Macrophages derived from human induced pluripotent stem cells (iPSCs) serve as a high-fidelity cellular model for investigating HIV-1, dengue, and influenza viruses.

Macrophages are important target cells for diverse viruses and thus represent a valuable system for studying virus biology. Isolation of primary human macrophages is done by culture of dissociated tissues or from differentiated blood monocytes, but these methods are both time consuming and result in low numbers of recovered macrophages. Here, we explore whether macrophages derived from human induced pluripotent stem cells (iPSCs)-which proliferate indefinitely and potentially provide unlimited starting material-could serve as a faithful model system for studying virus biology. Human iPSC-derived monocytes were differentiated into macrophages and then infected with HIV-1, dengue virus, or influenza virus as model human viruses. We show that iPSC-derived macrophages support the replication of these viruses with kinetics and phenotypes similar to human blood monocyte-derived macrophages. These iPSC-derived macrophages were virtually indistinguishable from human blood monocyte-derived macrophages based on surface marker expression (flow cytometry), transcriptomics (RNA sequencing), and chromatin accessibility profiling. iPSC lines were additionally generated from non-human primate (chimpanzee) fibroblasts. When challenged with dengue virus, human and chimpanzee iPSC-derived macrophages show differential susceptibility to infection, thus providing a valuable resource for studying the species-tropism of viruses. We also show that blood- and iPSC-derived macrophages both restrict influenza virus at a late stage of the virus lifecycle. Collectively, our results substantiate iPSC-derived macrophages as an alternative to blood monocyte-derived macrophages for the study of virus biology. IMPORTANCE: Macrophages have complex relationships with viruses: while macrophages aid in the removal of pathogenic viruses from the body, macrophages are also manipulated by some viruses to serve as vessels for viral replication, dissemination, and long-term persistence. Here, we show that iPSC-derived macrophages are an excellent model that can be exploited in virology.

LncNFYB promotes the proliferation of rheumatoid arthritis fibroblast-like synoviocytes via LncNFYB/ANXA2/ERK1/2 axis.

Long noncoding RNAs (lncRNAs) are specifically expressed in different diseases and regulate disease progression. To explore the functions of rheumatoid arthritis (RA)-specific lncRNA, we determined the lncRNA expression profile of fibroblast-like synoviocytes (FLS) obtained from patients with RA and osteoarthritis (OA) using a LncRNA microarray and identified up-regulated LncNFYB in RA as a potential therapeutic target. Using gain- and loss-of-function studies, LncNFYB was proven to promote FLS proliferation and cell cycle progress but not affect their invasion, migration, and apoptotic abilities. Further investigation discovered that LncRNA could combine with annexin A2 (ANXA2) and enhance the level of phospho-ANXA2 (Tyr24) in the plasma membrane area, which induced the activation of ERK1/2 to promote proliferation. These findings provide new insights into the biological functions of LncNFYB on modification of FLS, which may be exploited for the therapy of RA.

CD201+ fascia progenitors choreograph injury repair.

Optimal tissue recovery and organismal survival are achieved by spatiotemporal tuning of tissue inflammation, contraction and scar formation1. Here we identify a multipotent fibroblast progenitor marked by CD201 expression in the fascia, the deepest connective tissue layer of the skin. Using skin injury models in mice, single-cell transcriptomics and genetic lineage tracing, ablation and gene deletion models, we demonstrate that CD201+ progenitors control the pace of wound healing by generating multiple specialized cell types, from proinflammatory fibroblasts to myofibroblasts, in a spatiotemporally tuned sequence. We identified retinoic acid and hypoxia signalling as the entry checkpoints into proinflammatory and myofibroblast states. Modulating CD201+ progenitor differentiation impaired the spatiotemporal appearances of fibroblasts and chronically delayed wound healing. The discovery of proinflammatory and myofibroblast progenitors and their differentiation pathways provide a new roadmap to understand and clinically treat impaired wound healing.

