THOC7-AS1/OCT1/FSTL1 axis promotes EMT and serves as a therapeutic target in cutaneous squamous cell carcinoma.

BACKGROUND: THOC7-AS1 and FSTL1 expression are frequently upregulated in cutaneous squamous cell carcinoma (cSCC). However, their molecular biological mechanisms remain elusive and their potential as therapeutic targets needs urgent exploration. METHODS: Human tissue samples were used to evaluate clinical parameters. In vitro and in vivo experiments assessed biological functions. Quantitative PCR, western blot, immunohistochemistry, immunocytochemistry, immunoprecipitation, RNA fluorescence in situ hybridization, RNA pull-down, RNA immunoprecipitation, silver staining, chromatin immunoprecipitation, dual luciferase reporter assays etc. were utilized to explore the molecular biological mechanisms. RESULTS: We found FSTL1 is an oncogene in cSCC, with high expression in tumor tissues and cells. Its elevated expression closely associates with tumor size and local tissue infiltration. In vitro and in vivo, high FSTL1 expression promotes cSCC proliferation, migration and invasion, facilitating malignant behaviors. Mechanistically, FSTL1 interacts with ZEB1 to promote epithelial-to-mesenchymal transition (EMT) in cSCC cells. Exploring upstream regulation, we found THOC7-AS1 can interact with OCT1, which binds the FSTL1 promoter region and promotes FSTL1 expression, facilitating cSCC progression. Finally, treating tumors with THOC7-AS1 antisense oligonucleotides inhibited cSCC proliferative and migratory abilities, delaying tumor progression. CONCLUSIONS: The THOC7-AS1/OCT1/FSTL1 axis regulates EMT and promotes tumor progression in cSCC. This study provides clues and ideas for cSCC targeted therapy.

Unveiling potential drug targets for hyperparathyroidism through genetic insights via Mendelian randomization and colocalization analyses.

Hyperparathyroidism (HPT) manifests as a complex condition with a substantial disease burden. While advances have been made in surgical interventions and non-surgical pharmacotherapy for the management of hyperparathyroidism, radical options to halt underlying disease progression remain lacking. Identifying putative genetic drivers and exploring novel drug targets that can impede HPT progression remain critical unmet needs. A Mendelian randomization (MR) analysis was performed to uncover putative therapeutic targets implicated in hyperparathyroidism pathology. Cis-expression quantitative trait loci (cis-eQTL) data serving as genetic instrumental variables were obtained from the eQTLGen Consortium and Genotype-Tissue Expression (GTEx) portal. Hyperparathyroidism summary statistics for single nucleotide polymorphism (SNP) associations were sourced from the FinnGen study (5590 cases; 361,988 controls). Colocalization analysis was performed to determine the probability of shared causal variants underlying SNP-hyperparathyroidism and SNP-eQTL links. Five drug targets (CMKLR1, FSTL1, IGSF11, PIK3C3 and SLC40A1) showed significant causation with hyperparathyroidism in both eQTLGen and GTEx cohorts by MR analysis. Specifically, phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3) and solute carrier family 40 member 1 (SLC40A1) showed strong evidence of colocalization with HPT. Multivariable MR and Phenome-Wide Association Study analyses indicated these two targets were not associated with other traits. Additionally, drug prediction analysis implies the potential of these two targets for future clinical applications. This study identifies PIK3C3 and SLC40A1 as potential genetically proxied druggable genes and promising therapeutic targets for hyperparathyroidism. Targeting PIK3C3 and SLC40A1 may offer effective novel pharmacotherapies for impeding hyperparathyroidism progression and reducing disease risk. These findings provide preliminary genetic insight into underlying drivers amenable to therapeutic manipulation, though further investigation is imperative to validate translational potential from preclinical models through clinical applications.

A comprehensive multi-omics analysis identifies a robust scoring system for cancer-associated fibroblasts and intervention targets in colorectal cancer.

