mTOR Inhibition Prolongs Survival and Has Beneficial Effects on Heart Function After Onset of Lamin A/C Gene Mutation Cardiomyopathy in Mice.

BACKGROUND: Mutations in LMNA encoding nuclear envelope proteins lamin A/C cause dilated cardiomyopathy. Activation of the AKT/mTOR (RAC-α serine/threonine-protein kinase/mammalian target of rapamycin) pathway is implicated as a potential pathophysiologic mechanism. The aim of this study was to assess whether pharmacological inhibition of mTOR signaling has beneficial effects on heart function and prolongs survival in a mouse model of the disease, after onset of heart failure. METHODS: We treated male LmnaH222P/H222P mice, after the onset of heart failure, with placebo or either of 2 orally bioavailable mTOR inhibitors: everolimus or NV-20494, a rapamycin analog highly selective against mTORC1. We examined left ventricular remodeling, and the cell biological, biochemical, and histopathologic features of cardiomyopathy, potential drug toxicity, and survival. RESULTS: Everolimus treatment (n=17) significantly reduced left ventricular dilatation and increased contractility on echocardiography, with a 7% (P=0.018) reduction in left ventricular end-diastolic diameter and a 39% (P=0.0159) increase fractional shortening compared with placebo (n=17) after 6 weeks of treatment. NV-20494 treatment (n=15) yielded similar but more modest and nonsignificant changes. Neither drug prevented the development of cardiac fibrosis. Drug treatment reactivated suppressed autophagy and inhibited mTORC1 signaling in the heart, although everolimus was more potent. With regards to drug toxicity, everolimus alone led to a modest degree of glucose intolerance during glucose challenge. Everolimus (n=20) and NV-20494 (n=20) significantly prolonged median survival in LmnaH222P/H222P mice, by 9% (P=0.0348) and 11% (P=0.0206), respectively, compared with placebo (n=20). CONCLUSIONS: These results suggest that mTOR inhibitors may be beneficial in patients with cardiomyopathy caused by LMNA mutations and that further study is warranted.

A potential strategy for bladder cancer treatment: inhibiting autophagy to enhance antitumor effects of Nectin-4-MMAE.

Research and development on Nectin-4 antibody-drug conjugates (ADC) have been greatly accelerated since the approval of enfortumab vedotin to treat uroepithelial cancer. During the course of this study, we identified that autophagy serves as a cytoprotective mechanism during Nectin-4-MMAE treatment and proposed a strategy to enhance the antitumor effects of Nectin-4-MMAE in bladder cancer. Nectin-4-MMAE rapidly internalized into bladder cancer cells in 30 minutes and released MMAE, inducing the onset of caspase-mediated apoptosis and leading to the inhibition of tumor cell growth. Transcriptomics showed significant alterations in autophagy-associated genes in bladder cancer cells treated with Nectin-4-MMAE, which suggested autophagy was activated by Nectin-4-MMAE. Furthermore, autophagy activation was characterized by ultrastructural analysis of autophagosome accumulation, immunofluorescence of autophagic flux, and immunoblotting autophagy marker proteins SQSTM1 and LC3 I/II. Importantly, inhibiting autophagy by LY294002 and chloroquine significantly enhances the cytotoxicity effects of Nectin-4-MMAE in bladder cancer cells. Additionally, we detected the participation of the AKT/mTOR signaling cascade in the induction of autophagy by Nectin-4-MMAE. The combination of Nectin-4-MMAE and an autophagy inhibitor demonstrated enhanced antitumor effects in the HT1376 xenograft tumor model. After receiving a single dose of Nectin-4-MMAE, the group that received the combination treatment showed a significant decrease in tumor size compared to the group that received only one type of treatment. Notably, one mouse in the combination treatment group achieved complete remission of the tumor. The combination group exhibited a notable rise in apoptosis and necrosis, as indicated by H&E staining and immunohistochemistry (cleaved caspase-3, ki67). These findings demonstrated the cytoprotective role of autophagy during Nectin-4-MMAE treatment and highlighted the potential of combining Nectin-4-MMAE with autophagy inhibitors for bladder cancer treatment.

Improvement of diabetes-induced spinal cord axon injury with taurine via nerve growth factor-dependent Akt/mTOR pathway.

