FASEB Journal最新文献

Epithelial ovarian cancer is the deadliest gynecologic malignancy, characterized by high metastasis. Transforming growth factor-β1 (TGF-β1) drives epithelial- mesenchymal transformation (EMT), a key process in tumor metastasis. Tumor necrosis factor-α-induced protein 8 (TNFAIP8)-like 2 (TIPE2) acts as a negative regulator of innate and adaptive immunity and involves in various cancers. However, its relationship with TGF-β1 in ovarian cancer and its role in reversing TGF-β1-induced EMT remain unclear. This study examined TIPE2 mRNA and protein expression using quantitative RT-PCR (qRT-PCR), western blot and immunohistochemistry. The effects of TIPE2 overexpression and knockdown on the proliferation, migration and invasion of epithelial ovarian cancer cells were assessed through 5-ethynyl-2-deoxyuridine, colony-forming, transwell migration and invasion assays. The relationship between TIPE2 and TGF-β1 was investigated using qRT-PCR and enzyme-linked immunosorbent assay, while the interaction between TIPE2 and Smad2 was identified via co-immunoprecipitation. The results revealed that TIPE2 protein was significantly down-regulated in epithelial ovarian cancer tissues and correlated with the pathological type of tumor, patients' age, tumor differentiation degree and FIGO stage. TIPE2 and TGF-β1 appeared to play an opposite role to each other during the progression of human ovarian cancer cells. Furthermore, TIPE2 inhibited the metastasis and EMT of ovarian cancer cells by combining with Smad2 in vitro or in an intraperitoneal metastasis model. Consequently, these findings suggest that TIPE2 plays a crucial inhibitory role in ovarian cancer metastasis by modulating the TGF-β1/Smad2/EMT signaling pathway and may serve as a potential target for ovarian cancer, providing important direction for future diagnostic and therapeutic strategies.

Glutathione S-transferase-Pi 1 (GSTP1) is an isozyme that plays a key role in detoxification and antioxidative damage. It also confers resistance to tumor therapy. However, the specific role of GSTP1 in radiotherapy resistance in pancreatic cancer (PC) is not known. In this study, we investigated how GSTP1 imparts radioresistance in PC. The findings of previous studies and this study revealed that ionizing radiation (IR) induces ferroptosis in pancreatic cancer cells, primarily by upregulating the expression of ACSL4. Our results showed that after IR, GSTP1 prolonged the survival of pancreatic cancer cells by inhibiting ferroptosis but did not affect apoptosis. The expression of GSTP1 reduced cellular ferroptosis by decreasing the levels of ACSL4 and increasing the GSH content. These changes increase the resistance of pancreatic cancer cells and xenograft tumors to IR. Our findings indicate that ferroptosis participates in irradiation-induced cell death and that GSTP1 prevents IR-induced death of pancreatic cancer cells by inhibiting ferroptosis.

Platelets play a crucial role in tissue regeneration, and their involvement in liver regeneration is well-established. However, the specific contribution of platelet-derived Transforming Growth Factor Beta 1 (TGFβ1) to liver regeneration remains unexplored. This study investigated the role of platelet-derived TGFβ1 in initiating liver regeneration following 2/3 liver resection. Using platelet-specific TGFβ1 knockout (Plt.TGFβ1 KO) mice and wild-type littermates (Plt.TGFβ1 WT) as controls, the study assessed circulating levels and hepatic gene expression of TGFβ1, Platelet Factor 4 (PF4), and Thrombopoietin (TPO) at early time points post-hepatectomy (post-PHx). Hepatocyte proliferation was quantified through Ki67 staining and PCNA expression in total liver lysates at various intervals, and phosphohistone-H3 (PHH3) staining was employed to mark mitotic cells. Circulating levels of hepatic mitogens, Hepatocyte Growth Factor (HGF), and Interleukin-6 (IL6) were also assessed. Results revealed that platelet-TGFβ1 deficiency significantly reduced total plasma TGFβ1 levels at 5 h post-PHx in Plt.TGFβ1 KO mice compared to controls. While circulating PF4 levels, liver platelet recruitment and activation appeared normal at early time points, Plt.TGFβ1 KO mice showed more stable circulating platelet numbers with higher numbers at 48 h post-PHx. Notably, hepatocyte proliferation was significantly reduced in Plt.TGFβ1 KO mice. The results show that a lack of TGFβ1 in platelets leads to an unbalanced expression of IL6 in the liver and to strongly increased HGF levels 48 h after liver resection, and yet liver regeneration remains reduced. The study identifies platelet-TGFβ1 as a regulator of hepatocyte proliferation and platelet homeostasis in the early stages of liver regeneration.

