mTOR Research Articles

Nutritional quality regulates postnatal wing morph in pea aphids

Aphids can produce winged or wingless offspring in response to environmental changes. Host nutrition is one of the extensively studied environmental factors influencing the plasticity of wing morphs of aphids. In this study, we found that the pea aphid, Acyrthosiphon pisum, produced a low proportion of winged offspring when fed on plants, but a significantly higher proportion on the artificial diet. Interestingly, when newly born nymphs were transferred back to the artificial diet after feeding on plants for six hours or longer, most nymphs became wingless. These results suggest that the wing morph state of pea aphids can change postnatally, potentially determined by the nutritional quality of their food. Furthermore, aphids feeding on the artificial diet exhibited higher levels of glucose and stronger insulin signaling activity compared with aphids on plants. Conversely, the amino acid levels were lower, and TOR signaling was weaker in aphids fed on the artificial diet. Insulin and the target of rapamycin (TOR) are the primary nutrient-sensing signaling pathways involved in controlling organism growth and have been implicated in regulating aphid wing morph plasticity. We tested whether these nutrient responsive pathways were involved in postanal wing determination of aphids. However, reducing amino acid content in the diet or inhibiting TOR with rapamycin resulted in a decrease of the winged morph, suggesting that the lower amino acid levels or TOR activity was not responsible for the higher proportion of winged morph on the artificial diet. These results suggest that nutritional quality, particularly sugars like sucrose and glucose, may regulate the postnatal wing morph of the pea aphid, likely via the insulin signaling pathway.

Investigation of Ginseng-Ophiopogon Injection on Enhancing Physical Function by Pharmacogenomics and Metabolomics Evaluation.

Ginseng-ophiopogon injection (GOI) is a clinically commonly used drug for Qi deficiency syndrome characterized by decreased physical function in China. This study aimed to clarify common pharmacological mechanisms of GOI in enhancing physical function. We performed an integrative strategy of weight-loaded swimming tests in cold water (5.5 °C), hepatic glycogen and superoxide dismutase (SOD) detections, GC-TOF/MS-based metabolomics, multivariate statistical techniques, network pharmacology of known targets and constituents, and KEGG pathway analysis of GOI. Compared with the control group, GOI showed significant increases in the weightloaded swimming time, hepatic levels of glycogen and SOD. Additionally, 34 significantly differential serum metabolites referred to glycolysis, gluconeogenesis and arginine biosynthesis were affected by GOI. The target collection revealed 98 metabolic targets and 50 experimentreported drug targets of ingredients in GOI involved in enhancing physical function. Further, the PPI network analysis revealed that 8 ingredients of GOI, such as ginsenoside Re, ginsenoside Rf, ginsenoside Rg1, and notoginsenoside R1, were well-associated with 48 hub targets, which had good ability in enhancing physical function. Meanwhile, nine hub proteins, such as SOD, mechanistic target of Rapamycin (mTOR), and nitric oxide synthases, were confirmed to be affected by GOI. Finally, 98 enriched KEGG pathways (P<0.01 and FDR<0.001) of GOI were obtained from 48 hub targets of the PPI network. Among them, pathways in cancer, Chagas disease, lipid and atherosclerosis, and PI3K-Akt signaling pathway ranked top four. This study provided an integrative and efficient approach to understanding the molecular mechanism of GOI in enhancing physical function.

Involvement of everolimus‑induced ABCB1 downregulation in drug‑drug interactions.

