Biology subjects

Yin, L.

Publications and source records attributed to Yin, L..

At least 55 records · Page 3Linked to original sources

bioRxiv2023

Pancreatic islet α cell function and proliferation requires the arginine transporter SLC7A2

Interrupting glucagon signaling decreases gluconeogenesis and the fractional extraction of amino acids by liver from blood resulting in lower glycemia. The resulting hyperaminoacidemia stimulates cell proliferation and glucagon secretion via a liver- cell axis. We hypothesized that cells detect and respond to circulating amino acids levels via a unique amino acid transporter repertoire. We found that Slc7a2ISLC7A2 is the most highly expressed cationic amino acid transporter in cells with its expression being three-fold greater in than {beta} cells in both mouse and human. Employing cell culture, zebrafish, and knockout mouse models, we found that the cationic amino acid arginine and SLC7A2 are required for cell proliferation in response to interrupted glucagon signaling. Ex vivo and in vivo assessment of islet function in Slc7a2-/- mice showed decreased arginine-stimulated glucagon and insulin secretion. We found that arginine activation of mTOR signaling and induction of the glutamine transporter SLC38A5 was dependent on SLC7A2, showing that boths role in cell proliferation is dependent on arginine transport and SLC7A2. Finally, we identified single nucleotide polymorphisms in SLC7A2 associated with HbA1c. Together, these data indicate a central role for SLC7A2 in amino acid-stimulated cell proliferation and islet hormone secretion.

physiology↗

bioRxiv2023

Hierarchical Clustering and Omics Analysis Revealed Massive Molecular Shifts in a Tree under Combined Hypoxia and Salinity

Field and Greenhouse studies that attempted to describe the molecular responses of trees under waterlogging (WL) combined with salinity (ST) are quasi-inexistent. To dissect plant-specific molecular responses and patterns under SWL, we integrated transcriptional and metabolic analyses involving common differentially expressed genes (DEGs) and metabolites (DMs) patterns in Dalbergia odorifera leaflets. SWL-treated seedlings exhibited an impressively high number of DEGs and DMs compared to ST or WL. Although the main common DEGs and DMs showed a neutral pattern, gene ontology enrichment following the classification in different functional categories of SWL-transcripts displayed a predominant synergistic pattern mode. Hierarchical and silhouette analysis regrouped different morpho-physiological clusters following the treatment, SWL was mainly grouped with both single stress. SWL induced a massive shutdown of the photosynthesis apparatus through LHCBs- and PSA-related genes. Starch and plastoglobuli synthesis appeared to be drastically affected by SWL, while ABA content confirmed by ABA synthesis related-genes (ABF, ABA1 and NCED) variations showed a less-needed role. NXN (Nucleoredoxin) genes are the main factors that sustain the antioxidant system under SWL. Here we provide the first molecular responses, characterization and patterns of a tree under SWL that would significantly shed light on our understanding of the molecular mechanisms underlying combined stress.

plant biology↗

bioRxiv2023

Hardwired to attack: Transcriptionally defined amygdala subpopulations play distinct roles in innate social behaviors.

Social behaviors are innate and supported by dedicated neural circuits, but it remains unclear whether these circuits are developmentally hardwired or established through social experience. Here, we revealed distinct response patterns and functions in social behavior of medial amygdala (MeA) cells originating from two embryonically parcellated developmental lineages. MeA cells in male mice that express the transcription factor Foxp2 (MeAFoxp2) are specialized for processing male conspecific cues even before puberty and are essential for adult inter-male aggression. In contrast, MeA cells derived from the Dbx1-lineage (MeADbx1) respond broadly to social cues and are non-essential for male aggression. Furthermore, MeAFoxp2 and MeADbx1 cells show differential anatomical and functional connectivity. Altogether, our results support a developmentally hardwired aggression circuit at the level of the MeA and we propose a lineage-based circuit organization by which a cells embryonic transcription factor profile determines its social information representation and behavior relevance during adulthood. HighlightsO_LIMeAFoxp2 cells in male mice show highly specific responses to male conspecific cues and during attack while MeADbx1 cells are broadly tuned to social cues. C_LIO_LIThe male-specific response of MeAFoxp2 cells is present in naive adult males and adult social experience refines the response by increasing its trial-to-trial reliability and temporal precision. C_LIO_LIMeAFoxp2 cells show biased response to males even before puberty. C_LIO_LIActivation of MeAFoxp2, but not MeADbx1, cells promote inter-male aggression in naive male mice. C_LIO_LIInactivation of MeAFoxp2, but not MeADbx1, cells suppresses inter-male aggression. C_LIO_LIMeAFoxp2 and MeADbx1 cells show differential connectivity at both the input and output levels. C_LI