Large-conductance, calcium-activated potassium channels (BK channels) and the Na/K-ATPase are expressed universally in vascular smooth muscle. The Na/K-ATPase may act via changes in the intracellular Ca²⁺ concentration mediated by the Na/Ca exchanger (NCX) and via Src kinase. Both pathways are known to regulate BK channels. Whether BK channels functionally interact in vascular smooth muscle cells with the Na/K-ATPase remains to be elucidated. Thus, this study addressed the hypothesis that BK channels limit ouabain-induced vasocontraction. Rat mesenteric arteries were studied using isometric myography, FURA-2 fluorimetry and proximity ligation assay. The BK channel blocker iberiotoxin potentiated methoxamine-induced contractions. The cardiotonic steroid, ouabain (10⁻⁵ M), induced a contractile effect of IBTX at basal tension prior to methoxamine administration and enhanced the pro-contractile effect of IBTX on methoxamine-induced contractions. These facilitating effects of ouabain were prevented by the inhibition of either NCX or Src kinase. Furthermore, inhibition of NCX or Src kinase reduced the BK channel-mediated negative feedback regulation of arterial contraction. The effects of NCX and Src kinase inhibition were independent of each other. Co-localization of the Na/K-ATPase and the BK channel was evident. Our data suggest that BK channels limit ouabain-induced vasocontraction by a dual mechanism involving the NCX and Src kinase signaling. The data propose that the NCX and the Src kinase pathways, mediating the ouabain-induced activation of the BK channel, act in an independent manner.

The sensitivity of laryngeal squamous cell carcinoma (LSCC) to chemotherapy shows large heterogeneity. The role of miRNA in small extracellular vesicles (sEV) in chemotherapy resistance is under investigation. However, the regulation and sorting mechanism of sEV miRNAs remains unclear. In this study, small RNA sequencing was used to explore miRNA expression profiles in sEV of LSCC after cisplatin stimulation; RNA pull-down, mass spectrometry, and EMSA were used to clarify the binding of candidate RNA-binding protein (RBP) and candidate miRNA. Immunostaining and microRNA fluorescence in situ hybridization were performed to identify how candidate RBP affects miRNA stability and nuclear/cytoplasmic distribution. In vivo experiments were performed to verify the biological functions and response to cisplatin of candidate RBP. We found that cisplatin stimulation induced increased expression of miR-148a-3p and sEV sorting. ANXA11 binds to miR-148a-3p in a sequence-specific manner. ANXA11 inhibits tumor cell proliferation and drug resistance by binding to and retaining miR-148a-3p. Cisplatin stimulation reduced ANXA11 expression and promoted miR-148a-3p efflux through sEV pathways. ANXA11 overexpression reduced in vivo tumor proliferation and cisplatin-resistance. Taken together, ANXA11 mediates cisplatin resistance through sEV miRNA resorting. Mechanically, ANXA11 binds to miR-148a-3p in a sequence-specific manner to regulate its resorting and thus influences tumor proliferation and chemoresistance.