Everolimus is an oral mammalian target of rapamycin (mTOR) inhibitor used in cancer chemotherapy and transplantation. Due to its therapeutic properties, everolimus has been used long-term in clinical practice. Drug interactions with everolimus during gastrointestinal absorption can alter the oral bioavailability of everolimus and/or concomitant drugs. However, the effects of everolimus on gastrointestinal absorption remain unknown. The present study assessed the impact of continuous exposure to everolimus on expression and function of the ATP-binding cassette (ABC) transporter ABCB1 and ABCG2 using a Caco-2 intestinal cell model. Caco-2 subline, Caco/EV, was established by continuously exposing Caco-2 cells to 1 µM everolimus. Cell viability was evaluated using WST-1 assay. mRNA levels were measured by reverse transcription-quantitative PCR. Transport activity of ABCB1 was evaluated through the cellular accumulation of Rhodamin 123, a substrate for ABCB1. The half-maximal inhibitory concentration (IC50) values for everolimus in Caco-2 and Caco/EV cells were 0.31 and 4.33 µM, respectively, indicating 14-fold resistance in Caco/EV cells. Sensitivity to paclitaxel and 7-ethyl-10-hydroxycamptothecin, which are substrates for ABCB1 and ABCG2, respectively, was enhanced in Caco/EV, but not in Caco-2 cells. The IC50 values of cisplatin were comparable in both cell lines. Furthermore, mRNA expression levels of ABCB1 and ABCG2 were lower in Caco/EV cells than in Caco-2 cells, and the cellular accumulation of Rhodamine 123 was significantly higher in Caco/EV cells. These findings demonstrated that continuous exposure to everolimus suppressed the expression and function of ABCB1 and ABCG2, suggesting potential drug-drug interactions via the suppression of ABCB1 and ABCG2 in the intestinal tract.

The Favorable impact of everolimus on Chronic lung allograft dysfunction in lung transplant recipients

Standard immunosuppressive therapy for lung transplant recipients combines a calcineurin inhibitor, an antimetabolite, and corticosteroids. In an observational, retrospective, monocentric study, we sought to compare the development of chronic lung allograft dysfunction (CLAD) between 37 patients who received this standard therapy (triple-therapy group) and 59 patients who received the mammalian target of rapamycin (mTOR) inhibitor everolimus in addition to the standard therapy (quadruple-therapy group). In the quadruple-therapy group, the time elapsed from transplantation to everolimus introduction (median [25th-75th percentile]) was 12 [7–25] months. In 46/59 cases, the indication for everolimus introduction was renal function sparing. Median follow-up durations were 36 [20–62] months and 84 [52–123] months in the triple-therapy and quadruple-therapy groups, respectively (p = 0.004). The incidence of CLAD was lower in patients receiving everolimus than in those who did not with an adjusted odds ratio of 0.303 [0.118–0.775]. In addition, the median time from transplantation to CLAD was longer in patients receiving quadruple therapy comprising everolimus than in those who did not (63 [30–92] vs. 29 [12–44] months; p = 0.025). This suggests that the addition of everolimus to a standard triple could result in a lower incidence of CLAD in lung transplant recipients.

Targeting ferroptosis with polymerized platinum (IV) prodrugs nanoparticles with everolimus for enhancing therapeutic efficacy on cholangiocarcinoma

Strategies to induce ferroptosis in tumor cells have been widely adopted for the treatment of cancer. Traditional single-target ferroptosis inducers, however, have shown limited efficacy. Tumor cells often counteract these drugs through mechanisms by high levels of glutathione (GSH) detoxification of lipid peroxidases. To address these challenges, we have developed a GSH-responsive amphiphilic polymer with polymerized platinum(IV) prodrugs (Poly-CisPt (IV)), capable of encapsulating everolimus (a mTORC1 inhibitor) into nanoparticles (NP@Ev). This strategy facilitates the concurrent depletion of GSH and the release of cisplatin and everolimus. On the one hand, the released cisplatin simultaneously induces cell apoptosis and impairs the GPX4 enzyme. On the other hand, everolimus disrupts the mTOR signaling pathway, inhibiting tumor cell proliferation and inducing the production of reactive oxygen species (ROS) and lipid peroxides, which leads to mitochondrial dysfunction and ferroptosis. Our study indicated that NP@Ev effectively induced ferroptosis and significantly inhibited the progression of human cholangiocarcinoma in murine models, with limited toxicity. These findings underscore the potential of NP@Ev as a promising avenue for the clinical multimodal treatment of cholangiocarcinoma.