neuroscience↗

bioRxiv2023

Neural dynamics in the limbic system during male social behaviors

Sexual and aggressive behaviors are two evolutionarily conserved social behaviors vital for an animals survival and reproductive success. While an increasing number of brain regions in the limbic system have been identified as functionally relevant for these two types of behaviors, an understanding of how social cues are represented across brain regions and how social behaviors are generated via this network activity remains elusive. To gain a holistic view of the neural responses during social behaviors, we utilized multi-fiber photometry to simultaneously record Ca2+ signals of estrogen receptor alpha (Esr1)-expressing cells from 13 limbic brain regions in male mice during sexual and aggressive behaviors and compare the response magnitude and temporal patterns across regions. We find that conspecific sensory information, as well as social action initiation signals, are widely distributed in the limbic system and can be decoded from the network activity. Cross-region correlation analysis reveals striking increases in functional connectivity in the network during the action initiation phase of social behaviors whereas advanced copulation is accompanied by a "dissociated" network state. Based on the response patterns, we propose a mating-biased network (MBN) and an aggression-biased network (ABN) for mediating male sexual and aggressive behaviors, respectively.

neuroscience↗

bioRxiv2023

Antagonistic Neural Circuits Drive Opposing Behaviors towards the Young in Females

In many species, including mice, females show strikingly different pup-directed behaviors based on their reproductive state1,2. Naive wild female mice often kill pups while lactating females are dedicated to pup caring3,4. The neural mechanisms that mediate infanticide and its switch to maternal behaviors during motherhood remain unclear. Here, based on the hypothesis that maternal and infanticidal behaviors are supported by distinct and competing neural circuits5,6, we used the medial preoptic area (MPOA), a key site for maternal behaviors7-11, as a starting point and identified three MPOA-connected brain regions that drive differential negative pup-directed behaviors. Further functional manipulation and in vivo recording revealed that estrogen receptor alpha (Esr1) expressing cells in the principal nucleus of the bed nucleus of stria terminalis (BNSTprEsr1) are necessary, sufficient, and naturally activated during infanticide in female mice. Furthermore, MPOAEsr1 and BNSTprEsr1 neurons form reciprocal inhibition and change their excitability in opposite directions with reproductive state. The shift in balance between BNSTprEsr1 and MPOAEsr1 cell activity is likely a key mechanism for the behavioral switch during motherhood.

neuroscience↗

bioRxiv2023

Transcription Factor Dynamics in Cross-Regulation of Plant Hormone Signaling Pathways

Cross-regulation between hormone signaling pathways is indispensable for plant growth and development. However, the molecular mechanisms by which multiple hormones interact and co-ordinate activity need to be understood. Here, we generated a cross-regulation network explaining how hormone signals are integrated from multiple pathways in etiolated Arabidopsis (Arabidopsis thaliana) seedlings. To do so we comprehensively characterized transcription factor activity during plant hormone responses and reconstructed dynamic transcriptional regulatory models for six hormones; abscisic acid, brassinosteroid, ethylene, jasmonic acid, salicylic acid and strigolactone/karrikin. These models incorporated target data for hundreds of transcription factors and thousands of protein-protein interactions. Each hormone recruited different combinations of transcription factors, a subset of which were shared between hormones. Hub target genes existed within hormone transcriptional networks, exhibiting transcription factor activity themselves. In addition, a group of MITOGEN-ACTIVATED PROTEIN KINASES (MPKs) were identified as potential key points of cross-regulation between multiple hormones. Accordingly, the loss of function of one of these (MPK6) disrupted the global proteome, phosphoproteome and transcriptome during hormone responses. Lastly, we determined that all hormones drive substantial alternative splicing that has distinct effects on the transcriptome compared with differential gene expression, acting in early hormone responses. These results provide a comprehensive understanding of the common features of plant transcriptional regulatory pathways and how cross-regulation between hormones acts upon gene expression.

