Polystyrene microplastics induce autophagy and apoptosis in birds lungs via PTEN/PI3K/AKT/mTOR

Microplastics (MPs) seriously pollute and potentially threaten human health. Birds are sentinels of environmental pollutants, which respond quickly to contamination events and reveal current environmental exposure. Therefore, birds are good bioindicators for monitoring environmental pollutants. However, the mechanism of lung injury in birds and the role of the PTEN/PI3K/AKT axis are unknown. In this study, broilers treated with different polystyrene microplastics (PS-MPs) (0, 1, 10, and 100 mg/L) were exposed to drinking water for 6 weeks to analyze the effect of PS-MPs on lung injury of broilers. The results showed that with the increase of PS-MPs concentration, malonaldehyde (MDA) content increased, and catalase (CAT) and glutathione (GSH) activity decreased, further leading to oxidative stress. PS-MPs caused the PI3K/Akt/mTOR pathway to be inhibited by phosphorylation, and autophagy accelerated formation (LC3) and degradation (p62), causing autophagy. In PS-MPs exposed lung tissues, the expression of Bax/Bcl-2 and Caspase family increased, and MAPK signaling pathways (p38, ERK, and JNK) showed an increase in phosphorylation level, thus leading to cell apoptosis. Our research showed that PS-MPs could activate the antioxidant system. The antioxidant system unbalance-regulated Caspase family, and PTEN/PI3K/AKT pathways initiated apoptosis and autophagy, which in turn led to lung tissue damage in chickens. These results are of great significance to the toxicological study of PS-MPs and the protection of the ecosystem.     

PI3K/AKT/mTOR信号通路参与脊髓损伤后神经元自噬的研究进展

PI3K/AKT/mTOR信号通路是脊髓损伤后的一条经典的自噬途径,脊髓损伤后导致的神经元细胞凋亡、轴 突脱髓鞘和炎症反应等受 PI3K/AKT/mTOR 信号通路的调控,并和神经元自噬相关。介绍脊髓损伤后 PI3K/AKT/ mTOR信号通路在神经元自噬过程中的主要作用,为进一步研究脊髓损伤提供参考。     

Gaseous signal molecule SO2 regulates autophagy through PI3K/AKT pathway inhibits cardiomyocyte apoptosis and improves myocardial fibrosis in rats with type II diabetes

Myocardial fibrosis is a key link in the occurrence and development of diabetic cardiomyopathy. Its etiology is complex, and the effect of drugs is not good. Cardiomyocyte apoptosis is an important cause of myocardial fibrosis. The purpose of this study was to investigate the effect of gaseous signal molecule sulfur dioxide (SO₂) on diabetic myocardial fibrosis and its internal regulatory mechanism. Masson and TUNEL staining, Western-blot, transmission electron microscopy, RT-qPCR, immunofluorescence staining, and flow cytometry were used in the study, and the interstitial collagen deposition, autophagy, apoptosis, and changes in phosphatidylinositol 3-kinase (PI3K)/AKT pathways were evaluated from in vivo and in vitro experiments. The results showed that diabetic myocardial fibrosis was accompanied by cardiomyocyte apoptosis and down-regulation of endogenous SO₂-producing enzyme aspartate aminotransferase (AAT)_1/2. However, exogenous SO₂ donors could up-regulate AAT_1/2, reduce apoptosis of cardiomyocytes induced by diabetic rats or high glucose, inhibit phosphorylation of PI3K/AKT protein, up-regulate autophagy, and reduce interstitial collagen deposition. In conclusion, the results of this study suggest that the gaseous signal molecule SO₂ can inhibit the PI3K/AKT pathway to promote cytoprotective autophagy and inhibit cardiomyocyte apoptosis to improve myocardial fibrosis in diabetic rats. The results of this study are expected to provide new targets and intervention strategies for the prevention and treatment of diabetic cardiomyopathy.     