BACKGROUND: Cancer-associated fibroblasts (CAF) play a critical role in promoting tumor growth, metastasis, and immune evasion. While numerous studies have investigated CAF, there remains a paucity of research on their clinical application in colorectal cancer (CRC). METHODS: In this study, we collected differentially expressed genes between CAF and normal fibroblasts (NF) from previous CRC studies, and utilized machine learning analysis to differentiate two distinct subtypes of CAF in CRC. To enable practical application, a CAF-related genes (CAFGs) scoring system was developed based on multivariate Cox regression. We then conducted functional enrichment analysis, Kaplan-Meier plot, consensus molecular subtypes (CMS) classification, and Tumor Immune Dysfunction and Exclusion (TIDE) algorithm to investigate the relationship between the CAFGs scoring system and various biological mechanisms, prognostic value, tumor microenvironment, and response to immune checkpoint blockade (ICB) therapy. Moreover, single-cell transcriptomics and proteomics analyses have been employed to validate the significance of scoring system-related molecules in the identity and function of CAF. RESULTS: We unveiled significant distinctions in tumor immune status and prognosis not only between the CAF clusters, but also across high and low CAFGs groups. Specifically, patients in CAF cluster 2 or with high CAFGs scores exhibited higher CAF markers and were enriched for CAF-related biological pathways such as epithelial-mesenchymal transition (EMT) and angiogenesis. In addition, CAFGs score was identified as a risk index and correlated with poor overall survival (OS), progression-free survival (PFS), disease-free survival (DFS), and recurrence-free survival (RFS). High CAFGs scores were observed in patients with advanced stages, CMS4, as well as lymphatic invasion. Furthermore, elevated CAFG scores in patients signified a suppressive tumor microenvironment characterized by the upregulation of programmed death-ligand 1 (PD-L1), T-cell dysfunction, exclusion, and TIDE score. And high CAFGs scores can differentiate patients with lower response rates and poor prognosis under ICB therapy. Notably, single-cell transcriptomics and proteomics analyses identified several molecules related to CAF identity and function, such as FSTL1, IGFBP7, and FBN1. CONCLUSION: We constructed a robust CAFGs score system with clinical significance using multiple CRC cohorts. In addition, we identified several molecules related to CAF identity and function that could be potential intervention targets for CRC patients.

Identification and validation of immune and cuproptosis - related genes for diabetic nephropathy by WGCNA and machine learning.

Background: As the leading cause of chronic kidney disease, diabetic kidney disease (DKD) is an enormous burden for all healthcare systems around the world. However, its early diagnosis has no effective methods. Methods: First, gene expression data in GEO database were extracted, and the differential genes of diabetic tubulopathy were obtained. Immune-related genesets were generated by WGCNA and immune cell infiltration analyses. Then, differentially expressed immune-related cuproptosis genes (DEICGs) were derived by the intersection of differential genes and genes related to cuproptosis and immune. To investigate the functions of DEICGs, volcano plots and GO term enrichment analysis was performed. Machine learning and protein-protein interaction (PPI) network analysis helped to finally screen out hub genes. The diagnostic efficacy of them was evaluated by GSEA analysis, receiver operating characteristic (ROC) curve, single-cell RNA sequencing and the Nephroseq website. The expression of hub genes at the animal level by STZ -induced and db/db DKD mouse models was further verified. Results: Finally, three hub genes, including FSTL1, CX3CR1 and AGR2 that were up-regulated in both the test set GSE30122 and the validation set GSE30529, were screened. The areas under the curve (AUCs) of ROC curves of hub genes were 0.911, 0.935 and 0.922, respectively, and 0.946 when taking as a whole. Correlation analysis showed that the expression level of three hub genes demonstrated their negative relationship with GFR, while those of FSTL1 displayed a positive correlation with the level of serum creatinine. GSEA was enriched in inflammatory and immune-related pathways. Single-nucleus RNA sequencing indicated the main distribution of FSTL1 in podocyte and mesangial cells, the high expression of CX3CR1 in leukocytes and the main localization of AGR2 in the loop of Henle. In mouse models, all three hub genes were increased in both STZ-induced and db/db DKD models. Conclusion: Machine learning was combined with WGCNA, immune cell infiltration and PPI analyses to identify three hub genes associated with cuproptosis, immunity and diabetic nephropathy, which all have great potential as diagnostic markers for DKD and even predict disease progression.

FSTL1: A double-edged sword in cancer development.