plant biology↗

bioRxiv2023

Fast and accurate DNASeq Variant Calling workflow composed of LUSH toolkit

BackgroundWhole genome sequencing (WGS) is becoming increasingly prevalent for molecular diagnosis, staging and prognosis because of its declining costs and the ability to detect nearly all genes associated with a patients disease. The currently widely accepted variant calling pipeline, GATK, is limited in terms of its computational speed and efficiency, which cannot meet the growing analysis needs. MethodsIn this study, we propose a fast and accurate DNASeq variant calling workflow that is purely composed of tools from LUSH toolkit. The LUSH pipeline is highly optimized for the WGS pipeline based on SOAPnuke, BWA and GATK which can be deployed on any general-purpose CPU-based computing system. We validated the accuracy, speed and scalability of the LUSH pipeline on several standard WGS datasets. ResultsOur test results show that the LUSH pipeline and the GATK pipeline are highly consistent in terms of accuracy, achieving over 99% precision and recall on NA12878. For speed, the LUSH pipeline completes 30x WGS data in 1.6 hours, which is about 17x faster than the GATK pipeline. From BAM to VCF, LUSH_HC even takes only 12 minutes, about 76x faster than GATK. Moreover, the LUSH pipeline shows favorable scalability in terms of thread and sequencing depth. ConclusionThe LUSH pipeline provides far superior computational speed to GATK while maintaining a high level of accuracy comparable to that of GATK, which greatly facilitates bedside analysis of acute patients, large-scale cohort data analysis, and variant calling in crop breeding programs.

bioinformatics↗

bioRxiv2023

A robust method for the rapid generation of nanobodies.

Nanobody refers to the variable domain of heavy-chain-only antibodies. The distinctive advantages of nanobodies including small size, feasible expression in Escherichia coli (E. coli), and superior stability make them promising tools for applications in scientific research and therapies. So far, the screening and expression of nanobodies are mainly following similar methods used for conventional antibodies, suffering from amplification-caused losses of the diversity of libraries and requirements of subcloning of interests into the expression vector. Here, based on the unique properties of nanobodies, we developed an integrated method to screen and express nanobodies simultaneously with no bias of the library diversity. The library of nanobodies was cloned and secretively expressed into the culture medium. Target specifical binding nanobodies were isolated through 1-3 rounds of dilution and regrown steps in a way following the Poisson distribution to ensure no positive clones were dismissed, while the population of positive clones increased by more than 10 folds upon each round of dilution. Ultimately, 5 nanobodies against the death domain receptor 5 (DR5) and 5 nanobodies against the Pyrococcus furiosus (Pfu) DNA polymerase were produced directly out of their immunized libraries, respectively. Additionally, our approach allowed nanobody screening even without any specialized instruments/devices, demonstrating general applicability in the routine production of monoclonal nanobodies for diverse biomedical applications.

biochemistry↗

bioRxiv2023

Antagonism among DUX family members evolved from an ancestral toxic single homeodomain protein