Diabetic neuropathy (DN) is a common neurological complication caused by diabetes mellitus (DM). Axonal degeneration is generally accepted to be the major pathological change in peripheral DN. Taurine has been evidenced to be neuroprotective in various aspects, but its effect on spinal cord axon injury (SCAI) in DN remains barely reported. This study showed that taurine significantly ameliorated axonal damage of spinal cord (SC), based on morphological and functional analyses, in a rat model of DN induced by streptozotocin (STZ). Taurine was also found to induce neurite outgrowth in cultured cerebral cortex neurons with high glucose exposure. Moreover, taurine up-regulated the expression of nerve growth factor (NGF) and neurite outgrowth relative protein GAP-43 in rat DN model and cultured cortical neurons/VSC4.1 cells. Besides, taurine increased the activating phosphorylation signals of TrkA, Akt, and mTOR. Mechanistically, the neuroprotection by taurine was related to the NGF-pAKT-mTOR axis, because either NGF-neutralizing antibody or Akt or mTOR inhibitors was found to attenuate its beneficial effects. Together, our results demonstrated that taurine promotes spinal cord axon repair in a model of SCAI in STZ-induced diabetic rats, mechanistically associating with the NGF-dependent activation of Akt/mTOR pathway.

Astragaloside-IV promotes autophagy via the Akt/mTOR pathway to improve cellular lipid deposition.

The current study aimed to investigate the potential role of astragaloside IV (AS-IV) in improving cellular lipid deposition and its underlying mechanism. A fatty liver cell model was established by treating hepatoma cells with palmitic acid. AS-IV and SC79 were used for treatment. Oil Red O staining was applied to detect intracellular lipid deposition, and transmission electron microscopy was utilized to assess autophagosome formation. Immunofluorescence double staining was applied to determine microtubule-associated proteins 1A/1B light chain 3 (LC3) expression. Western blot analysis was performed to detect the expression of LC3, prostacyclin, Beclin-1, V-akt murine thymoma viral oncogene homolog (Akt), phosphorylated Akt, mTOR, and phosphorylated mTOR. Oil Red O staining revealed that AS-IV reduced intracellular lipid accumulation. Further, it increased autophagosome synthesis and the expression of autophagy proteins LC3 and Beclin-1 in the cells. It also reduced the phosphorylation levels of Akt and mTOR and the levels of prostacyclin. However, the effects of AS-IV decreased with SC79 treatment. In addition, LC3B + BODIPY493/503 fluorescence double staining showed that AS-IV reduced intracellular lipid deposition levels by enhancing autophagy. AS-IV can reduce lipid aggregation in fatty liver cells, which can be related to enhanced hepatocyte autophagy by inhibiting the Akt/mTOR signaling pathway.

mTOR signaling pathway regulation HIF-1 α effects on LPS induced intestinal mucosal epithelial model damage.

BACKGROUND: Sepsis-induced small-intestinal injury is associated with increased morbidity and mortality. Our previous study and other papers have shown that HIF-1α has a protective effect on intestinal mucosal injury in septic rats. The purpose of this study is to further verify the protective effect of HIF-1α on intestinal mucosa and its molecular mechanism in vitro experiments. METHODS: Caco-2 cells were selected and experiment was divided into 2 parts. Part I: HIF-1α activator and inhibitor were used to treat lipopolysacchrides (LPS)-stimulated Caco-2 cells respectively, to explore the effect of HIF-1α on LPS induced Caco-2 cell epithelial model; Part II: mTOR activator or inhibitor combined with or without HIF-1α activator, inhibitor to treat LPS-stimulated Caco-2 cells respectively, and then the molecular mechanism of HIF-1α reducing LPS induced Caco-2 cell epithelial model damage was detected. RESULTS: The results showed that HIF-1α activator decreased the permeability and up regulated tight junction (TJ) expression, while HIF-1α inhibitor had the opposite effect with the HIF-1α activator. mTOR activation increased, while mTOR inhibition decreased HIF-1α protein and expression of its downstream target molecules, which can be attenuated by HIF-1α activator or inhibitor. CONCLUSION: This study once again confirmed that HIF-1α alleviates LPS-induced mucosal epithelial model damage through P70S6K signalling pathway. It is of great value to explore whether HIF-2α plays crucial roles in the regulation of mucosal epithelial model functions in the future.

[High-intensity interval training (HIIT) induces hepatic ketone body production possibly through altering expression of mTORC1, PPARα and FGF21 in mice].

The present study aims to investigate the production of ketone body in the liver of mice after 6 weeks of high-intensity interval training (HIIT) intervention and explore the possible mechanisms. Male C57BL/6J mice (7-week-old) were randomly divided into control and HIIT groups. The control group did not engage in exercise, while the HIIT group underwent a 6-week HIIT (10° slope treadmill exercise). Changes in weight and body composition were recorded, and blood ketone body levels were measured before, immediately after, and 1 h after each HIIT exercise. After 6-week HIIT, the levels of free fatty acids in the liver and serum were detected using reagent kits, and expression levels of regulatory factors and key enzymes of ketone body production in the mouse liver were detected by Western blot and qPCR. The results showed that, the blood ketone body levels in the HIIT group significantly increased immediately after a single HIIT and 1 h after HIIT, compared with that before HIIT. The body weight of the control group gradually increased within 6 weeks, while the HIIT group mice did not show significant weight gain. After 6-week HIIT, compared with the control group, the HIIT group showed decreased body fat ratio, increased lean body weight ratio, and increased free fatty acid levels in liver and serum. Liver carnitine palmitoyl transferase-I (CPT-I), peroxisome proliferator activated receptor α (PPARα), and fibroblast growth factor 21 (FGF21) protein expression levels were up-regulated, whereas mammalian target of rapamycin complex 1 (mTORC1) protein expression level was significantly down-regulated in the HIIT group, compared with those in the control group. These results suggest that HIIT induces hepatic ketone body production through altering mTORC1, PPARα and FGF21 expression in mice.