Angiogenin as a Possible Mediator of Macrophage-Mediated Regulation of Fibroblast Functions.

We studied angiogenin production by human macrophages and evaluated the role of this factor in the macrophage-mediated regulation of fibroblasts. All macrophage subtypes, and especially the efferocytosis-polarized macrophages, M2(LS), actively produced angiogenin. Exogenous recombinant angiogenin dose-dependently enhanced the proliferation and differentiation of dermal fibroblasts. The addition of the angiogenin inhibitor to fibroblasts cultures suppressed the stimulating effect of exogenous angiogenin or M2(LS) conditioned media. These findings indicate the involvement of angiogenin in the macrophage-mediated paracrine regulation of skin fibroblasts.

Cell culture media dependent in vitro dynamics and culture characteristics of adult caprine dermal fibroblast cells.

The enhanced availability of functional fibroblasts from precious tissue samples requires an ideal cell-culture system. Therefore, this study was designed to investigate the performance of caprine adult fibroblast cells (cadFibroblast) when cultivated in different culture media. The cadFibroblast cell lines from adult Barbari (Capra hircus) bucks were established and the effect of different media viz. DMEM/F-12 [with low-glucose (5.5 mM; DL) and high-glucose (30 mM; DH)], α-MEM [with low-glucose (5.5 mM; ML) and with high-glucose (30 mM; MH)], and fibroblast growth medium (FGM) were evaluated. Cells were then compared for growth characteristics and in-vitro dynamics through cellular morphology, proliferation, population-doubling time, double-immunocytochemistry, colony-forming units, wound healing, transwell migration, and differential expression of fibroblast-specific markers (FSP-1 and vimentin). The results of immunocytochemistry, transwell migration/invasion, and wound healing assays showed the superiority of DH over DL and other media tested. Whereas, similar effects of glucose supplementation and expression of FSP-1 were not observed in α-MEM. Transwell migration was significantly (p < 0.05) lower in FGM compared with other media tested. Overall, our results illustrate the media-dependent deviation in in-vitro dynamics and culture characteristics of cadFibroblasts that may be useful to develop strategies to cultivate these cells efficiently for research and downstream applications.

Spatially resolved multiomics of human cardiac niches.

The function of a cell is defined by its intrinsic characteristics and its niche: the tissue microenvironment in which it dwells. Here we combine single-cell and spatial transcriptomics data to discover cellular niches within eight regions of the human heart. We map cells to microanatomical locations and integrate knowledge-based and unsupervised structural annotations. We also profile the cells of the human cardiac conduction system1. The results revealed their distinctive repertoire of ion channels, G-protein-coupled receptors (GPCRs) and regulatory networks, and implicated FOXP2 in the pacemaker phenotype. We show that the sinoatrial node is compartmentalized, with a core of pacemaker cells, fibroblasts and glial cells supporting glutamatergic signalling. Using a custom CellPhoneDB.org module, we identify trans-synaptic pacemaker cell interactions with glia. We introduce a druggable target prediction tool, drug2cell, which leverages single-cell profiles and drug-target interactions to provide mechanistic insights into the chronotropic effects of drugs, including GLP-1 analogues. In the epicardium, we show enrichment of both IgG+ and IgA+ plasma cells forming immune niches that may contribute to infection defence. Overall, we provide new clarity to cardiac electro-anatomy and immunology, and our suite of computational approaches can be applied to other tissues and organs.

Direct Reprogramming of Resident Non-Myocyte Cells and Its Potential for In Vivo Cardiac Regeneration.