Double homeobox (DUX) genes are unique to eutherian mammals and normally expressed transiently during zygotic genome activation. The canonical member, DUX4, is involved in facioscapulohumeral muscular dystrophy (FSHD) and cancer, when misexpressed in other contexts. We evaluate the 3 human DUX genes and the ancestral single homeobox gene sDUX from the non-eutherian mammal, platypus, and find that DUX4 activities are not shared with DUXA or DUXB, which lack transcriptional activation potential, but surprisingly are shared with platypus sDUX. In human myoblasts, platypus sDUX drives cytotoxicity, inhibits myogenesis, and induces DUX4 target genes, particularly those associated with zygotic genome activation (ZGA), by binding DNA as a homodimer in a way that overlaps the DUX4 homeodomain crystal structure. DUXA lacks transcriptional activity but has DNA-binding and chromatin accessibility overlap with DUX4 and sDUX, including on ZGA genes and LTR elements, and can actually be converted into a DUX4-like cytotoxic factor by fusion to a synthetic transactivation domain. DUXA competition antagonizes the activity of DUX4 on its target genes, including in FSHD patient cells. Since DUXA is an early DUX4 target gene, this activity potentiates feedback inhibition, constraining the window of DUX4 activity. The DUX gene family therefore comprises cross-regulating members of opposing function, with implications for their roles in ZGA, FSHD, and cancer. HIGHLIGHTSO_LIPlatypus sDUX is toxic and inhibits myogenic differentiation. C_LIO_LIDUXA targets overlap substantially with those of DUX4. C_LIO_LIDUXA fused to a synthetic transactivation domain acquires DUX4-like toxicity. C_LIO_LIDUXA behaves as a competitive inhibitor of DUX4. C_LI

molecular biology↗

bioRxiv2023

ATP is a major determinant of phototrophic bacterial longevity in growth arrest.

How bacteria transition into growth arrest as part of stationary phase has been well-studied, but our knowledge of features that help cells to stay alive in the following days and weeks is incomplete. Most studies have used heterotrophic bacteria that are growth-arrested by depletion of substrates used for both biosynthesis and energy generation, making is difficult to disentangle the effects of the two. In contrast, when grown anaerobically in light, the phototrophic bacterium Rhodopseudomonas palustris generates ATP from light via cyclic photophosphorylation and builds biomolecules from organic substrates such as acetate. As such, energy generation and carbon utilization are independent from one another. Here we compared the physiological and molecular responses of R. palustris to growth arrest caused by carbon source depletion in light (energy-replete) and dark (energy-depleted) conditions. Both sets of cells remained viable for six to ten days, at which point dark-incubated cells lost viability whereas light-incubated cells remained fully viable for 60 days. Dark-incubated cells were depleted in intracellular ATP prior to losing viability, suggesting that ATP depletion is a cause of cell death. Dark-incubated cells also shut down measurable protein synthesis, whereas light-incubated cells continued to synthesize proteins at low levels. Cells incubated in both conditions continued to transcribe genes. We suggest that R. palustris may completely shut down protein synthesis in dark, energy-depleted, conditions as a strategy to survive the nighttime hours of day/night cycles it experiences in nature, where there is a predictable source of energy in the form of sunlight during days. IMPORTANCEThe molecular and physiological basis of bacterial longevity in growth arrest is important to investigate for several reasons. Such investigations could improve treatment of chronic infections, advance use of non-growing bacteria as biocatalysts to make high yields of value-added products, and improve estimates of microbial activities in natural habitats, where cells are often growing slowly or not at all. Here we compared survival of the phototrophic bacterium Rhodopseudomonas palustris under conditions where it generates ATP (incubation in light) and where it does not generate ATP (incubation in dark) to directly assess effects of energy depletion on long-term viability. We found that ATP is important for long-term survival over weeks. However, R. palustris survives 12h periods of ATP depletion without loss of viability, apparently in anticipation of sunrise and restoration of its ability to generate ATP. Our work suggests that cells respond to ATP depletion by shutting down protein synthesis.

microbiology↗

bioRxiv2022

Retrograde mitochondrial signaling governs the identity and maturity of metabolic tissues

