Unveiling the role of ABI3 and hub senescence-related genes in macrophage senescence for atherosclerotic plaque progression.

BACKGROUND: Atherosclerosis, characterized by abnormal arterial lipid deposition, is an age-dependent inflammatory disease and contributes to elevated morbidity and mortality. Senescent foamy macrophages are considered to be deleterious at all stages of atherosclerosis, while the underlying mechanisms remain largely unknown. In this study, we aimed to explore the senescence-related genes in macrophages diagnosis for atherosclerotic plaque progression. METHODS: The atherosclerosis-related datasets were retrieved from the Gene Expression Omnibus (GEO) database, and cellular senescence-associated genes were acquired from the CellAge database. R package Limma was used to screen out the differentially expressed senescence-related genes (DE-SRGs), and then three machine learning algorithms were applied to determine the hub DE-SRGs. Next, we established a nomogram model to further confirm the clinical significance of hub DE-SRGs. Finally, we validated the expression of hub SRG ABI3 by Sc-RNA seq analysis and explored the underlying mechanism of ABI3 in THP-1-derived macrophages and mouse atherosclerotic lesions. RESULTS: A total of 15 DE-SRGs were identified in macrophage-rich plaques, with five hub DE-SRGs (ABI3, CAV1, NINJ1, Nox4 and YAP1) were further screened using three machine learning algorithms. Subsequently, a nomogram predictive model confirmed the high validity of the five hub DE-SRGs for evaluating atherosclerotic plaque progression. Further, the ABI3 expression was upregulated in macrophages of advanced plaques and senescent THP-1-derived macrophages, which was consistent with the bioinformatics analysis. ABI3 knockdown abolished macrophage senescence, and the NF-κB signaling pathway contributed to ABI3-mediated macrophage senescence. CONCLUSION: We identified five cellular senescence-associated genes for atherogenesis progression and unveiled that ABI3 might promote macrophage senescence via activation of the NF-κB pathway in atherogenesis progression, which proposes new preventive and therapeutic strategies of senolytic agents for atherosclerosis.

Metabolomics reveals metabolites associated with hair follicle cycle in cashmere goats.

BACKGROUND: The hair follicle is a skin accessory organ that regulates hair development, and its activity varies on a regular basis. However, the significance of metabolites in the hair follicle cycle has long been unknown. RESULTS: Targeted metabolomics was used in this investigation to reveal the expression patterns of 1903 metabolites in cashmere goat skin during anagen to telogen. A statistical analysis was used to investigate the potential associations between metabolites and the hair follicle cycle. The findings revealed clear changes in the expression patterns of metabolites at various phases and in various feeding models. The majority of metabolites (primarily amino acids, nucleotides, their metabolites, and lipids) showed downregulated expression from anagen (An) to telogen (Tn), which was associated with gene expression, protein synthesis and transport, and cell structure, which reflected, to some extent, that the cells associated with hair follicle development are active in An and apoptotic in An-Tn. It is worth mentioning that the expression of vitamin D3 and 3,3',5-triiodo-L-thyronine decreased and then increased, which may be related to the shorter and longer duration of outdoor light, which may stimulate the hair follicle to transition from An to catagen (Cn). In the comparison of different hair follicle development stages (An, Cn, and Tn) or feeding modes (grazing and barn feeding), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that common differentially expressed metabolites (DEMs) (2'-deoxyadenosine, L-valine, 2'-deoxyuridine, riboflavin, cytidine, deoxyguanosine, L-tryptophan, and guanosine-5'-monophosphate) were enriched in ABC transporters. This finding suggested that this pathway may be involved in the hair follicle cycle. Among these DEMs, riboflavin is absorbed from food, and the expression of riboflavin and sugars (D-glucose and glycogen) in skin tissue under grazing was greater and lower than that during barn feeding, respectively, suggesting that eating patterns may also alter the hair follicle cycle. CONCLUSIONS: The expression patterns of metabolites such as sugars, lipids, amino acids, and nucleotides in skin tissue affect hair follicle growth, in which 2'-deoxyadenosine, L-valine, 2'-deoxyuridine, riboflavin, cytidine, deoxyguanosine, L-tryptophan, and guanosine-5'-monophosphate may regulate the hair follicle cycle by participating in ABC transporters. Feeding practices may regulate hair follicle cycles by influencing the amount of hormones and vitamins expressed in the skin of cashmere goats.