Annexin A2 combined with TTK accelerates esophageal cancer progression via the Akt/mTOR signaling pathway.

Annexin A2 (ANXA2) is a widely reported oncogene. However, the mechanism of ANXA2 in esophageal cancer is not fully understood. In this study, we provided evidence that ANXA2 promotes the progression of esophageal squamous cell carcinoma (ESCC) through the downstream target threonine tyrosine kinase (TTK). These results are consistent with the up-regulation of ANXA2 and TTK in ESCC. In vitro experiments by knockdown and overexpression of ANXA2 revealed that ANXA2 promotes the progression of ESCC by enhancing cancer cell proliferation, migration, and invasion. Subsequently, animal models also confirmed the role of ANXA2 in promoting the proliferation and metastasis of ESCC. Mechanistically, the ANXA2/TTK complex activates the Akt/mTOR signaling pathway and accelerates epithelial-mesenchymal transition (EMT), thereby promoting the invasion and metastasis of ESCC. Furthermore, we identified that TTK overexpression can reverse the inhibition of ESCC invasion after ANXA2 knockdown. Overall, these data indicate that the combination of ANXA2 and TTK regulates the activation of the Akt/mTOR pathway and accelerates the progression of ESCC. Therefore, the ANXA2/TTK/Akt/mTOR axis is a potential therapeutic target for ESCC.

FBXO32-mediated degradation of PTEN promotes lung adenocarcinoma progression.

FBXO32, a member of the F-box protein family, is known to play both oncogenic and tumor-suppressive roles in different cancers. However, the functions and the molecular mechanisms regulated by FBXO32 in lung adenocarcinoma (LUAD) remain unclear. Here, we report that FBXO32 is overexpressed in LUAD compared with normal lung tissues, and high expression of FBXO32 correlates with poor prognosis in LUAD patients. Firstly, we observed with a series of functional experiments that FBXO32 alters the cell cycle and promotes the invasion and metastasis of LUAD cells. We further corroborate our findings using in vivo mouse models of metastasis and confirmed that FBXO32 positively regulates LUAD tumor metastasis. Using a proteomic-based approach combined with computational analyses, we found a positive correlation between FBXO32 and the PI3K/AKT/mTOR pathway, and identified PTEN as a FBXO32 interactor. More important, FBXO32 binds PTEN via its C-terminal substrate binding domain and we also validated PTEN as a bona fide FBXO32 substrate. Finally, we demonstrated that FBXO32 promotes EMT and regulates the cell cycle by targeting PTEN for proteasomal-dependent degradation. In summary, our study highlights the role of FBXO32 in promoting the PI3K/AKT/mTOR pathway via PTEN degradation, thereby fostering lung adenocarcinoma progression.

Macrophage-derived mir-100-5p orchestrates synovial proliferation and inflammation in rheumatoid arthritis through mTOR signaling.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by synovial inflammation, causing substantial disability and reducing life quality. While macrophages are widely appreciated as a master regulator in the inflammatory response of RA, the precise mechanisms underlying the regulation of proliferation and inflammation in RA-derived fibroblast-like synoviocytes (RA-FLS) remain elusive. Here, we provide extensive evidence to demonstrate that macrophage contributes to RA microenvironment remodeling by extracellular vesicles (sEVs) and downstream miR-100-5p/ mammalian target of rapamycin (mTOR) axis. RESULTS: We showed that bone marrow derived macrophage (BMDM) derived-sEVs (BMDM-sEVs) from collagen-induced arthritis (CIA) mice (cBMDM-sEVs) exhibited a notable increase in abundance compared with BMDM-sEVs from normal mice (nBMDM-sEVs). cBMDM-sEVs induced significant RA-FLS proliferation and potent inflammatory responses. Mechanistically, decreased levels of miR-100-5p were detected in cBMDM-sEVs compared with nBMDM-sEVs. miR-100-5p overexpression ameliorated RA-FLS proliferation and inflammation by targeting the mTOR pathway. Partial attenuation of the inflammatory effects induced by cBMDM-sEVs on RA-FLS was achieved through the introduction of an overexpression of miR-100-5p. CONCLUSIONS: Our work reveals the critical role of macrophages in exacerbating RA by facilitating the transfer of miR-100-5p-deficient sEVs to RA-FLS, and sheds light on novel disease mechanisms and provides potential therapeutic targets for RA interventions.