Astaxanthin‐S‐Allyl Cysteine Ester Protects Pancreatic β‐Cell From Glucolipotoxicity by Suppressing Oxidative Stress, Endoplasmic Reticulum Stress and mTOR Pathway Dysregulation

ABSTRACTGlucolipotoxicity (GLT) has emerged as established mechanism in the progression of diabetes. Identifying compounds that mitigate GLT‐induced deleterious effect on β‐cells are considered important strategy to overcome diabetes. Hence, in the present study, astaxanthin‐s‐allyl cysteine (AST‐SAC) diester was studied against GLT in β‐cells. Mus musculus pancreatic β‐cell line (βTC‐tet) was treated with high glucose (25 mM; HG) and 95 μM palmitate (PA) for 24 h to induce GLT. AST‐SAC at various concentrations (5, 10, and 15 μg/ml) were treated to understand the protective effect against HG + PA exposure in β‐cells. Under HG + PA exposure conditions oxidative stress, deregulation of mTOR pathway and endoplasmic reticulum (ER) stress are witnessed. AST‐SAC treatment eased oxidative stress, mitochondrial depolarization, DNA damage, calcium overload and accumulation of autophagosome against HG + PA exposure conditions thereby protected the cell viability of β‐cells. AST‐SAC maintained the level of proteins involved in mTOR pathway under HG + PA exposure conditions. Also, AST‐SAC treatment has mitigated the increased expression of genes and proteins such as IRE1 and PERK involved in ER stress‐mediated unfolded protein response (UPR) signaling pathways. In correspondence to it, the expression of genes involved in insulin secretion was preserved by AST‐SAC. Due to these protective effects of AST‐SAC the insulin secretion was well‐maintained in β‐cells under HG + PA exposure conditions. AST‐SAC through normalizing antioxidant status and mTOR axis as well as preventing the harmful effect of ER‐stress mediated UPR pathway has promoted the β‐cell survival and insulin secretion against GLT. Simultaneously targeting oxidative stress/mTOR axis/ER stress is required to efficiently overcome GLT in β‐cells.

Aflatoxin Exposure-Caused Male Reproductive Toxicity: Molecular Mechanisms, Detoxification, and Future Directions

Widespread endocrine disorders and infertility caused by environmental and food pollutants have drawn considerable global attention. Aflatoxins (AFTs), a prominent class of mycotoxins, are recognized as one of the key contributors to environmental and food contamination. Aflatoxin B1 (AFB1) is the most potent and toxic pollutant among them and is known to cause multiple toxic effects, including neuro-, nephro-, hepato-, immune-, and genotoxicity. Recently, concerns have been raised regarding AFB1-induced infertility in both animals and humans. Exposure to AFB1 can disrupt the structure and functionality of reproductive organs, leading to gametogenesis impairment in males, subsequently reducing fertility. The potential molecular mechanisms have been demonstrated to involve oxidative stress, cell cycle arrest, apoptosis, inflammatory responses, and autophagy. Furthermore, several signaling pathways, including nuclear factor erythroid 2-related factor 2; NOD-, LRR-, and pyrin domain-containing protein 3; nuclear factor kappa-B; p53; p21; phosphoinositide 3-kinase/protein kinase B; the mammalian target of rapamycin; adenosine 5′-monophosphate-activated protein kinase; and mitochondrial apoptotic pathways, are implicated in these processes. Various interventions, including the use of small molecules, Chinese herbal extracts, probiotic supplementation, and camel milk, have shown efficacy in ameliorating AFB1-induced male reproductive toxicity, by targeting these signaling pathways. This review provides a comprehensive summary of the harmful impacts of AFB1 exposure on male reproductive organs in mammals, highlighting the potential molecular mechanisms and protective agents.