Flolistatin-related protein 1 (FSTL1), a secreted glycoprotein that is involved in many physiological functions, has attracted much interest and has been implicated in a wide range of diseases, including heart diseases and inflammatory diseases. In recent years, the involvement of FSTL1 in cancer progression has been implicated and researched. FSTL1 plays a contradictory role in cancer, depending on the cancer type as well as the contents of the tumor microenvironment. As reviewed here, the structure and distribution of FSTL1 are first introduced. Subsequently, the expression and clinical significance of FSTL1 in various types of cancer as a tumor enhancer or inhibitor are addressed. Furthermore, we discuss the functional role of FSTL1 in various processes that involve tumor cell proliferation, metastasis, immune responses, stemness, cell apoptosis, and resistance to chemotherapy. FSTL1 expression is tightly controlled in cancer, and a multitude of cancer-related signaling cascades like TGF-ß/BMP/Smad signaling, AKT, NF-κB, and Wnt-ß-catenin signaling pathways are modulated by FSTL1. Finally, FSTL1 as a therapeutic target using monoclonal antibodies is stated. Herein, we review recent findings showing the double-edged characteristics and mechanisms of FSTL1 in cancer and elaborate on the current understanding of therapeutic approaches targeting FSTL1.

LncRNA HCG18 promotes inflammation and apoptosis in intervertebral disc degeneration via the miR-495-3p/FSTL1 axis.

Intervertebral disc degeneration (IDD) causes pain in the back and neck. This study investigated the role of long non-coding RNA HLA complex group 18 (HCG18) in a cell model of IDD. An IDD model was established by stimulating nucleus pulposus (NP) cells with interleukin (IL)-1ß. MTT assay was performed to evaluate NP cell viability. The apoptosis was detected by flow cytometry. The expressions of HCG18, microRNA (miR)-495-3p, and follistatin-like protein-1 (FSTL1) were measured by RT-qPCR. The interactions of miR-495-3p with HCG18 and FSTL1 were analyzed by luciferase reporter assay. IL-1ß stimulation upregulated HCG18 and FSTL1, but downregulated miR-495-3p in NP cells. Silencing of HCG18 or FSTL1, as well as miR-495-3p overexpression in NP cells alleviated IL-1ß-induced apoptosis and inflammation of NP cells. Both HCG18 and FSTL1 had binding sites for miR-495-3p. Overexpression of FSTL1 abolished the effects of HCG18 silencing on IL-1ß-induced apoptosis and inflammation. The HCG18/miR-495-3p/FSTL1 axis is essential for IDD development. Therapeutic strategies targeting this axis may be used for IDD treatment.

Follistatin-like 1 is a myokine regulating lipid mobilization during endurance exercise and recovery.

OBJECTIVE: The aim of this study was to investigate the role of the follistatin-like 1 (Fstl1) and disco-interacting protein 2 homolog A (DIP2a) axis in relation to lipid metabolism during and after endurance exercise and to elucidate the mechanisms underlying the metabolic effects of Fstl1 on adipocytes, considering its regulation by exercise and muscle mass and its link to obesity. METHODS: Twenty-nine sedentary males participated in endurance exercise, and blood samples were collected during and after the exercise. Body composition, Fstl1, glycerol, epinephrine, growth hormone, and atrial natriuretic peptide were measured. 3T3-L1 adipocytes, with or without DIP2a knockdown, were treated with Fstl1 to assess glycerol release, cyclic AMP/cyclic GMP production, and hormone sensitive lipase phosphorylation. The association between DIP2a gene expression levels in human adipose tissues and exercise-induced lipolysis was examined. RESULTS: Fstl1 levels significantly increased during endurance exercise and following recovery, correlating with lean body mass and lipolysis. In 3T3-L1 adipocytes, Fstl1 increased glycerol release, cyclic GMP production, and hormone sensitive lipase activation, but these effects were attenuated by DIP2a knockdown. DIP2a gene expression in human adipose tissues correlated with serum glycerol concentrations during endurance exercise. CONCLUSIONS: Fstl1 is a myokine facilitating lipid mobilization during and after endurance exercise through DIP2a-mediated lipolytic effects in adipocytes.

Endothelial extracellular vesicles induce acute lung injury via follistatin-like protein 1.

