PTEN directs developmental and metabolic signaling for innate-like T cell fate and tissue homeostasis

TMEM41B is an endoplasmic reticulum Ca2+ release channel maintaining naive T cell quiescence and responsiveness

In mammalian cells, endoplasmic reticulum (ER) passively releases Ca2+ under steady state, but channels involved remain elusive. Here, we report that TMEM41B, an ER-resident membrane protein critical for autophagy, lipid metabolism, and viral infection, functions as an ER Ca2+ release channel. Biochemically, purified recombinant TMEM41B forms a concentration-dependent Ca2+ channel in single-channel electrophysiology assays. Cellularly, TMEM41B deficiency causes ER Ca2+ overload, while overexpression of TMEM41B depletes ER Ca2+. Immunologically, ER Ca2+ overload leads to upregulation of IL-2 and IL-7 receptors in naive T cells, which in turn increases basal signaling of JAK-STAT, AKT-mTOR, and MAPK pathways. This dysregulation drives TMEM41B-deficient naive T cells into a metabolically activated yet immunologically naive state. ER Ca2+ overload also downregulates CD5, lowering the activation threshold of TMEM41B-deficient T cells and leading to heightened T cell responses during infections. In summary, we identify TMEM41B as a concentration-dependent ER Ca2+ release channel, revealing an unexpected role of ER Ca2+ in naive T cell quiescence and responsiveness.

Decoding PTEN: from biological functions to signaling pathways in tumors

The tumor suppressor gene Phosphatase and tensin homologue deleted on chromosome 10 (PTEN), possessing both protein and lipid phosphatase activities, is frequently mutated in various human cancers. PTEN aberrations disrupt critical cellular processes like proliferation, apoptosis, migration, and invasion, thereby promoting tumor growth. In the cells, PTEN localizes to the nucleus, cytoplasm, or cell membrane, and its roles depends on the subcellular localization. PTEN is regulated at the transcriptional, post-transcriptional, and post-translational levels, implying that its functions on the tumors are complex. The relationship between PTEN abnormalities and tumors has garnered significant interest in recent years. PTEN regulates essential cellular processes involved in tumorigenesis. Mutations or deletions in the PTEN gene often correlate with unfavorable prognosis and increased cancer recurrence. Numerous studies suggest that PTEN expression levels in tumors could be a valuable biomarker for cancer diagnosis, treatment, and predicting patient outcomes. This paper provides a comprehensive review of the biological function, regulatory mechanisms, and post-translational modifications of PTEN. Furthermore, this review explores the expression and regulation of PTEN in different tumor types, as well as its interactions with environmental factors in tumorigenesis. This comprehensive analysis aims to deepen our understanding of the signaling pathways between PTEN and cancer.

Early pregnancy exposure to Microcystin-LR compromises endometrial decidualization in mice via the PI3K/AKT/FOXO1 signaling pathway

Previous experimental studies have found that exposure to Microcystin-leucine arginine can impact pregnancy outcomes in female mice. The impact of MC-LR on early pregnancy in mammals is not yet well understood. Both mice and humans need to undergo decidualization to maintain pregnancy. In this study, we tried to evaluate whether MC-LR affects decidualization process in mice. Our research showed that MC-LR decreased maternal weight gain, uterine weight, and implantation site weight. These findings suggested that MC-LR exerted adverse effects on decidualization. In mice, we examined decreased number of polyploid decidual cells, but marked proliferation of mouse endometrial stromal cells the expression levels of prolactin (PRL)and insulin-like growth factor binding protein 1 (IGFBP1) were significantly downregulated in the decidual tissue and primary endometrial stromal cells following MC-LR treatment. Furthermore, further in vitro experiments identified that MC-LR promoted endometrial stromal cell division and cycle transition. Lastly, our study demonstrated that MC-LR impaired decidualization through the PI3K/AKT/FOXO1 pathway. Collectively, these data suggested that exposure to MC-LR impaired decidualization during early pregnancy.

Gpx4 Regulates Invariant NKT Cell Homeostasis and Function by Preventing Lipid Peroxidation and Ferroptosis

Invariant NKT (iNKT) cells are a group of innate-like T cells that plays important roles in immune homeostasis and activation. We found that iNKT cells, compared with CD4+ T cells, have significantly higher levels of lipid peroxidation in both mice and humans. Proteomic analysis also demonstrated that iNKT cells express higher levels of phospholipid hydroperoxidase glutathione peroxidase 4 (Gpx4), a major antioxidant enzyme that reduces lipid peroxidation and prevents ferroptosis. T cell-specific deletion of Gpx4 reduces iNKT cell population, most prominently the IFN-γ-producing NKT1 subset. RNA-sequencing analysis revealed that IFN-γ signaling, cell cycle regulation, and mitochondrial function are perturbed by Gpx4 deletion in iNKT cells. Consistently, we detected impaired cytokine production, elevated cell proliferation and cell death, and accumulation of lipid peroxides and mitochondrial reactive oxygen species in Gpx4 knockout iNKT cells. Ferroptosis inhibitors, iron chelators, vitamin E, and vitamin K2 can prevent ferroptosis induced by Gpx4 deficiency in iNKT cells and ameliorate the impaired function of iNKT cells due to Gpx4 inhibition. Last, vitamin E rescues iNKT cell population in Gpx4 knockout mice. Altogether, our findings reveal the critical role of Gpx4 in regulating iNKT cell homeostasis and function, through controlling lipid peroxidation and ferroptosis.

Bibliometric analysis of PTEN in neurodevelopment and neurodegeneration

Phosphatase and tensin homologue deleted on chromosome ten (PTEN) was initially recognized as a significant regulator of cancer suppression and could impede cancer cell survival, proliferation, and energy metabolism. PTEN is highly expressed in neurons and performs crucial functions in neurogenesis, synaptogenesis, and neuronal survival. Disruption of PTEN activity may also result in abnormal neuronal function and is associated with various neurological disorders, including stroke, seizures, and autism. Although several studies have shown that PTEN is involved in the development and degenerative processes of the nervous system, there is still a lack of in-depth studies that summarize and analyse patterns of cooperation between authors, institutions, countries, and journals, as well as research hotspots and trends in this important field. To identify and further visualize the cooperation and comprehend the development and trends of PTEN in the nervous system, especially in neural development and neurological diseases, we used a bibliometric analysis to identify relevant publications on this topic. We first found that the number of publications displayed a growing trend with time, but this was not stable. Universities, institutions, and authors from the United States are leading in this area of research. In addition, many cutting-edge research results have been discovered, such as key regulatory molecules and cellular mechanisms of PTEN in the nervous system, which may provide novel intervention targets and precise therapeutic strategies for related pathological injuries and diseases. Finally, the literature published within the last 5 years is discussed to identify future research trends regarding PTEN in the nervous system. Taken together, our findings, analysed using bibliometrics, may reflect research hotspots and trends, providing a reference for studying PTEN in the nervous system, especially in neural development and neurological diseases. These findings can assist new researchers in developing their research interests and gaining basic information. Moreover, our findings also may provide precise clinical guidelines and strategies for treating nervous system injuries and diseases caused by PTEN dysfunction.