Tendons enable locomotion by transmitting high tensile mechanical forces between muscle and bone via their dense extracellular matrix (ECM). The application of extrinsic mechanical stimuli via muscle contraction is necessary to regulate healthy tendon function. Specifically, applied physiological levels of mechanical loading elicit an anabolic tendon cell response, while decreased mechanical loading evokes a degradative tendon state. Although the tendon response to mechanical stimuli has implications in disease pathogenesis and clinical treatment strategies, the cell signaling mechanisms by which tendon cells sense and respond to mechanical stimuli within the native tendon ECM remain largely unknown. Therefore, we explored the role of cell–ECM adhesions in regulating tendon cell mechanotransduction by perturbing the genetic expression and signaling activity of focal adhesion kinase (FAK) through both in vitro and in vivo approaches. We determined that FAK regulates tendon cell spreading behavior and focal adhesion morphology, nuclear deformation in response to applied mechanical strain, and mechanosensitive gene expression. In addition, our data reveal that FAK signaling plays an essential role in in vivo tendon development and postnatal growth, as FAK-knockout mouse tendons demonstrated reduced tendon size, altered mechanical properties, differences in cellular composition, and reduced maturity of the deposited ECM. These data provide a foundational understanding of the role of FAK signaling as a critical regulator of in situ tendon cell mechanotransduction. Importantly, an increased understanding of tendon cell mechanotransductive mechanisms may inform clinical practice as well as lead to the discovery of diagnostic and/or therapeutic molecular targets.

The function of hydroxysteroid dehydrogenase 12 (HSD17B12) in lipid metabolism is poorly understood. To study this further, we created mice with hepatocyte-specific knockout of HSD17B12 (LiB12cKO). From 2 months on, these mice showed significant fat accumulation in their liver. As they aged, they also had a reduced whole-body fat percentage. Interestingly, the liver fat accumulation did not result in the typical formation of large lipid droplets (LD); instead, small droplets were more prevalent. Thus, LiB12KO liver did not show increased macrovesicular steatosis with the increasing fat content, while microvesicular steatosis was the predominant feature in the liver. This indicates a failure in the LD expansion. This was associated with liver damage, presumably due to lipotoxicity. Notably, the lipidomics data did not support an essential role of HSD17B12 in fatty acid (FA) elongation. However, we did observe a decrease in the quantity of specific lipid species that contain FAs with carbon chain lengths of 18 and 20 atoms, including oleic acid. Of these, phosphatidylcholine and phosphatidylethanolamine have been shown to play a key role in LD formation, and a limited amount of these lipids could be part of the mechanism leading to the dysfunction in LD expansion. The increase in the Cidec expression further supported the deficiency in LD expansion in the LiB12cKO liver. This protein is crucial for the fusion and growth of LDs, along with the downregulation of several members of the major urinary protein family of proteins, which have recently been shown to be altered during endoplasmic reticulum stress.

In clinical settings, addressing large bone defects remains a significant challenge for orthopedic surgeons. The use of genetically modified bone marrow mesenchymal stem cells (BMSCs) has emerged as a highly promising approach for these treatments. Signal peptide-CUB-EGF domain-containing protein 3 (SCUBE3) is a multifunctional secreted glycoprotein, the role of which remains unclear in human hBMSCs. This study used various experimental methods to elucidate the potential mechanism by which SCUBE3 influences osteogenic differentiation of hBMSCs in vitro. Additionally, the therapeutic efficacy of SCUBE3, in conjunction with porous GeLMA microspheres, was evaluated in vivo using a mouse bone defect model. Our findings indicate that SCUBE3 levels increase significantly during early osteogenic differentiation of hBMSCs, and that reducing SCUBE3 levels can hinder this differentiation. Overexpressing SCUBE3 elevated osteogenesis gene and protein levels and enhanced calcium deposition. Furthermore, treatment with recombinant human SCUBE3 (rhSCUBE3) protein boosted BMP2 and TGF-β expression, activated mitophagy in hBMSCs, ameliorated oxidative stress, and restored osteogenic function through SMAD phosphorylation. In vivo, GELMA/OE treatment effectively accelerated bone healing in mice. In conclusion, SCUBE3 fosters osteogenic differentiation and mitophagy in hBMSCs by activating the BMP2/TGF-β signaling pathway. When combined with engineered hydrogel cell therapy, it could offer valuable guidance for the clinical management of extensive bone defects.