Cardiac diseases are the foremost cause of morbidity and mortality worldwide. The heart has limited regenerative potential; therefore, lost cardiac tissue cannot be replenished after cardiac injury. Conventional therapies are unable to restore functional cardiac tissue. In recent decades, much attention has been paid to regenerative medicine to overcome this issue. Direct reprogramming is a promising therapeutic approach in regenerative cardiac medicine that has the potential to provide in situ cardiac regeneration. It consists of direct cell fate conversion of one cell type into another, avoiding transition through an intermediary pluripotent state. In injured cardiac tissue, this strategy directs transdifferentiation of resident non-myocyte cells (NMCs) into mature functional cardiac cells that help to restore the native tissue. Over the years, developments in reprogramming methods have suggested that regulation of several intrinsic factors in NMCs can help to achieve in situ direct cardiac reprogramming. Among NMCs, endogenous cardiac fibroblasts have been studied for their potential to be directly reprogrammed into both induced cardiomyocytes and induced cardiac progenitor cells, while pericytes can transdifferentiate towards endothelial cells and smooth muscle cells. This strategy has been indicated to improve heart function and reduce fibrosis after cardiac injury in preclinical models. This review summarizes the recent updates and progress in direct cardiac reprogramming of resident NMCs for in situ cardiac regeneration.

Neonatal and adult cardiac fibroblasts exhibit inherent differences in cardiac regenerative capacity.

Directly reprogramming fibroblasts into cardiomyocytes improves cardiac function in the infarcted heart. However, the low efficacy of this approach hinders clinical applications. Unlike the adult mammalian heart, the neonatal heart has an intrinsic regenerative capacity. Consequently, we hypothesized that birth imposes fundamental changes in cardiac fibroblasts which limit their regenerative capabilities. In support, we found that reprogramming efficacy in vitro was markedly lower with fibroblasts derived from adult mice versus those derived from neonatal mice. Notably, fibroblasts derived from adult mice expressed significantly higher levels of pro-angiogenic genes. Moreover, under conditions that promote angiogenesis, only fibroblasts derived from adult mice differentiated into tube-like structures. Targeted knockdown screening studies suggested a possible role for the transcription factor Epas1. Epas1 expression was higher in fibroblasts derived from adult mice, and Epas1 knockdown improved reprogramming efficacy in cultured adult cardiac fibroblasts. Promoter activity assays indicated that Epas1 functions as both a transcription repressor and an activator, inhibiting cardiomyocyte genes while activating angiogenic genes. Finally, the addition of an Epas1 targeting siRNA to the reprogramming cocktail markedly improved reprogramming efficacy in vivo with both the number of reprogramming events and cardiac function being markedly improved. Collectively, our results highlight differences between neonatal and adult cardiac fibroblasts and the dual transcriptional activities of Epas1 related to reprogramming efficacy.

Fast and scarless: Prx1+ fibroblasts turbocharge healing.

Our oral cavity has evolved a capacity for rapid healing without scarring. In this issue of JEM, Ko et al. (2022. J. Exp. Med.https://doi.org/10.1084/jem.20221350) identify a Prx1+ fibroblast progenitor that drives oral regeneration by summoning pro-healing TGFß1+ macrophages.

Response of genes related to iron and porphyrin transport in Porphyromonas gingivalis to blue light.

BACKGROUND: Antimicrobial blue light (aBL) kills a variety of bacteria, including Porphyromonas gingivalis. However, little is known about the transcriptomic response of P. gingivalis to aBL therapy. This study was designed to evaluate the selective cytotoxicity of aBL against P. gingivalis over human cells and to further investigate the genetic response of P. gingivalis to aBL at the transcriptome level. METHODS: Colony forming unit (CFU) testing, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM) were used to investigate the antimicrobial effectiveness of blue light against P. gingivalis. The temperatures of the irradiated targets were measured to prevent overheating. Multiple fluorescent probes were used to quantify reactive oxygen species (ROS) generation after blue-light irradiation. RNA sequencing (RNA-seq) was used to investigate the changes in global gene expression. Following the screening of target genes, real-time quantitative polymerase chain reaction (RT-qPCR) was performed to confirm the regulation of gene expression. RESULTS: A 405 nm aBL at 100 mW/cm2 significantly killed P. gingivalis within 5 min while sparing human gingival fibroblasts (HGFs). No obvious temperature changes were detected in the irradiated surface under our experimental conditions. RNA-seq showed that the transcription of multiple genes was regulated, and RT-qPCR revealed that the expression levels of the genes RgpA and RgpB, which may promote heme uptake, as well as the genes Ftn and FetB, which are related to iron homeostasis, were significantly upregulated. The expression levels of the FeoB-2 and HmuR genes, which are related to hydroxyl radical scavenging, were significantly downregulated. CONCLUSIONS: aBL strengthens the heme uptake and iron export gene pathways while reducing the ROS scavenging pathways in P. gingivalis, thus improving the accumulation of endogenous photosensitizers and enhancing oxidative damage to P. gingivalis.