Microglial- neuronal crosstalk in chronic viral infection through mTOR, SPP1/OPN and inflammasome pathway signaling.

HIV-infection of microglia and macrophages (MMs) induces neuronal injury and chronic release of inflammatory stimuli through direct and indirect molecular pathways. A large percentage of people with HIV-associated neurologic and psychiatric co-morbidities have high levels of circulating inflammatory molecules. Microglia, given their susceptibility to HIV infection and long-lived nature, are reservoirs for persistent infection. MMs and neurons possess the molecular machinery to detect pathogen nucleic acids and proteins to activate innate immune signals. Full activation of inflammasome assembly and expression of IL-1ß requires a priming event and a second signal. Many studies have demonstrated that HIV infection alone can activate inflammasome activity. Interestingly, secreted phosphoprotein-1 (SPP1/OPN) expression is highly upregulated in the CNS of people infected with HIV and neurologic dysfunction. Interestingly, all evidence thus far suggests a protective function of SPP1 signaling through mammalian target of rapamycin (mTORC1/2) pathway function to counter HIV-neuronal injury. Moreover, HIV-infected mice knocked down for SPP1 show by neuroimaging, increased neuroinflammation compared to controls. This suggests that SPP1 uses unique regulatory mechanisms to control the level of inflammatory signaling. In this mini review, we discuss the known and yet-to-be discovered biological links between SPP1-mediated stimulation of mTOR and inflammasome activity. Additional new mechanistic insights from studies in relevant experimental models will provide a greater understanding of crosstalk between microglia and neurons in the regulation of CNS homeostasis.

Effects of supplementing coated methionine in a high plant-protein diet on growth, antioxidant capacity, digestive enzymes activity and expression of TOR signaling pathway associated genes in gibel carp, Carassius auratus gibelio.

This study explored the impacts of supplementation of different levels of coated methionine (Met) in a high-plant protein diet on growth, blood biochemistry, antioxidant capacity, digestive enzymes activity and expression of genes related to TOR signaling pathway in gibel carp (Carassius auratus gibeilo). A high-plant protein diet was formulated and used as a basal diet and supplemented with five different levels of coated Met at 0.15, 0.30, 0.45, 0.60 and 0.75%, corresponding to final analyzed Met levels of 0.34, 0.49, 0.64, 0.76, 0.92 and 1.06%. Three replicate groups of fish (initial mean weight, 11.37 ± 0.02 g) (20 fish per replicate) were fed the test diets over a 10-week feeding period. The results indicated that with the increase of coated Met level, the final weight, weight gain (WG) and specific growth rate initially boosted and then suppressed, peaking at 0.76% Met level (P< 0.05). Increasing dietary Met level led to significantly increased muscle crude protein content (P< 0.05) and reduced serum alanine aminotransferase activity (P< 0.05). Using appropriate dietary Met level led to reduced malondialdehyde concentration in hepatopancreas (P< 0.05), improved superoxide dismutase activity (P< 0.05), and enhanced intestinal amylase and protease activities (P< 0.05). The expression levels of genes associated with muscle protein synthesis such as insulin-like growth factor-1, protein kinase B, target of rapamycin and eukaryotic initiation factor 4E binding protein-1 mRNA were significantly regulated, peaking at Met level of 0.76% (P< 0.05). In conclusion, supplementing optimal level of coated Met improved on fish growth, antioxidant capacity, and the expression of TOR pathway related genes in muscle. The optimal dietary Met level was determined to be 0.71% of the diet based on quadratic regression analysis of WG.

Ginsenoside Rg1 Induces Autophagy in Colorectal Cancer through Inhibition of the Akt/mTOR/p70S6K Pathway.

This study aimed to elucidate the anti-colon cancer mechanism of ginsenoside Rg1 in vitro and in vivo. Cell viability rate was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tetrazolium assay. The inhibitory effect of ginsenoside Rg1 against CT26 cell proliferation gradually increased with increasing concentration. The in vivo experiments also demonstrated an antitumor effect. The monodansylcadaverine (MDC), transmission electron microscopy (TEM), and expression of autophagy marker proteins confirmed that ginsenoside Rg1 induced autophagy in vitro. Ginsenoside Rg1 induced autophagy death of CT26 cells, but this effect could be diminished by autophagy inhibitor (3-methyladenine, 3-MA). Additionally, in a xenograft model, immunohistochemical analysis of tumor tissues showed that the LC3 and Beclin-1 proteins were highly expressed in the tumors from the ginsenoside Rg1-treated nude mice, confirming that ginsenoside Rg1 also induced autophagy in vivo. Furthermoer, both in vivo and in vitro, the protein expressions of p-Akt, p-mTOR, and p-p70S6K were inhibited by ginsenoside Rg1, which was verified by Akt inhibitors. These results indicated that the mechanism of ginsenoside Rg1 against colon cancer was associated with autophagy through inhibition of the Akt/mTOR/p70S6K signaling pathway.