L-arginine Supplementation in Endurance Athletes: A Systematic Review of Recovery Mechanisms and Performance Enhancement

L-arginine, a semi-essential amino acid, has garnered significant attention for its potential to enhance athletic performance, particularly within endurance sports. Recognized for its multifaceted roles in cardiovascular, immune, and metabolic functions, L-arginine serves as a precursor to biologically active molecules, including nitric oxide (NO), creatine, and polyamines, which are integral to muscle function and recovery. Through its ability to stimulate NO production, L-arginine promotes vasodilation, enhancing blood flow and oxygen delivery to active muscles, thereby improving exercise efficiency and endurance. Additionally, L-arginine influences muscle protein synthesis (MPS) via activation of the mTOR signaling pathway, aids in ammonia detoxification within the urea cycle, and supports cellular energetics by facilitating ATP production. These mechanisms collectively underscore its potential to support prolonged physical exertion, reduce muscle fatigue, and expedite post-exercise recovery. This systematic review examines current evidence on L-arginine supplementation in endurance athletes, focusing on its physiological impacts, mechanisms of action, and potential to enhance recovery and performance. Despite promising findings, variability in individual responses and mixed results across studies highlight the need for refined dosing strategies and further research into long-term safety and efficacy. This review provides a comprehensive overview of L-arginine's potential as a supplement in sports nutrition, aiming to inform evidence-based recommendations for its application in endurance training and recovery strategies.

Activation of the mTOR pathway enhances PPARγ/SREBP-mediated lipid synthesis in human meibomian gland epithelial cells.

The involvement of the mechanistic targets of rapamycin (mTOR) pathway in lipid metabolism has been recently elucidated. However, its specific role in the Meibomian gland, where lipid metabolism is significant, remains not fully understood. We investigated the role of mTOR signaling system in the lipogenesis and differentiation of human meibomian gland epithelial cells (HMGECs). Treatment of HMGECs with rapamycin resulted in a reduction in lipid synthesis and the expression of PPARγ and SREBP-1, the major regulators of lipid synthesis. The phosphorylation of p70S6kinase and AKT, which are downstream signals of mTOR complexes 1 and 2, respectively, decreased following rapamycin treatment. In addition, when both mTOR complex 1 and 2 were suppressed using siRNA, there was a significant reduction in the expression of PPARγ and SREBP-1, along with a decrease in lipid synthesis in HMGECs. Our findings suggest that inhibiting the mTOR pathway diminishes the differentiation and adipogenesis of meibomian gland epithelial cells, and both mTOR complexes 1 and 2 appear to play a role in this activity.

Whole-exome sequencing reveals novel genomic signatures and potential therapeutic targets during the progression of rectal neuroendocrine neoplasm.

Rectal neuroendocrine neoplasms (rNENs) are among the most frequent gastrointestinal neuroendocrine neoplasms and pose a serious challenge for clinical management. The size of the primary neoplasm is considered to be the most important predictor of disease progression, but the genetic alterations that occur during the progression of rNENs remain unknown. Here, we performed a comprehensive whole-exome sequencing study on 54 tumor-normal paired, formalin-fixed paraffin-embedded specimens from patients locally diagnosed with rNENs. Of these, 81.5% (n = 44) were classified as small-sized (≤2 cm) rNENs, while the remainder (18.5%, n = 10) were classified as large-sized (>2 cm) rNEN samples. Comparative analysis revealed marked disparities in the mutational landscape between small- and large-sized rNEN samples, and between large-sized rNEN samples with or without lymph node metastases. The high-confidence driver genes RHPN2, MUC16, and MUC4 were significantly mutated in both small- and large-sized rNEN specimens, whereas mutations in MAN2A1, and BAG2 were only identified in large-sized specimens diagnosed with lymph node metastases. Correspondingly, we observed that the mTOR and MAPK pathways were preferentially enriched in the large-sized rNEN specimens. Signature-based analysis revealed that mutational processes associated with defective DNA base excision repair (SBS30) significantly accumulated in large-sized rNEN samples with lymph node metastases, highlighting the important role of this mutagenic process in promoting rNEN progression. We further found that most rNEN subjects, regardless of tumor size, harbored at least one alteration with targeted therapeutic implications. Taken together, these results elucidate the genetic features associated with tumor size and lymphatic metastasis in rNEN patients, which will deepen our understanding of the genetic changes during rNEN progression and potentially directing improvements in rNEN treatment strategies.