Comparative analysis of porcine iPSCs derived from Sertoli cells and fibroblasts.

Porcine embryonic fibroblasts (PEFs) can be directly reprogrammed into porcine induced pluripotent stem cells (piPSCs). However, the reprogramming process is generally lengthy and inefficient. Here, we established a fast and efficient induction system of piPSCs from porcine Sertoli cells (SCs) via forced expression of pig Yamanaka factors. The alkaline phosphatase (AP)-positive colonies from SCs developed on Day 3 after lentivirus infection, and were expanded and then picked up on Day 7, whereas reprogramming process from PEFs did not show any colonies in the same period. The picked piPSCs strongly expressed pluripotent genes, had the differentiation capacity to three germ layers, and could be also induced into primordial germ cell-like cells. Screening for transcription factor combinations showed that POU class 5 homeobox 1 (OCT4) is the core factor for AP-positive colony formation, and two factors (OCT4 and c-MYC) could successfully reprogram SCs into piPSCs. We then compared the RNA-sequencing data of piPSCs derived from SCs and PEFs, and found that the most significant difference was the activation of Transforming Growth Factor ß signaling pathway. We also compared the RNA levels of SCs and PEFs, and found that SCs exhibited higher Wnt signaling activity and Bone Morphogenetic Protein 4 expression than PEFs, which might be correlated with higher cell proliferation rate and reprogramming efficiency. In summary, the data demonstrated that starting cell sources of piPSCs significantly affect reprogramming dynamics and SCs could serve as cell sources for efficient reprogramming.

Exosome Release by Glucose Deprivation Is Important for the Viability of TSC-Null Cells.

The control of exosome release is associated with numerous physiological and pathological activities, and that release is often indicative of health, disease, and environmental nutrient stress. Tuberous sclerosis complex (TSC) regulates the cell viability via the negative regulation of the mammalian target of rapamycin complex (mTORC1) during glucose deprivation. However, the mechanism by which viability of TSC-null cells is regulated by mTORC1 inhibition under glucose deprivation remains unclear. Here, we demonstrated that exosome release regulates cell death induced by glucose deprivation in TSC-null cells. The mTORC1 inhibition by rapamycin significantly increased the exosome biogenesis, exosome secretion, and cell viability in TSC-null cells. In addition, the increase in cell viability by mTORC1 inhibition was attenuated by two different types of inhibitors of exosome release under glucose deprivation. Taken together, we suggest that exosome release inhibition might be a novel way for regression of cell growth in TSC-null cells showing lack of cell death by mTORC1 inhibition.

The Role of the Fibronectin Synergy Site for Skin Wound Healing.