HSFAS mediates fibroblast proliferation, migration, trans-differentiation and apoptosis in hypertrophic scars via interacting with ADAMTS8.

Hypertrophic scar (HS) is one of the most common sequelae of patients, especially after burns and trauma. The roles of regulatory long noncoding RNAs (lncRNAs) in mediating HS remain underexplored. Human hypertrophic scar-derived fibroblasts (HSFBs) have been shown to exert more potent promoting effects on extracellular matrix (ECM) accumulation than normal skin-derived fibroblasts (NSFBs) and are associated with enhanced HS formation. The purpose of this study is to search for lncRNAs enriched in HSFBs and investigate their roles and mechanisms. LncRNA MSTRG.59347.16 is one of the most highly expressed lncRNAs in HS detected by lncRNA-seq and qRT-PCR and named as hypertrophic scar fibroblast-associated lncRNA (HSFAS). HSFAS overexpression significantly induces fibroblast proliferation, migration, and myofibroblast trans-differentiation and inhibits apoptosis in HSFBs, while knockdown of HSFAS results in augmented apoptosis and attenuated proliferation, migration, and myofibroblast trans-differentiation of HSFBs. Mechanistically, HSFAS suppresses the expression of A disintegrin and metalloproteinase with thrombospondin motifs 8 (ADAMTS8). ADAMTS8 knockdown rescues downregulated HSFAS-mediated fibroblast proliferation, migration, myofibroblast trans-differentiation and apoptosis. Thus, our findings uncover a previously unknown lncRNA-dependent regulatory pathway for fibroblast function. Targeted intervention in the HSFAS-ADAMTS8 pathway is a potential therapy for HS.

Inhibition of autophagy via 3-methyladenine alleviates the progression of preeclampsia.

Autophagy is a cellular mechanism for self-renewal that involves the breakdown of cytoplasmic proteins or organelles within lysosomes. Although preeclampsia (PE) exhibits several characteristics that could imply disrupted autophagy, there is limited evidence supporting the notion that impaired placental autophagy directly causes PE, as indicated by differential expression profiling of whole placental tissue. In this study, we aim to explore the significance of autophagy in maintaining pregnancy and its association with PE. First, the RNA-seq results show that 218 genes are differentially expressed in placentas from preeclamptic pregnancies. Notably, KEGG pathway analysis reveals significant enrichment of genes related to autophagy-related signaling pathways, including the PI3K-Akt signaling pathway, the AMPK signaling pathway, and the mTOR signaling pathway. Additionally, our findings indicate an increase in autophagy in placentas from pregnancies complicated by preeclampsia as well as in trophoblasts subjected to hypoxic conditions. Next, we examine the impact of 3-methyladenine (3-MA), a targeted inhibitor of autophagy, on the progression of PE. The administration of 3-MA profoundly alleviates the severity of PE-like symptoms in rats subjected to reduced uterine perfusion pressure (RUPP). The findings from our study suggest that inhibiting autophagy may serve as a promising approach for adjuvant chemotherapy for PE.

The mechanism by which piR-000699 targets SLC39A14 regulates ferroptosis in aging myocardial ischemia/reperfusion injury.