Disruption of the PI3K/AKT/mTOR signaling cascade and induction of apoptosis in HL-60 cells by an essential oil from Monarda citriodora

We have isolated an essential oil from Monarda citriodora (MC) and characterized its 22 chemical constituents with thymol (82%), carvacrol (4.82%), β-myrcene (3.45%), terpinen-4-ol (2.78%) and p-cymene (1.53%) representing the major constituents. We have reported for the first time the chemotherapeutic potential of MC in human promyelocytic leukemia HL-60 cells by means of apoptosis and disruption of the PI3K/AKT/mTOR signaling cascade. MC and its major constituent, thymol, inhibit the cell proliferation in different types of cancer cell lines like HL-60, MCF-7, PC-3, A-549 and MDAMB-231. MC was found to be more cytotoxic than thymol in HL-60 cells with an IC₅₀ value of 22 μg/ml versus 45 μg/ml for thymol. Both MC and thymol induce apoptosis in HL-60 cells, which is evident by Hoechst staining, cell cycle analysis and immuno-expression of Bcl-xL, caspase-3,-8,-9 and PARP-1 cleavage. Both induce apoptosis by extrinsic and intrinsic apoptotic pathways that were confirmed by enhanced expression of death receptors (TNF-R1, Fas), caspase-9, loss of mitochondrial membrane potential and regression of Bcl-2/Bax ratio. Interestingly, both MC and thymol inhibit the downstream and upstream signaling of PI3K/AKT/mTOR pathway. The degree of apoptosis induction and disruption of the PI3K signaling cascade by MC was significantly higher when compared to thymol.     

6-Paradol alleviates Diclofenac-induced acute kidney injury via autophagy enhancement-mediated by AMPK/AKT/mTOR and NLRP3 inflammasome pathways

Diclofenac (DIC)-induced acute kidney injury (AKI) causes high morbidity and mortality. With the absence of satisfactory treatment, we investigated the protective effects of 6-Paradol (PDL) against DIC-induced AKI, with focus on renal autophagy and NLRP3 inflammasome pathways . PDL has anti-inflammatory, antioxidant and AMPK-activation properties. PDL was administered to DIC-challenged rats. Nephrotoxicity, oxidative stress, inflammatory, and autophagy markers and histopathological examinations were evaluated. Compared to DIC, PDL restored serum nephrotoxicity, renal oxidative stress and pro-inflammatory markers. PDL almost restored renal architecture, upregulated renal Nrf2 pathway via enhancing Nrf2 mRNA expression and HO-1 levels. PDL suppressed renal NF-κB mRNA expression, and NLRP3 inflammasome pathway expression. Moreover, PDL enhanced renal autophagy through upregulating LC3B, AMPK and SIRT-1, and suppressed mTOR, p-AKT mRNA expressions and phosphorylated-p62 levels. Our study confirmed that autophagy suppression mediates DIC-induced AKI via AMPK/mTOR/AKT and NLRP3-inflammasome pathways. Also, PDL’s nephroprotective effects could provide a promising therapeutic approach against DIC-induced AKI.     

PI3K/Akt/mTOR通路在炎症相关疾病中分子机制研究进展

炎症是一种机体应对感染、组织损伤或者细胞应激的反应,并且可以通过修复机制恢复组织功能。炎症发生时会引起多条信号通路的激活,包括核转录因子-κB（NF-κB）通路、Janus激酶/信号转导与转录激活子（JAK/STAT）通路、丝裂原活化蛋白激酶（MAPK）通路以及磷脂酰肌醇-3-激酶/蛋白激酶B /雷帕霉素靶蛋白（PI3K/Akt/mTOR）通路等。本文综述了近年来磷脂酰肌醇-3-激酶/蛋白激酶B /雷帕霉素靶蛋白通路在炎症相关疾病中的分子作用机制,为研发以磷脂酰肌醇-3-激酶/蛋白激酶B /雷帕霉素靶蛋白为靶点的药物提供理论依据。     

AKG induces cell apoptosis by inducing reactive oxygen species-mediated endoplasmic reticulum stress and by suppressing PI3K/AKT/mTOR-mediated autophagy in renal cell carcinoma

