enhances susceptibility to M. oryzae but with little impact on its target transcription factors MADS27b and MADS57. Altered expression of the target mimicry of Osa-miR444b.2 resulted in enhanced resistance to blast [Osa-miR444a has been shown to positively regulate immunity against the rice stripe virus (RSV) by upregulating OsRDR1 expression, which is facilitated by suppressing target MADS-box genes [The to blast . The Osaox genes .Osa-miR1432 has been shown to fine-tune resistance to disease as well as yield potential by targeting the OsEFH1 (EF-hand family protein 1). Overexpression of Osa-miR1432 has been shown to compromise resistance to M. oryzae with concomitant adverse effects on yield. On the other hand, inhibition of Osa-miR1432 expression has enhanced resistance with positive effects on yield, attributed to the enhancement of PTI responses [M. oryzae infection, immunity and yield in rice are also balanced by the Osa-miR1871. Inhibition of Osa-miR1871 expression greatly enhances resistance and yield, by virtue of the effects on the targetOsMFAP1 (Microfibrillar-associated protein 1) gene. In contrast, overexpression of Osa-miR1871 had been shown to cause susceptibility to blast, with concomitant negative effects on grain yield [The esponses . During in yield .Osa-miR1873 appeared to regulate resistance to rice blast in a negative manner. It has been shown that expression of Osa-miR1873 leads to disease susceptibility through the suppression of a target gene with an unknown function . Suppression of Osa-miR1873 through the expression of the target mimicry mutant has been shown to enhance defense response against blast by fine-tuning host plant immunity and growth [Osa-miR167d modulates plant developmental and stress responses by targeting auxin response factor (ARF) genes. The Osa-miR167d also seemed to play a negative role in rice immunity against M. oryzae by blocking ARF12 genes. Suppression of Osa-miR167d by overexpressing a target disease mimic mutant led to enhanced resistance to blast [Osa-miR396 revealed its negative effect on defense response against M. oryzae by silencing multiple OsGRF genes. Overexpression of Osa-miR396 promotes susceptibility to blast through the downregulation of OsGRFs genes. Suppression of Osa-miR396 by expressing the target disease mimics mutant enhanced resistance to blast with concomitant improvement in yield [The d growth . The Osato blast . Charactin yield .Xanthomonas oryzae pv. oryzae (Xoo). Another class of miRNAs has been shown to positively regulate resistance against the bacterial foot rot disease caused by Dickeya zeae. Of the miRNAs involved in responses to BB, the Osa-miR159b has been shown to function as a positive regulator, while the others function as negative regulators. The Osa-miR159b enhances resistance to BB by repressing its target transcription factor OsGAMYB involved in gibberellic acid (GA) signaling. This process leads to negative effects on nitrogen assimilation as an outcome of the repression of the GA signaling pathway [Five classes of miRNAs have been shown to modulate resistance against bacterial blight (BB) caused by  pathway .Osa-miR167 has also been shown to be involved in rice immunity to bacterial pathogens [Osa-miR167d abates immunity upon Xanthomonas oryzae pv. oryzae (Xoo) infection by suppressing the target gene OsWD40–174, which downregulates the lignin biosynthetic gene OsKNOX during leaf development [Osa-miR164a showed enhanced susceptibility to Xoo by virtue of the downregulation of the OsNAC60 transcription factor [miR164a/OsNAC60 regulatory module in blast resistance has been discussed earlier in this review. The Osa-miR169o represents the coordinated crosstalk regulation between BB and Nitrogen-use efficiency (NUE) in rice. Overexpression of the miR169o enhances NUE and promotes susceptibility to BB by suppressing the nuclear factor Y-A (NF-YA), which in turn causes significant downregulation of several defense-related genes, including PR10b, PR1b, PR10a, and PAL [Osa-miR156 negatively regulates immunity against bacterial blight [IPA1  under the control of a pathogen-inducible promoter of OsHEN1 have been shown to enhance both disease resistance and yield.The athogens , 61. Forelopment . Downregelopment . Transgen factor . The rol and PAL . The Osal blight . TransgeOsa-miR396f was shown to play a positive role in conferring resistance against bacterial foot rot disease caused by Dickeya zeae. Overexpression of Osa-miR396f in the susceptible rice variety Nipponbare showed enhanced immunity to D. zeae by suppressing the target gene OsGRFs (Growth-Regulating Factors). However, the precise molecular mechanism underpinning the immunity against bacterial foot roots mounted by OsGRFs is still unknown [More recently,  unknown .The miRNA-mediated gene regulation has emerged as a novel strategy to enhance antiviral defenses in crop plants, including rice . Plants Osa-miR528 is well characterized and known to be involved in regulating defenses against the rice stripe virus (RSV). In cleavage-defective AGO18 mutants of rice, the Osa-miR528 is sequestered away from AGO1, upon RSV infection. These, in turn, prevent the formation of a functional RNA-induced silencing complex. These events further lead to the enhanced expression of downstream gene AO, encoding an L-ascorbate oxidase and functions in the initiation of defense response against RSV through the accumulation of ROS [OsSPL9 specifically regulates the expression of the Osa-miR528-AO module by binding to the promoter of the Osa-miR528. Mutation of OsSPL9 has been shown to cause the dramatic downregulation of Osa-miR528, thereby inducing AO expression that leads to enhanced resistance to RSV [MicroRNAs provide an additional layer of intrinsic defense against viral attacks. In rice, the n of ROS . Furthere to RSV .Osa-miR168 upon RSV infection. It has been shown that AGO18 competes with AGO1 for binding to Osa-miR168, resulting in an elevated level of AGO1-mediated resistance [Osa-miR444, which positively regulates immune response. Transgenic plants overexpressing the Osa-miR444 displayed a broad-spectrum resistance to RSV by inducing OsRDR1 and by silencing several MADS-box transcription factors [The AGO18 also sequesters the sistance . RSV inf factors .Osa-miR171. Such impaired expression has been shown to severely affect plant height and chlorophyll content, thereby causing RSV-like symptoms. It has been demonstrated that plants expressing miR171b were less susceptible to RSV characterized by attenuated RSV symptoms [Osa-miR319 acts as a negative regulator of immunity against the ragged stunt virus (RRSV) in rice. Transgenic plants overexpressing the Osa-miR319 have exhibited severe disease-like symptoms by negatively affecting the target gene OsTCP21 (TEOSINTE BRANCHED/CYCLOIDEA/PCF) and subsequently suppressing JA-mediated plant defense pathways [RSV infection of host rice plants perturbs the expression of symptoms . Similarpathways .Bph15 in comparison to a susceptible genotype. Several known miRNAs, along with 183 other novel BPH-responsive miRNAs, have been identified to be involved in the regulation of either basal defenses or targeted resistance to BPH [Bph6 and wild-type [Osa-miR156 was found to function as a negative regulator of the BPH resistance. Sequestration of the Osa-miR156 using a target mimic mutant of Osa-miR156 displayed enhanced resistance to BPH by positively regulating the OsMPK3 and OsMPK6 genes. The transcript level of OsWRKY70 transcription factor was found to be significantly reduced in the Osa-miR156-sequestered target mimic mutant that represses jasmonic acid (JA) biosynthesis and signaling [Osa-miR396, also acts as a negative regulator of BPH resistance. Downregulation of Osa-miR396 enhances the expression of the growth-regulating factor 8 (OsGRF8) gene, which in turn positively regulates the flavanone 3-hydroxylase (OsF3H) gene involved in the flavonoid biosynthesis. The OsF3H positively regulates the BPH resistance through its positive effects on the salicylic acid (SA) pathway and negative effects on the jasmonic acid (JA) pathway [.Rice is host to more than 200 insect pests at different stages of its life cycle. Advances in genomics have greatly expanded the understanding of the role of miRNAs in the regulation of immune response to insect pests. During brown planthopper (BPH) infestation of rice, differentially expressed miRNAs have been identified by deep sequencing in an introgression line carrying the resistance gene e to BPH . Similarild-type . Osa-miRignaling . Another pathway .Modern cultivars are being developed by pyramiding multiple R-genes as well as other types of genes involved in quantitative mechanisms as a major strategy to avoid substantial losses to crop yield due to diseases and pests. However, it has been shown that constitutive expression of R-genes often imposes high fitness costs, mainly with deleterious consequences to plant growth and development. Therefore, the expression of R-genes must be optimized in the right spatial and temporal manner to minimize trade-offs.Emerging