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A chemical investigation of the deep‐sea‐derived fungus Penicillium allii‐sativi resulted in the discovery of four new (1—4) and one known (5) meroterpenoids. Compound 3 significantly blocked the mTOR signaling pathway, resulting in the arrest of cell cycle at G0‐G1 phase and triggering mitochondrial apoptosis in Hela cells. While macrophorin A effectively triggered cell death in MDA‐MB‐231 cancer cells by activating apoptosis pathways involving death receptors, mitochondria, mTOR, and TNF. More details are discussed in the article by Yang et al. on pages 3283—3292. image

Succinylation modification-mediated upregulation of Sp1 promotes hepatocellular carcinoma cell proliferation.

Hepatocellular carcinoma (HCC) remains one of the most prevalent malignant tumors globally, characterized by high incidence and mortality rates. Despite ongoing research, the underlying molecular mechanisms of HCC development are not yet fully understood. Utilizing bioinformatic analysis, real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), and Western blot assays, we identified that the expression of specificity protein 1 (Sp1) was significantly elevated in HCC cells compared to normal cells. Knockdown of the Sp1 gene led to a marked reduction in the viability and clonogenic potential of HCC cells. Further investigation revealed that the succinylation level of Sp1 was also increased in HCC cells. The upregulation of Sp1 expression was attributed to its succinylation, mediated by KAT2A, with lysine (K)562 identified as the succinylation site. Additionally, KAT2A and Sp1 were found to influence the upregulation of mTOR phosphorylation. Collectively, these findings suggest that KAT2A-promoted succinylation of Sp1 enhances the proliferative capacity of HCC cells by activating the mTOR pathway, providing a theoretical foundation for potential therapeutic strategies against HCC.

Targeting the mTOR-Autophagy Axis: Unveiling Therapeutic Potentials in Osteoporosis

Osteoporosis (OP) is a widespread age-related disorder marked by decreased bone density and increased fracture risk, presenting a significant public health challenge. Central to the development and progression of OP is the dysregulation of the mechanistic target of the rapamycin (mTOR)-signaling pathway, which plays a critical role in cellular processes including autophagy, growth, and proliferation. The mTOR-autophagy axis is emerging as a promising therapeutic target due to its regulatory capacity in bone metabolism and homeostasis. This review aims to (1) elucidate the role of mTOR signaling in bone metabolism and its dysregulation in OP, (2) explore the interplay between mTOR and autophagy in the context of bone cell activity, and (3) assess the therapeutic potential of targeting the mTOR pathway with modulators as innovative strategies for OP treatment. By examining the interactions among autophagy, mTOR, and OP, including insights from various types of OP and the impact on different bone cells, this review underscores the complexity of mTOR’s role in bone health. Despite advances, significant gaps remain in understanding the detailed mechanisms of mTOR’s effects on autophagy and bone cell function, highlighting the need for comprehensive clinical trials to establish the efficacy and safety of mTOR inhibitors in OP management. Future research directions include clarifying mTOR’s molecular interactions with bone metabolism and investigating the combined benefits of mTOR modulation with other therapeutic approaches. Addressing these challenges is crucial for developing more effective treatments and improving outcomes for individuals with OP, thereby unveiling the therapeutic potentials of targeting the mTOR-autophagy axis in this prevalent disease.

Neuregulin 4 attenuates pancreatic β-cell apoptosis induced by lipotoxicity via activating mTOR-mediated autophagy

