Autophagy In Cells Research Articles

Restoration of autophagy reduces diabetes-induced endothelial dysfunction

Abstract Introduction Diabetes leads to endothelial dysfunction, a main determinant of several cardiovascular diseases. The molecular mechanisms underlying the effects of hyperglycemia in endothelial cells are not fully characterized. Autophagy, the intracellular process by which the cell digests and recycles senescent or damaged cytoplasmic elements, exerts cardiovascular protective effects, limiting cardiac and vascular injury in the presence of stress. However, it is unclear how hyperglycemia modulates autophagy in endothelial cells. Purpose In this study, we elucidated the role of autophagy in vascular damage induced by diabetes. We also tested whether the restoration autophagy attenuates diabetes-induced endothelial damage. Methods We evaluated the effects of high-glucose (HG, 30 mM for 6 and 24 hours) on markers of endothelial function, autophagy, autophagic flux, and mitophagy in human umbilical endothelial cells (HUVEC) in vitro and in mesenteric arteries from wild-type mice (WT) ex vivo. We tested the effects of autophagy reactivation using the natural polyamine spermidine or ATG7 overexpression (ATG7ov) on apoptosis and angiogenesis in HUVEC treated with HG. Vascular reactivity experiments in the presence of autophagy activation were performed in HG-treated mouse mesenteric arteries and human saphenous veins from patients with peripheral artery disease. Finally, we evaluated the level of autophagy in the mammary arteries of newly discovered diabetic patients undergoing coronary artery bypass graft surgery. Results We found that HG reduces autophagy (0.6 fold p<0.05) and mitophagy (1.5 fold p<0.001) in HUVECs. We also demonstrated that endothelial cells undergoing hyperglycemia fail to activate autophagy under hypoxic conditions (0.6 fold p<0.05). Reactivation of autophagy by ATG7ov rescues apoptosis (0.52 fold p<0.05) and angiogenesis (2.3 fold p<0.05) in HUVEC treated with HG. We further observed that HG exacerbates endothelial dysfunction in a mouse model of genetic inhibition (Beclin 1 +/- mice), compared to WT mice (-19.16 % +-4.97 SEM vs -48.39 % +-2.18 SEM p<0.001). Mechanistically, HG increases cellular acetylation status (0.7 fold p<0.05) and activates p300 (1 fold p<0.05), an autophagy inhibitor. ATG7ov or spermidine, a p300 inhibitor, rescue endothelial-dependent relaxation in mesenteric arteries of WT mice treated with HG (ATG7ov -62.48 % +-5.16 SEM; SP -63.01 +-3.22 SEM; HG -40.67 % +-3.82 p<0.001). Finally, we observed reduced levels of autophagy in mammary arteries from diabetic patients and demonstrated that SP improves vascular function in human saphenous veins (-37.6 % +-12.76 SEM vs -12.52 % +-5.6 SEM p<0.001). Conclusion Our results suggest that the impairment of autophagy is a strong contributor of diabetes induced-endothelial dysfunction. Targeting autophagy may represent a valid therapeutic strategy to counteract the cardiovascular consequences of metabolic stress.

Sex differences in the expression of metabolic and pro-inflammatory markers in the initial post-COVID-19 phase

Abstract Cardiovascular complications are a common manifestation of post-acute COVID-19 infection. Post-COVID-19 syndrome is often associated with the female sex and exacerbated inflammation; however, the underlying molecular mechanisms of this sex difference remain poorly understood. In the present study, we aimed to investigate several metabolic, mitochondrial, autophagy, oxidative stress, and inflammatory markers in peripheral blood mononuclear cells (PBMCs) and plasma isolated from older (>75) male and female patients at the initial phase (1-2 weeks) after COVID-19 pneumonia. Age-matched non-infected women and men were used as a control group. We found a significantly higher plasma TNF-α in post-COVID-19 women, but not in men, compared to the control group. Similarly, a significant elevation of IL-1β and IL-18 mRNA in PBMCs from post-COVID-19 women, but not men, was observed. These effects were associated with marked activation of AMPK (defined as pAMPK/AMPK ratio), suggesting potential metabolic stress in female post-COVID-19 PBMCs. Further analysis revealed increased expression of mitochondrial genes, which may be due to AMPK activation as a compensatory reaction to metabolic stress. Analysis of autophagy or oxidative stress (serum 8-OHdG) markers did not reveal any differences between the groups investigated. We conclude that women in the initial phase of post-COVID-19 have elevated expression of inflammatory markers in plasma and in immune cells, which is associated with metabolic stress. This may contribute to the cardiovascular complications in female post-COVID-19 patients.