Myocardial ischemia/reperfusion (I/R) injury is a classic type of cardiovascular disease characterized by injury to cardiomyocytes leading to different types of cell death. The degree of irreversible myocardial damage is closely related to age, and ferroptosis is involved in cardiomyocyte damage. However, the mechanisms underlying ferroptosis regulation in aging myocardial I/R injury are still unclear. The present study aims to explore the underlying mechanism of piRNA regulation in ferroptosis. Using left anterior descending coronary artery ligation in an aging rat model and a D-galactose-induced rat cardiomyocyte line (H9C2) to construct an aging cardiomyocyte model, we investigate whether ferroptosis occurs after reperfusion injury in vitro and in vivo. This study focuses on the upregulation of piR-000699 after hypoxia/reoxygenation treatment in aging cardiomyocytes by observing hypoxia/reoxygenation (H/R) injury indicators and ferroptosis-related indicators and clarifying the role of piR-000699 in H/R injury caused by ferroptosis in aging cardiomyocytes. Bioinformatics analysis reveals that SLC39A14 is a gene that binds to piR-000699. Our data show that ferroptosis plays an important role in I/R injury both in vivo and in vitro. Furthermore, the results show the potential role of piR-000699 in regulating SLC39A14 in ferroptosis in aging cardiomyocytes under hypoxia/reoxygenation conditions. Together, our results reveal that the mechanism by which piR-000699 binds to SLC39A14 regulates ferroptosis in aging myocardial I/R injury.

Drivers of plateau adaptability in cashmere goats revealed by genomic and transcriptomic analyses.

BACKGROUND: The adaptive evolution of plateau indigenous animals is a current research focus. However, phenotypic adaptation is complex and may involve the interactions between multiple genes or pathways, many of which remain unclear. As a kind of livestock with important economic value, cashmere goat has a high ability of plateau adaptation, which provides us with good materials for studying the molecular regulation mechanism of animal plateau adaptation. RESULTS: In this study, 32 Jiangnan (J) and 32 Tibetan (T) cashmere goats were sequenced at an average of 10. Phylogenetic, population structure, and linkage disequilibrium analyses showed that natural selection or domestication has resulted in obvious differences in genome structure between the two breeds. Subsequently, 553 J vs. T and 608 T vs. J potential selected genes (PSGs) were screened. These PSGs showed potential relationships with various phenotypes, including myocardial development and activity (LOC106502520, ATP2A2, LOC102181869, LOC106502520, MYL2, ISL1, and LOC102181869 genes), pigmentation (MITF and KITLG genes), hair follicles/hair growth (YAP1, POGLUT1, AAK1, HES1, WNT1, PRKAA1, TNKS, WNT5A, VAX2, RSPO4, CSNK1G1, PHLPP2, CHRM2, PDGFRB, PRKAA1, MAP2K1, IRS1, LPAR1, PTEN, PRLR, IBSP, CCNE2, CHAD, ITGB7, TEK, JAK2, and FGF21 genes), and carcinogenesis (UBE2R2, PIGU, DIABLO, NOL4L, STK3, MAP4, ADGRG1, CDC25A, DSG3, LEPR, PRKAA1, IKBKB, and ABCG2 genes). Phenotypic analysis showed that Tibetan cashmere goats has finer cashmere than Jiangnan cashmere goats, which may allow cashmere goats to better adapt to the cold environment in the Tibetan plateau. Meanwhile, KRTs and KAPs expression in Jiangnan cashmere goat skin was significantly lower than in Tibetan cashmere goat. CONCLUSIONS: The mutations in these PSGs maybe closely related to the plateau adaptation ability of cashmere goats. In addition, the expression differences of KRTs and KAPs may directly determine phenotypic differences in cashmere fineness between the two breeds. In conclusion, this study provide a reference for further studying plateau adaptive mechanism in animals and goat breeding.

TREM-1 triggers necroptosis of macrophages through mTOR-dependent mitochondrial fission during acute lung injury.