Skin is constantly exposed to injuries that are repaired with different outcomes, either regeneration or scarring. Scars result from fibrotic processes modulated by cellular physical forces transmitted by integrins. Fibronectin (FN) is a major component in the provisional matrix assembled to repair skin wounds. FN enables cell adhesion binding of α5ß1/αIIbß3 and αv-class integrins to an RGD-motif. An additional linkage for α5/αIIb is the synergy site located in close proximity to the RGD motif. The mutation to impair the FN synergy region (Fn1syn/syn) demonstrated that its absence permits complete development. However, only with the additional engagement to the FN synergy site do cells efficiently resist physical forces. To test how the synergy site-mediated adhesion affects the course of wound healing fibrosis, we used a mouse model of skin injury and in-vitro migration studies with keratinocytes and fibroblasts on FNsyn. The loss of FN synergy site led to normal re-epithelialization caused by two opposing migratory defects of activated keratinocytes and, in the dermis, induced reduced fibrotic responses, with lower contents of myofibroblasts and FN deposition and diminished TGF-ß1-mediated cell signalling. We demonstrate that weakened α5ß1-mediated traction forces on FNsyn cause reduced TGF-ß1 release from its latent complex.

Dose-dependent dominance: How cell densities design stromal cell functions during soft tissue healing.

Regular soft tissue healing relies on the well-organized interaction of different stromal cell types with endothelial cells. However, spatiotemporal conditions might provoke high densities of one special stromal cell type, potentially leading to impaired healing. Detailed knowledge of the functions of rivaling stromal cell types aiming for tissue contraction and stabilization as well as vascular support is mandatory. By the application of an in vitro approach comprising the evaluation of cell proliferation, cell morphology, myofibroblastoid differentiation, and cytokine release, we verified a density-dependent modulation of these functions among juvenile and adult fibroblasts, pericytes, and adipose-derived stem cells during their interaction with microvascular endothelial cells in cocultures. Results indicate that juvenile fibroblasts rather support angiogenesis via paracrine regulation at the early stage of healing, a role potentially compromised in adult fibroblasts. In contrast, pericytes showed a more versatile character aiming at angiogenesis, vessel stabilization, and tissue contraction. Such a universal character was even more pronounced among adipose-derived stem cells. The explicit knowledge of the characteristic functions of stromal cell types is a prerequisite for the development of new analytical and therapeutic approaches for impaired soft tissue healing. The present study delivers new considerations concerning the roles of rivaling stromal cell types within a granulation tissue, pointing to extraordinary properties of pericytes and adipose-derived stem cells.

Exosomal Dvl3 promoted the aggressive phenotypic transformation of RA-FLS via wnt pathway.

OBJECTIVE: This study was performed to explore the function and mechanism of Dvl3 in RA-FLS by exosome intervention. METHODS: The expression pattern of Dvl3 was examined by IHC, WB, and qPCR. Modified exosomes obtained from culturing supernatant of RA-FLS infected with Dvl3 over expression (OE) lentivirus were administrated to the target RA-FLS. The ability of survival, migration, and the production of inflammatory factor influenced by exosomal Dvl3 were detected by CKK8 kits, Tunel, migration test, qPCR, and enzyme-linked immunosorbent assay (ELISA) respectively; Flow cytometry analysis was conducted to explorer the inflammatory moderate role of exosomes on CD4+ T cells. The possible downstream pathways of Dvl3 were screened by qPCR and WB and verified by double luciferase reporter experiment. RESULTS: The expression level of Dvl3 was significantly increased in RA and CIA. Exosomes from the OE group could significantly promote cell proliferation activity, migration/invasion ability. The augment of TNF-α, IL-1ß, IL-17, and IL-21 was observed in exosomal Dvl3-OE group. Th1 and Th17 cells polarisation and cytokines related were both enhanced by Exosomal Dvl3. Over expression of Dvl3 was accompanied by the significant increase of ß-catenin and RhoA activities. CONCLUSION: This study discovered the high expression of Dvl3 of exosomes derived from RA patients which may possessed the ability to promote phenotypic transformation of RA-FLS through Wnt pathway.

First Characterization of Human Dermal Fibroblasts Showing a Decreased Xylosyltransferase-I Expression Induced by the CRISPR/Cas9 System.