Cordycepin Activates Autophagy to Suppress FGF9-induced TM3 Mouse Leydig Progenitor Cell Proliferation.

Fibroblast growth factor 9 (FGF9) is a member of the human FGF family known for its pivotal roles in various biological processes, such as cell proliferation, tissue repair, and male sex determination including testis formation. Cordycepin, a bioactive compound found in Cordyceps sinensis, exhibits potent antitumor effects by triggering apoptosis and/or autophagy pathways. Our research has unveiled that FGF9 promotes proliferation and tumorigenesis in MA-10 mouse Leydig tumor cells, as the phenomena are effectively countered by cordycepin through apoptosis induction. Moreover, we have observed FGF9-mediated stimulation of proliferation and tumorigenesis in TM3 mouse Leydig progenitor cells, prompting an investigation into the potential inhibitory effect of cordycepin on TM3 cell proliferation under FGF9 treatment. Hence, we hypothesized that cordycepin induces cell death via apoptosis and/or autophagy in FGF9-treated TM3 cells. TM3 cells were treated with cordycepin and/or FGF9, and the flow cytometry, immunofluorescent plus western blotting assays were used to determine how cordycepin regulated Leydig cell death under FGF9 treatment. Our findings reveal that cordycepin restricts cell viability and colony formation while inducing morphological alterations associated with cell death in FGF9-treated TM3 cells. Surprisingly, cordycepin fails to elicit the expression of key apoptotic markers, suggesting an alternate mechanism of action. Although the expression of certain autophagy-related proteins remains unaltered, a significant up-regulation of LC3-II, indicative of autophagy, is observed in cordycepin-treated TM3 cells under FGF9 influence. Moreover, the inhibition of autophagy by chloroquine reverses cordycepin-induced TM3 cell death, highlighting the crucial role of autophagy in this process. Our study demonstrates that cordycepin activates autophagy to induce cell death in TM3 cells under FGF9 treatment conditions.

Autophagy and proteasomes in thymic epithelial cells: essential bulk protein degradation systems for immune homeostasis maintenance

The thymus is a central organ that controls T cell development. Thymic epithelial cells (TECs) create a unique microenvironment essential for the differentiation of major histocompatibility complex (MHC)-restricted and self-tolerant T cells. TECs present a complex of self-peptides and MHC molecules (self-pMHCs) to immature T cells and regulate their survival and differentiation based on their affinity for self-pMHCs. The processing of self-peptides in TECs depends on bulk protein degradation systems, specifically autophagy and proteasomes. Studies using autophagy- and proteasome-deficient mouse models have demonstrated that these degradation systems in TECs are indispensable for maintaining immune homeostasis. Although autophagy and proteasomes are ubiquitous in nearly all eukaryotic cells, TECs exhibit unique characteristics in their autophagy and proteasome functions. Autophagy in TECs is constitutively active and independent of stress responses, while TEC proteasomes contain specialized catalytic subunits. This review summarizes the distinctive characteristics of autophagy and proteasomes in TECs and their roles in immune system regulation.

Anti-tumor mechanism of artesunate

Artesunate (ART) is a classic antimalarial drug with high efficiency, low toxicity and tolerance. It has been shown to be safe and has good anti-tumor effect. Existing clinical studies have shown that the anti-tumor mechanisms of ART mainly include inducing apoptosis and autophagy of tumor cells, affecting tumor microenvironment, regulating immune response, overcoming drug resistance, as well as inhibiting tumor cell proliferation, migration, invasion, and angiogenesis. ART has been proven to fight against lung cancer, hepatocarcinoma, lymphoma, multiple myeloma, leukemia, colorectal cancer, ovarian cancer, cervical cancer, malignant melanoma, oral squamous cell carcinoma, bladder cancer, prostate cancer and other neoplasms. In this review, we highlight the effects of ART on various tumors with an emphasis on its anti-tumor mechanism, which is helpful to propose the potential research directions of ART and expand its clinical application.