BACKGROUND: Necroptosis of macrophages is a necessary element in reinforcing intrapulmonary inflammation during acute lung injury (ALI). However, the molecular mechanism that sparks macrophage necroptosis is still unclear. Triggering receptor expressed on myeloid cells-1 (TREM-1) is a pattern recognition receptor expressed broadly on monocytes/macrophages. The influence of TREM-1 on the destiny of macrophages in ALI requires further investigation. METHODS: TREM-1 decoy receptor LR12 was used to evaluate whether the TREM-1 activation induced necroptosis of macrophages in lipopolysaccharide (LPS)-induced ALI in mice. Then we used an agonist anti-TREM-1 Ab (Mab1187) to activate TREM-1 in vitro. Macrophages were treated with GSK872 (a RIPK3 inhibitor), Mdivi-1 (a DRP1 inhibitor), or Rapamycin (an mTOR inhibitor) to investigate whether TREM-1 could induce necroptosis in macrophages, and the mechanism of this process. RESULTS: We first observed that the blockade of TREM-1 attenuated alveolar macrophage (AlvMs) necroptosis in mice with LPS-induced ALI. In vitro, TREM-1 activation induced necroptosis of macrophages. mTOR has been previously linked to macrophage polarization and migration. We discovered that mTOR had a previously unrecognized function in modulating TREM-1-mediated mitochondrial fission, mitophagy, and necroptosis. Moreover, TREM-1 activation promoted DRP1Ser616 phosphorylation through mTOR signaling, which in turn caused surplus mitochondrial fission-mediated necroptosis of macrophages, consequently exacerbating ALI. CONCLUSION: In this study, we reported that TREM-1 acted as a necroptotic stimulus of AlvMs, fueling inflammation and aggravating ALI. We also provided compelling evidence suggesting that mTOR-dependent mitochondrial fission is the underpinning of TREM-1-triggered necroptosis and inflammation. Therefore, regulation of necroptosis by targeting TREM-1 may provide a new therapeutic target for ALI in the future.

Integration of GWAS and eGWAS to screen candidate genes underlying green head traits in male ducks.

Sexually dimorphic plumage coloration is widespread in birds. The male possesses more brightly colored feathers than the female. Dark green head feathers comprise one of the most typical appearance characteristics of the male Ma duck compared with the female. However, there are noticeable individual differences observed in these characteristics. Herein, genome-wide association studies (GWAS) were employed to investigate the genetic basis of individual differences in male duck green head-related traits. Our results showed that 165 significant SNPs were associated with green head traits. Meanwhile, 71 candidate genes were detected near the significant SNPs, including four genes (CACNA1I, WDR59, GNAO1 and CACNA2D4) related to the individual differences in the green head traits of male ducks. Additionally, the eGWAS identified three SNPs located within two candidate genes (LOC101800026 and SYNPO2) associated with TYRP1 gene expression, and might be important regulators affecting the expression level of TYRP1 in the head skin of male ducks. Our data also suggested that transcription factor MXI1 might regulate the expression of TYRP1, thereby causing differences in the green head traits among male ducks. This study provided primary data for further analysis of the genetic regulation of duck feather color.

Cooperation between NSPc1 and DNA methylation represses HOXA11 expression and promotes apoptosis of trophoblast cells during preeclampsia.

Accumulating evidence has shown that the apoptosis of trophoblast cells plays an important role in the pathogenesis of preeclampsia, and an intricate interplay between DNA methylation and polycomb group (PcG) protein-mediated gene silencing has been highlighted recently. Here, we provide evidence that the expression of nervous system polycomb 1 (NSPc1), a BMI1 homologous polycomb protein, is significantly elevated in trophoblast cells during preeclampsia, which accelerates trophoblast cell apoptosis. Since NSPc1 acts predominantly as a transcriptional inactivator that specifically represses HOXA11 expression in trophoblast cells during preeclampsia, we further show that NSPc1 is required for DNMT3a recruitment and maintenance of the DNA methylation in the HOXA11 promoter in trophoblast cells during preeclampsia. In addition, we find that the interplay of DNMT3a and NSPc1 represses the expression of HOXA11 and promotes trophoblast cell apoptosis. Taken together, these results indicate that the cooperation between NSPc1 and DNMT3a reduces HOXA11 expression in preeclampsia pathophysiology, which provides novel therapeutic approaches for targeted inhibition of trophoblast cell apoptosis during preeclampsia pathogenesis.

Single-molecule long-read sequencing reveals the potential impact of posttranscriptional regulation on gene dosage effects on the avian Z chromosome.