evidence suggests that miRNAs and secondary siRNA play important roles in the regulation of R-gene function by silencing the immune-response receptors when the host plant is not under attack by the pathogen. This mechanism is important in stabilizing basal transcript levels to limit the fitness costs of an overactive immune response. Plants have evolved specific miRNAs that can target the conserved domains of the R-gene in two major pathways, either by direct targeting of R-gene or indirect targeting of R-gene via phasiRNA Fig. . In the miR472 was the first to be involved in the direct targeting of the CC-NBS-LRRs domain-containing immune receptor genes in Arabidopsis [N gene transcripts that conditions resistance to tobacco mosaic virus (TMV) has been shown to be mediated by nta-miR6019 and nta-miR6020 modules in the Solanaceae family [miR482/2118 super-family targeting NB-LRR genes have also been well characterized in tomato, and its prime importance in the regulation of immune response is well documented [miR1885 is involved in a dynamic balance between plant growth and immunity to viral pathogen in Brassica by direct silencing the R-gene [Osa-miR1876 has been shown to epigenetically regulate the expression of the NBS8R gene encoding an NB-ARC domain protein that confers resistance to X. oryzae [The bidopsis . Since ie family . The miRcumented . A recene R-gene . More retrans to silence the addition of R-gene transcripts. In rice, no phasiRNA that regulates R-genes has so far been characterized. However, phasiRNAs regulating reproductive development has been reported.Besides the direct targeting of NLRs, miRNAs have also been shown to indirectly regulate R-genes by targeting other genes that are part of the R-gene networks . For exarabidopsis, and citrus [Medicago truncatula, 22-nt miRNAs including miR2275, miR2109, and miR2118 have been shown to trigger the production of phasiRNA that are specifically associated with the regulation of other genes encoding NBS-LRR immune receptors [The phasiRNA targeting R-genes remains unknown in rice. The phasiRNA that targets the conserved motifs of CC-NBS-LRR has been explored in diverse plant species, including spruce, grapevine, poplar, cotton, Ad citrus , 76. Gend citrus . Furthereceptors , 78. TheHigh-yielding rice cultivars with resistance to multiple pathogens and pests are paramount to sustainable production. With major accomplishments by breeding, the caveat appeared to be that strong defense responses often come with unintended trade-offs in terms of significant losses to yield as the photosynthetic source-sink dynamics that should favor plant growth tend to be diverted towards defense-related processes . Modern Osa-miR159, Osa-miR162, Osa-miR396, Osa-miR530, Osa-miR1432, and Osa-1871 have been shown to have positive effects on yield component traits even when the plant is challenged by pathogens [Osa-miR156, fine-tunes resistance without significant penalty to yield, while Osa-miR1873 confers resistance with only a minor penalty to yield [Recent reports have shown that many miRNAs facilitate the maintenance of fitness and resistance with minimal or no penalty to yield. General observations indicate that miRNAs enhance the immunity to pathogens and herbivores with significant positive effects on yield maintenance in most cases. For example, the athogens –38. For to yield , 39.Osa-miR162 synergizes the mechanisms involved in resistance to blast with the genetic potential for yield through the OsDCL1 that causes the accumulation of intracellular H2O2. Nevertheless, overexpression of Osa-miR162 showed significantly narrower grains, lower seed weight, and poor seed set, leading to a significant penalty to grain yield. Silencing of Osa-miR162 showed positive effects on yield by increasing the number of grains per panicle during M. oryzae infection [Osa-miR530 induces early flowering and seed maturation, with positive effects on grain number per panicle and grain weight. The underlying regulatory networks that balance yield-related processes and immunity is an area that is currently under investigation [The nfection . Similartigation .Osa-miR1432 enhances both immunity and yield by targeting the OsEFH1 protein [miR1871-MFAP1 module. Transgenic rice overexpressing Osa-miR1871 as well as the mfap1 mutants exhibit significant reductions in grain yield. Conversely, downregulation of Osa-miR1871 displayed the opposite effects. These results suggested that Osa-miR1871 regulates yield-related traits and immunity through the function of MFAP1 [Osa-miR396 induces multiple growth-regulating factor (GRF) genes that enhance resistance to blast and BPH [Osa-miR396 also plays important roles in the regulation of cellular processes that are critical in the maintenance of inherent potentials for grain size, grain yield, inflorescence development, panicle branching, as well as tolerance to saline and alkaline soil and water [Likewise, downregulation of  protein . The resof MFAP1 . Suppres and BPH . The Osand water –81.Osa-miR156 negatively regulates host immunity against blast, bacterial blight, and BPH by targeting the IPA1 , OsSPLs (SQUAMOSA Promoter-binding protein-like transcription factors), and several OsWRKY genes. Sequestering Osa-miR156 by target mimicry led to enhanced resistance to all three biotic stressors by affecting the accumulation of target transcripts, including the products of defense-related genes [OsSPL14 promotes the panicle branching, which leads to improvements in the number of spikelets per panicle, stronger culm, and tiller reduction. These effects contributed to a significant enhancement of grain yield [The ed genes , 41, 51.in yield , 83.IPA1 gene under the control of bacterial effector-induced promoter leads to enhanced resistance to BB, with concomitant improvement in grain size, plant architecture, and grain yield [Osa-miR1873 has been shown to balance the cellular processes involved in the expression of resistance to blast and maintenance of plant growth. Overexpression of Osa-miR1873 has been shown to compromise resistance with additional negative effects to plant growth and developments as manifested by a significant reduction in yield potential due to the reduction of seed-set as indicated by the proportion of filled grains per panicle. In contrast, studies that sequestered Osa-miR1873 showed that proper regulation causes no significant effects on yield [Osa-miR159, Osa-miR160, Osa-miR164, Osa-miR167, and Osa-miR398 have been shown to affect different traits that are a critical component of yield potential, independently.Transgenic studies showed that inducible expression of the in yield . The Osaon yield . Other mOsa-miR156 is known to regulate a total of eleven (11) SPL genes involved in diverse biological and developmental processes in rice. The Ideal Plant Architecture 1, which encodes a SQUAMOSA Promoter-binding protein-like transcription factors is known to be targeted by Osa-miR156. Overexpression of OsSPL14 enhanced resistance to bacterial blight accompanied by a substantial improvement in yield caused by the reduction in the number of unproductive tillers and enhancement of panicle branching [OsSPL14 perturbs Osa-miR156-mediated regulation of OsSPL14, leading to positive gains in yield maintenance as indicated by the reduction of unproductive tillers and stronger culm [OsSPL14 also enhanced the number of grains per panicle by increasing the panicle branching [MicroRNAs rarely work independently. Single miRNA-encoding loci often function in the regulation of multiple cellular processes, hence more than one trait. Recent studies in rice showed that the role of miRNAs is not limited to the regulation of defense response mechanisms, but they are also involved in the regulation of complex traits Table . For exaranching . Mutatioger culm . Furtherranching .Table 2LOsa-miR156fhl-3p enhances host plant immunity to M. oryzae by positively affecting OsSPL14 and WRKY45 [Panicle blast 1 (Pb1), a panicle blast resistance gene encoding a coiled-coil, nucleotide-binding site, leucine-rich repeat (CC-NBS-LRR) protein, interacts with a WRKY45 transcription factor, which plays a critical role in the expression of induced resistance through the salicylic acid signaling pathway regulated by the ubiquitin-proteasome system [Osa-miR156 could promote seed dormancy by inducing the expression of OsSPL14 and repressing the GA pathway [OsSPL13 promotes yield in rice by improving grain size and panicle length [OsSPL16 improves grain size by binding to GW7 [OsSPL18 binds to the promoter of DEP1 and negatively regulates the cellular process for grain number potential [OsSPL7 negatively affects tiller number and positively affects plant height [OsSPL9 is involved in the regulation of Osa-miR528, which promotes flowering under long-day conditions by repressing the Red and Far-red Insensitive 2 (OsRFI2) gene [OsSPL9 regulates the Osa-miR528/L-Ascorbate Oxidase (AO) transcriptional module, which enhances anti-viral defenses [Osa-miR528 regulates pollen intine formation by targeting the uclacyanin gene OsUCL23 [Osa-miR528 