Mitochondrial damage is a hallmark of metabolic diseases, including diabetes and metabolic dysfunction-associated steatotic liver disease, yet the consequences of impaired mitochondria in metabolic tissues are often unclear. Here, we report that dysfunctional mitochondrial quality control engages a retrograde (mitonuclear) signaling program that impairs cellular identity and maturity across multiple metabolic tissues. Surprisingly, we demonstrate that defects in the mitochondrial quality control machinery, which we observe in pancreatic {beta} cells of humans with type 2 diabetes, cause reductions of {beta} cell mass due to dedifferentiation, rather than apoptosis. Utilizing transcriptomic profiling, lineage tracing, and assessments of chromatin accessibility, we find that targeted deficiency anywhere in the mitochondrial quality control pathway (e.g., genome integrity, dynamics, or turnover) activate the mitochondrial integrated stress response and promote cellular immaturity in {beta} cells, hepatocytes, and brown adipocytes. Intriguingly, pharmacologic blockade of mitochondrial retrograde signaling in vivo restores {beta} cell mass and identity to ameliorate hyperglycemia following mitochondrial damage. Thus, we observe that a shared mitochondrial retrograde response controls cellular identity across metabolic tissues and may be a promising target to treat or prevent metabolic disorders.

cell biology↗

bioRxiv2022

Unbiased Classification of the Human Brain Proteome Resolves Distinct Clinical and Pathophysiological Subtypes of Cognitive Impairment

The hallmark amyloid-{beta} and tau deposition of Alzheimers disease (AD) represents only a fraction of its diverse pathophysiology. Molecular subtyping using large-scale -omic strategies can help resolve this biological heterogeneity. Using quantitative mass spectrometry, we measured ~8,000 proteins across >600 dorsolateral prefrontal cortex tissues from Religious Orders Study and Rush Memory and Aging Project participants with clinical diagnoses of no cognitive impairment, mild cognitive impairment (MCI), and AD dementia. Unbiased classification of MCI and AD cases based on individual proteomic profiles resolved three classes with expression differences across numerous cell types and biological ontologies. Two classes displayed molecular signatures atypical of those previously observed in AD neurodegeneration, such as elevated synaptic and decreased inflammatory markers. In one class, these atypical proteomic features were associated with clinical and pathological hallmarks of cognitive resilience. These results promise to better define disease heterogeneity within AD and meaningfully impact its diagnostic and therapeutic precision.

neuroscience↗

bioRxiv2022

An overlapped natural antisense lncRNA FCER1A-AS controls anaphylactic reaction by promoting FcϵRIα expression

Functioned as -subunit of the high-affinity immunoglobulin E receptor (Fc{varepsilon} RI), Fc{varepsilon} RI plays a central role in the pathogenesis of Ig-E-mediated allergy and other IgE-related disorders. Fc{varepsilon} RI is normally expressed only in limited spectrum of cells like basophils and mast cells, but the mechanism of controlling Fc{varepsilon} RI expression in these cells is less well understood. In this study, we found fully overlapped natural antisense transcript (NATs) of Fc{varepsilon} RI (FCER1A-AS) is co-expressed with cognate sense transcript (FCER1A-S) in IL-3 induced Fc{varepsilon} RI-expressing cells or in high Fc{varepsilon} RI-expressing cell line MC/9. When FCER1A-AS is selectively knocked down by CRISPR/RfxCas13d (CasRx) approach in MC/9, expression of mRNA and proteins of FCER1A-S is also markedly decreased. Furthermore, deficiency of FCER1A-AS along with lack of FCER1A-S expression is found in two different lines of gene-targeted mice in which FCER1A locus is disturbed at different sites. More importantly, the FCER1A-AS-deficient homozygous mice display similarly diminished anaphylactic reaction as FCER1A gene knockout mice. Thus, we uncovered in this investigation that the expression of FCER1A-S is positively regulated by co-expressed fully overlapped antisense transcript.

immunology↗

bioRxiv2022

hibayes: An R Package to Fit Individual-Level, Summary-Level and Single-Step Bayesian Regression Models for Genomic Prediction and Genome-Wide Association Studies