Protective effects of Silibinin and cinnamic acid against paraquat-induced lung toxicity in rats: impact on oxidative stress, PI3K/AKT pathway, and miR-193a signaling.

Levels of reactive oxygen species (ROS) are the primary determinants of pulmonary fibrosis. It was discovered that antioxidants can ameliorate pulmonary fibrosis caused by prolonged paraquat (PQ) exposure. However, research on the precise mechanisms by which antioxidants influence the signaling pathways implicated in pulmonary fibrosis induced by paraquat is still insufficient. This research utilized a rat model of pulmonary fibrosis induced by PQ to examine the impacts of Silibinin (Sil) and cinnamic acid (CA) on pulmonary fibrosis, with a specific focus on pro-fibrotic signaling pathways and ROS-related autophagy. Lung injury induced by paraquat was demonstrated to be associated with oxidative stress and inflammation of the lungs, downregulated (miR-193a), and upregulated PI3K/AKT/mTOR signaling lung tissues. Expression levels of miR-193a were determined with quantitative real-time PCR, protein level of protein kinase B (Akt), and phosphoinositide 3-Kinase (PI3K) which were determined by western blot analysis. Hydroxyproline levels (HYP) and transforming growth factor-β1 (TGF-β1) were measured by ELISA, malondialdehyde (MDA), total antioxidant capacity (TAC), glutathione peroxidase (GSH), and catalase and were measured in lung tissue homogenates colorimetrically using spectrophotometer. Long-term exposure to paraquat resulted in decreased PI3K/AKT signaling, decreased cell autophagy, increased oxidative stress, and increased pulmonary fibrosis formation. Silibinin and cinnamic acid also decreased oxidative stress by increasing autophagy and miR-193a expression, which in turn decreased pulmonary fibrosis. These effects were associated by low TGF-β1. Silibinin and cinnamic acid inhibited PQ-induced PI3K/AKT by stimulating miR-193-a expression, thus attenuating PQ-induced pulmonary fibrosis.

TRIM7 knockdown protects against LPS-induced autophagy, ferroptosis, and inflammatory responses in human bronchial epithelial cells.

Asthma is one of the most common respiratory diseases in pediatric department. Several asthma-associated events including inflammatory responses, autophagy, and ferroptosis have been identified as typical pathological processes. TRIM7 is a member of TRIM proteins family associated with several types of diseases. Nevertheless, its role in asthma is still elusive. The current research showed that TRIM7 was involved in the pathogenesis of asthma mainly by regulating the Akt signaling pathway. In detail, we found that TRIM7 was highly expressed in patients with asthma and in an in vitro model of asthma. The following analysis indicated that TRIM7 knockdown attenuated the expression and secretion of inflammatory cytokines including TNF-α, IL-1β and IL-6 in lipopolysaccharide (LPS)-exposed human bronchial epithelial cells (HBECs). Meanwhile, knockdown of TRIM7 exerted inhibitory effects on LPS-induced autophagy and ferroptosis. Further mechanistic studies showed that TRIM7 knockdown inhibited LPS-induced activation of Akt pathway, while overexpression of Akt attenuated the inhibitory effects of TRIM7 knockdown on LPS-exposed HBECs. Collectively, we reported here that TRIM7 knockdown inhibited LPS-induced autophagy, ferroptosis, and inflammatory cytokine secretion in HBECs via regulating the Akt pathway, providing a new insight into the strategies for improving asthma treatments.

Synergistic effects of anlotinib and DDP on breast cancer: targeting the VEGF/JAK2/STAT3 axis