ABSTRACT Neuregulin 4 (Nrg4) is a brown fat-enriched endocrine factor that ameliorates lipid metabolism disorders. Autophagy is critical for pancreatic β-cell to counteract lipotoxicity-induced apoptosis. This study aimed at exploring whether Nrg4 attenuates lipotoxicity-induced β-cell apoptosis by regulating autophagy. The mouse pancreatic β-cell line MIN6 was cultured in palmitic acid (PA) with or without Nrg4 administration. Apoptosis rate, together with anti-apoptotic and pro-apoptotic protein levels, was investigated. Autophagic flux and autophagy-related protein levels along with related signaling pathways that regulate autophagy were also evaluated. Results showed that Nrg4 decreased PA-induced MIN6 apoptosis, enhanced anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) expression and reduced pro-apoptotic proteins Bcl-2-associated X protein (Bax) and cleaved-caspase 3 expressions. Autophagy levels in MIN6 also decreased with PA treatment and Nrg4 administration reactivated autophagy. Further, Nrg4 administration activated autophagy via the mammalian target of rapamycin (mTOR) signaling pathway. In addition, when the mTOR pathway was stimulated or autophagy was suppressed, the beneficial effects of Nrg4 administration on MIN6 apoptosis were diminished. These results imply that Nrg4 administration attenuates MIN6 apoptosis by promoting mTOR-dependent autophagy and thus may lead to a new therapeutic method for type 2 diabetes mellitus (T2DM).

The apoptotic and anti-proliferative effects of Neosetophomone B in T-cell acute lymphoblastic leukaemia via PI3K/AKT/mTOR pathway inhibition.

The phosphatidylinositol 3-kinase/Protein Kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling pathway is pivotal in various cancers, including T-cell acute lymphoblastic leukaemia (T-ALL), a particularly aggressive type of leukaemia. This study investigates the effects of Neosetophomone B (NSP-B), a meroterpenoid fungal metabolite, on T-ALL cell lines, focusing on its anti-cancer mechanisms and therapeutic potential. NSP-B significantly inhibited the proliferation of T-ALL cells by inducing G0/G1 cell cycle arrest and promoting caspase-dependent apoptosis. Additionally, NSP-B led to the dephosphorylation and subsequent inactivation of the PI3K/AKT/mTOR signalling pathway, a critical pathway in cell survival and growth. Molecular docking studies revealed a strong binding affinity of NSP-B to the active site of AKT, primarily involving key residues crucial for its activity. Interestingly, NSP-B treatment also induced apoptosis and significantly reduced proliferation in phytohemagglutinin-activated primary human CD3+ T cells, accompanied by a G0/G1 cell cycle arrest. Importantly, NSP-B did not affect normal primary T cells, indicating a degree of selectivity in its action, targeting only T-ALL cells and activated T cells. In conclusion, our findings highlight the potential of NSP-B as a novel therapeutic agent for T-ALL, specifically targeting the aberrantly activated PI3K/AKT/mTOR pathway and being selective in action. These results provide a strong basis for further investigation into NSP-B's anti-cancer properties and potential application in T-ALL clinical therapies.

Epimedium polysaccharides ameliorate ulcerative colitis by inhibiting oxidative stress and regulating autophagy.

Epimedium polysaccharide (EPS) is a bioactive compound derived from the traditional Chinese herb Epimedium brevicornum. The objective of this study was to investigate the protective effects of EPS on ulcerative colitis (UC) and to elucidate the underlying mechanisms involved. The findings showed that EPS treatment mitigated UC symptoms, including weight loss, anal bleeding, elevated disease activity index (DAI), and colon shortening. Hematoxylin and eosin (H&E) and Alcian blue-periodic acid-Schiff (AB-PAS) staining demonstrated that EPS alleviated histopathological damage and improved the integrity of the colonic mucosa. Mechanistically, EPS was found to substantially decrease inflammation by inhibiting the Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling pathway and to alleviate oxidative stress through modulation of the Kelch-like ECH-associated protein 1/nuclear factor erythroid-derived 2-like 2 (Keap1/Nrf2) pathway. Notably, EPS failed to exert protective effects against dextran sulfate sodium (DSS)-induced UC in Nrf2-knockout (Nrf2-/-) mice. Additionally, Western blotting and immunohistochemical analysis demonstrated that EPS facilitated autophagy via the adenosine monophosphate-dependent protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathway. In vitro experiments revealed that EPS effectively suppressed lipopolysaccharide (LPS)-mediated cellular damage and oxidative stress by regulating Keap1/Nrf2 pathway. Transcriptomic analysis of LPS-treated Caco-2 cells following EPS treatment revealed a significant up-regulation of Nrf2 expression. In conclusion, the findings of this study suggest that EPS exerts protective effects against DSS-induced UC through the inhibition of the TLR4/NF-κB signaling pathway, regulation of the Keap1/Nrf2 pathway, and promotion of autophagy via the AMPK/mTOR pathway. Consequently, EPS may represent a potential therapeutic target for the treatment of UC. © 2024 Society of Chemical Industry.