BACKGROUND: Xylosyltransferases-I and II (XT-I and XT-II) catalyze the initial and rate limiting step of the proteoglycan (PG) biosynthesis and therefore have an import impact on the homeostasis of the extracellular matrix (ECM). The reason for the occurrence of two XT-isoforms in all higher organisms remains unknown and targeted genome-editing strategies could shed light on this issue. METHODS: XT-I deficient neonatal normal human dermal fibroblasts were generated by using the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated proteins (Cas) 9 system. We analyzed if a reduced XT-I activity leads to abnormalities regarding ECM-composition, myofibroblast differentiation, cellular senescence and skeletal and cartilage tissue homeostasis. RESULTS: We successfully introduced compound heterozygous deletions within exon 9 of the XYLT1 gene. Beside XYLT1, we detected altered gene-expression levels of further, inter alia ECM-related, genes. Our data further reveal a dramatically reduced XT-I protein activity. Abnormal myofibroblast-differentiation was demonstrated by elevated alpha-smooth muscle actin expression on both, mRNA- and protein level. In addition, wound-healing capability was slightly delayed. Furthermore, we observed an increased cellular-senescence of knockout cells and an altered expression of target genes knowing to be involved in skeletonization. CONCLUSION: Our data show the tremendous relevance of the XT-I isoform concerning myofibroblast-differentiation and ECM-homeostasis as well as the pathophysiology of skeletal disorders.

Receptor activity-modifying protein 1 regulates mouse skin fibroblast proliferation via the Gαi3-PKA-CREB-YAP axis.

BACKGROUND: Skin innervation is crucial for normal wound healing. However, the relationship between nerve receptors and wound healing and the intrinsic mechanism remains to be further identified. In this study, we investigated the role of a calcitonin gene-related peptide (CGRP) receptor component, receptor activity-modifying protein 1 (RAMP1), in mouse skin fibroblast (MSF) proliferation. METHODS: In vivo, Western blotting and immunohistochemical (IHC) staining of mouse skin wounds tissue was used to detect changes in RAMP1 expression. In vitro, RAMP1 was overexpressed in MSF cell lines by infection with Tet-On-Flag-RAMP1 lentivirus and doxycycline (DOX) induction. An IncuCyte S3 Live-Cell Analysis System was used to assess and compare the proliferation rate differences between different treatment groups. Total protein and subcellular extraction Western blot analysis, quantitative real-time-polymerase chain reaction (qPCR) analysis, and immunofluorescence (IF) staining analysis were conducted to detect signalling molecule expression and/or distribution. The CUT & RUN assay and dual-luciferase reporter assay were applied to measure protein-DNA interactions. RESULTS: RAMP1 expression levels were altered during skin wound healing in mice. RAMP1 overexpression promoted MSF proliferation. Mechanistically, total Yes-associated protein (YAP) and nuclear YAP protein expression was increased in RAMP1-overexpressing MSFs. RAMP1 overexpression increased inhibitory guanine nucleotide-binding protein (G protein) α subunit 3 (Gαi3) expression and activated downstream protein kinase A (PKA), and both elevated the expression of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) and activated it, promoting the transcription of YAP, elevating the total YAP level and promoting MSF proliferation. CONCLUSIONS: Based on these data, we report, for the first time, that changes in the total RAMP1 levels during wound healing and RAMP1 overexpression alone can promote MSF proliferation via the Gαi3-PKA-CREB-YAP axis, a finding critical for understanding RAMP1 function, suggesting that this pathway is an attractive and accurate nerve target for skin wound treatment. Video Abstract.

Early SRC activation skews cell fate from apoptosis to senescence.