Effects of moxibustion with wheat-grain size cone at "Zusanli" (ST 36) on vascular injury and oxidative stress in high-fat diet rats through mTOR/HIF-1α/VEGF signaling pathway. / 基于mTOR/HIF-1α/VEGF信号通路探讨麦粒灸"足三里"å¯¹é«˜è„‚é¥®é£Ÿå¤§é¼ è¡€ç®¡æŸä¼¤å’Œæ°§åŒ–åº”æ¿€çš„å½±å“.

OBJECTIVES: To explore the effect mechanism of moxibustion with wheat-grain size cone at "Zusanli" (ST 36) on vascular injury and oxidative stress in hyperlipidemia through mammalian target of rapamycin (mTOR)/hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway. METHODS: Forty healthy male SD rats with SPF grade were randomly divided into a normal group, a model group, a moxibustion group, and an inhibitor group, with 10 rats in each one. The hyperlipidemia model was established by feeding a high-fat diet for 8 weeks in rats of the model group, the moxibustion group and the inhibitor group. The moxibustion with wheat-grain size cone was delivered at bilateral "Zusanli" (ST 36) of each rat in the moxibustion group and the inhibitor group, with 3 cones on each acupoint in each intervention, once daily for 4 weeks. In the inhibitor group, before each intervention with moxibustion, rapamycin solution was injected intraperitoneally, 2.0 mg/kg. After modeling and intervention, using ELISA, the levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in the serum of rats were determined. After intervention, with HE staining and oil red O staining adopted, the abdominal aortic morphology and peripheral lipid deposition were observed. Separately, using WST-1, TBA and micro-plate method, the superoxide dismutase (SOD) activity and the levels of malondialdehyde (MDA) and nitric oxide (NO) in the serum were detected. The protein expression of mTOR, HIF-1α and VEGF in abdominal aorta were measured by Western blot method. RESULTS: Compared with those in the normal group, the levels of TC, TG and LDL-C increased (P<0.01) and HDL-C decreased (P<0.01) in the serum of the rats in the model group, the moxibustion group and the inhibitor group after model establishment. When compared with the normal group after intervention, in the model group, the serum levels of TC, TG, LDL-C and MDA increased (P<0.01), HDL-C level, SOD activity and NO level were reduced (P<0.01); the cell structure of the abdominal arota was abnormal, the peripheral lipids deposited seriously; and the protein expression of mTOR, HIF-1α and VEGF of abdominal aorta was elevated (P<0.01, P<0.05). In comparison with the model group, the levels of TC, TG, LDL-C and MDA were reduced (P<0.01), HDL-C levels, SOD activities and NO levels elevated (P<0.01, P<0.05), as well as the protein expression of mTOR, HIF-1α and VEGF of abdominal aorta (P<0.01, P<0.05) in the moxibustion group and the inhibitor group; besides, the vascular structure was ameliorated and the lipid deposition reduced in the moxibustion group, while, the vascular structure was still abnormal and the lipid deposition declined in the inhibitor group. When compared with the inhibitor group, the serum SOD activity and NO level increased (P<0.05) and MDA decreased (P<0.05); and the protein expression of mTOR, HIF-1α and VEGF of abdominal aorta was elevated (P<0.01, P<0.05) in the moxibustion group. CONCLUSIONS: The vascular injury due to hyperlipidemia is repaired by moxibustion with wheat-grain size cone at "Zusanli" (ST 36) through ameliorating oxidative stress, which is associated potentially with the modulation of mTOR/HIF-1α/VEGF signaling pathway.

[Effect of Erchen Decoction on liver mitochondrial function by inhibiting mTORC1/SREBP1/CAV1 pathway in mice with high-fat diet].