enhances tolerance to salinity and nitrogen-starvation [It was recently shown that downregulation of d WRKY45 . Furthere system . Evidenc pathway . Expresse length . The OsSg to GW7 , 123. Thotential , 125. Ovt height . In riceI2) gene . The OsSdefenses . Moreove OsUCL23 . Likewisarvation .auxin response factors (ARFs) are known to be targeted by Osa-miR160 and Osa-miR167. The Osa-miR160 is known to positively regulate blast resistance, whereas Osa-miR167 acts in an antagonistic fashion. Furthermore, alteration in auxin signaling in rice through the upregulation of Osa-miR160-resistant OsARF18 has been shown to cause severe defects in overall plant growth as well as reproductive development, with negative effects on seed size and seed set [Osa-miR167 promotes an efficient response to auxin, which translates to the concomitant enhancement of tiller number and grain weight [growth regulating factors (GRFs) targeted by Osa-miR396 regulates diverse biological processes. It has been shown that manipulating the Osa-miR396-OsGRFs module substantially increases grain size and yield. Specifically, mutation of the OsGRF4 (GS2) perturbs the function of Osa-miR396 and its regulatory role over OsGRF4 [Osa-miR396 promotes panicle branching by regulating OsGRF6 [.Hormones are the foundations of cellular signaling that integrate growth-related and defense-related responses . In riceseed set , 93. Then weight –103. Ther OsGRF4 , 87, 108g OsGRF6 .Osa-miR164, which is important in processes that control grain yield and other plant architecture traits in rice, has been shown to affect drought tolerance [Osa-miR166 is involved in the regulation of cellular processes determining nutrient and ion uptake, drought tolerance, and cadmium tolerance [Osa-miR169 has been shown to regulate nitrogen uptake and salinity tolerance in rice [Osa-miR319 regulates leaf morphogenesis, plant height, and improves cold tolerance [Osa-miR398 not only modulates panicle length, grain number, and grain size but also regulates various abiotic stresses [Osa-miR444 modulates MADS-box transcription factors to regulate tillering and nitrate signaling [Osa-miR528 regulates tolerance to arsenite and low temperature in rice [Several immune-responsive miRNAs play a critical role in regulating cellular processes that determine nutrient uptake as well as responses to other types of abiotic stresses. For example, the olerance , 97. Theolerance , 127. Th in rice , 104. Tholerance –107. Thestresses , 113. Thignaling –116. The in rice –120.Knock-out mutation of miRNAs is an important approach to validating cellular functions through the identification of their downstream target genes. Furthermore, miRNAs belong to conserved families comprised of multiple members with potentially redundant functions. Therefore, loss-of-function analysis of miRNA-encoding loci has become a major challenge. Traditional methods of mutagenesis  are largely ineffective due to the small size of miRNA molecules. Currently, target mimics (TMs), short tandem target mimics (STTMs), molecular sponges (SPs), and artificial miRNAs (amiRNAs) are the most commonly used techniques for loss-of-function analysis of miRNAs. Among them, the miRNA decoy techniques such as TMs and STTMs have been widely adopted for functional analysis . TMs andGenome editing technologies such as zinc finger nuclease (ZFN), transcription activator-like effector nucleases (TALEN), and clustered regularly interspaced short palindromic repeats (CRISPR)-based system are the more recent cutting-edge approaches for the control of endogenous miRNA abundance . These sZinc-finger nucleases (ZFNs) are artificial restriction enzymes generated by fusing zinc-finger-based DNA-recognition modules with the DNA-cleavage domain. Each zinc finger typically recognizes and binds to a nucleotide triplet, and fingers are often assembled into groups to bind to specific DNA sequences. TALENS is equipped with the same tenet as ZFN with a target specificity from the protein-DNA association. In addition, it can recognize a single nucleotide using specific amino acid repeats to recognize a single nucleotide, thus providing more choices for selecting the target locus. CRISPR-mediated genome editing has revolutionized nuclease targeting –133. In Osa-miR396e and Osa-miR396f using the CRISPR/Cas9 system have been shown to create genetic gains through the enhancing effects to yield component traits such as grain size and panicle branching, particularly under nitrogen deficit conditions [Osa-miR396ef has been shown to promote the efficiency of GA signaling, with concomitant enhancement in grain yield contributed by improvements in grain size, leaf blade and sheath anatomy and morphology [, Osa-miR408, Osa-miR528) or entire miRNA gene families  has been achieved by a CRISPR/Cas9 mediated strategy in rice. It has been shown that under salinity stress, larger deletion in Osa-miR528 led to elevated transcript levels from the target genes [. Similarly, targeted mutagenesis of OsSPL9 using CRISPR)/Cas9 led to a significant reduction in Osa-miR528 expression, suggesting a critical role of OsSPL9 in transcriptional regulation of Osa-miR528 [Recently, CRISPR/Cas9 was efficiently used in rice to introduce heritable mutations in mature miRNAs –136. Knonditions . CRISPR/rphology . Targeteet genes . Similara-miR528 .Osa-miR156 have been investigated for their effects on seed dormancy [superoxide dismutase (SOD) genes to examine their effects on Osa-miR398-mediated resistance to M. oryzae [OsARF12) of Osa-miR167d using the CRISPR/Cas9 method to investigate Osa-miR167-ARF12 interaction in immunity against rice blast disease [Furthermore, a series of CRISPR/Cas9-mediated mutations in dormancy . CRISPR/. oryzae . Targete disease .Continuously emerging evidence from various experimental systems and approaches established the essentiality of miRNA-mediated regulatory mechanisms in integrating defense-related responses to fungal, bacterial, and viral pathogens, and insect herbivores, with growth and development-related responses. MicroRNA regulatory mechanisms have direct roles in host plant immunity by directly suppressing target genes with either negative or positive effects, or by indirectly inducing signaling pathways with different classes of phytohormones and other small molecules such as ROS. Genomics-enabled biology offers an excellent opportunity to identify more miRNAs involved in fine-tuning resistance to biotic stresses to minimize trade-offs to productivity. Harnessing these miRNAs could be useful in breeding disease and pest-resistant rice cultivars without the drags to the agronomic potential that are typically observed when manipulating R-genes alone.Identifying new miRNAs associated with defense mechanisms against pests and diseases could be achieved by employing high-throughput sequencing technologies. Specifically, this approach involves the identification of differentially expressed miRNAs under stress via miRNA-Seq followed by in silico analysis and degradome sequencing to predict miRNA targets. Once the specific roles of the miRNAs and target genes are identified, it would be possible to engineer them through genome-editing technologies. Site-specific mutagenesis of target genes impairs the cleavage by miRNA, which allows the development of transgenic plants with disease and insect resistance. In addition to functional analysis, miRNAs are usually conserved in nature, hence limited sequence diversity. The miRNA binds to their target genes in a sequence-specific manner. Variation in miRNAs leads to a variable level of transcript accumulation that causes compounded phenotypes.


Older adults have adjusted better to the COVID-19 pandemic in terms of their psychological well-being than younger adults. We investigated individual differences in vulnerability within older adulthood as pandemic severity changed, providing a more refined prediction of older adults’ adjustment to COVID-19. Participants from this longitudinal study were included if they had at least one semiannual assessment before and one during the COVID-19 era . There were 1,098 pre-COVID-19 assessments  and 265 post-COVID-19 . At each assessment, participants reported on six cognitive complaints (MOS), five depressive symptoms , and six domains of undesirability-weighted stressful life events . Daily national, state, and regional COVID-19 case and death rates were obtained from the Centers for Disease Control and summed for the week preceding each assessment. In multilevel ZIP models, the COVID-19 era significantly increased depressive symptoms  and stressful events , but did not significantly affect severity of cognitive complaints. Older age was associated with greater impact of COVID-19 on depressive symptoms and stressful events; women reported more stressful events when pandemic severity was high, but men reported more stressful events when pandemic severity was low. Although older adults in general have adjusted better to the pandemic than younger adults, the old-old had greater vulnerability to this unavoidable event than the young-old.