BACKGROUND: Mammalian sex chromosomes provide dosage compensation, but avian lack a global mechanism of dose compensation. Herein, we employed nanopore sequencing to investigate the genetic basis of gene expression and gene dosage effects in avian Z chromosomes at the posttranscriptional level. RESULTS: In this study, the gonad and head skin of female and male duck samples (n = 4) were collected at 16 weeks of age for Oxford nanopore sequencing. Our results revealed a dosage effect and local regulation of duck Z chromosome gene expression. Additionally, AS and APA achieve tissue-specific gene expression, and male-biased lncRNA regulates its Z-linked target genes, with a positive regulatory role for gene dosage effects on the duck Z chromosome. In addition, GO enrichment and KEGG pathway analysis showed that the dosage effects of Z-linked genes were mainly associated with the cellular response to hormone stimulus, melanin biosynthetic, metabolic pathways, and melanogenesis, resulting in sex differences. CONCLUSIONS: Our data suggested that post transcriptional regulation (AS, APA and lncRNA) has a potential impact on the gene expression effects of avian Z chromosomes. Our study provides a new view of gene regulation underlying the dose effects in avian Z chromosomes at the RNA post transcriptional level.

Homocysteine facilitates endoplasmic reticulum stress and apoptosis of hepatocytes by suppressing ERO1α expression via cooperation between DNMT1 and G9a.

Endoplasmic reticulum (ER) stress and apoptosis play a critical role in liver injury. Endoplasmic reticulum oxidoreductase 1α (ERO1α) is an oxidase that exists in the luminal side of the ER membrane, participating in protein folding and secretion and inhibiting apoptosis, but the underlying mechanism on liver injury induced by homocysteine (Hcy) remains obscure. In this study, hyperhomocysteinemia (HHcy) mice model was established in cbs+/- mice by feeding a high-methionine diet for 12 weeks; and cbs+/- mice fed with high-methionine diet exhibited more severe liver injury compared to cbs+/+ mice. Mechanistically, we found that Hcy promoted ER stress and apoptosis of hepatocytes and thereby aggravated liver injury through inhibiting ERO1α expression; accordingly, overexpression of ERO1α remarkably alleviated ER stress and apoptosis of hepatocytes induced by Hcy. Epigenetic modification analysis revealed that Hcy significantly increased levels of DNA methylation and H3 lysine 9 dimethylation (H3K9me2) on ERO1α promoter, which attributed to upregulated DNA methyltransferase 1 (DNMT1) and G9a, respectively. Further study showed that DNMT1 and G9a cooperatively regulated ERO1α expression in hepatocytes exposed to Hcy. Taken together, our work demonstrates that Hcy activates ER stress and apoptosis of hepatocytes by downregulating ERO1α expression via cooperation between DNMT1 and G9a, which provides new insight into the mechanism of Hcy-induced ER stress and apoptosis of hepatocytes in liver injury.

Comparative Analyses of the Gut Microbiome of Two Fox Species, the Red Fox (Vulpes Vulpes) and Corsac Fox (Vulpes Corsac), that Occupy Different Ecological Niches.

The gut microbiome is integral for the host's living and environmental adaptation and crucially important for understanding host adaptive mechanisms. The red fox (Vulpes vulpes) dominates a wider ecological niche and more complicated habitat than that of the corsac fox (V. corsac). However, the adaptive mechanisms (in particular, the gut microbiome responsible for this kind of difference) are still unclear. Therefore, we investigated the gut microbiome of these two species in the Hulunbuir grassland, China, and evaluated their microbiome composition, function, and adaptive mechanisms. We profiled the gut microbiome and metabolism function of red and corsac foxes via 16S rRNA gene and metagenome sequencing. The foxes harbored species-specific microbiomes and functions that were related to ecological niche and habitat. The red fox had abundant Bacteroides, which leads to significant enrichment of metabolic pathways (K12373 and K21572) and enzymes related to chitin and carbohydrate degradation that may help the red fox adapt to a wider niche. The corsac fox harbored large proportions of Blautia, Terrisporobacter, and ATP-binding cassette (ABC) transporters (K01990, K02003, and K06147) that can help maintain corsac fox health, allowing it to live in harsh habitats. These results indicate that the gut microbiome of the red and corsac foxes may have different abilities which may provide these species with differing capabilities to adapt to different ecological niches and habitats, thus providing important microbiome data for understanding the mechanisms of host adaptation to different niches and habitats.

miR-30a-5p promotes glomerular podocyte apoptosis via DNMT1-mediated hypermethylation under hyperhomocysteinemia.