Cells responding to DNA damage implement complex adaptive programs that often culminate in one of two distinct outcomes: apoptosis or senescence. To systematically identify factors driving each response, we analyzed human IMR-90 fibroblasts exposed to increasing doses of the genotoxin etoposide and identified SRC as a key kinase contributing early to this dichotomous decision. SRC was activated by low but not high levels of etoposide. With low DNA damage, SRC-mediated activation of p38 critically promoted expression of cell survival and senescence proteins, while SRC-mediated repression of p53 prevented a rise in proapoptotic proteins. With high DNA damage, failure to activate SRC led to elevation of p53, inhibition of p38, and apoptosis. In mice exposed to DNA damage, pharmacologic inhibition of SRC prevented the accumulation of senescent cells in tissues. We propose that inhibiting SRC could be exploited to favor apoptosis over senescence in tissues to improve health outcomes.

S100A16 promotes acute kidney injury by activating HRD1-induced ubiquitination and degradation of GSK3ß and CK1α.

The pathogenesis of acute kidney injury (AKI) is associated with the activation of multiple signaling pathways, including Wnt/ß-catenin signaling. However, the mechanism of Wnt/ß-catenin pathway activation in renal interstitial fibroblasts during AKI is unclear. S100 calcium-binding protein A16 (S100A16), a new member of calcium-binding protein S100 family, is a multi-functional signaling factor involved in various pathogenies, including tumors, glycolipid metabolism disorder, and chronic kidney disease (CKD). We investigated the potential participation of S100A16 in Wnt/ß-catenin pathway activation during AKI by subjecting wild-type (WT) and S100A16 knockout (S100A16+/-) mice to the ischemia-reperfusion injury (IRI), and revealed S100A16 upregulation in this model, in which knockout of S100A16 impeded the Wnt/ß-catenin signaling pathway activation and recovered the expression of downstream hepatocyte growth factor (HGF). We also found that S100A16 was highly expressed in Platelet-derived growth factor receptor beta (PDGFRß) positive renal fibroblasts in vivo. Consistently, in rat renal interstitial fibroblasts (NRK-49F cells), both hypoxia/reoxygenation and S100A16 overexpression exacerbated fibroblasts apoptosis and inhibited HGF secretion; whereas S100A16 knockdown or Wnt/ß-catenin pathway inhibitor ICG-001 reversed these changes. Mechanistically, we showed that S100A16 promoted Wnt/ß-catenin signaling activation via the ubiquitylation and degradation of ß-catenin complex members, glycogen synthase kinase 3ß (GSK3ß) and casein kinase 1α (CK1α), mediated by E3 ubiquitin ligase, the HMG-CoA reductase degradation protein 1 (HRD1). Our study identified the S100A16 as a key regulator in the activation of Wnt/ß-catenin signaling pathway in AKI.

Bio-fabrication of stem-cell-incorporated corneal epithelial and stromal equivalents from silk fibroin and gelatin-based biomaterial for canine corneal regeneration.

Corneal grafts are the imperative clinical treatment for canine corneal blindness. To serve the growing demand, this study aimed to generate tissue-engineered canine cornea in part of the corneal epithelium and underlying stroma based on canine limbal epithelial stem cells (cLESCs) seeded silk fibroin/gelatin (SF/G) film and canine corneal stromal stem cells (cCSSCs) seeded SF/G scaffold, respectively. Both cell types were successfully isolated by collagenase I. SF/G corneal films and stromal scaffolds served as the prospective substrates for cLESCs and cCSSCs by promoting cell adhesion, cell viability, and cell proliferation. The results revealed the upregulation of tumor protein P63 (P63) and ATP-binding cassette super-family G member 2 (Abcg2) of cLESCs as well as Keratocan (Kera), Lumican (Lum), aldehyde dehydrogenase 3 family member A1 (Aldh3a1) and Aquaporin 1 (Aqp1) of differentiated keratocytes. Moreover, immunohistochemistry illustrated the positive staining of tumor protein P63 (P63), aldehyde dehydrogenase 3 family member A1 (Aldh3a1), lumican (Lum) and collagen I (Col-I), which are considerable for native cornea. This study manifested a feasible platform to construct tissue-engineered canine cornea for functional grafts and positively contributed to the body of knowledge related to canine corneal stem cells.