Cardiopulmonary bypass has been speculated to elicit systemic inflammation to initiate acute lung injury (ALI), including acute respiratory distress syndrome (ARDS), in patients after cardiac surgery. We previously found that post-operative patients showed an increase in endothelial cell-derived extracellular vesicles (eEVs) with components of coagulation and acute inflammatory responses. However, the mechanism underlying the onset of ALI owing to the release of eEVs after cardiopulmonary bypass, remains unclear. Plasma plasminogen-activated inhibitor-1 (PAI-1) and eEV levels were measured in patients with cardiopulmonary bypass. Endothelial cells and mice (C57BL/6, Toll-like receptor 4 knockout (TLR4-/-) and inducible nitric oxide synthase knockout (iNOS-/-)) were challenged with eEVs isolated from PAI-1-stimulated endothelial cells. Plasma PAI-1 and eEVs were remarkably enhanced after cardiopulmonary bypass. Plasma PAI-1 elevation was positively correlated with the increase in eEVs. The increase in plasma PAI-1 and eEV levels was associated with post-operative ARDS. The eEVs derived from PAI-1-stimulated endothelial cells could recognize TLR4 to stimulate a downstream signaling cascade identified as the Janus kinase 2/3 (JAK2/3)-signal transducer and activator of transcription 3 (STAT3)-interferon regulatory factor 1 (IRF-1) pathway, along with iNOS induction, and cytokine/chemokine production in vascular endothelial cells and C57BL/6 mice, ultimately contributing to ALI. ALI could be attenuated by JAK2/3 or STAT3 inhibitors (AG490 or S3I-201, respectively), and was relieved in TLR4-/- and iNOS-/- mice. eEVs activate the TLR4/JAK3/STAT3/IRF-1 signaling pathway to induce ALI/ARDS by delivering follistatin-like protein 1 (FSTL1), and FSTL1 knockdown in eEVs alleviates eEV-induced ALI/ARDS. Our data thus demonstrate that cardiopulmonary bypass may increase plasma PAI-1 levels to induce FSTL1-enriched eEVs, which target the TLR4-mediated JAK2/3/STAT3/IRF-1 signaling cascade and form a positive feedback loop, leading to ALI/ARDS after cardiac surgery. Our findings provide new insight into the molecular mechanisms and therapeutic targets for ALI/ARDS after cardiac surgery.

Follistatin-like 1 protects endothelial function in the spontaneously hypertensive rat by inhibition of endoplasmic reticulum stress through AMPK-dependent mechanism.

OBJECTIVE: Endothelial dysfunction is a critical initiating factor in the development of hypertension and related complications. Follistatin-like 1 (FSTL1) can promote endothelial cell function and stimulates revascularization in response to ischemic insult. However, it is unclear whether FSTL1 has an effect on ameliorating endothelial dysfunction in spontaneously hypertensive rats (SHRs). METHODS: Wistar Kyoto (WKY) and SHRs were treated with a tail vein injection of vehicle (1 mL/day) or recombinant FSTL1 (100 µg/kg body weight/day) for 4 weeks. Blood pressure was measured by tail-cuff plethysmograph, and vascular reactivity in mesenteric arteries was measured using wire myography. RESULTS: We found that treatment with FSTL1 reversed impaired endothelium-dependent relaxation (EDR) in mesenteric arteries and lowered blood pressure of SHRs. Decreased AMP-activated protein kinase (AMPK) phosphorylation, elevated endoplasmic reticulum (ER) stress markers, increased reactive oxygen species (ROS), and reduction of nitric oxide (NO) production in mesenteric arteries of SHRs were also reversed by FSTL1 treatment. Ex vivo treatment with FSTL1 improved the impaired EDR in mesenteric arteries from SHRs and reversed tunicamycin (ER stress inducer)-induced ER stress and the impairment of EDR in mesenteric arteries from WKY rats. The effects of FSTL1 were abolished by cotreatment of compound C (AMPK inhibitor). CONCLUSIONS: These results suggest that FSTL1 prevents endothelial dysfunction in mesenteric arteries of SHRs through inhibiting ER stress and ROS and increasing NO production via activation of AMPK signaling.

Disco interacting protein 2 homolog A (DIP2A): A key component in the regulation of brain disorders.