BackgroundAnlotinib, a highly selective inhibitor of VEGFR2, has demonstrated significant anti-tumor effects in various cancers. However, its potential synergistic effects with DDP (cisplatin) in breast cancer (BRCA) remain to be fully elucidated. This study aims to discover the therapeutic efficacy of anlotinib on BRCA, specifically the synergistic effects with DDP, and to elucidate the underlying molecular mechanisms.MethodsBRCA cells were treated with anlotinib and/or DDP. The proliferation, migration and invasion capabilities of BRCA cells were evaluated using CCK-8 assays, cell cycle distribution, clone formation assays, wound healing assays and transwell assays. Cell apoptosis was detected by flow cytometry technique and Hoechst33342 fluorescence staining. The potential mechanism of anlotinib in the development of BRCA was predicted through bioinformatics analysis, and the mRNA or protein levels were subsequently quantified using qPCR, immunofuorescence and western blot. The anti-breast cancer efficacy of anlotinib was evaluated in vivo using a xenograft tumor model.ResultsOur findings reveal that increased VEGFA expression in BRCA patients is associated with poorer prognosis, underscoring the need for targeted therapeutic strategies. We also demonstrate that both anlotinib and DDP independently inhibit BRCA cell growth, migration, and invasion, while their combination exhibits a synergistic effect, significantly enhancing the inhibition of these oncogenic processes. This synergy is further evident through the induction of apoptosis and autophagy in BRCA cells. Mechanistically, anlotinib’s effectiveness is linked to its inhibition of the JAK2/STAT3 pathway, a critical axis in BRCA progression. In vivo study further support these results, showing that anlotinib markedly inhibits tumor growth in xenografted mice.ConclusionThis study confirms the efficacy of anlotinib or in combination with DDP and elucidates the mechanism behind anlotinib’s effectiveness, highlighting its role in inhibiting the JAK2/STAT3 pathway.

Photobiomodulation and Physical Exercise Modulate of Cell Survival Proteins in the Skeletal Muscle of Rats with Heart Failure and Diabetes Mellitus.

Introduction: Heart failure (HF) and type 2 diabetes mellitus (DM2) are global health problems that often lead to muscle atrophy. These conditions are associated with increased autophagy and apoptosis in the muscle cells, resulting in decreased muscle mass. Physical exercise associated with photobiomodulation (PBM) seems promising to attenuate the skeletal muscle changes caused by HF and DM2, due to its direct effects on mitochondria, which may result in an increase in antioxidant capacity. Objective: To verify the influence of physical exercise and the association with PBM on autophagy, apoptosis, and cell survival signaling pathways in myocytes from rats with HF and DM2. Materials and Methods: Male rats were assigned to one of four groups: control (CT), HF+DM (disease model), exercise+HF+DM (EX+HF+DM), and EX+HF+DM+PBM (EX+HF+DM+PBM). To induce DM2, we administered streptozotocin (STZ) (0.25 mL/kg, intraperitoneally). HF was induced by coronary ligation. One week post-induction, an 8-week aerobic exercise and PBM protocol was initiated. Western blot analysis was used to measure the expression of apoptosis-related proteins and autophagy. Results: The EX+HF+DM+PBM group showed a substantial increase in Nrf2, p-AKT, and LC3-I levels compared to the HF+DM group. Conclusions: These findings suggest that physical exercise combined with PBM can upregulate proteins that promote myocyte survival in rats with HF and DM2.

Honokiol inhibits human osteosarcoma MG63 cell migration by upregulating FTO and Smad6 to promote autophagy

BackgroundOsteosarcoma (OS) is a common primary malignant tumor of bone, most commonly seen in children and adolescents, which has a low survival rate and is a serious threat to patients' lives. Honokiol (HKL) is the main active components of Magnolia officinalis, which have significant anti-tumor properties. The aim of this study was to observe the autophagic and migratory effects of HKL on MG63 cells and to investigate whether the mechanism of action was related to FTO and Smad6. MethodsFirstly, we cultured MG63 cells in vitro and intervened with different concentrations of HKL to detect cell activity by CCK8, apoptosis by flow cytometry, cell migration ability by scratch assay, cell invasion ability by transwell assay and MMP2, P62, LC3 I/II, FTO and Smad6 protein expression by Western blot. ResultsHKL inhibited MG63 cells activity and that this effect was dose and time dependent. Although there was no significant effect on apoptosis and invasive ability, HKL could act through effects such as promoting cell autophagy and inhibiting migration. HKL increased the protein expression levels of FTO, Smad6, MMP2, LC3 I/II and P62, and this effect was reduced after silencing of Smad6. ConclusionsHKL induced autophagy and inhibited cell migration in MG63 cells by increasing the expression of FTP and Smad6. It can be seen that HKL may be a promising drug for the treatment of OS.