PLAC1 augments the malignant phenotype of cervical cancer through the mTOR/HIF-1α/snail signaling pathway.

This study investigated the molecular mechanisms of placenta-specific protein 1 (PLAC1) in cervical cancer (CCa), aiming to elucidate its role in tumorigenesis through in vitro and in vivo experiments. CCa cell lines with overexpressed or silenced PLAC1 were established to evaluate its impact on cell cycle, apoptosis and the expression of key proteins in the PLAC1/mTOR/HIF-1α/Snail signaling pathways. Functional assays were conducted to assess the influence of the PLAC1/mTOR/HIF-1α/Snail regulatory pathway on cell proliferation, migration and invasion. The role of the mTOR signaling pathway in PLAC1-mediated modulation of CCa characteristics was validated using a mTOR activator (MHY1485) and a mTOR inhibitor (Rapamycin) respectively. HIF1A siRNA was introduced to confirm the role of HIF1A. Furthermore, an in vivo nude mouse model was constructed to confirm PLAC1's influence on tumorigenesis and metastasis in CCa. PLAC1 upregulated hypoxia-inducible factor (HIF)-1α and Snail, promoting CCa cell proliferation, migration, and invasion via the mTOR/HIF-1α/Snail pathway. Enrichment analysis of PLAC1-associated differentially expressed genes implicated their involvement in CCa and tumor promotion. In a xenograft mouse model, PLAC1 exhibited a pro-tumorigenic effect, which can be reversed by siRNA targeting HIF1A. This study enhances our understanding of PLAC1's role and molecular mechanisms in CCa progression, highlighting its potential as a diagnostic, prognostic, and therapeutic marker for the management of CCa.

Analysis of hsa_circ_0136256 as a biomarker for fibrosis in systemic sclerosis.

Exploration of whether circRNAs in the skin of systemic sclerosis (SSc) model mice interact with 4E-BP1 protein to mediate the mTOR signaling pathway to regulate SSc fibrosis is crucial to identify homologous human circRNAs as markers to guide the diagnosis and treatment of SSc. C57BL/6 mice aged 6-8 weeks and weighing approximately 20 g were subcutaneously injected with bleomycin (BLM) to establish an SSc model. High-throughput sequencing was used to screen the differentially expressed circRNA in the skin of SSc model mice and control mice. RNA immunoprecipitation and RNA pulldown confirmed the interaction between circRNA and 4E-BP1 protein. SSc model mice were treated with empty plasmid (OE-NC), overexpression plasmid of mmu_circ_0005372 (OE-circ_0005372), interference plasmid of mmu_circ_0005372 (sh-circ5372), mutant plasmid of mmu_circ_0005372 (circ5372-MT), mTOR activator (MHY1485), mTOR inhibitor (omipalisib), or JAK1/2 inhibitor (ruxolitinib). Sections of mouse skin tissue were stained with Hematoxylin and eosin and Masson's stain. The collagen volume fraction (CVF) was calculated as CVF = area of blue collagen/total area with ImageJ. The correlation between homologous human circRNAs and clinical data was analyzed. Compared to the control group, 21,839 circRNAs were upregulated and 27, 946 circRNAs were downregulated in the skin tissue of mice in the SSc model group. Among them was mmu_circ_0005372, which is derived from the FZD3 gene, is closely related to fibrosis, and is involved in the mTOR signaling pathway. Hsa_circ_0136256 was identified as the homologous human circRNA of mmu_circ_0005372. RT-qPCR confirmed that the expression of mmu_circ_0005372 was significantly reduced in the skin tissue of SSc mice, and the expression of hsa_circ_0136256 was significantly reduced in the peripheral blood mononuclear cells of patients with SSc. The interaction between mmu_circ_0005372 and 4E-BP1 protein was inhibited in the skin tissue of SSc model mice. The results showed that the CVF of OE-circ_0005372 group was significantly lower than that of the sh-circ5372, circ5372-MT, and MHY1485 groups, indicating that OE-circ5372 significantly improved skin fibrosis in the SSc mice. ROC curve analysis was performed on hsa_circ_0136256 (AUC = 0.719, P = 0.035). The expression of hsa_circ_0136256 was negatively correlated with COL IV, RDW-SD, and RDW-CV, and positively correlated with VC, PLT, and PCT. The results suggested that hsa_circ_0136256 may have important roles in the clinical diagnosis of SSc. Mmu_circ_0005372 and homologous human hsa_circ_0136256 may be biomarkers and therapeutic targets for SSc fibrosis.