Lasso peptides are a subclass of ribosomally synthesized and post-translationally modified peptides (RiPPs) and feature the threaded, lariat knot-like topology. The basic post-translational modifications (PTMs) of lasso peptide contain two steps, including the leader peptide removal of the ribosome-derived linear precursor peptide by an ATP-dependent cysteine protease, and the macrolactam cyclization by an ATP-dependent macrolactam synthetase. Recently, advanced bioinformatic tools combined with genome mining have paved the way to uncover a rapidly growing number of lasso peptides as well as a series of PTMs other than the general class-defining processes. Despite abundant reviews focusing on lasso peptide discoveries, structures, properties, and physiological functionalities, few summaries concerned their unique PTMs. In this review, we summarized all the unique PTMs of lasso peptides uncovered to date, shedding light on the related investigations in the future. Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a family of natural products with remarkable structural variety and functional diversity due to their extensive post-translational modifications (PTMs) ,2. An inGenerally, at least three gene products are involved in the biosynthesis of lasso peptides: a precursor peptide (A), an ATP-dependent cysteine protease (B), and an ATP-dependent macrolactam synthetase (C). The ribosome-derived linear precursor peptide consists of an N-terminal leader region for the recognition by different PTM enzymes and a C-terminal core region that makes up the structural backbone of lasso peptides. The cysteine protease (B) encompasses a ribosomal recognition element (RRE) domain in the N-terminus to recognize and bind the leader peptide, after which the C-terminal protease domain cleaves the leader peptide to release the leaderless core peptide  , f, fStreptThe mysterious class III lasso peptides comprise very few representatives including BI-32169  and 9401filE homologous genes are founded in the BGCs of the other two reported class IV lasso peptides LP2006 . B. BPaenibproteins b [25]. OSphingobium yanoikuyae ATCC 51230 revealed the attractive polyphosphorylation on their precursor peptides ThcoA and SyanA, despite their low substrate identity except the conserved C-terminal Ser residue .β-hydroxylated canucin A is ruled out  antagonists. RES-701-2 and RES-701-4 contain a C-terminal 7-hydroxy-tryptophan compared to the unhydroxylated RES-701-1 and RES-701-3 . F. Fpad gel-isoaspartyl methyltransferases (PIMTs) usually have a crucial role in protein repair, recognizing and repairing abnormal isoaspartate (isoAsp) residues to l-Asp through a SAM-dependent methyl esterification reaction ..l-isoaspA involved in the biosynthesis of lanthipeptide OlvA (BCSA), since the OlvSA catalytic succinimide group was followed with non-enzymatic hydrolysis to either Asp or isoAsp and this process was reversible as isoAsp could be recognized by OlvSA as well to regenerate succinimide .Isopeptidases only hydrolyze lasso peptides derived from the cognate BGCs. As they are located in different lasso peptide BGCs, AtxE1 and AtxE2 showed no hydrolytic activity toward the lasso peptide derived from the other BGC . In tota2 spectra, but no alteration was observed for unthreaded astexin-2 with AtxE2, suggesting the requirement of lariat knot configuration [β-propeller domain and a C-terminal α/β-hydrolase domain [The threaded topology is proved to be necessary for isopeptidase hydrolysis. The hydrolyzation could be detected by retention time changes in HPLC and mass increases in MSguration . The crye domain ,65. The e domain ,63,65. CAnother intriguing insight into substrate recognition is provided by isopeptidase BenE . Upon heIt seems that the expression and degradation of lasso peptides produced by isopeptidase-containing clusters are under strict regulation. All the isopeptidase clusters uncovered to date share an almost constant gene architecture in which a GntR-like transcriptional regulator is located preceding the precursor gene, TonB-dependent transporter as well as σ/anti-σ factor pairs are found downstream of the isopeptidase gene ,67,68,69Miscellaneous PTMs have always been the highlight of RiPP characteristics, which often bestow diversified generating strategies and improved functionalities on this class of natural products, albeit derived from the limited proteinogenic amino acids. In consideration of their unique lariat knot structure and resistance against thermal and proteolytic inactivation, and especially the eximious physiological functions such as antimicrobial activities against Gram-positive bacteria (e.g., arcumycin , LP2006 Although no lasso peptides are currently used as marketed drugs or tested in clinical trials as far as we know, it is noteworthy that two antitumor candidates termed LAS-103 and LAS-20x are under investigation by Lassogen, Inc., a company that aim to unlock the potential of lasso peptides for cancer treatment . These calbT completely abolished the production of albusnodin and no unacetylated intermediate was detected [The auxiliary PTMs such as phosphorylation, methylation, hydroxylation, and epimerization recognize the linear precursors ahead of the removal of leader peptides ,26,31, odetected . The sucdetected ,62,63,66d-amino acids in the stability of peptide structures and resistibility for proteolysis [d-Trp residue in some class I lasso peptides might play an analogic role.The unusual PTMs mentioned further expand the structural diversity of lasso peptides. The disulfide bridges in class I, III, and IV lasso peptides are of vital importance for the knot-like threaded topology and bioactivities ,5. Howevteolysis , and theteolysis ,56, the The identification of unique PTMs is facilitated by the enzymes generally located in the flanking of BGCs, and the types are relatively predictable through analysis of the protein sequences. The uncovered tailoring enzymes of lasso peptides are limited compared with other highly modified RiPPs, whereas tremendous uncharacterized enzymes have been identified from steadily growing genomic data. The characterized tailoring enzymes can be used as candidates in bioengineering of lasso peptides for optimizing the properties and functionalities. Future study would not only focus on expansion of novel post-translationally modified lasso peptides, but also their catalytic mechanisms, especially for the recognition or interactions among tailoring enzymes, substrates, and other components such as B1 proteins. Moreover, mining peculiar physiological functionalities and better understanding the interactions of tailored lasso peptides with their biological targets would provide more information about the significance of these unusual PTMs.