This study aims to investigate the effect of Erchen Decoction(ECD) on liver mitochondrial function in mice with a high-fat diet and its possible mechanism. A total of sixty C57BL/6J mice were randomly divided into a normal group, high-fat group, ECD group, mTORC1 activator(MHY) group, ECD+MHY group, and polyene phosphatidyl choline(PPC) group, with 10 rats in each group. The normal group was given a normal diet, and the other groups were fed a high-fat diet for 20 weeks. At the 17th week, the ECD group and ECD+MHY group were given ECD(8.7 g·kg~(-1)) daily, and the PPC group was given PPC(0.18 g·kg~(-1)) daily, while the remaining groups were given normal saline(0.01 mL·g~(-1)) daily for four weeks. In the 19th week, the MHY group and ECD+MHY group were injected intraperitoneally with MHY(5 mg·kg~(-1)) every other day for two weeks. During the experiment, the general conditions of the mice were observed. The contents of triglyceride(TG) and total cholesterol(TC) in serum were measured. Morphological changes in liver tissue were examined through HE and oil red O staining. The content of adenosine triphosphate(ATP) was determined using chemiluminescence, and mitochondrial membrane potential was assessed using a fluorescence probe(JC-1). Western blot was performed to detect the expression of rapamycin target protein complex 1(mTOR1), ribosomal protein S6 kinase B1(S6K), sterol regulatory element binding protein 1(SREBP1), and caveolin 1(CAV1). RESULTS:: revealed that compared with the normal group, the mice in the high-fat group exhibited significant increases in body weight and abdominal circumference(P<0.01). Additionally, there were significant increases in TG and TC levels(P<0.01). HE and oil red O staining showed that the boundaries of hepatic lobules were unclear; hepatocytes were enlarged, round, and irregularly arranged, with obvious lipid droplet deposition and inflammatory cell infiltration. The liver ATP content and mitochondrial membrane potential decreased significantly(P<0.01). The expression of p-mTOR, p-S6K, and n-SREBP1 increased significantly(P<0.01), while the expression of CAV1 decreased significantly(P<0.01). Compared with the high-fat group, the body weight and TG content of mice in the ECD group and PPC group decreased significantly(P<0.05). Improvements were observed in hepatocyte morphology, lipid deposition, and inflammatory cell infiltration. Furthermore, there were significant increases in ATP content and mitochondrial membrane potential(P<0.05 or P<0.01). The expression of p-mTOR, p-S6K, and n-SREBP1 decreased significantly in the ECD group(P<0.01), while CAV1 expression increased significantly(P<0.01). However, the indices mentioned above did not show improvement in the MHY group. When the ECD+MHY group was compared with the MHY group, there were significant reductions in body weight and TG contents(P<0.05). The morphological changes of hepatocytes, lipid deposition, and inflammatory cell infiltration were recovered. Moreover, there were significant increases in liver ATP content and mitochondrial membrane potential(P<0.05 or P<0.05). The expression of p-mTOR, p-S6K, and n-SREBP1 decreased significantly(P<0.01), while CAV1 expression increased significantly(P<0.01). In conclusion, ECD can improve mitochondrial function by regulating the mTORC1/SREBP1/CAV1 pathway. This mechanism may be involved in the resolution of phlegm syndrome and the regulation of lipid metabolism.

[Total polyphenols of Cydonia oblonga inhibited proliferation and migration of renal cancer cells by PI3K/Akt/mTOR pathway].

The mechanism of total polyphenols of Cydonia oblonga Miller(TPCOM) against kidney cancer was elucidated through a combination of network pharmacology, bioinformatics, and experimental verification. The active polyphenolic compounds from C. oblonga were screened by network pharmacological techniques and kidney cancer-related targets were collected through the database. The differential gene expression analysis was performed on RNA sequencing data from tumor tissue and normal tissue of kidney cancer patients obtained from the Gene Expression Omnibus(GEO) database. The results of network pharmacology predictions and differential gene expression analysis were used to identify the core genes targeted by TPCOM in kidney cancer. Survival analysis was conducted to identify key targets that could impact patient survival, followed by Kyoto Encyclopedia of Genes and Genomes(KEGG) and Gene Ontology(GO) enrichment analyses. Cell proliferation and activity experiments(cell counting kit-8) were conducted using TPCOM at concentrations ranging from 20 to 640 µg·mL~(-1) on 786-O and Renca cells. Additionally, TPCOM at concentrations of 40, 80, and 160 µg·mL~(-1) was applied to kidney cancer cells to assess its effect on cell migration and its regulation of protein expression levels related to the protein kinase B(Akt), mammalian target of rapamycin(mTOR), and phosphoinositide 3-kinase(PI3K) signaling pathways. Network pharmacology predicted eight active polyphenolic compounds from C. oblonga. Survival analysis revealed 15 significantly differentially expressed genes in kidney cancer that were affected by TPCOM and had a significant impact on patient survival. KEGG and GO analysis results indicated that these 15 targets were primarily associated with the PI3K/Akt signaling pathway, cell migration, and proliferation. The results showed that TPCOM could inhibit the proliferation of 786-O and Renca cells, with IC_(50) values of 121.4 and 137.9 µg·mL~(-1), respectively. TPCOM was also found to inhibit the migration of these cells and suppress the PI3K/Akt/mTOR signaling pathway. TPCOM may exert its anti-kidney cancer effects by inhibiting the activation of the PI3K/Akt/mTOR signaling pathway, thereby restraining the proliferation and migration of kidney cancer cells. This study provides a foundation for the research on the anti-tumor effects of natural product C. oblonga, particularly in Xinjiang, and holds significance for further promoting its development and utilization.