Pro-inflammatory cytokines in muscle play a pivotal role in physiological responses and in the pathophysiology of inflammatory disease and muscle atrophy. Lactobacillus delbrueckii (LD), as a kind of probiotics, has inhibitory effects on pro-inflammatory cytokines associated with various inflammatory diseases. This study was conducted to explore the effect of dietary LD on the lipopolysaccharide (LPS)—induced muscle inflammation and atrophy in piglets and to elucidate the underlying mechanism. A total of 36 weaned piglets (Duroc × Landrace × Large Yorkshire) were allotted into three groups with six replicates (pens) of two piglets: (1) Nonchallenged control; (2) LPS-challenged (LPS); (3) 0.2% LD diet and LPS-challenged (LD+LPS). On d 29, the piglets were injected intraperitoneally with LPS or sterilized saline, respectively. All piglets were slaughtered at 4 h after LPS or saline injection, the blood and muscle samples were collected for further analysis. Our results showed that dietary supplementation of LD significantly attenuated LPS-induced production of pro-inflammatory cytokines IL-6 and TNF-α in both serum and muscle of the piglets. Concomitantly, pretreating the piglets with LD also clearly inhibited LPS-induced nuclear translocation of NF-κB p65 subunits in the muscle, which correlated with the anti-inflammatory effects of LD on the muscle of piglets. Meanwhile, LPS-induced muscle atrophy, indicated by a higher expression of muscle atrophy F-box, muscle RING finger protein (MuRF1), forkhead box O 1, and autophagy-related protein 5 (ATG5) at the transcriptional level, whereas pretreatment with LD led to inhibition of these upregulations, particularly genes for MuRF1 and ATG5. Moreover, LPS-induced mRNA expression of endoplasmic reticulum stress markers, such as eukaryotic translational initiation factor 2α (eIF-2α) was suppressed by pretreatment with LD, which was accompanied by a decrease in the protein expression levels of IRE1α and GRP78. Additionally, LD significantly prevented muscle cell apoptotic death induced by LPS. Taken together, our data indicate that the anti-inflammatory effect of LD supply on muscle atrophy of piglets could be likely regulated by inhibiting the secretion of pro-inflammatory cytokines through the inactivation of the ER stress/NF-κB singling pathway, along with the reduction in protein degradation.

Systemic sclerosis (SSc) is a life-threatening autoimmune disease characterized by widespread fibrosis in the skin and several internal organs. Nudix Hydrolase 21 (NUDT2 or CFIm25) downregulation in fibroblasts is known to play detrimental roles in both skin and lung fibrosis. This study aims to investigate the upstream mechanisms that lead to NUDT21 repression in skin fibrosis. We identified transforming growth factor β (TGFβ1) as the primary cytokine that downregulated NUDT21 in normal skin fibroblasts. In the bleomycin-induced dermal fibrosis model, consistent with the peak activation of TGFβ1 at the late fibrotic stage, NUDT21 was downregulated at this stage, and delayed NUDT21 knockdown during this fibrotic phase led to enhanced fibrotic response to bleomycin. Further investigation suggested TGFβ downregulated NUDT21 through microRNA (miRNA) 181a and 181b induction. Both miR-181a and miR-181b were elevated in bleomycin-induced skin fibrosis in mice and primary fibroblasts isolated from SSc patients, and they directly targeted NUDT21 and led to its downregulation in skin fibroblasts. Functional studies demonstrated that miR-181a and miR-181b inhibitors attenuated bleomycin-induced skin fibrosis in mice in association with decreased NUDT21 expression, while miR-181a and miR-181b mimics promoted bleomycin-induced fibrosis. Overall, these findings suggest a novel role for miR-181a/b in SSc pathogenesis by repressing NUDT21 expression.