Abnormal elevation of homocysteine (Hcy) level is closely related to the development and progression of chronic kidney disease (CKD), with the molecular mechanisms that are not fully elucidated. Given the demonstration that miR-30a-5p is specifically expressed in glomerular podocytes, in the present study we aimed to investigate the role and potential underlying mechanism of miR-30a-5p in glomerular podocyte apoptosis induced by Hcy. We found that elevated Hcy downregulates miR-30a-5p expression in the mice and Hcy-treated podocytes, and miR-30a-5p directly targets the 3'-untranslated region (3'-UTR) of the forkhead box A1 (FOXA1) and overexpression of miR-30a-5p inhibits FOXA1 expression. By nMS-PCR and MassARRAY quantitative methylation analysis, we showed the increased DNA methylation level of miR-30a-5p promoter both and . Meanwhile, dual-luciferase reporter assay showed that the region between --1400 and --921 bp of miR-30a-5p promoter is a possible regulatory element for its transcription. Mechanistic studies indicated that DNA methyltransferase enzyme 1 (DNMT1) is the key regulator of miR-30a-5p, which in turn enhances miR-30a-5p promoter methylation level and thereby inhibits its expression. Taken together, our results revealed that epigenetic modification of miR-30a-5p is involved in glomerular podocyte injury induced by Hcy, providing a diagnostic marker candidate and novel therapeutic target in CKD induced by Hcy.

A novel lncRNA FPASL regulates fibroblast proliferation via the PI3K/AKT and MAPK signaling pathways in hypertrophic scar.

Hypertrophic scar is a problem for numerous patients, especially after burns, and is characterized by increased fibroblast proliferation and collagen deposition. Increasing evidence demonstrates that lncRNAs contribute to the development and progression of various diseases. However, the function of lncRNAs in hypertrophic scar formation remains poorly characterized. In this study, a novel fibroblast proliferation-associated lncRNA, named lncRNA FPASL (MSTRG.389905.1), which is mainly localized in the cytoplasm, is found to be downregulated in hypertrophic scar, as detected by lncRNA microarray and qRT-PCR. The full-length FPASL is characterized and further investigation confirms that it has no protein-coding potential. FPASL knockdown in fibroblasts triggers fibroblast proliferation, whereas overexpression of FPASL directly attenuates the proliferation of fibroblasts. Furthermore, target genes of the differentially expressed lncRNAs in hypertrophic scars and the matched adjacent normal tissues are enriched in fibroblast proliferation signaling pathways, including the PI3K/AKT and MAPK signaling pathways, as determined by GO annotation and KEGG enrichment analysis. We also demonstrate that knockdown of FPASL activates the PI3K/AKT and MAPK signaling pathways, and specific inhibitors of the PI3K/AKT and MAPK signaling pathways can reverse the proliferation of fibroblasts promoted by FPASL knockdown. Our findings contribute to a better understanding of the role of lncRNAs in hypertrophic scar and suggest that FPASL may act as a potential novel therapeutic target for hypertrophic scar.

Extracellular-superoxide dismutase DNA methylation promotes oxidative stress in homocysteine-induced atherosclerosis.

