lncRNA PAPPA-AS1 Induces the Development of Hypertrophic Scar by Upregulating TLR4 through Interacting with TAF15

Linking pesticide exposure to neurodegenerative diseases: An in vitro investigation with human neuroblastoma cells

Although many organochlorine pesticides (OCPs) have been banned or restricted because of their persistence and linkage to neurodegenerative diseases, there is evidence of continued human exposure. In contrast, registered herbicides are reported to have a moderate to low level of toxicity; however, there is little information regarding their toxicity to humans or their combined effects with OCPs. This study aimed to characterize the mechanism of toxicity of banned OCP insecticides (aldrin, dieldrin, heptachlor, and lindane) and registered herbicides (trifluralin, triallate, and clopyralid) detected at a legacy contaminated pesticide manufacturing and packing site using SH-SY5Y cells. Cell viability, LDH release, production of reactive oxygen species (ROS), and caspase 3/7 activity were evaluated following 24 h of exposure to the biocides. In addition, RNASeq was conducted at sublethal concentrations to investigate potential mechanisms involved in cellular toxicity. Our findings suggested that aldrin and heptachlor were the most toxic, while dieldrin, lindane, trifluralin, and triallate exhibited moderate toxicity, and clopyralid was not toxic to SH-SY5Y cells. While aldrin and heptachlor induced their toxicity through damage to the cell membrane, the toxicity of dieldrin was partially attributed to necrosis and apoptosis. Moreover, toxic effects of lindane, trifluralin, and triallate, at least partially, were associated with ROS generation. Gene expression profiles suggested that decreased cell viability induced by most of the tested biocides was related to inhibited cell proliferation. The dysregulation of genes encoding for proteins with anti-apoptotic properties also supported the absence of caspase activation. Identified enriched terms showed that OCP toxicity in SH-SY5Y cells was mediated through pathways associated with the pathogenesis of neurodegenerative diseases. In conclusion, this study provides a basis for elucidating the molecular mechanisms of pesticide-induced neurotoxicity. Moreover, it introduced SH-SY5Y cells as a relevant in vitro model for investigating the neurotoxicity of pesticides in humans.

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.

Non-coding RNAs in hypertrophic scars and keloids: Current research and clinical relevance: A review

Hypertrophic scars (HS) and keloids (KD) are lesions that develop as a result of excessive fibroblast proliferation and collagen deposition in response to dermal injury, leading to dysregulation of the inflammatory, proliferative, and remodeling phases during wound healing. HS and KD affect up to 90 % of the population and are associated with lower quality of life, physical health, and mental status in patients. Efficient targeted treatment represents a significant challenge, primarily due to our limited understanding of their underlying pathogenesis. Non-coding RNAs (ncRNAs), which constitute a significant portion of the human transcriptome with minimal or no protein-coding capacity, have been implicated in various cellular physiologies and pathologies and may serve as diagnostic indicators or therapeutic targets. NcRNAs have been found to be aberrantly expressed and regulated in HS and KD. This review provides a summary of the expression profiles and molecular mechanisms of three common ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in HS and KD. It also discusses their potential as biomarkers for the diagnosis and treatment of these diseases and provides novel insights into epigenetic-based diagnosis and treatment strategies for HS and KD.

TAF15 exacerbates nonalcoholic steatohepatitis progression by regulating lipid metabolism and inflammation via FASN and p65 NF-κB

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) consists of a broad spectrum of conditions, and nonalcoholic steatohepatitis (NASH) is the advanced form of NAFLD. TAF15 is a DNA and RNA binding protein and is involved in crucial inflammatory signalling pathways. We aimed to investigate the role of TAF15 in the progression of NASH and the underlying molecular mechanism.

METHODS

We generated mice with hepatocyte-specific knockdown and overexpression of TAF15 using a specific adeno-associated virus (AAV). NASH models were established by feeding mice high-fat and high-cholesterol diets and methionine- and choline-deficient diets. Cleavage under targets and tagmentation and dual-luciferase reporter assays were performed to investigate the effect of TAF15 on FASN transcription. Coimmunoprecipitation and immunofluorescence assays were conducted to explore the interaction of TAF15 and p65. In vitro coculture systems were established to study the interactions of hepatocytes, macrophages and HSCs.

RESULTS

TAF15 was significantly increased in the livers of mouse NASH models and primary hepatocyte NASH model. Knockdown of TAF15 inhibited steatosis, inflammation and fibrosis, while overexpression of TAF15 promoted NASH phenotypes. Mechanistically, TAF15 bound directly to the promoter region of FASN to facilitate its expression, thereby promoting steatosis. Moreover, TAF15 interacted with p65 and activated the NF-κB signalling pathway, increasing the secretion of proinflammatory cytokines and triggering M1 macrophage polarization. Treatment with the FASN inhibitor orlistat partially reversed the phenotypes.

CONCLUSIONS

These results suggested that TAF15 exacerbated NASH progression by regulating lipid metabolism and inflammation via transcriptional activation of FASN and interacting with p65 to activate the NF-κB signalling pathway.

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.

circVMA21 combining with TAF15 stabilizes SOCS3 mRNA to relieve septic lung injury through regulating NF-κB activation

BACKGROUND

Lung injury is a severe complication of sepsis, which brings great threats and challenges to human health. CircVMA21 has exhibited powerful anti- inflammation capacity. However, its underlying molecule mechanism remains blurry.

METHODS

Lipopolysaccharide (LPS) was used to treat mice and WI-38 cells to establish models of lung injury caused by sepsis. Lung injury was evaluated using HE staining. Cell apoptosis was tested by TUNEL and flow cytometry. Levels of inflammatory cytokines were detected using ELISA assay. CircVMA21 and SOCS3 expression was measured using RT-qPCR. The ROS, MDA, SOD and GSH production were monitored by commercial kits. The protein expression was examined with western blot. The correlations among circVMA21, SOCS3 and TAF15 were confirmed using RIP and RNA-pull down.

RESULTS

The expression of circVMA21 and SOCS3 was downregulated in LPS-induced lung injury of mice and WI-38 cells. Overexpressing circVMA21 or SOCS3 assuaged LPS-induced cell injury through repressing the levels of inflammatory factors, oxidative stress and cell apoptosis. NF-κB signaling pathway was inactivated by circVMA21 or SOCS3 overexpression. circVMA21 enhanced the stabilization of SOCS3 mRNA via interplaying with TAF15. SOCS3 knockdown destroyed the beneficial impacts of circVMA21 overexpression on LPS-induced cell injury.

CONCLUSION

CircVMA21 suppressed LPS-induced the levels of inflammatory factors, oxidative stress and cell apoptosis and improved LPS-induced lung injury by mediating TAF15/SOCS3/NF-κB axis.

A Novel lncRNA FPASL regulates fibroblasts proliferation via 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.