Background: Admission laboratory screening for asymptomatic COVID-19 has been utilized to mitigate healthcare-associated SARS-CoV-2 transmission. A better understanding of the impact of such testing across a variety of patient populations is needed. Methods: Beginning April 2020, every patient admitted within an academic healthcare system underwent SARS-CoV-2 PCR testing upon admission. Between April 20, 2020 through June 14, 2021, results were analyzed in asymptomatic patients across 4 inpatient facilities: a tertiary-care adult hospital, a free-standing pediatric hospital, a community-based hospital, and a behavioral health hospital. Positivity rates and the number needed to test (NNT) to identify 1 asymptomatic infected patient were calculated overall, by hospital type, by patient vaccination status, and by CDC-defined levels of community transmission. Weekly community incidence rates of COVID-19 for the system’s metropolitan service area  were obtained from Tennessee Department of Health records. Weekly COVID-19 incidence rates per 100,000 people were calculated using US Census Bureau data. Using a national survey of hospital epidemiologists, a clinically meaningful NNT was identified . A crude admission testing cost  was obtained from operational data ($50 per test) to assess testing utility. Results: In total, 51,187 tests were collected during the study period with a positivity rate of 1.8%. No periods of low transmission were observed (Table Discussion: Implementing an asymptomatic patient admission testing program can provide clinically relevant value based on the NNT, even during lower periods of transmission and in different patient populations. Limiting admission testing to non–fully vaccinated patients during periods of lower transmission may be a strategy to address cost and resource concerns around this practice. Further investigations into the impact of booster vaccination and newer SARS-CoV-2 variants on admission testing programs are also necessary. Although the impact of such testing on healthcare-associated COVID-19 among patients and healthcare workers could not be clearly determined, these data provide important information as facilities weigh the costs and benefits of such testing.Funding: NoneDisclosures: None


TP53 mutation. Similarly, sabatolimab  plus hypomethylating agents have shown durable responses in higher-risk MDS and AML in early clinical trials. Randomized trials are currently ongoing to confirm the efficacy of these agents. In this review, we will present the current progress and future directions of immune checkpoint inhibition in AML and MDS.Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many solid tumors, with limited progress made in the area of myeloid malignancies. The low mutational burden of acute myeloid leukemia (AML) is one potential reason behind the lack of activity of T-cell harnessing ICIs, particularly CTLA-4 and PD-1 inhibitors. Innate immune checkpoints play a critical role in the immune escape of AML and myelodysplastic syndromes (MDS). The CD47 targeting agent, magrolimab, has shown promising activity when combined with azacitidine in early phase trials conducted in AML and higher-risk MDS, especially among patients harboring a  Allogeneic stem cell transplantation  represents the most effective immune-based treatment modality, to date, in myeloid neoplasms due to the antileukemic effect of allogeneic grafts mediated mainly by their graft-versus-leukemia (GVL) effect . Long-teImmune checkpoint inhibitors (ICIs) have revolutionized the outcomes of many solid tumors ,5. CytotTP53 mutation, providing the basis for several ongoing randomized clinical trials . Re. Re99]. Given the modest single-agent activity of ICIs, combination regimens leading to dual-targeting blockade are being developed to further enhance the restoration of immune surveillance and improve outcomes for patients with AML and MDS. Inspired by the melanoma experience, double blockade of CTLA-4 and PD-1/PD-L1 is a promising combination regimen . Trials Interestingly, the adaptive immune system plays a major role in the anti-tumor activity of anti-CD47 inhibitors. Anti-CD47-mediated phagocytosis of malignant cells by antigen-presenting cells (macrophages and dendritic cells) triggers an anti-tumor cytotoxic T-cell immune response ,104. In +/CD4+/CD8+ T-cells in these patients [Identifying the optimal timing to introduce ICIs and the subgroup of patients with the best response to therapy is essential for the proper incorporation of ICIs in the treatment of AML and MDS. In the study conducted by Daver et al., patients with lower leukemic burden had the best response to azacitidine plus nivolumab, which was thought to be due to the higher population of bone marrow CD3patients . This dapatients . Althougpatients ,107. TP53-mutant disease. Sabatolimab has also shown promising clinical activity when combined with HMAs, particularly in patients with HR-MDS, with responses preserved in patients with high-risk mutations. Numerous trials are currently being conducted to further explore the role of TIM-3 blockade in myeloid malignancies. Although CTLA-4 and PD-1/PD-L1 inhibitors have not shown robust clinical activity in AML, the addition of PD-1 inhibitors to intensive chemotherapy and HMAs achieved encouraging rates of MRD negative CR, suggesting their potential role in MRD eradication. This observation is currently being investigated in randomized trials. Dual targeting of different immune checkpoints has the potential for harnessing the immune system and improving anti-leukemic responses. Clinical trials exploring the synergy between various combinations of ICIs and HMAs or cytotoxic chemotherapy are underway.Immune checkpoint inhibition remains an area of intense clinical research in AML and MDS. CD47/SIRPα axis-targeting agents are promising additions to the current therapeutic armamentarium in myeloid malignancies. Early phase trials have shown encouraging results with the combined use of azacitidine and magrolimab in AML and HR-MDS. Randomized studies are currently ongoing to validate the efficacy of this combination and explore its potential therapeutic role in various molecular subgroups of AML and MDS, such as


Breast cancer (BC) is the most common malignancy among females worldwide, and high resistance to drugs and metastasis rates are the leading causes of death in BC patients. Releasing anti-cancer drugs precisely to the tumor site can improve the efficacy and reduce the side effects on the body. Natural polymers are attracting extensive interest as drug carriers in treating breast cancer. Hyaluronic acid (HA) is a natural polysaccharide with excellent biocompatibility, biodegradability, and non-immunogenicity and is a significant component of the extracellular matrix. The CD44 receptor of HA is overexpressed in breast cancer cells and can be targeted to breast tumors. Therefore, many researchers have developed nano drug delivery systems (NDDS) based on the CD44 receptor tumor-targeting properties of HA. This review examines the application of HA in NDDSs for breast cancer in recent years. Based on the structural composition of NDDSs, they are divided into HA NDDSs, Modified HA NDDSs, and HA hybrid NDDSs. Cancer is one of the significant causes of death in the world. Cancer can occur in many body areas, such as the liver, lungs, prostate, or breasts. Breast cancer is the most common cancer among women, accounting for nearly 30% of all cancers . AccordiChemotherapy is an effective way to treat breast cancer. This strategy involves treating breast cancer by using chemotherapeutic drugs to prevent the mitosis and growth of cancer cells . So far,Compared to conventional medical systems, NDDS has distinct advantages, including the ability to increase the solubility of anti-breast cancer drugs, control and prolong drug release, achieve targeted drug delivery by enhancing the permeability to the tumor and the enhanced permeability and retention effect (EPR) and reduce the side effects of drugs at other sites . So far,in vivo  is a natural linear mucopolysaccharide composed of alternating repeats of D-glucuronic acid and nacetyl-D-glucosamine, the main component of the extracellular matrix . The excin vivo . In addiin vivo , enablinin vivo .It is well known that the CD44 receptor is one of the many transmembrane glycoproteins that have great potential in achieving active targeting therapy. Meanwhile, CD44 is a primary receptor for HA . StandarWe focus on the review of HA as NDDSs in breast cancer therapy in recent years, including HA NDDSs, Modified HA NDDSs, and HA nanohybrid NDDSs .Chemotherapeutic agents used to treat breast cancer generally have disadvantages such as low water solubility, slow delivery, and non-specific biodistribution and targeting, hence restricting their clinical applications .HA with anti-cancer drugs provides better hydrophilicity and stability and improves drug absorption efficiency by targeting CD44 receptors while reducing the side effects of drugs on healthy cells . Table 1Lapatinib (LPT) is an anti-cancer drug approved to treat advanced HER2 + breast cancer . Agrawalin vivo, and showed better anti-cancer effects in mice loaded with 4t1 with negligible systemic side effects. HA@Cur-NCs provide a new alternative for the future clinical treatment of breast cancer (Curcumin (Cur) is one of the dietary polyphenolic compounds with anti-cancer effects . To imprt cancer .