In the present study, we investigate the effect of homocysteine (Hcy) on extracellular-superoxide dismutase (EC-SOD) DNA methylation in the aorta of mice, and explore the underlying mechanism in macrophages, trying to identify the key targets of Hcy-induced EC-SOD methylation changes. ApoE -/- mice are fed different diets for 15 weeks, EC-SOD and DNA methyltransferase 1 (DNMT1) expression levels are detected by RT-PCR and western blot analysis. EC-SOD methylation levels are assessed by ntMS-PCR. After EC-SOD overexpression or knockdown in macrophages, following the transfection of macrophages with pEGFP-N1-DNMT1, the methylation levels of EC-SOD are detected. Our data show that the concentrations of Hcy and the area of atherogenic lesions are significantly increased in ApoE -/- mice fed with a high-methionine diet, and have a positive correlation with the levels of superoxide anions, which indicates that Hcy-activated superoxide anions enhance the development of atherogenic lesions. EC-SOD expression is suppressed by Hcy, and the content of superoxide anion is increased when EC-SOD is silenced by RNAi in macrophages, suggesting that EC-SOD plays a major part in oxidative stress induced by Hcy. Furthermore, the promoter activity of EC-SOD is increased following transfection with the -1/-1100 fragment, and EC-SOD methylation level is significantly suppressed by Hcy, and more significantly decreased upon DNMT1 overexpression. In conclusion, Hcy may alter the DNA methylation status and DNMT1 acts as the essential enzyme in the methyl transfer process to disturb the status of EC-SOD DNA methylation, leading to decreased expression of EC-SOD and increased oxidative stress and atherosclerosis.

LncRNA FPASL suppresses fibroblast proliferation through its DNA methylation via DNMT3b in hypertrophic scar.

Long noncoding RNAs (lncRNAs) are increasingly being implicated as key regulators of cell proliferation, apoptosis, and differentiation. However, the molecular mechanisms of specific lncRNAs in the context of hypertrophic scar remain largely unclear. Here, we find that the lncRNA FPASL (fibroblast proliferation-associated LncRNA) is downregulated in HS, and FPASL reduces fibroblast proliferation and colony formation and blocks cell cycle progression. Using GO annotation enrichment analysis along with AZC (a specific inhibitor of DNA methylation), we identify that DNA methylation is responsible for downregulating FPASL in hypertrophic scar. Subsequent studies demonstrate that high expression of DNMT3b inhibits FPASL expression in HS. Mechanistic study reveals a significant increase in fibroblast proliferation after transfection with LNA-FPASL, which is further inhibited by knockdown of DNMT3b. Thus, our study reveals that DNMT3b mediates hypermethylation of the lncRNA FPASL promoter and the downregulation of lncRNA FPASL promotes fibroblast proliferation in hypertrophic scar.

Progress on the formation mechanism of sexual dimorphism plumage color in birds.

Sexually dimorphic plumage coloration is widespread in birds in which the male plumage is brighter than the female. This phenomenon is related to the environmental constraints on sexual selection or intraspecific competition between males and females in birds. The physiological factors and genetic regulation mechanism affecting the color of sexual dimorphism plumages in birds have always attracted significant attention in research. Understanding the diversity of sexually dimorphic traits provides insights into the mating strategies of the sexes and their behavior, ecology, and evolution. Interestingly, the ASIP, MC1R, TYRP1, and BCO2 genes have been identified to play a potential role in the coloration of melanin and carotenoids in bird sexual dimorphism plumages, either by controlling the rate and type of melanin or carotene synthesis or degradation by exerting an effect on the pigment biosynthetic pathway. In this review, we systematically summarize the biological significance, the direct causes (chemical and physical color), and the influence of sex hormones in sexually dimorphic plumage coloration. We also investigate the molecular mechanism underlying the roles of some genes on sexual dimorphism coloration, thereby providing a reference for in-depth understanding on the formation mechanism(s) of sexual dimorphic coloration in birds.

Genome-wide association analysis reveals that EDNRB2 causes a dose-dependent loss of pigmentation in ducks.

