International Journal of Biological Sciences最新文献

Background: Ovulation disorders represent the most common cause of infertility in women. Previous studies have reported that continuous light exposure can induce anovulation. However, the underlying mechanisms remain unclear. Methods: We assessed the phenotypes of ovulation disorders by using vaginal smears, hormone levels, and ovarian morphology. Metabolomics and RNA sequencing were employed to identify key metabolites and explore potential underlying mechanisms. Additionally, we investigated the effects of a leucine-rich diet on the phenotypes of ovulation disorders and autophagy. Serum levels of branched-chain amino acids (BCAAs) in patients with polycystic ovary syndrome (PCOS) were also measured. Causality was explored by using Mendelian randomization (MR) methods based on GWAS summary data. Results: Female SD rats subjected to continuous light exhibited disrupted estrous cycles and polycystic ovaries, as well as increased anti-Müllerian hormone (AMH) levels. Metabolic profiling revealed that leucine was a pivotal metabolite. Specifically, a high-leucine diet induced anovulation and polycystic morphology, along with reducing autophagy, in rats under normal light conditions; additionally, leucine restriction alleviated these effects in recovered rats. Moreover, the mTOR-ULK1-LC3-II/I autophagy pathway was influenced both in vivo and in vitro by leucine. In patients with PCOS, elevated serum BCAA levels (especially leucine) were observed to be correlated with increased AMH levels, higher luteinizing hormone (LH)-to-follicle-stimulating hormone (FSH) ratios, and higher antral follicle counts. MR analysis indicated that night shift work may increase the risk of PCOS through elevated serum leucine levels. Conclusions: These results suggest that the disruption of the leucine-mTOR-autophagy axis in granulosa cells (GCs) mediates continuous light-induced ovulation disorders. The potential therapeutic targeting of leucine-mTOR pathways for managing PCOS should be investigated.

Background: Transarterial chemoembolization (TACE) combined with sorafenib is a common therapeutic strategy for hepatocellular carcinoma (HCC). However, sorafenib resistance (SFR) remains a major clinical obstacle. Evidence suggest that TACE reshapes the tumor microenvironment (TME), creating an external high-glucose (HG) and internal low-glucose (LG) niche. In this context, hyperglycemia-driven lysophosphatidic acid (LPA) production accelerates HCC progression. Moreover, intercellular communication via extracellular vesicles (EVs) has been linked to drug resistance. Despite these insights, the SFR mechanism by which HG-induced LPA regulates EV uptake and signaling is unclear. Methods: ELISA, immunohistochemistry, Western blot, CCK-8, Annexin V-7AAD, bioinformatics, and hyperglycemic models were performed to assess the HG-LPA-EV connection in cell, blood, and surgical samples. Nanoparticle characterization, confocal imaging, GST pull-down, dominant mutants, and UEA-1 blot were used to check Arf6 activation, CD147 fucosylation, and EV-stimulated signaling. Bilateral CDX models, GFP-CD63 imaging, and combinational treatments were performed to further elucidate the SFR mechanism. Results: SFR emerges in hyperglycemic HCC patients with elevated LPA levels. Mechanistically, HG-induced LPA elevation promotes the uptake of LG-derived EVs (LG-EVs), thereby driving resistance. LPA activates ADP-ribosylation factor 6 (Arf6), which enhances macropinocytosis-mediated LG-EV uptake. Further, LG conditions increase fucosyltransferase 1 (FUT1)-dependent CD147 fucosylation on EV surfaces. Uptake of CD147⁺ LG-EVs subsequently promotes SFR by activating the fucosylation-dependent AKT/mTOR/4EBP1 signaling pathway. Importantly, inhibition of LPA-Arf6-mediated EV macropinocytosis significantly improves the sorafenib efficacy. Conclusion: Our findings uncover a previously unrecognized mechanism mediated by differential TME and CD147⁺ EV macropinocytosis in HCC and highlight the LPA-Arf6-macropinocytosis as a novel targeting axis to overcome SFR in HCC.