+ CSC, hence CD44-HA interactions can be considered an excellent vehicle to improve the efficiency of anti-cancer drugs against CSC. Cytotoxicity and scratch assays demonstrated that HA-NPs not only had a significant targeting effect on RAW264.7, HUVEC, and MCF-7 in terms of toxicity but also had a better inhibitory effect on MCF-7 than free NAP. The system also allowed a reduced dose of NAP for pro-apoptotic and anti-migration activity. Overall, HA-NPs can potentially improve the treatment of advanced breast cancer  is a significant indicator for regulating biological functions . ROS levEuphorbia Fischer Diana Steud, has attracted the interest of researchers. In clinical cancer therapy, low water solubility and bioavailability are the main factors limiting its application , a diterpenoid from the roots of lication . Liu et t cancer .Quercetin is a natural candidate for novel anti-inflammatory and anti-cancer agents; recently, it has attracted attention for its anti-tumor activity . EveroliAdriamycin (DOX) has also been studied to be modified and coupled with HA to form NDDSs for drug delivery targeting breast cancer. Liu et al. used triphenylphosphine (TPP) to bind with HA through ionic bonding, to form a supramolecular self-assembled structure HA-ionic-TPP-DOX between TPP-DOX and HA. HA-ionic-TPP-DOX possessed the ability to target mitochondria inside breast cancer cells through the CD44 receptor targeting of HA and the property of TPP to accumulate inside mitochondria. HA-ionic-TPP-DOX in MCF-7 cells can accumulate more DOX in mitochondria, increasing reactive oxygen species (ROS) levels and decreasing mitochondrial membrane potential, resulting in superior anti-tumor effects in MCF-7/ADR cells in zebrafish. In conclusion, HA-ionic-TPP-DOX is promising in treating breast cancer .By modifying the hydrophilic HA surface with hydrophobic tips  and obtaining amphiphilic NDDSs by self-assembly . These NRecently, Shahriari et al. developed a novel hyaluronic acid-polycaprolactone (HA-PCL) nanopolymer, encapsulated doxorubicin (DOX) in HA-PCL, and studied the therapeutic index and biodistribution of HA-PCL-DOX for a 4T1 metastatic mouse breast cancer model. The obtained results confirmed that HA-PCL-DOX has a higher uptake rate than PEG-PCL-DOX and free DOX in 2 cell types (4T1 and MCF-7), owing to the targeting of the CD44 receptor. In addition, HA-PCL-DOX was shown to be non-significantly toxic to mice organs and to have optimal tumor suppression, effectively prolonging the survival rate of mice. Accordingly, HA-PCL may be considered a potential ideal candidate for DOX delivery in breast cancer treatment .In vivo and tumor penetration studies showed significantly better tumor accumulation and lung distribution of DOX-HA-PLA compared to DOX-PLA controls. When co-administered with iGRD, DOX-HA-PLA accumulation at tumor and lung metastasis sites was dramatically increased. The combined administration remarkably enhanced the tumor suppressive effect and survival time of the mice, and no significant lung metastasis was observed. The combined delivery strategy of DOX-HA-PLA and iGRD enhances DOX inhibition of breast cancer tumor growth and metastasis, providing a promising new strategy for breast cancer treatment  can improve the aqueous solubility and bioavailability of anticancer drugs . Howevervia disulfide bonds. HA-ss-BF could be a drug delivery carrier for DOX by self-assembly (DOX/HA-ss-BF). In vitro, DOX/HA-ss-BF showed excellent inhibition of metastasis  and improved cell uptake through CD44 receptor mediation. In addition, HA-ss-BF effectively down-regulated the biological levels of COX-2 in 4T1 cells by CD44 receptor- and redox-response-triggered BF release. In vivo, DOX/HA-ss-BF showed excellent biosafety and remained capable of rapid accumulation at tumor sites via HA-CD44 interactions. In addition, Dox/HA-ss-BF had a good suppressive effect on 4T1 tumor growth  and metastasis by reducing intracellular COX-2 levels through BF release and the obstruction of tumor growth in situ by DOX. DOX/HA-ss-BF shows potential for effective treatment of metastatic breast cancer and offers a novel direction for targeted combination drug delivery for breast cancer treatment (Glutathione (GSH) is an antioxidant widely found in mammals. GSH levels are higher in tumor cells than in extracellular and normal cells . Thereforeatment .via disulfide bonding to obtain amphiphilic HA derivatives HA-cys-DHA/Ce6 (CHD) for encapsulation of doxorubicin (DTX) for targeted treatment of breast cancer to achieve combined chemotherapy and photodynamic therapy (PDT), and in vivo fluorescence imaging by Ce6 to provide aid in tumor diagnosis and treatment. DTX/CHD nanoparticles increased the uptake of MCF-7 cells through the CD44 receptor, thus reducing side effects and realizing redox response in tumor cells to enable the release of DTX and Ce6. Meanwhile, DTX and Ce6 exerted favorable anti-tumor effects under the action of NIR light. The combination therapy of chemotherapy and PDT was realized  and chlorin e6 (Ce6) realized .In addition to the preparation of NDDSs using linear HA polymers, NDDSs obtained by coupling glycodendrons with HA to obtain dendronized polymers can further improve the drug-carrier interactions and effectively enhance the drug delivery efficiency . Wang etvia CD44 receptors and could release SFN rapidly to tumor ecological niche based on pH and redox responses. Therefore, SFN/M-HA-SS-TA exhibited better suppression of BCSC in vitro and in vivo compared to free SFN. Overall, M-HA-SS-TA provides a new strategy for both the preparation of amphiphilic nanoparticles and the treatment of breast cancer  and HA pretreatment groups. Therefore, HA-DOX-CDDP showed a better internalization effect as well as CD44 targeting. Moreover, HA-DOX-CDDP showed enhanced drug penetration in 3D 4T1 cell cultures. HA-DOX-CDDP has the best in vivo tumor suppression effect compared to other experimental groups while ensuring lower toxicity to systemic tissues and organs. Compared with the free drug group, mice treated with HA-DOX-CDDP tumor sections showed increased PARP expression and decreased survivin expression with sound anti-tumor effects  with HA chelation and loading DOX by electron interaction. The pH sensitivity of HA-DOX-CDDP resulted in its significantly enhanced drug release efficiency under acidic conditions. In  effects   evasion is a capability possessed by most NDDSs but is powerless against the metastasis of inflammatory tumors . The antIn order to improve the effectiveness of breast cancer treatment, it is necessary to give some other advantages to NDDSs composed of HA, including high drug loading, more precise targeting, and more effective inhibition of cancer cell growth and metastasis, etc. The development of HA hybrid NDDSs composed of HA and other substances offers the possibility of better treatment of breast cancer. In recent years, HA hybrid NDDSs composed of HA in combination with other substances (both organic and inorganic) are shown in in vivo (Mesoporous silica (MSN) has received widespread attention as an alternative material for synthesizing NDDS due to its large specific surface area, adjustable particle and pore size, excellent biocompatibility, and high drug encapsulation efficiency . Recentlin vivo . bMID NPin vivo .in vivo circulation time and aggregation at the tumor site compared to spherical ones , used to modify GNRs, and carried DOX through an unstable hydrazone bond with a pH response. The results showed that trifunctionalized HA increased the morphological stability of GNRs-HA-FA-DOX, increased tumor targeting, and prolonged in vivo circulation time, where the addition of FA further promoted the endocytosis of GNRs and DOX by MCF-7 cells compared to the CD44 targeting of HA. In vitro and in vivo, GNRs-HA-FA-DOX showed excellent chemotherapy/PTT synergism, outperforming chemotherapy or PTT alone. In vivo studies, mouse tumors were eliminated after 20 d of treatment, with no recurrence and severe side effects. In conclusion, GNRs-HA-FA-DOX shows excellent potential in breast cancer treatment, maximizes the effect of combined chemotherapy/photothermal treatment, and provides new ideas for designing multifunctional nanocarriers (Gold nanorods (GNRs) are promising nanomaterials in biomedicine. Au NRs are frequently used for photothermal therapy (PTT) in the treatment of breast cancer due to the strong surface plasmon resonance absorption in the near-infrared spectral region (NIR) while converting NIR to heat with an efficiency close to 100% . Furthercal ones . Howevercarriers .in vivo and endowed the active targeting of CD44 receptor of nanoparticles as well as increased the penetration of nanoparticles while degrading at tumor sites. Besides, the nanoparticles showed significantly enhanced penetration ability for breast cancer cells by the synergistic effect of hyaluronidase degradation and NO regulation of the tumor microenvironment. Under the effect of combined treatment by delivering PTX and ICG, AuNC@CBSA-PTX-ICG@HA-NO3 exhibited excellent inhibition of in situ breast cancer tumor growth (∼95.3%) and lung metastasis (∼88.4%), providing an efficient potential strategy for the treatment of breast cancer , and inhibited poly (ADP-ribose) polymerase (PARP), increased double-strand breaks (DSBs) accumulation and inhibited tumor growth. CuQDA/IO@HA provides a novel chemotherapy-free, drug-free regimen for breast cancer treatment through Cu(II)-induced DNA damage in breast cancer cells and further inhibition of DNA repair by quercetin (Superparamagnetic iron oxide nanoparticles (SPIONs) are generally used in cancer treatment and diagnosis, with biodegradability and excellent magnetic properties . SPIONs uercetin .Graphene oxide (GO), an oxidized derivative of graphene, has been widely used as a carrier to deliver drugs due to its high specific surface area and easy functionalization . Recentlvia a pH-responsive linker (HA-CD@p-CBA-DOX). The presence of HA conferred better structural stability and hemocompatibility to HA-CD@p-CBA-DOX and showed high cytotoxicity against 4T1 cells through CD44 receptor targeting and acid-sensitive DOX release. HA-CD@p-CBA-DOX exhibited excellent antitumor effects compared to free DOX without significant side effects. These results suggest that HA-CD@p-CBA-DOX deserves further study as a promising novel nano-drug delivery system for breast cancer treatment (Carbon dots (CDs) are novel nanomaterials with favorable biocompatibility and potential for surface modification . In recereatment .HER2) to prepare multifunctional polysaccharide-based nanocomplexes, and to chemically couple DOX and the photosensitizing prodrug 5-aminolevulinic acid (ALA) to AHA via Schiff base bonding to synthesize DOX/ALA- AHCS/HAHER2 nanocomplexes. The nanocomplex significantly enhanced the uptake of breast cancer MCF-7 cells through the active targeting of CD44 and HER2 antibodies. Furthermore, ALA in the nanocomplex could be effectively converted into endogenous photosensitizer PpIX in MCF-7 cells and achieve pH-responsive rapid release of DOX in the acidic microenvironment of cancer cells. Combining chemotherapy and photodynamic therapy (PDT) could effectively kill breast cancer MCF-7 cells (HER2 (DOX/CDDP) nanopolymer. The introduction of CDDP by cross-linking improves the stability of nanoparticles, but the combination of CDDP and DOX can achieve excellent anti-tumor ability without the need for an external excitation light source, completely overcoming the previous drawbacks. The experimental results showed that NPHER2 (DOX/CDDP) uptake by MCF-7 cells was significantly enhanced by the active targeting of CD44 and HER2 receptors. Due to the micro-acidic environment inside cancer cells, DOX and CDDP acidic pH-sensitive release significantly increased the mortality rate of breast cancer MCF-7 cells. The synergistic treatment of DOX/CDDP exhibited higher toxicity to breast cancer MCF-7 cells compared to DOX release alone. In summary, in vitro trials demonstrated the potential of NPHER2 (DOX/CDDP) for the treatment of breast cancer tumors, and this novel nanoplatform is expected to be further used for synergistic combination chemotherapy in breast cancer (Chitosan (CS) is one of the most commonly used natural biopolymers with good biocompatibility and degradability . CS and -7 cells . Althougt cancer .Besides the efficiency of breast cancer suppression can be improved by combining multiple drugs for chemotherapy, the introduction of MicroRNA34a (miR34a) to reverse the resistance of breast cancer (BCa) cells and treat with chemotherapeutic drugs has also been studied. Yang et al. introduced miR34a and DOX into conjugated linoleic acid (CLA)-modified CS NPs and modified HA on the surface to obtain a novel targeting nanosystem (CCMDH NPs). CCMDH NPs increase the targeting of breast cancer cells through CD44 receptor action and utilize the miR34a to reverse Dox resistance in BCa to enhance DOX anti-tumor effects. The experimental data showed that CCmDHNPs suppressed and facilitated apoptosis by modulating protein expression of B-cell lymphoma-2 (Bcl-2) and poly (ADP-ribose) polymerase (PARP), producing sound inhibitory effects on xenograft tumors in nude mice, as well as effectively suppressed invasion, metastasis, and adhesion of breast cancer cells by regulating the levels of E-cadherin, N-cadherin, MMP2, CD44, and Snail molecules. CCmDHNPs have shown good inhibitory effects on the growth and migration of anti-DOX metastatic BCa tumors, providing an effective and novel therapeutic strategy for breast cancer treatment .in vitro. In addition, HA-Zein-HNK upregulated E-calmodulin expression in breast cancer cells and simultaneously downregulated Vimentin expression, significantly attenuating the invasion and migration of 4T1 cells. In the 4T1 tumor-bearing mice model, HA-Zein-HNK demonstrated a superior ability to suppress tumor growth and metastasis without significant systemic toxicity during treatment. HA-Zein-HNK provides a novel and promising strategy for preparing simple and efficient nanoparticles from natural material complexes to treat breast cancer  and its derivatives have good biocompatibility, biodegradability, and ease of modification. Through hydrophobic, electrostatic phase, and hydrogen bonding interactions, these nano micelles generally exhibit high hydrophobic drug loading capacity or high hydrophilic ability to modify hydrophobic segments. More importantly, these micelles have pH-sensitive drug release capability to ensure precise drug release in tumor tissues . Liu et in vivo combination of photothermal therapy and immunotherapy against tumors, the P@CH + laser irradiation + anti-PD-L1 (P@CH-L-IT) group had surprising results compared to other experimental groups, where 4T1-fluc tumor bearing mice with in situ breast cancer tumors were completely eliminated and did not recur throughout the 24-day observation period, with mice surviving over 60 days, much longer than other treatment groups. In the tumor metastasis trial observation, all treatment groups had several pulmonary metastatic nodules, except for the P@CH-L-IT combination treatment group. In addition, the P@CH-L-IT group activated a systemic anti-tumor immune response to suppress lung metastasis and tumor recurrence in the long term. The combined therapy of P@CH-L-IT has an excellent effect on treating and preventing breast cancer recurrence. More excitingly, the PAI/FMI imaging properties of P@CH can be further used for image-guided chemoradiotherapy of breast tumors. This potential therapeutic strategy opens up a new path and direction for the clinical management of breast cancer and other malignant tumors. (Polypyrrole (PPy) has been innovatively applied to photothermal therapy for cancer due to its good biocompatibility and efficient photothermal conversion ability . Camptot tumors.  , a cationic polymer, has been extensively studied as an anticancer drug delivery carrier . α-naphtD-ɑ-tocopheryl polyethylene glycol succinate (TPGS or Vitamin E TPGS) is approved by the FDA as a safe adjuvant. TPGS has the characteristics of excellent biocompatibility, improving drug solubility and permeability, and inhibiting the activity of ATP-dependent P-glycoprotein, so it is widely used in the delivery system of anticancer drugs . Liu et D-α-tocopherol succinate (TS) is a vitamin derivative with nontoxicity and good biocompatibility. Due to the poor water solubility of TS, it can be used as the hydrophobic core of self-assembled nanoparticles . In addiin vitro and higher cytotoxicity compared to PTX solution. In vivo, Esbp-HA-PTX/PTX exhibited prolonged cycling time and excellent dual-cell targeting ability. More importantly, Esbp-HA-PTX/PTX exhibited excellent capability to inhibit tumor proliferation and metastasis without significant toxic side effects based on the suppression of intra-tumor microvasculature and tumor cell growth. Overall, Esbp-HA-PTX/PTX micelles provide a compelling new strategy for multicellular targeted breast cancer treatment (E-selectin (CD62E) is an inducible transmembrane adhesion protein expressed on endothelial cells activated by cytokines such as TNF-α and IL1-β during inflammation and tumors . In addireatment .50 = 5.98 ± 0.9 μg/ml, 24 h; 5.48 ± 1.4 μg/ml, 48 h) with targeting potential and antiproliferative solid activity. TMX-PAP-HA-SS-LCA improves the bioavailability of TMX through enhanced mucosal permeation without significant systemic toxicity, providing a novel and feasible strategy for endocrine therapy to inhibit the growth of breast tumors  is considered one of the preferable treatment modalities due to its low morbidity and mortality . Tamoxift tumors .In vivo, tumor growth and lung metastasis could be effectively inhibited by 4T1 cell targeting of Cur@ZIF8@HA and the release of Cur in response to acidic pH. Cur@ZIF-8@HA showed excellent potential in breast cancer therapy and combining HA and MOF to prepare nanoparticles provides a new direction for developing anti-breast cancer drug delivery systems , zeolitic imidazolate framework-8 nanoparticle (ZIF-8) is frequently used as drug delivery carriers with good biocompatibility and ph-responsive degradability . Yu et a systems .HA has been extensively studied as a targeting ligand in the preclinical stage. HA-based NDDSs have shown enhanced anticancer activity and a higher safety profile than conventional regimens for cancer treatment. The classification of HA conjugates as new chemical entities (NCE) is one of the barriers to their treatment of cancer. Various anticancer drugs combined with HA for targeted therapy  have been