Loureirin B ameliorates cholestatic liver fibrosis via AKT/mTOR/ATG7-mediated autophagy of hepatic stellate cells.

AIM OF THE STUDY: Chronic cholestasis leads to liver fibrosis, which lacks effective treatment. In this study, we investigated the role and mechanisms of action of loureirin B (LB) in cholestatic liver fibrosis. MATERIALS AND METHODS: Bile duct ligation (BDL)-induced hepatic fibrosis mice were used as in vivo models. Transforming growth factor-ß1 (TGF-ß1)-pretreated HSC-T6 cells were used to explore the mechanism by which LB attenuates liver fibrosis in vitro. RNA sequencing, quantitative PCR (qPCR), western blotting, immunohistochemistry and immunofluorescence were performed to detect the fibrosis markers and measure autophagy levels. Flow cytometry, cell counting kit-8 (CCK-8) assay, and 5'-ethynyl-2'-deoxyuridine (EdU) assay were conducted to detect cell proliferation and viability. GFP-RFP-LC3 adenovirus, autophagy-related protein 7 (ATG7) siRNA, and bafilomycin A1 (BafA1) were used to verify autophagic flux. RESULTS: Our results showed that LB ameliorates liver injury, inhibits collagen deposition, and decreases the expressions of fibrosis-related markers in BDL-induced mouse livers. In vitro, we found that LB inhibited proliferation and migration, promoted apoptosis, and inhibited the activation of HSC-T6 cells pretreated with TGF-ß1. RNA sequencing analysis of HSC-T6 cells showed that LB treatment predominantly targeted autophagy-related pathways. Further protein analysis indicated that LB downregulated the expression of phosphorylated AKT (p-AKT) and phosphorylated mTOR (p-mTOR), and upregulated LC3-II, p62, and ATG7 both in vivo and in vitro. Intriguingly, ATG7 inactivation reversed the antifibrotic effects of LB on HSC-T6 cells. CONCLUSIONS: LB can improve BDL-induced liver fibrosis by inhibiting the activation and proliferation of HSCs and is expected to be a promising antifibrotic drug.

The involvement of Akt, mTOR, and S6K in the in vivo effect of IGF-1 on the regulation of rat cardiac Na+/K+-ATPase.

BACKGROUND: We previously demonstrated that insulin-like growth factor-1 (IGF-1) regulates sodium/potassium adenosine triphosphatase (Na+/K+-ATPase) in vascular smooth muscle cells (VSMC) via phosphatidylinositol-3 kinase (PI3K). Taking into account that others' work show that IGF-1 activates the PI3K/protein kinase B (Akt) signaling pathway in many different cells, we here further questioned if the Akt/mammalian target of rapamycin (mTOR)/ribosomal protein p70 S6 kinase (S6K) pathway stimulates Na+/K+-ATPase, an essential protein for maintaining normal heart function. METHODS AND RESULTS: There were 14 adult male Wistar rats, half of whom received bolus injections of IGF-1 (50 µg/kg) for 24 h. We evaluated cardiac Na+/K+-ATPase expression, activity, and serum IGF-1 levels. Additionally, we examined the phosphorylated forms of the following proteins: insulin receptor substrate (IRS), phosphoinositide-dependent kinase-1 (PDK-1), Akt, mTOR, S6K, and α subunit of Na+/K+-ATPase. Additionally, the mRNA expression of the Na+/K+-ATPase α1 subunit was evaluated. Treatment with IGF-1 increases levels of serum IGF-1 and stimulates Na+/K+-ATPase activity, phosphorylation of α subunit of Na+/K+-ATPase on Ser23, and protein expression of α2 subunit. Furthermore, IGF-1 treatment increased phosphorylation of IRS-1 on Tyr1222, Akt on Ser473, PDK-1 on Ser241, mTOR on Ser2481 and Ser2448, and S6K on Thr421/Ser424. The concentration of IGF-1 in serum positively correlates with Na+/K+-ATPase activity and the phosphorylated form of mTOR (Ser2448), while Na+/K+-ATPase activity positively correlates with the phosphorylated form of IRS-1 (Tyr1222) and mTOR (Ser2448). CONCLUSION: These results indicate that the Akt/mTOR/S6K signalling pathway may be involved in the IGF-1 regulating cardiac Na+/K+-ATPase expression and activity.

STING-dependent trained immunity contributes to host defense against Clostridium perfringens infection via mTOR signaling.