Disco Interacting Protein 2 Homolog A (DIP2A) is expressed throughout the body and abundantly expressed in the brain tissue. It is activated by Follistatin-like 1 (FSTL1). Activated DIP2A interacts with several pathways, such as AMPK/mTOR and AKT pathways, to contribute to many biological processes, such as oxidative stress, transcriptional regulation, and apoptosis. Dysregulated DIP2A activation has been implicated in numerous processes in the brain. If the upstream pathways of DIP2A remain globally unexplored, many proteins, including cortactin, AMPK, and AKT, have been identified as its downstream targets in the literature. Recent studies have linked DIP2A to a variety of mechanisms in many types of brain disorders, suggesting that regulation of DIP2A could provide novel diagnostic and therapeutic approaches for brain disorders. In this review, we comprehensively summarized and discussed the current research on DIP2A in various brain disorders, such as stroke, autism spectrum disorders (ASD), Alzheimer's disease (AD), dyslexia, and glioma.

FSTL3 partially mediates the association of increased nonalcoholic fatty liver disease fibrosis risk with acute myocardial infarction in patients with type 2 diabetes mellitus.

BACKGROUND: The study aimed to investigate an association of increased liver fibrosis with acute myocardial infarction (AMI), and to investigate the mediating effect of serum follistatin-like protein 3 (FSTL3) on the association in patients with type 2 diabetes mellitus (T2DM). METHOD: A total of 1424 participants were included in this study, and were firstly divided into two groups: 429 T2DM patients and 995 T2DM patients with NAFLD to assess the association of NAFLD and AMI. Then 995 T2DM co-existent NAFLD patients were categorized by NAFLD fibrosis risk to explore the association between NAFLD fibrosis risk and AMI. Immunohistochemistry staining and semi-quantitative analysis of liver FSTL3 were performed in 60 patients with NAFLD. There were 323 individuals (191 without AMI and 132 with AMI) in T2DM co-existent NAFLD patients who had serum samples, and serum FSTL3 was tested and mediation effect of FSTL3 in association of NAFLD fibrosis and AMI was performed. RESULTS: First, increased NAFLD fibrosis risk was an independent risk factor for AMI in patients with T2DM and co-existent NAFLD. In addition, analysis of Gene Expression Omnibus (GEO) database and immunohistochemical staining confirmed the increased expression of FSTL3 in the liver of NAFLD patients with fibrosis. Serum FSTL3 significantly increased in patients with high NAFLD fibrosis risk and AMI, and closely associated with NAFLD fibrosis and AMI severity in T2DM patients with co-existent NAFLD. Most importantly, analysis of the level of mediation revealed that increased serum FSTL3 partially mediated the association of increased NAFLD fibrosis risk with AMI in T2DM patients with co-existent NAFLD. CONCLUSIONS: NAFLD fibrosis was closely associated with AMI in T2DM patients. FSTL3 expression was enriched in the liver of NAFLD patients with significant and advanced fibrosis, and serum FSTL3 partially mediated the association of increased liver fibrosis risk with AMI in T2DM patients.

Analysis of the expression and mechanism of follistatin­like protein 1 in cervical cancer.

The abnormal expression of follistatin­like protein 1 (FSTL1) in various tumors is a crucial regulator of the biological process of tumorigenesis. Nonetheless, the regulatory role of FSTL1 in cervical cancer is yet to be elucidated. Hence, the present study aimed to explore the expression, function, and molecular mechanism of FSTL1 in cervical cancer. The expression of FSTL1 in normal and cervical cancer tissues was examined using quantitative reverse transcription­polymerase chain reaction and immunohistochemistry assays. The effects of abnormal expression of FSTL1 on cervical cancer cells were assessed using colony formation, MTT, wound­healing, Transwell, apoptosis, and nude mouse tumorigenicity assays. FSTL1­related molecular mechanisms were screened using gene chip analysis. Western blotting analysis was used to verify the regulatory mechanisms of FSTL1 in cervical cancer. The results indicated that the expression of FSTL1 was downregulated in cervical cancer tissues and that its downregulation was associated with tumor differentiation, pathologic type, and infiltration depth. Moreover, FSTL1 inhibited the proliferation, migration, and invasion of cervical cancer cells as well as xenograft tumor growth and promoted cell apoptosis. In addition, the findings of gene chip analysis suggested that the differentially expressed genes of FSTL1 were predominantly enriched in multiple signaling pathways, of which the insulin­like growth factor (IGF)­1 signaling pathway was significantly activated. Western blotting suggested the involvement of FSTL1 in the regulation of the IGF­1R/PI3K/AKT/BCL­2 signaling pathway. These data establish the downregulation of FSTL1 in cervical cancer tissues. FSTL1 inhibited the proliferation, migration, and invasion of cervical cancer cells and promoted their apoptosis. Furthermore, xenograft tumor growth in nude mice was inhibited. FSTL1 may be involved in the regulation of the IGF­1R/PI3K/AKT/BCL­2 signaling pathway in cervical cancer. Therefore, FSTL1 may be employed as a novel biomarker to determine the extent of disease progression in patients with cervical cancer.