Background: Alpha-ketoglutarate (AKG) or 2-oxoglutarate is a key substance in the tricarboxylic acid cycle (TCA) and has been known to play an important role in cancerogenesis and tumor progression. Renal cell carcinoma (RCC) is the most common type of kidney cancer, and it has a high mortality rate. Autophagy is a phenomenon of self-digestion, and its significance in tumor genesis and progression remains debatable. However, the mechanisms underlying how AKG regulates autophagy in RCC remain unknown. Thus, the purpose of this study was to assess the therapeutic efficacy of AKG and its molecular mechanisms. Methods: RCC cell lines 786O and ACHN were treated with varying doses of AKG for 24 h. CCK-8, Transwell, and scratch wound healing assays were utilized to evaluate the role of AKG in RCC cells. Autophagy protein and PI3K/AKT/mTOR pathway protein levels were analyzed by Western blot. Results: AKG inhibited the proliferation of RCC cells 786O and ACHN in a dose-dependent manner according to the CCK-8 assay. In addition, flow cytometry and Western blot analysis revealed that AKG dose-dependently triggered apoptosis and autophagy in RCC cells. By promoting cell apoptosis and autophagy, AKG dramatically suppressed tumor growth. Mechanistically, AKG induces autophagy by promoting ROS generation and inhibiting the PI3K/AKT/mTOR pathway. Conclusions: The anti-tumor effect of AKG promotes autophagy in renal cancer cells via mediating ROS-PI3K/Akt/mTOR, and may be used as a potential anticancer drug for kidney cancer.     

雷公藤红素通过PI3K/AKT/mTOR信号通路对胃癌MFC细胞增殖和凋亡的影响

目的研究雷公藤红素对胃癌MFC细胞内PI3K/AKT/mTOR信号通路的影响及其对胃癌MFC细胞增殖的抑制和促凋亡作用机制。方法分别设置对照组和雷公藤红素低、中、高剂量(5、10、20 mmol/L)组,采用MTT法检测雷公藤红素对胃癌MFC细胞增殖的影响;采用流式细胞技术检测雷公藤红素对胃癌MFC细胞周期的影响及MFC细胞凋亡的情况;Western blotting检测雷公藤红素对胃癌MFC细胞内凋亡相关蛋白Bax、Bcl-2和PI3K、AKT和mTOR蛋白表达的影响;实时定量PCR检测雷公藤红素对胃癌MFC细胞内PI3K、AKT和mTORm RNA表达的影响。结果与对照组比较,雷公藤红素能够呈剂量相关性地显著抑制胃癌MFC细胞的增殖(P0.05);与对照组比较,雷公藤红素能够呈剂量相关性地显著引起MFC细胞G2/M期阻滞(P0.05);与对照组比较,雷公藤红素能够呈剂量相关性地显著促进MFC细胞的凋亡(P0.05);与对照组比较,雷公藤红素能够呈剂量相关性地显著抑制MFC细胞内抗凋亡蛋白Bcl-2蛋白和PI3K、AKT、mTOR蛋白的表达(P0.05),显著促进MFC细胞内促凋亡蛋白Bax的表达(P0.05);与对照组比较,雷公藤红素能够呈剂量相关性地显著抑制MFC细胞内PI3K、AKT和mTORm RNA的表达(P0.05)。结论雷公藤红素能够抑制胃癌MFC细胞的增殖并促进胃癌MFC细胞凋亡,其作用机制可能是通过抑制胃癌MFC细胞内PI3K/AKT/mTOR信号通路中PI3K、AKT、mTOR等蛋白的表达而抑制胃癌MFC细胞的增殖,进而促进胃癌MFC细胞内促凋亡蛋白Bax的表达,同时抑制抗凋亡蛋白Bcl-2的表达,从而促进胃癌MFC细胞凋亡。     