Exosomes derived from IFNγ-stimulated mesenchymal stem cells protect photoreceptors in RCS rats by restoring immune homeostasis through tsRNAs.

Retinitis pigmentosa is a neurodegenerative disease with major pathologies of photoreceptor apoptosis and immune imbalance. Mesenchymal stem cells (MSCs) have been approved for clinical application for treating various immune-related or neurodegenerative diseases. The objective of this research was to investigate the mechanisms underlying the safeguarding effects of MSC-derived exosomes in a retinal degenerative disease model. Interferon gamma-stimulated exosomes (IFNγ-Exos) secreted from MSCs were isolated, purified, and injected into the vitreous body of RCS rats on postnatal day (P) 21. Morphological and functional changes in the retina were examined at P28, P35, P42, and P49 in Royal College of Surgeons (RCS) rats. The mechanism was explored using high-throughput sequencing technology and confirmed in vitro. Treatment with IFNγ-Exo produced better protective effects on photoreceptors and improved visual function in RCS rats. IFNγ-Exo significantly suppressed the activated microglia and inhibited the inflammatory responses in the retina of RCS rats, which was also confirmed in the lipopolysaccharide-activated microglia cell line BV2. Furthermore, through tRNA-derived small RNA (tsRNA) sequencing, we found that IFNγ-Exos from MSCs contained higher levels of Other-1_17-tRNA-Phe-GAA-1-M3, Other-6_23-tRNA-Lys-TTT-3, and TRF-57:75-GLN-CGG-2-m2 than native exosomes, which mainly regulated inflammatory and immune-related pathways, including the mTOR signaling pathway and EGFR tyrosine kinase inhibitor resistance. IFNγ stimulation enhanced the neuroprotective effects of MSC-derived exosomes on photoreceptors of the degenerative retina, which may be mediated by immune regulatory tsRNAs acting on microglia. In conclusion, IFNγ-Exo is a promising nanotherapeutic agent for the treatment of retinitis pigmentosa.

Phosphatidic acid directly activates mTOR and then regulates SREBP to promote ganoderic acid biosynthesis under heat stress in Ganoderma lingzhi.

Ganoderic acids (GAs), a class of secondary metabolites produced by the traditional medicinal mushroom Ganoderma, are a group of triterpenoids with superior biological activities. Heat stress (HS) is one of the most important environmental abiotic stresses. Understanding how organisms sense temperature and integrate this information into their metabolism is important for determining how organisms adapt to climate change and for applying this knowledge to breeding. We previously reported that HS induced GA biosynthesis, and phospholipase D (PLD)-mediated phosphatidic acid (PA) was involved in HS-induced GA biosynthesis. We screened a proteome to identify the PA-binding proteins in G. lingzhi. We reported that PA directly interacted with mTOR and positively correlated with the ability of mTOR to promote GA biosynthesis under HS. The PA-activated mTOR pathway promoted the processing of the transcription factor sterol regulatory element-binding protein (SREBP) under HS, which directly activated GA biosynthesis. Our results suggest that SREBP is an intermediate of the PLD-mediated PA-interacting protein mTOR in HS-induced GA biosynthesis. Our report established the link between PLD-mediated PA production and the activation of mTOR and SREBP in the HS response and HS-induced secondary metabolism in filamentous fungi.