Clostridium perfringens (C. perfringens) infection is recognized as one of the most challenging issues threatening food safety and perplexing agricultural development. To date, the molecular mechanisms of the interactions between C. perfringens and the host remain poorly understood. Here, we show that stimulator of interferon genes (STING)-dependent trained immunity protected against C. perfringens infection through mTOR signaling. Heat-killed Candida albicans (HKCA) training elicited elevated TNF-α and IL-6 production after LPS restimulation in mouse peritoneal macrophages (PM). Although HKCA-trained PM produced decreased levels of TNF-α and IL-6, the importance of trained immunity was demonstrated by the fact that HKCA training resulted in enhanced bacterial phagocytic ability and clearance in vivo and in vitro during C. perfringens infection. Interestingly, HKCA training resulted in the activation of STING signaling. We further demonstrate that STING agonist DMXAA is a strong inducer of trained immunity and conferred host resistance to C. perfringens infection in PM. Importantly, corresponding to higher bacterial burden, reduction in cytokine secretion, phagocytosis, and bacterial killing were shown in the absence of STING after HKCA training. Meanwhile, the high expression levels of AKT/mTOR/HIF1α were indeed accompanied by an activated STING signaling under HKCA or DMXAA training. Moreover, inhibiting mTOR signaling with rapamycin dampened the trained response to LPS and C. perfringens challenge in wild-type (WT) PM after HKCA training. Furthermore, STING­deficient PM presented decreased levels of mTOR signaling-related proteins. Altogether, these results support STING involvement in trained immunity which protects against C. perfringens infection via mTOR signaling.

The PI3K/AKT/mTOR signaling pathway in breast cancer: Review of clinical trials and latest advances.

Breast cancer (BC) is the most commonly diagnosed cancer and the leading cause of cancer mortality in women. As the phosphatidylinositol 3-kinase (PI3K) signaling pathway is involved in a wide range of physiological functions of cells including growth, proliferation, motility, and angiogenesis, any alteration in this axis could induce oncogenic features; therefore, numerous preclinical and clinical studies assessed agents able to inhibit the components of this pathway in BC patients. To the best of our knowledge, this is the first study that analyzed all the registered clinical trials investigating safety and efficacy of the PI3K/AKT/mTOR axis inhibitors in BC. Of note, we found that the trends of PI3K inhibitors in recent years were superior as compared with the inhibitors of either AKT or mTOR. However, most of the trials entering phase III and IV used mTOR inhibitors (majorly Everolimus) followed by PI3K inhibitors (majorly Alpelisib) leading to the FDA approval of these drugs in the BC context. Despite favorable efficacies, our analysis shows that the majority of trials are utilizing PI3K pathway inhibitors in combination with hormone therapy and chemotherapy; implying monotherapy cannot yield huge clinical benefits, at least partly, due to the activation of compensatory mechanisms. To emphasize the beneficial effects of these inhibitors in combined-modal strategies, we also reviewed recent studies which investigated the conjugation of nanocarriers with PI3K inhibitors to reduce harmful toxicities, increase the local concentration, and improve their efficacies in the context of BC therapy.

Targeting the EGFR pathway: An alternative strategy for the treatment of tuberous sclerosis complex?

INTRODUCTION: Tuberous sclerosis complex (TSC) is caused by variants in TSC1/TSC2, leading to constitutive activation of the mammalian target of rapamycin (mTOR) complex 1. Therapy with everolimus has been approved for TSC, but variations in success are frequent. Recently, caudal late interneuron progenitor (CLIP) cells were identified as a common origin of the TSC brain pathologies such as subependymal giant cell astrocytomas (SEGA) and cortical tubers (CT). Further, targeting the epidermal growth factor receptor (EGFR) with afatinib, which is expressed in CLIP cells, reduces cell growth in cerebral TSC organoids. However, investigation of clinical patient-derived data is lacking. AIMS: Observation of EGFR expression in SEGA, CT and focal cortical dysplasia (FCD) 2B human brain specimen and investigation of whether its inhibition could be a potential therapeutic intervention for these patients. METHODS: Brain specimens of 23 SEGAs, 6 CTs, 20 FCD2Bs and 17 controls were analysed via immunohistochemistry to characterise EGFR expression, cell proliferation (via Mib1) and mTOR signalling. In a cell-based assay using primary patient-derived cells (CT n = 1, FCD2B n = 1 and SEGA n = 4), the effects of afatinib and everolimus on cell proliferation and cell viability were observed. RESULTS: EGFR overexpression was observed in histological sections of SEGA, CT and FCD2B patients. Both everolimus and afatinib decreased the proliferation and viability in primary SEGA, tuber and FCD2B cells. CONCLUSION: Our study demonstrates that EGFR suppression might be an effective alternative treatment option for SEGAs and tubers, as well as other mTOR-associated malformations of cortical development, including FCD2B.