BACKGROUND: Birds have various plumage color patterns, and spot is a common phenotype. Herein, we conducted genome-wide association studies (GWAS) in a population of 225 ducks with different sized black spots to reveal the genetic basis of this phenomenon. RESULTS: First, we quantified the black spot phenotype within the duck population. The results showed that the uncolored area of the body surface first appeared on the ventral side. With increasing duck age, the area of the black spots was highly conserved across the whole body surface. The GWAS results identified a 198 kb (Chr4: 10,149,651 bp to 10,348,068 bp) genetic region that was significantly associated with the black spot phenotype. The conditional GWAS and linkage disequilibrium (LD) analysis further narrowed the ultimate candidate region to 167 kb (Chr4: 10,180,939 bp to 10,348,068 bp). A key gene regulating melanoblast migration and differentiation, EDNRB2 (Endothelin B receptor-like), was found in the candidate region and having significant mRNA expression level changes in embryonic duck skin tissue with different spot sizes. The significant SNPs (single nucleotide polymorphisms) associated with the EDNRB2 gene were annotated, and two mutations (Chr4: 10,180,939 T > C and Chr4: 10,190,671 A > T) were found to result in the loss of binding sites for two trans-factors, XBP1 and cMYB. The phenotypic effect of these two mutations suggested that they can regulate the size of black spots in a dose-dependent manner, and Chr4: 10,180,939 T > C was the major allele locus. CONCLUSIONS: Our results revealed that EDNRB2 was the gene responsible for the variation in duck body surface spot size. Chr4: 10,180,939 T > C was the major allele that explained 49.5 % (dorsal side) and 32.9 % (ventral side) of the variation in duck body surface spot size, while 32.1 % (dorsal side) and 19.1 % (ventral side) of the variation could be explained by Chr4: 10,190,671 A > T. The trans-factor prediction also suggested that XBP1 and cMYB have the potential to interact with EDNRB2, providing new insights into the mechanism of action of these genes.

A single nucleotide polymorphism variant located in the cis-regulatory region of the ABCG2 gene is associated with mallard egg colour.

Avian egg coloration is shaped by natural selection, but its genetic basis remains unclear. Here, we used genome-wide association analysis and identity by descent to finely map green egg colour to a 179-kb region of Chr4 based on the resequencing of 352 ducks (Anas platyrhynchos) from a segregating population resulting from the mating of Pekin ducks (white-shelled eggs) and mallards (green-shelled eggs). We further narrowed the candidate region to a 30-kb interval by comparing genome divergence in seven indigenous duck populations. Among the genes located in the finely mapped region, only one transcript of the ABCG2 gene (XM_013093252.2) exhibited higher uterine expression in green-shelled individuals than in white-shelled individuals, as supported by transcriptome data from four populations. ABCG2 has been reported to encode a protein that functions as a membrane transporter for biliverdin. Sanger sequencing of the whole 30-kb candidate region (Chr4: 47.41-47.44 Mb) and a plasmid reporter assay helped to identify a single nucleotide polymorphism (Chr4: 47,418,074 G>A) located in a conserved predicted promoter region whose variation may alter ABCG2 transcription activity. We provide a useful molecular marker for duck breeding and contribute data to the research on ecological evolution based on egg colour patterns among birds.

Effect of feed restriction on the intestinal microbial community structure of growing ducks.

In poultry, feed restriction is common feeding management to limit poultry nutrients intake so that poultry only intake the essential energy, meeting the basic need of growth and development. Our study investigated whether feeding restriction affects the diversity of the intestinal microbiota of growing breeding ducks. In this research, the 60-120-day-old ducks were raised in restricted and free-feeding groups. After slaughtering, the carcass traits and the cecal contents were collected for 16S rRNA sequencing analysis. After feeding restriction, the growth rate of ducks was limited, the weight and rate of abdominal fat decreased, and the rate of chest and leg muscles increased. In addition, feeding restriction can also change the diversity of intestinal microorganisms in breeding ducks, such as the increase of Firmicutes abundance and the decrease of Bacteroidetes abundance. After analyzing of correlation, significant correlations between gut microbiota and carcass phenotypes were found. The results indicated that gut microbiota might be involved in the life activities associated with phenotypic changes. This study proved the effect of feeding methods on the intestinal microbiota of ducks, providing a theoretical basis of the microbial angle for raising ducks in a feeding-restricted period.