Divergent regulation of long non-coding RNAs H19 and PURPL affects cell senescence in human dermal fibroblasts.

Cellular senescence is a permanent cell growth arrest that occurs in response to various intrinsic and extrinsic stimuli and is associated with cellular and molecular changes. Long non-coding RNAs (lncRNAs) are key regulators of cellular senescence by affecting the expression of many important genes involved in senescence-associated pathways and processes. Here, we evaluated a panel of lncRNAs associated with senescence for their differential expression between young and senescent human dermal fibroblasts (NHDFs) and studied the effect of a known senomorphic compound, resveratrol, on the expression of lncRNAs in senescent NHDFs. As markers of senescence, we evaluated cell growth, senescence-associated (SA)-β-Gal staining, and the expression of p21, Lamin B1 and γH2AX. We found that H19 and PURPL were the most altered lncRNAs in replicative, in doxorubicin (DOXO) and ionising radiation (IR)-induced senescence models. We then investigated the function of H19 and PURPL in cell senescence by siRNA-mediated silencing in young and senescent fibroblasts, respectively. Our results showed that H19 knockdown reduced cell viability and induced cell senescence and autophagy of NHDFs through the regulation of the PI3K/AKT/mTOR pathway; conversely, PURPL silencing reversed senescence by reducing (SA)-β-Gal staining, recovering cell proliferation with an increase of S-phase cells, and reducing the p53-dependent DNA damage response. Overall, our data highlighted the role of H19 and PURPL in the senescent phenotype and suggested that these lncRNAs may have important implications in senescence-related diseases.

Application of Peptide-Conjugated Photosensitizers for Photodynamic Cancer Therapy: A Review

Photodynamic therapy (PDT) is a clinically approved therapeutic option for the treatment of various types of cancer. PDT calls for the application of photosensitizers (PSs) and photoactivation with a particular light wavelength while tissue oxygen is present. Anticancer efficacy depends on the combination of these three substrates leading to the generation of cytotoxic reactive oxygen species (ROS) that promote apoptosis, necrosis, and autophagy of cancer cells. However, one of the biggest problems with conventional PDT is the poor accumulation and targeting of PSs to tumor tissues, resulting in undesirable side effects and unfavorable therapeutic outcomes. To overcome this, new photosensitizers have been developed through bioconjugation and encapsulation with targeting molecules, such as peptides, allowing a better accumulation and targeting in tumor cells. Several studies have been conducted to test the efficacy of several peptide-conjugated photosensitizers and improve PDT efficacy. This review aims to present current insights into various types of peptide-conjugated photosensitizers, with the goal of enhancing cancer treatment efficacy, addressing the limitations of conventional PDT, and expanding potential applications in medicine.

Polyphenol-mediated redox-active hydrogel with H2S gaseous-bioelectric coupling for periodontal bone healing in diabetes.

Excessive oxidative response, unbalanced immunomodulation, and impaired mesenchymal stem cell function in periodontitis in diabetes makes it a great challenge to achieve integrated periodontal tissue regeneration. Here, a polyphenol-mediated redox-active algin/gelatin hydrogel encapsulating a conductive poly(3,4-ethylenedioxythiopene)-assembled polydopamine-mediated silk microfiber network and a hydrogen sulfide sustained-release system utilizing bovine serum albumin nanoparticles is developed. This hydrogel is found to reverse the hyperglycemic inflammatory microenvironment and enhance functional tissue regeneration in diabeticperiodontitis. Polydopamine confers the hydrogel with anti-oxidative and anti-inflammatory activity. Theslow, sustained release of hydrogen sulfide from the bovine serum albumin nanoparticles recruits mesenchymal stem cells and promotes subsequent angiogenesis and osteogenesis. Moreover, poly(3,4-ethylenedioxythiopene)-assembled polydopamine-mediated silk microfiber confers the hydrogel with good conductivity, which enables it to transmit endogenous bioelectricity, promote cell arrangement, and increase the inflow of calcium ion. In addition, the synergistic effects of hydrogen sulfide gaseous-bioelectric coupling promotes bone formation by amplifying autophagy in periodontal ligament stem cells and modulating macrophage polarization via lipid metabolism regulation. This study provides innovative insights into the synergistic effects of conductivity, reactive oxygen species scavenging, and hydrogen sulfide on the periodontium in a hyperglycemic inflammatory microenvironment, offering a strategy for the design of gaseous-bioelectric biomaterials to promote functional tissue regeneration in immune-related diseases.