白杨素通过PI3K/AKT信号通路抑制LPS诱导的软骨细胞自噬

Aim To explore the effect of chrysin on chondrocyte autophagy in rat chondrocyte osteoarthritis model induced by lipopolysaccharide and its mechanism. Methods Normal articular cartilage cells of 10 SPF SD rats were isolated and cultured in vitro, and the autophagy of rat chondrocytes was induced by LPS. The experiment was divided into blank control group, LPS group, chrysin (CHR) group and LPS + CHR group, the activity of cells in each group was detected by CCK-8 method, the mitochondrial membrane potential of cells in each group was detected by Rhodaminel23, and the protein expression of PI3K, AKT, p-PI3K, p-AKT, Beclin-1 and LC3 II in cells of each group was detected by reactive oxygen species, Western blot method of DCFH-DA. Results Chrysin could inhibit the autophagy induced by LPS, especially when the concentration of chrysin was 10 mmol · L^-1. Chrysin could inhibit the increase of reactive oxygen species (ROS) induced by LPS induced by LPS, inhibit the decrease of mitochondrial membrane potential after injury, and inhibit the expression of Beclin-1 and LC3 II protein and the phosphorylation of PI3K and AKT. Conclusions Chrysin may inhibit autophagy by inhibiting PI3K/AKT signaling pathway and down-regulating the expression of autophagy proteins Beclin-1 and LC3 II, thus protecting chondrocytes. © 2021 Publication Centre of Anhui Medical University. All rights reserved.     

Investigational PI3K/AKT/mTOR inhibitors in development for endometrial cancer

Introduction: Endometrial cancer (EC) is the most common neoplasm of the female genital tract in developed countries. Despite the progress in early detection and treatment, a significant number of cases of advanced ECs are still diagnosed. These patients have few treatment options and a poor prognosis. Our understanding of EC pathogenesis and progression has been enhanced by recent genomic studies. Among the relevant biological pathways, phosphatidylinositol 3-kinase/AKT (PIK3/AKT)-mammalian target of rapamycin (mTOR) signaling is frequently upregulated in this cancer.

Areas covered: This review covers investigational EC therapeutics acting on the PI3K/AKT/mTOR pathway. The authors review the results of clinical studies and highlight ongoing trials.

Expert opinion: Several new agents are under evaluation for treating patients with metastatic, recurrent, and persistent EC. Clinical trials investigating PI3K/AKT/mTOR inhibitors have yielded controversial results. In the near future, new studies with dual inhibitors or multi-pathways inhibitors as mono or combination therapies with conventional chemotherapy (CT) or other targeted drugs may provide more promising data. Moreover, the evaluation of new serum and histological biomarkers is an attractive strategy for patient selection.     

PI3K/AKT/mTOR信号通路抑制剂在卵巢癌治疗中的研究进展

卵巢癌是女性生殖系统最致命的恶性肿瘤。目前,针对卵巢癌的规范治疗方案是肿瘤细胞减灭术辅以紫杉醇/铂类联合化疗,然而大多数晚期卵巢癌患者最终因对化疗药物耐药而复发。PI3K/AKT/m TOR信号通路作为一条重要的原癌基因通路,在卵巢癌中激活并在卵巢癌的增殖、侵袭、细胞周期进程、血管形成及耐药中发挥着重要的作用,抑制该通路是卵巢癌的一个潜在治疗方法。对PI3K/AKT/m TOR信号通路抑制剂在卵巢癌治疗中的研究进展进行综述。     

川芎嗪通过抑制PI3K/Akt/mTOR通路诱导自噬改善糖尿病肾病大鼠肾损害

目的 探讨川芎嗪对糖尿病肾病（DN）大鼠肾脏 PI3K/Akt/mTOR信号通路和自噬标志蛋白 LC3B表达以及 尿微量白蛋白与尿肌酐比值（UACR）、肾脏病理的影响。方法 采用链脲佐菌素建立 DN大鼠模型,将模型大鼠随机 分为模型组,川芎嗪低、中、高剂量组,厄贝沙坦组;另设正常组,每组 12只。分别干预 8周后,采用酶法测定尿肌酐, 免疫比浊法测定尿微量白蛋白,计算 UACR;取肾组织,经甲醛固定后,进行苏木精-伊红（HE）和过碘酸-雪夫（PAS） 染色;通过蛋白免疫印迹法（Western blot）和免疫组化检测大鼠肾组织 PI3K/Akt/mTOR信号通路以及自噬标志蛋白 LC3B 表达的变化。结果 川芎嗪能减缓 DN 大鼠 UACR 的升高,改善其肾脏病理变化,其中川芎嗪中、高剂量组 UACR显著低于模型组（P＜0.05）,且川芎嗪中、高剂量组与厄贝沙坦组间比较差异无统计学意义（P＞0.05）。此外, 川芎嗪能抑制 DN大鼠肾组织 p-PI3K、p-Akt、p-mTOR的表达,进而提高自噬标志蛋白 LC3B的表达水平和 LC3B-Ⅱ/ LC3B-Ⅰ比值。结论 川芎嗪能降低 DN大鼠 UACR的升高、改善其肾脏病理变化,发挥以上肾保护作用的机制可能 与其抑制 PI3K/Akt/mTOR信号通路,进而促进肾脏自噬有关。     