Hepatocellular carcinoma (HCC), which makes up about 90% of liver cancer, is the third leading cause of cancer-related death. Recent studies suggest that metabolites derived from the gut microbiome may offer new therapeutic opportunities for HCC. In this study, we explored whether microbial metabolites could enhance the effectiveness of sorafenib, a first-line multi-kinase inhibitor used in advanced HCC. Through a screen of a microbiome metabolite library, we identified spermine and sphingosine as potential candidates that boosted anticancer effects of sorafenib in HepG2, Huh7, and SK-Hep-1 cells. These metabolites worked synergistically with sorafenib to suppress tumor growth in cultured HCC cells, patients-derived HCC organoids, and a xenograft mouse model. Mechanistically, spermine triggered cell cycle arrest at the S phase, while sphingosine and sorafenib induced G1 arrest, contributing to an increased sub-G1 population and apoptosis when combined. Notably, sorafenib treatment led to the downregulation of SMOX (a key catabolic enzyme for spermine), as well as SPHK1 and CERS1 (critical enzymes involved in sphingosine metabolism), whose high expression levels are associated with poorer survival outcomes in liver cancer patients according to TCGA data. A 16S rRNA sequencing analysis revealed that combination of sorafenib with spermine or sphingosine alters the gut microbiome, increasing the relative abundance of Faecalibaculum, inversely correlated with tumor sizes in a xenograft mouse model. Therefore, we propose that combining sorafenib with spermine or sphingosine could enhance its anti-HCC effects by promoting apoptosis and reducing the expression of metabolic enzymes. Moreover, Faecalibaculum may serve as a potential microbiome-based prognostic marker for HCC.

Endometriosis is an estrogen-dependent chronic inflammatory disorder. Cholesterol (CHO) has been reported to be closely associated with estrogen synthesis and inflammatory responses. Nevertheless, the mechanisms underlying the effects of cholesterol on endometriosis progression and immune response remain to be elucidated. Our research revealed that cholesterol accumulation in ectopic lesions acts as a crucial catalyst for the progression of endometriosis. Using a co-culture system, we simulated a cholesterol-abundant ectopic milieu and demonstrated cholesterol induced M2 macrophage polarization via the STAT6/PPARγ pathway, connecting cholesterol metabolism to immune response in endometriosis. Notably, cholesterol-induced M2 macrophage polarization accelerated the aggressive behavior of ectopic endometrial stromal cells (EESCs). Furthermore, we identified solute carrier family 25 member 1 (SLC25A1) as a pivotal target for regulating cholesterol metabolism in endometriosis, as it significantly upregulated in ectopic lesions and markedly increased intracellular and extracellular cholesterol content. In vitro and in vivo experiments revealed that cholesterol supplementation reversed the cellular and immune microenvironment alterations caused by SLC25A1 knockdown. Collectively, our results demonstrated that SLC25A1 upregulated the cholesterol metabolism in EESCs and mediated M2 macrophages polarization via the STAT6/PPARγ signaling pathway. Our study on the molecular mechanisms underlying cholesterol accumulation and function may provide potential targets and therapeutic strategies for endometriosis management.

Abnormal cytoplasmic accumulation of TAR DNA-binding protein 43 (TDP-43) is a common pathological feature of TDP-43 proteinopathies. Since non-human primate models can better recapitulate this neuropathology than rodents, we used a monkey model to evaluate the therapeutic potential of stem cells for TDP-43-mediated neuropathology. We established a cynomolgus monkey model by expressing mutant TDP-43 (M337V) in the monkey striatum through AAV injection. This model exhibited motor dysfunction and abnormal cytoplasmic TDP-43 accumulation. Using multi-gene modified stem cells (NILB-hiPSCs) that can be induced to differentiate in vivo with doxycycline treatment, we found that transplanted NILB-hiPSCs improved the limb movements of the TDP-43-injected monkeys, differentiated into mature neurons, and were integrated with neural circuit activity in the monkey brain. Furthermore, NILB-hiPSC therapy reduced reactive gliosis and diminished the abnormal cytoplasmic localization of mutant TDP-43. These results highlight the potential of in vivo inducible stem cells for the treatment of TDP-43 proteinopathies.