Cancer-associated fibroblasts impair the cytotoxic function of NK cells in gastric cancer by inducing ferroptosis via iron regulation.

As the predominant immunosuppressive component within the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs) inhibit Natural Killer cell (NK cell) activity to promote tumor progression and immune escape; however, the mechanisms of cross-talk between CAFs and NK cells in gastric cancer (GC) remain poorly understood. In this study, we demonstrate that NK cell levels are inversely correlated with CAFs abundance in human GC. CAFs impair the anti-tumor capacity of NK cells by inducing ferroptosis, a cell death process characterized by the accumulation of iron-dependent lipid peroxides. CAFs induce ferroptosis in NK cells by promoting iron overload; conversely, decreased intracellular iron levels protect NK cells against CAF-induced ferroptosis. Mechanistically, CAFs increase the labile iron pool within NK cells via iron export into the TME, which is mediated by the upregulated expression of iron regulatory genes ferroportin1 and hephaestin in CAFs. Moreover, CAF-derived follistatin like protein 1(FSTL1) upregulates NCOA4 expression in NK cells via the DIP2A-P38 pathway, and NCOA4-mediated ferritinophagy is required for CAF-induced NK cell ferroptosis. In a human patient-derived organoid model, functional targeting of CAFs using a combination of deferoxamine and FSTL1-neutralizing antibody significantly alleviate CAF-induced NK cell ferroptosis and boost the cytotoxicity of NK cells against GC. This study demonstrates a novel mechanism of suppression of NK cell activity by CAFs in the TME and presents a potential therapeutic approach to augment the immune response against GC mediated by NK cells.

Pro-Inflammatory Biomarkers Combined with Body Composition Display a Strong Association with Knee Osteoarthritis in a Community-Based Study.

Knee osteoarthritis (KOA) is one of the most common progressive, age-dependent chronic degenerative joint diseases. KOA often develops as a result of a gradual articular cartilage loss caused by its wear and tear. Numerous studies suggest that the degradation of the knee joint involves inflammatory components. This process is also associated with body composition, particularly being overweight and muscle mass loss. The present study aimed to search for novel circulating KOA inflammatory biomarkers, taking into account body composition characteristics. To this aim, we recruited 98 patients diagnosed and radiologically confirmed with KOA and 519 healthy controls from the Arab community in Israel. A panel of soluble molecules, related to inflammatory, metabolic, and musculoskeletal disorders, was measured by ELISA in plasma samples, while several body composition parameters were assessed with bioimpedance analysis. Statistical analysis, including multivariable logistic regression, revealed a number of the factors significantly associated with KOA, independently of age and sex. The most significant independent associations [OR (95% CI)] were fat body mass/body weight index-1.56 (1.20-2.02), systemic immune-inflammation index-4.03 (2.23-7.27), circulating vaspin levels-1.39 (1.15-1.68), follistatin/FSTL1 ratio-1.32 (1.02-1.70), and activin A/FSTL1 ratio-1.33 (1.01-1.75). Further clinical studies are warranted to confirm the relevance of these KOA-associated biological factors. Hereafter, they could serve as reliable biomarkers for KOA in the general human population.

Metabolic crosstalk between skeletal muscle cells and liver through IRF4-FSTL1 in nonalcoholic steatohepatitis.