PI3K/AKT/mTOR信号通路参与自身免疫性

自身免疫性疾病（autoimmune disease,AD）是机体因自身抗原免疫耐受障碍而对自身抗原产生免疫反应,从而引起机体组织损伤的一类疾病。近年研究发现,磷脂酰肌醇-3-激酶/蛋白激酶B/雷帕霉素靶蛋白（phosphatidylin ositol 3-kinase/protein kinase B/mechanistic target ofrapamycin kinase,PI3K/AKT/mTOR）信号通路与AD发病密切相关,其主要参与免疫细胞增殖分化、炎性细胞因子分泌、自噬及氧化应激等过程。本文重点概述PI3K/AKT/mTOR信号通路参与AD发病机理的研究进展。     

PI3K/AKT/mTOR信号通路抑制剂在宫颈癌治疗中的研究进展

宫颈癌是女性常见恶性肿瘤之一。针对局部晚期及复发转移的宫颈癌患者尚未有令人满意的治疗手段,因此探索和发展更有效的治疗方案具有重要的意义。PI3K/AKT/m TOR信号通路在人类子宫颈癌细胞的增殖、分化和凋亡中具有重要的调节作用,有希望成为开发宫颈癌治疗药物的新型靶标。综述了近年来PI3K/AKT/m TOR信号通路的单一及双重靶点抑制剂针对宫颈癌的临床前及临床研究情况,包括PI3K抑制剂(wortmannin、LY294002、吲哚-3-甲醇)、AKT抑制剂(SC-66、MK-2206、木黄酮、冬凌草甲素和雷公藤)、m TOR抑制剂(替西罗莫司和依维莫司)及双重靶点抑制剂(GSK2126458、BEZ235、BGT226、PF04691502、GDC-0980和PKI-587)等。     

Role of PI3K/AKT/mTOR signaling pathway in DBP-induced apoptosis of testicular sertoli cells in vitro

Dibutyl phthalate (DBP) has significant male reproductive toxicity, and the Sertoli cells are the target cells of DBP. This study was to investigate the injury effect induced by DBP on rat testicular Sertoli cells in vitro. MTT results showed that DBP can significantly reduce the survival rate of Sertoli cells; Hoechst staining results showed that the Sertoli cells treated with DBP emerged with typical morphological characteristics of apoptosis, nuclear condensation and chromatin condensation; flow cytometry results showed that DBP significantly increased the apoptotic rate of Sertoli cells, and dose-dependent; Western blotting showed that the expression of PTEN protein in Sertoli cells was significantly higher than that in the control group after treated with different concentrations of DBP for 24 h, while the expression of p-PI3K1, p-AKT, p70S6K and 4E-BP1 protein in the PI3K/AKT/mTOR signal pathway were significantly decreased. It is speculated that PTEN/PI3K/AKT/mTOR signaling pathway plays an important role in DBP-induced apoptosis of testicular Sertoli cells in rats.     

磷脂酰肌醇-3磷酸激酶/AKT/雷帕霉素靶蛋白信号通路参与中枢神经损伤保护与修复的研究进展

中枢神经细胞对各种损伤刺激耐受差,损伤后神经修复困难.因此促进神经保护增强神经再生能力已成为神经治疗关键.磷脂酰肌醇-3磷酸激酶/AKT/雷帕霉素靶蛋白(PI3K/AKT/mTOR)信号通路是调节细胞周期的重要通路,在细胞增殖、生长、分化过程中起中心调控作用,在神经损伤过程中通过激活PI3K/AKT/mTOR信号通路可减少神经细胞死亡,促进神经修复.该文对PI3K/AKT/mTOR信号通路在中枢神经损伤保护作用、修复机制及可能风险作一综述,探讨将PI3K/AKT/mTOR信号通路作为靶点治疗中枢神经疾病.     