Immune evasion remains a major obstacle to effective cancer immunotherapy. While the regulatory mechanisms of the tumor biochemical microenvironment are relatively well-characterized, the role of its mechanical microenvironment-particularly pathologically elevated matrix stiffness-in immune evasion remains to be fully elucidated. Immune cells, as dynamic responders within the tumor microenvironment, are not merely passive recipients of mechanical signals but also active participants in driving pathological matrix stiffening. This review focuses on the elevated matrix stiffness resulting from abnormal deposition and crosslinking of the tumor extracellular matrix, systematically elucidating how it impairs immune cell function and drives immune evasion through physical barriers and mechanotransduction. Additionally, we further propose an innovative concept: the "matrix stiffness-immune cell bidirectional regulatory axis." Dissecting this regulatory loop provides an essential mechanical perspective for understanding immune evasion and offers a conceptual framework for developing matrix-targeted strategies to enhance immunotherapy. By integrating current evidence, this review aims to clarify the role of this bidirectional axis and to identify novel therapeutic targets and strategies that may improve the efficacy of cancer immunotherapies.

Rifampicin (RIF), a cornerstone drug in tuberculosis treatment, is associated with hepatotoxicity, which represents a significant adverse effect that frequently causes discontinuation of therapy. However, a comprehensive evaluation of the mechanisms underlying RIF-induced hepatotoxicity remains limited, and the identification of highly effective, low-toxicity therapeutic interventions is urgently needed. In this study, we employed a RIF-induced mouse hepatotoxicity model to systematically investigate the cellular and molecular events associated with RIF-induced liver injury. By integrating single-cell RNA sequencing, bulk RNA-seq, and mass spectrometry-based proteomics and metabolomics, we identified region-specific hepatocyte damage characterized by elevated reactive oxygen species (ROS) levels and activation of the fatty acid oxidation pathway. At the molecular level, RIF treatment resulted in the upregulation of pregnane X receptor (PXR) and Cyp3a11, along with the downregulation of key antioxidant genes. Moreover, decreased mTOR expression and increased expression of fatty acid oxidation-related genes including Acox1 and Acaa1b suggested an enhanced oxidative metabolism. Recruitment of macrophages further exacerbated hepatocyte damage. Importantly, Rosmarinic acid (RA) administration was shown to attenuate RIF-induced hepatotoxicity. These findings provide a comprehensive molecular and cellular perspective on RIF-induced hepatotoxicity and suggest the potential clinical application of RA as a therapeutic agent in the management of RIF-induced liver injury.

Aims: Myocardial infarction (MI) induces pathological cardiac fibrosis and ventricular remodeling, which leads to cardiac dysfunction and heart failure. Mesenchyme homeobox 1 (Meox1) was shown to be an essential transcriptional switch in fibroblasts activation; however, whether Meox1 is involved in the fibrosis process following MI remains unknown. We aimed to explore the role of Meox1 in cardiac fibrosis and remodeling post-MI and its underlying mechanisms. Methods and results: Herein, we identified that Meox1 was highly expressed in activated fibroblasts (myofibroblasts, Myofbs), in response to MI in mice or transforming growth factor beta 1 (TGF-β1) stimulation in primary cardiac fibroblasts (CFs). Knockdown of Meox1 in Myofbs remarkably attenuated cardiac fibrosis and adverse remodeling post-MI and improved cardiac function. In vitro, Meox1 silencing inhibited the activation, proliferation, migration and fibrotic gene expression of primary CFs, whereas Meox1 overexpression resulted in the opposite biological effects. Mechanistically, Meox1 transcriptionally activated collagen triple helix repeat containing 1 (Cthrc1), which further promoted downstream Smad2/3 phosphorylation, thereby leading to CFs-to-Myofbs conversion. Overexpression of Cthrc1 abolished the cardioprotective effects of Meox1 silencing in mice. Moreover, Cthrc1 knockdown in primary CFs suppressed the effects of Meox1 on facilitating the phosphorylation of Smad2/3 and profibrotic phenotypes. Conclusions: Our study revealed the key regulatory role of Meox1 in promoting cardiac fibrosis and heart failure by inducing the transformation of CFs-to-Myofbs through activating Cthrc1/p-Smad2/3 post-MI. Therefore, Meox1/Cthrc1/p-Smad2/3 signaling pathway might be a promising therapeutic target for cardiac fibrosis and remodeling in MI patients.