Inter-organ crosstalk has gained increasing attention in recent times; however, the underlying mechanisms remain unclear. In this study, we elucidate an endocrine pathway that is regulated by skeletal muscle interferon regulatory factor (IRF) 4, which manipulates liver pathology. Skeletal muscle specific IRF4 knockout (F4MKO) mice exhibited ameliorated hepatic steatosis, inflammation, and fibrosis, without changes in body weight, when put on a nonalcoholic steatohepatitis (NASH) diet. Proteomics analysis results suggested that follistatin-like protein 1 (FSTL1) may constitute a link between muscles and the liver. Dual luciferase assays showed that IRF4 can transcriptionally regulate FSTL1. Further, inducing FSTL1 expression in the muscles of F4MKO mice is sufficient to restore liver pathology. In addition, co-culture experiments confirmed that FSTL1 plays a distinct role in various liver cell types via different receptors. Finally, we observed that the serum FSTL1 level is positively correlated with NASH progression in humans. These data indicate a signaling pathway involving IRF4-FSTL1-DIP2A/CD14, that links skeletal muscle cells to the liver in the pathogenesis of NASH.

Maternal Serum Activin A, Inhibin A and Follistatin-Related Proteins across Preeclampsia: Insights into Their Role in Pathogenesis and Prediction.

BACKGROUND: Within the endocrine-paracrine signalling network at the maternal-foetal interface, the activin-inhibin-follistatin system modulates extravillous trophoblast invasion, suggesting a potential role in preeclampsia pathogenesis. This study aimed to compile the evidence published in the last decade regarding the variation in maternal serum activins, inhibin- and follistatin-related proteins in preeclamptic pregnancies compared to healthy pregnancies, and to discuss their role in predicting and understanding the pathophysiology of preeclampsia. MATERIAL AND METHODS: A scoping review was conducted in MEDLINE, EMBASE and LILACS databases to identify studies published within the last ten years (2012-2022). RESULTS: Thirty studies were included. None of the studies addressed maternal serum changes of isoforms different from activin A, inhibin A, follistatin, and follistatin-like 3. Sixteen studies evaluated the potential of these isoforms in predicting preeclampsia through the area under the curve from a receiver operating characteristic curve. CONCLUSIONS: In preeclampsia, inhibin A is upregulated in all trimesters, whereas activin A increases exclusively in the late second and third trimesters. Serum follistatin levels are reduced in women with preeclampsia during the late second and third trimesters. However, changes in follistatin-like 3 remain inconclusive. Inhibin A and activin A can potentially serve as biomarkers of early-onset preeclampsia based on the outcomes of the receiver operating characteristic curve analysis. Further investigations are encouraged to explore the feasibility of quantifying maternal serum levels of activin A and inhibin A as a clinical tool in early preeclampsia prediction.

Cardiac RGS7 and RGS11 drive TGFß1-dependent liver damage following chemotherapy exposure.

Off target damage to vital organ systems is an unfortunate side effect of cancer chemotherapy and remains a major limitation to the use of these essential drugs in the clinic. Despite decades of research, the mechanisms conferring susceptibility to chemotherapy driven cardiotoxicity and hepatotoxicity remain unclear. In the livers of patients with a history of chemotherapy, we observed a twofold increase in expression of G protein regulator RGS7 and a corresponding decrease in fellow R7 family member RGS11. Knockdown of RGS7 via introduction of RGS7 shRNA via tail vein injection decreased doxorubicin-induced hepatic collagen and lipid deposition, glycogen accumulation, and elevations in ALT, AST, and triglycerides by approximately 50%. Surprisingly, a similar result could be achieved via introduction of RGS7 shRNA directly to the myocardium without impacting RGS7 levels in the liver directly. Indeed, doxorubicin-treated cardiomyocytes secrete the endocrine factors transforming growth factor ß1 (TGFß1) and TGFß superfamily binding protein follistatin-related protein 1 (FSTL1). Importantly, RGS7 overexpression in the heart was sufficient to recapitulate the impacts of doxorubicin on the liver and inhibition of TGFß1 signaling with the receptor blocker GW788388 ameliorated the effect of cardiac RGS7 overexpression on hepatic fibrosis, steatosis, oxidative stress, and cell death as well as the resultant elevation in liver enzymes. Together these data demonstrate that RGS7 controls both the release of TGFß1 from the heart and the profibrotic and pro-oxidant actions of TGFß1 in the liver and emphasize the functional significance of endocrine cardiokine signaling in the pathogenesis of chemotherapy drive multiorgan damage.

Single-cell transcriptome analysis reveals cellular heterogeneity and highlights Fstl1-regulated alveolar myofibroblasts in mouse lung at birth.