紫草素抑制PI3K/Akt/mTOR信号通路诱导人结肠癌SW480细胞凋亡和自噬的作用研究

目的 探讨紫草素对人结肠癌SW480细胞凋亡和自噬的影响及其机制。方法 取对数生长期人结肠癌SW480细胞,设对照组（DMSO）、紫草素（0.3、0.5、0.7 μg/mL）和LY294002（PI3K特异性抑制剂,5 μg/mL）组。药物干预48 h后,四甲基偶氮唑盐（MTT）法检测SW480细胞增殖抑制率,Annexin V-FITC流式细胞术分析细胞凋亡状况,蛋白免疫印迹法（Western blotting）检测p-PI3K、p-Akt、p-mTOR、Caspase-3、cleaved Caspase-3、Bcl-2、Bax、LC3蛋白表达并计算Bax/Bcl-2和LC3-II/LC3-I值。结果 与对照组比较,经紫草素0.3、0.5、0.7 μg/mL或LY294002 5 μg/mL干预能够显著提高人结肠癌SW480细胞增殖抑制率和凋亡率（P<0.01）;经紫草素0.5、0.7 μg/mL或LY294002 5 μg/mL干预能够显著下调p-PI3K、p-Akt、p-mTOR、Bcl-2蛋白表达,并上调Caspase-3、cleaved Caspase-3、Bax蛋白表达（P<0.05、0.01）,提高Bax/Bcl-2和LC3-II/LC3-I值（P<0.01）。与LY294002组比较,经紫草素0.7 μg/mL干预能够显著提高SW480细胞增殖抑制率和凋亡率（P<0.05、0.01）,下调p-PI3K、p-Akt、p-mTOR蛋白表达并上调Caspase-3、cleaved Caspase-3、Bax蛋白表达（P<0.05、0.01）,提高Bax/Bcl-2和LC3-II/LC3-I值（P<0.01）。结论 紫草素能够促进人结肠癌SW480细胞凋亡和自噬,作用机制可能与抑制PI3K/Akt/mTOR信号通路活化有关。     

Urolithin A suppresses tumor progression and induces autophagy in gastric cancer via the PI3K/Akt/mTOR pathway

Urolithin A (UA) is a microbial metabolite of natural polyphenols ellagitannins and ellagic acid with well-established antitumor properties against various malignancies. However, the exact role of UA in gastric cancer (GC) progression remains largely unclear. In the present study, we investigated the effects and potential mechanisms of UA in GC in vitro and in vivo. Our results revealed that UA could suppress GC cell proliferation, inhibit migration and invasion, promote apoptosis, and induce autophagy via the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin pathway in vitro. The autophagy inhibitors 3-methyladenine and chloroquine augmented the inhibitory effect of UA on proliferation and promoted apoptosis, implying that UA mediated the cytoprotective role of autophagy. Meanwhile, the in vivo experiments showed that UA effectively suppressed tumor growth, enhanced the therapeutic effects, and alleviated chemotherapy toxicity in xenograft models. Overall, these findings offer novel insights into the role of UA in tumor therapy and suggest that UA may possess potential therapeutic applications for GC.     

The PI3K/Akt/mTOR pathway: A potential pharmacological target in COVID-19

Coronavirus disease 2019 (COVID-19) has emerged as a serious threat to global health. The disregulation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) cell signaling pathway observed in patients with COVID-19 has attracted attention for the possible use of specific inhibitors of this pathway for the treatment of the disease. Here, we review emerging data on the involvement of the PI3K/Akt/mTOR pathway in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the clinical studies investigating its tailored inhibition in COVID-19. Current in silico, in vitro, and in vivo data convergently support a role for the PI3K/Akt/mTOR pathway in COVID-19 and suggest the use of specific inhibitors of this pathway that, by a combined mechanism entailing downregulation of excessive inflammatory reactions, cell protection, and antiviral effects, could ameliorate the course of COVID-19.