With the rapid development of sequencing technology, the costs of individual genotyping have been reduced dramatically, leading to genomic prediction and genome-wide association studies being widely promoted and used to predict the unknown phenotypes and to locate causal or candidate genes for animal and plant economic traits and, increasingly, for human diseases. Developing newly advanced statistical models to improve accuracy in predicting and locating for the traits with various genetic architectures has always been a hot topic in those two research domains. The Bayesian regression model (BRM) has played a crucial role in the past decade, and it has been used widely in relevant genetic analyses owing to its flexible model assumptions on the unknown genetic architecture of complex traits. To fully utilize the available data from either a self-designed experimental population or a public database, statistical geneticists have constantly extended the fitting capacity of BRM, and a series of new methodologies have been proposed for different application scenarios. Here we introduce hibayes, which is the only one tool that can implement three types of Bayesian regression models. With the richest methods achieved thus far, it covers almost all the functions involved in genetic analyses for genomic prediction and genome-wide association studies, potentially addressing a wide range of research problems, while retaining an easy-to-use and transparent interface. We believe that hibayes will facilitate the researches conducted by human geneticists, as well as plant and animal breeders. The hibayes package is freely available from CRAN at https://cran.r-project.org/package=hibayes.

genetics↗

bioRxiv2021

Broadly neutralizing antibodies overcome SARS-CoV-2 Omicron antigenic shift

The recently emerged SARS-CoV-2 Omicron variant harbors 37 amino acid substitutions in the spike (S) protein, 15 of which are in the receptor-binding domain (RBD), thereby raising concerns about the effectiveness of available vaccines and antibody therapeutics. Here, we show that the Omicron RBD binds to human ACE2 with enhanced affinity relative to the Wuhan-Hu-1 RBD and acquires binding to mouse ACE2. Severe reductions of plasma neutralizing activity were observed against Omicron compared to the ancestral pseudovirus for vaccinated and convalescent individuals. Most (26 out of 29) receptor-binding motif (RBM)-directed monoclonal antibodies (mAbs) lost in vitro neutralizing activity against Omicron, with only three mAbs, including the ACE2-mimicking S2K146 mAb1, retaining unaltered potency. Furthermore, a fraction of broadly neutralizing sarbecovirus mAbs recognizing antigenic sites outside the RBM, including sotrovimab2, S2X2593 and S2H974, neutralized Omicron. The magnitude of Omicron-mediated immune evasion and the acquisition of binding to mouse ACE2 mark a major SARS-CoV-2 mutational shift. Broadly neutralizing sarbecovirus mAbs recognizing epitopes conserved among SARS-CoV-2 variants and other sarbecoviruses may prove key to controlling the ongoing pandemic and future zoonotic spillovers.

immunology↗

bioRxiv2021

Reversible regulation of Cas12a activities by AcrVA5-mediated acetylation and CobB-mediated deacetylation

The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR associated (Cas) system protects bacteria and archaea from the invasion of foreign genetic elements. To cope with the host CRISPR systems, phages have evolved many strategies, including the anti-CRISPR (Acr) proteins, to inactivate the Cas nucleases. Recently, it has been reported that the type V-A Cas12a effector can be acetylated and inactivated by AcrVA5, which is a GNAT-family acetyltransferase. However, it is unclear whether the host has any coping strategies to reactivate the defense system. Here we show that the AcrVA5-acetylated Cas12a can be deacetylated by bacterial deacetylase CobB, reactivating Cas12a for both in vitro cleavage of target DNA sequences and in vivo protection of the host from invasion of foreign nucleic acids. Therefore, this study not only shows the reversible regulation of Cas12a activities by post-translational modification but also reveals CobB as a secondary safeguard to bacterial CRISPR defense systems. In addition, we demonstrate that AcrVA5 is a wide-spectrum acetyltransferase, acetylating a large number of target proteins besides Cas12a, and the AcrVA5-acetylated targets can also be deacetylated by CobB.

molecular biology↗

bioRxiv2021

Genetic, epigenetic, and environmental mechanisms govern allele-specific gene expression