The matricellular protein, follistatin-like 1 (FSTL1), regulates lung development and saccular formation. Here, we employed single-cell RNA sequencing (scRNA-seq) to construct a transcriptomic atlas of 22,774 individual cells from wild-type (WT) and Fstl1-/- lung (E18.5) samples and identified 27 cell subtypes. We observed abnormal population sizes and gene expression profiles in diverse cell subtypes in Fstl1-/- lung samples. We identified Pdgfra and Tgfbi as genetic markers specifically expressed in postnatal myofibroblasts (MyoFBs). Fstl1 deletion decreased the number of MyoFB cells and downregulated their roles in ECM organization and muscle tissue/vasculature development, partly through the TGF-ß1/BMP4 signaling pathway. Our data provide a single-cell view of the cellular heterogeneity and the molecular mechanisms underlying abnormal saccular formation and atelectatic lungs in Fstl1-/- mice.

From Phenomenon to Essence: A Newly Involved lncRNA Kcnq1ot1 Protective Mechanism of Bone Marrow Mesenchymal Stromal Cells in Liver Cirrhosis.

Bone marrow mesenchymal stromal cells (BMSCs) have a protective effect against liver cirrhosis. Long noncoding RNAs (lncRNAs) play crucial roles in the progression of liver cirrhosis. Therefore, it is aimed to clarify the lncRNA Kcnq1ot1 involved protective mechanism of BMSCs in liver cirrhosis. This study found that BMSCs treatment attenuates CCl4 -induced liver cirrhosis in mice. Additionally, the expression of lncRNA Kcnq1ot1 is upregulated in human and mouse liver cirrhosis tissues, in addition to TGF-ß1-treated LX2 cells and JS1 cells. The expression of Kcnq1ot1 in liver cirrhosis is reversed with BMSCs treatment. The knockdown of Kcnq1ot1 alleviated liver cirrhosis both in vivo and in vitro. Fluorescence in situ hybridization (FISH) confirms that Kcnq1ot1 is mainly distributed in the cytoplasm of JS1 cells. It is predicted that miR-374-3p can directly bind with lncRNA Kcnq1ot1 and Fstl1, which is verified via luciferase activity assay. The inhibition of miR-374-3p or the overexpression of Fstl1 can attenuate the effect of Kcnq1ot1 knockdown. In addition, the transcription factor Creb3l1 is upregulated during JS1 cells activation. Moreover, Creb3l1 can directly bind to the Kcnq1ot1 promoter and positively regulate its transcription. In conclusion, BMSCs alleviate liver cirrhosis by modulating the Creb3l1/lncRNA Kcnq1ot1/miR-374-3p/Fstl1 signaling pathway.

FSTL1 promotes alveolar epithelial cell aging and worsens pulmonary fibrosis by affecting SENP1-mediated DeSUMOylation.

Alveolar epithelial cell (AEC) senescence-induced changes of lung mesenchymal cells are key to starting the progress of pulmonary fibrosis. Follistatin-like 1 (FSTL1) plays a central regulatory role in the complex process of senescence and pulmonary fibrosis by enhancing transforming growth factor-ß1 (TGF-ß1) signal pathway activity. Activation of Smad4 and Ras relies on SUMO-specific peptidase 1 (SENP1)-mediated deSUMOylation during TGF-ß signaling pathway activation. We hypothesized that SENP1-mediated deSUMOylation may be a potential therapeutic target by modulating FSTL1-regulated cellular senescence in pulmonary fibrosis. In verifying this hypothesis, we found that FSTL1 expression was upregulated in the lung tissues of patients with idiopathic pulmonary fibrosis and that SENP1 was overexpressed in senescent AECs. TGF-ß1-induced FSTL1 not only promoted AEC senescence but also upregulated SENP1 expression. Interfering with SENP1 expression inhibited FSTL1-dependent promotion of AEC senescence and improved pulmonary fibrosis in mouse lungs. FSTL1 enhancement of TGF-ß1 signaling pathway activation was dependent on SENP1 in senescent AEC. Our work identifies a novel mechanism by which FSTL1 is involved in AEC senescence. Inhibition of SENP1 in epithelial cells alleviated pulmonary fibrosis by blocking FSTL1-enhanced TGF signaling.