studied in clinical trials. HA-irinotecan was shown to be biosafety and well-tolerated without reducing irinotecan drug activity in a phase 1 clinical trial of 12 patients . In anotIn recent decades, nanotechnology has been dramatically developed in cancer therapy. Presently, NDDSs play a critical role in the targeted delivery of breast cancer treatment, which can realize high accumulation and release of anticancer drugs at the tumor site to improve the therapeutic efficiency of drugs while reducing the toxic side effects on the normal tissues and organs of the human body, which not only overcomes the limitations of traditional drugs for breast cancer treatment but also has the potential to reduce the cost of conventional treatment, thereby solving a significant obstacle in breast cancer treatment.Improving tumor-specific targeting is one of the critical factors for NDDSs to improve the efficacy of treating breast tumors. HA can target overexpressing breast cancer cells CD44 receptor, which is suitable as a potential target for breast cancer-targeting NDDSs. In addition, HA has good biocompatibility and excellent hydrophilicity, which provides advantages such as better hydrophilicity and long internal circulation time for inorganic or organic nanoparticles, including hydrophobic anticancer drugs. Therefore, HA is highly suitable for clinical application in breast cancer treatment.via passive EPR and active CD44 receptor-mediated endocytosis, providing a simple and efficient way to target breast cancer cells for drug delivery actively. More excitingly, HA can be easily modified due to its wealthy chemical groups and can be combined with other inorganic or organic compounds to give HA NDDSs other advantages, such as increased drug loading, enhanced targeting, and some synergistic therapies. The HA NDDSs section of the review summarizes the progress of research on HA as a hydrophilic fraction for encapsulation or coupling of chemotherapeutic drugs, which directly enriches chemotherapeutic drugs at breast tumors through CD44 targeting, improving drug utilization and reducing systemic toxicity. In order to enhance the drug loading capacity and functionalization of HA NDDSs, researchers developed Modified HA NDDSs, which were further modified to confer higher drug loading capacity and tumor environment-sensitive drug release, significantly improving the anti-cancer effects of HA NDDSs. Many substances have anticancer potential, but their application is greatly limited because they do not possess the ability to target breast tumors or have poor biocompatibility on their own. HA nanohybrid NDDSs section summarizes the application of HA as an increase in the targeting ability or increased biocompatibility of other NDDSs, and the introduction of HA has dramatically broadened the choice of nano drugs in the treatment of breast cancer. They are resulting in Modified HA NDDSs and HA nanohybrid NDDSs with excellent performance for treating, preventing, and diagnosing breast cancer.In this review, we have discussed recent advances in treating breast cancer with HA-containing NDDSs. In recent years, many studies have shown that nano-delivery systems with HA can effectively target breast cancer cells in situ tumors (Unfortunately, until now, artificial mouse xenograft cancer models have been widely used due to the lack of suitable animal models, thereby having the disadvantage of not being able to mimic the different mutations carried by multiple cancer cells in human tumors, resulting in the inability to accurately mimic the immune landscape of u tumors . Althougu tumors . HoweverNanomedicine is an emerging approach to cancer treatment, and a growing number of researchers continue to develop NDDSs with superior properties that offer more promising options for the treatment of breast cancer. Among these, HA-containing NDDSs are typically biocompatible and show significant potential for drug delivery and breast cancer tumor targeting. Although clinical data are lacking in breast cancer, HA has demonstrated its potential for clinical utilization in several clinical trials. These data provide strong evidence for continued research into the use of HA for future clinical breast cancer treatment.


Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a class of autoimmune diseases that can cause kidney failure because of mononuclear cell infiltration and the destruction of small and medium-sized blood vessels. Coronavirus disease 2019 (COVID-19) may trigger or exacerbate autoimmune diseases. We present a case of ANCA-associated vasculitis in a patient with rheumatoid arthritis after a COVID-19 infection, who presented with intermittent hemoptysis and dyspnea and was diagnosed with COVID-19 pneumonia three weeks ago. Her clinical, radiological, and serological picture was concerned with pulmonary-renal syndrome. Her serum was positive for antinuclear antibody and ANCAs, and renal biopsy showed pauci-immune crescentic glomerulonephritis. She was diagnosed clinicopathologically with pauci-immune glomerulonephritis in the setting of rheumatoid arthritis (RA) after a COVID-19 infection. Her condition improved after she was treated with rituximab and pulse dose methylprednisolone. Vasculitis induced by antineutrophil cytoplasmic antibody (ANCA) represents a group of small vessel vasculitides characterized by granulomatous and neutrophilic tissue inflammation, often associated with the production of antibodies against neutrophilic antigens . ANCAs pA 79-year-old woman with ischemic heart disease and rheumatoid arthritis (RA) presented with intermittent hemoptysis and dyspnea for the last three days. She was diagnosed with RA three years ago and was commenced on methotrexate and analgesia; however, she was not compliant with her RA medications. She also reported subjective weight loss. She was also admitted to the hospital three weeks ago for COVID-19 pneumonia, and she was discharged four days later after improvement in her condition.On evaluation, she was afebrile, pale, and vitally stable except for hypoxemia (SpO2=90%). On physical examination, there were diffuse crackles and trace edema in the lower extremities. Laboratory studies were significant for low hemoglobin levels and increased levels of creatinine and brain natriuretic peptide Table . UrinalyAdditional pertinent studies included abdominal ultrasonography, which revealed normal kidney size and parenchymal echogenicity. Her serum was positive for ANCAs, and antinuclear antibodies (titer 1:160), and the staining pattern was homogenous and diffuse. Her serology titer for anti-MPO antibody (c-ANCA) was high (1:100), and for anti-PR3 antibody (p-ANCA) was 79 U/ml. She was negative for other autoantibodies except for the anti-cyclic citrullinated peptide (anti-CCP) antibody Table . She undRenal involvement in rheumatoid arthritis (RA) is a complex situation. The most common causes of glomerular involvement in RA are secondary amyloidosis and medications, such as non-steroidal anti-inflammatory drugs and traditional disease-modifying antirheumatic drugs . OverlapIn COVID-19 and AAV, lung involvement is very common. Radiological picture of the patients with COVID-19 predominantly have ground-glass opacities distributed posteriorly and peripherally and consequent overlapping of consolidations, often accompanied by cavitation and pleural effusion . In AVV,The pathophysiology of COVID-19 suggests that it may cause autoimmunity in genetically susceptible patients or exacerbate existing autoimmune diseases. Previous studies also verified that systemic bacterial or viral infections might lead to autoimmunity and cause pauci-immune granulomatous polyangiitis ,12. SomePathophysiology of autoimmunity following COVID-19 infection may involve molecular mimicry, epitope spreading, bystander killing, viral persistence, and neutrophil extracellular trap formation. An elevated level of neutrophil extracellular traps has been observed in blood and kidney biopsy specimens of patients diagnosed with AAV . These nTreatment with a chimeric anti-CD20 agent and steroids is an effective therapeutic approach in ANCA-associated vasculitis ,5. The pOur patient was diagnosed clinicopathologically with pauci-immune glomerulonephritis in the setting of RA after COVID-19 infection, who developed worsening of her renal and pulmonary functions, which was not caused by disease-modifying drugs. Her condition improved after commencing rituximab and pulse dose methylprednisolone, followed by a tapering course of prednisone and a follow-up dose of rituximab. Therefore, obtaining urine analysis and renal function tests in patients with RA is obligatory when serum creatinine level is high as a baseline and fails to improve despite appropriate interventions.Diagnosis of new-onset or flare of antibody-associated vasculitis in patients with RA following coronavirus disease is challenging. The infections, particularly COVID-19, may trigger the new onset or flare of vasculitis in individuals with RA, and a decline in renal function can help the differential diagnosis regardless of the pulmonary involvement. Immunological markers should be obtained in the presence of such clinical findings to assess or rule out vasculitis. Early recognition and appropriate management are mandatory to prevent or slow the progression of renal failure to end-stage renal disease.