Allele-specific expression (ASE) is a phenomenon where one allele is preferentially expressed over the other. Genetic and epigenetic factors cause ASE by altering the final allelic composition of a genes product, leading to expression imbalances that can have functional consequences on phenotypes. Environmental signals also impact allele-specific gene regulation, but how they contribute to this crosstalk remains understudied. Here, we explored how allelic genotype, parent-of-origin, tissue type, sex, and dietary fat simultaneously influence ASE biases in a F1 reciprocal cross mouse model. Male and female mice from a F1 reciprocal cross of the LG/J and SM/J strains were fed a high fat or low fat diet. We harnessed strain-specific variants to distinguish between two classes of ASE: parent-of-origin dependent (unequal expression based on an alleles parental origin) and sequence dependent (unequal expression based on an alleles nucleotide identity). We present a comprehensive map of ASE patterns in 2,853 genes across three metabolically-relevant tissues and nine environmental contexts. We found that both ASE classes are highly dependent on tissue type and environmental context. They vary across metabolic tissues, between males and females, and in response to dietary fat levels. Surprisingly, we found 45 genes with inconsistent ASE biases that switched direction across tissues and/or contexts (e.g. SM/J biased in one cohort, LG/J biased in another). We also integrated ASE and QTL data from populations at various degrees of intercrossing the LG/J and SM/J strains. ASE genes in these tissues are often enriched in QTLs for metabolic and musculoskeletal traits, highlighting how this orthogonal approach can prioritize candidate genes for functional validation. Together, our results provide novel insights into how genetic, epigenetic, and environmental mechanisms govern allele-specific gene regulation, which is an essential step towards deciphering the genotype to phenotype map.

genomics↗

bioRxiv2021

The exosomes derived from urine of premature infants target MAPK8 via miR-30a-5p to protect cisplatin-induced acute kidney injury in mice

AimAcute kidney injury (AKI), a global public health issue, not only causes millions of deaths every year, but is also a susceptible factor for chronic kidney disease (CKD). Nephrotoxic drugs are an important cause of AKI. There is still a lack of effective and satisfactory prevention method in clinical practice. This study investigated the protective effect of the exosomes derived from urine of premature infants on cisplatin-induced acute kidney injury. MethodsIsolation of exosomes from fresh urine of premature infants: The characteristics of exosomes were determined by flow cytometry, transmission electron microscopy and Western blotting. A C57BL/6 mice model of cisplatin-induced acute kidney injury was established. The mice in the experimental group were given 100ug exosomes dissolved in 200ul solution. The mice in the control group were given normal saline (200ul). These treatments were performed 24 hours after AKI was induced by intraperitoneal injection of cisplatin. To evaluate renal function, blood was drawn 24 hours after AKI model was established and serum creatinine (sCr) was measured. The mice were euthanized 72 hours after exosome treatment. The kidneys were collected for pathological examination, RNA and protein extraction, and the evaluation of renal tubular damage and apoptosis. In the in-vitro experiment, human renal cortex/proximal tubular cells (HK2) was induced by cisplatin to assess the protective ability of the exosomes derived from urine of premature infants. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western Blotting were used to evaluate the effect of exosomes treatment on the apoptosis of HK2 cells induced by cisplatin. Exosome microRNA sequencing technology and bioinformatics analysis method were applied to investigate the miRNAs enriched in exosomes and their target genes. The dual luciferase gene reporter system was used to detect the interaction of target genes. ResultsTreatment of exosomes derived from urine of premature infants could decrease the level of serum creatinine and the apoptosis of renal tubular cell, inhibit the infiltration of inflammatory cell, protect mice from acute kidney injury induced by cisplatin and reduce mortality. In addition, miR-30a-5p was the most abundant miRNA in the exosomes derived from urine of premature infants. It protected HK2 cells from cisplatin-induced apoptosis by targeting and down-regulating the 3UTR of mitogen-activated protein kinases (MAPK8) mRNA. ConclusionsAccording to our results, the exosomes derived from urine of premature infants alleviated cisplatin-induced acute kidney injury in mice and inhibited the apoptosis of human proximal tubular cells (HK2) induced by cisplatin in vitro. MiR-30a-5p in exosomes inhibited cisplatin-induced MAPK activation, ameliorated apoptosis, and protected renal function. The exosomes derived from urine of premature infants provided a promising acellular therapy for AKI.

molecular biology↗