Intestinal injury in sepsis contributes to life-threatening systemic infections, accompanied by disruptions in macrophage abundance and function. Forkhead Box O1 (FoxO1) is a critical transcription factor involved in regulating inflammatory responses; however, its role in sepsis-induced intestinal injury remains unclear. In this study, we found that FoxO1 expression was upregulated in intestinal macrophages of septic mice. To investigate its function, myeloid-specific FoxO1 conditional knockout (FoxO1^M-KO) mice were established. Sepsis-induced intestinal barrier dysfunction and oxidative stress were significantly alleviated in these mice, along with improvements in systemic inflammation. Specifically, FoxO1 deletion increased the proportion of Tim4⁺ resident macrophages in intestinal lamina propria and Peyer's patches (PPs) of septic mice. Mechanistically, FoxO1 interacted with the corepressor Sin3a to restrict Tim4 transcription in macrophages. Functionally, FoxO1 knockdown reduced glycolysis in Tim4⁺ macrophages through MAP4K4 signaling, exerting an anti-inflammatory effect that mitigated intestinal injury. Adoptive transfer of Tim4-knockdown primary macrophages into septic mice reversed the protective effects observed in FoxO1^M-KO mice, underscoring the crucial role of FoxO1-regulated Tim4⁺ macrophages in inflammation. Furthermore, the traditional Chinese medicine Huashi Baidu formula (HSBD) inhibited FoxO1 in Tim4⁺ macrophages and ameliorated septic intestinal injury. In conclusion, this study reveals the immunomodulatory and inflammatory role of myeloid FoxO1, identifying it as a novel regulator and therapeutic target for septic intestinal injury.

It has been a consensus that hepatic microenvironment composed by the non-parenchymal cells networks play a critical role during liver fibrogenesis, with the crosstalk between hepatic stellate cells (HSCs) and macrophages being of paramount importance. Interleukin 11(IL-11) has been implicated as a pro-fibrogenic cytokine, where its function in/between hepatocytes and HSCs has been revealed. But whether IL-11 participates in the interaction of HSCs and macrophages and related mechanism remains obscure. Our research demonstrates that HSC-derived IL-11 operates through a dual mechanism of autocrine activation and paracrine reprogramming to drive the fibrosis. AAV6-mediated IL-11 overexpression in the HSCs aggravated hepatic fibrosis induced by CCl₄ in C57/B6 mice, accompanied by a marked increase of M2 macrophages. Mechanistically, the autocrine signaling of IL-11 activated HSCs directly, potently enhancing the contractility, migration, and collagen production of HSCs through GP130-SFK-YAP pathway. Furthermore, IL-11 also functioned as a paracrine signal of HSCs activation that synergized with IL-4 to polarize macrophages into a profibrotic M2-like phenotype. This reprogramming was achieved through the coordinated activation of PI3K-mTOR signaling to promote TGF-β synthesis and STAT3 pathway to elevate chemokine levels. The necessity of macrophages in this process was proven when their depletion blunted the pro-fibrogenic effects of IL-11 overexpression. Consequently, therapeutic inhibition of IL-11 with a nanobody alleviated fibrosis and reversed macrophage polarization. Our findings proposed a self-amplifying loop where HSC-derived IL-11 directly activates fibrogenesis and simultaneously reprograms macrophages to create a feed-forward cycle that relentlessly drives disease progression.