Resatovir Combined with Glycyrrhizic Acid Ameliorates Osteoarthritis and Enhances Autophagy in Chondrocytes

Background Osteoarthritis (OA) is a chronic disease worldwide. With resatovir usually used as an inhibitor, resatovir and glycyrrhizic acid have several pharmacological activities. Purpose We intend to explore the mechanism underlying resatovir combined with glycyrrhizic acid in OA. Methods After the establishment of an animal model of OA through anterior cruciate ligament transection and destabilization of the medial meniscus, the rats were subjected to intramuscular injection of resatovir combined with glycyrrhizic acid (60 mg/kg) or 5% glucose (60 mg/kg) every day for 4 weeks. During the progress, the rat movement and the bend score of knees were observed through behavioral studies. Additionally, the SKP2 gene expression and toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB)-related signaling pathways were examined, as apoptosis and autophagy were evaluated by flow cytometry. Results With increased inflammatory cells in the model group, treatment with resatovir combined with glycyrrhizic acid significantly decreased the number of inflammatory cells. Meanwhile, the treatment resulted in decreased SKP2 expression in OA cells when hindering the migration of preosteoclast cells. Interestingly, it was observed that the bend score increased over the treatment with resatovir plus glycyrrhizic acid and TIPPI% declined dramatically. Resatovir treatment enhanced autophagy and apoptosis in OA cells and decreased pP65, P65, and LC3 expression. Conclusion Resatovir combined with glycyrrhizic acid can inhibit the inflammatory response through decreasing SKP2 expression and induce autophagy activation in OA cells through TLR4/NF-κB signaling, thereby attenuating OA progression.

Discovery of Arene Ruthenium(II) Complexes as Potential VEGF Inhibitors for Glioblastoma Metastasis Suppression.

Developing drugs for treating glioblastoma has been a significant challenge. Herein, a series of arene ruthenium(II) complexes have been synthesized and investigated as potential candidates to suppress the proliferation and metastasis of glioblastoma. It is found that para-substituent-modified molecules, especially 6, exhibit higher antitumor activity than ortho-substituents. Further studies show that 6 can trigger tumor cell autophagy by regulating the PI3K/AKT/mTOR pathway. Moreover, it is also found that 6 can induce DNA damage in glioblastoma cells through binding and stabilizing VEGF G-quadruplex DNA. Furthermore, it is confirmed that 6 can inhibit the proliferation and metastasis of U87-MG glioblastoma cell in situ xenograft in the zebrafish model. Hence, arene ruthenium(II) complexes can be developed as promising therapeutic agents for glioblastoma treatment in the future.

Anticancer Effects of Weizmannia coagulans MZY531 Postbiotics in CT26 Colorectal Tumor-Bearing Mice by Regulating Apoptosis and Autophagy

Weizmannia coagulans has been shown to have anticancer properties. However, there is limited research on the effects of postbiotic W. coagulans on colorectal cancer cell proliferation. Additionally, the exact mechanisms through which it influences apoptosis- and autophagy-related signaling pathways are yet to be thoroughly elucidated. This study explored the role of W. coagulans MZY531 as a postbiotic in inhibiting tumor growth by modulating apoptosis and autophagy in tumor cells. During the experimental period in the model group, tumors proliferated, tumor markers increased significantly, and immunofluorescence results showed that caspase-3 and terminal deoxynucleotidyl transferase dUTP nick-end labeling were significantly decreased. Conversely, supplementation with W. coagulans MZY531 postbiotics significantly reduced the levels of tumor markers carcinoembryonic antigen, colon cancer antigen, and extracellular protein kinase A and promoted cell apoptosis by increasing the caspase-3-positive count and terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells in tumor tissue. Mechanistically, W. coagulans MZY531 postbiotics inhibit tumor growth through the modulation of the Bax/Bcl-2/caspase-3 and JAK2/STAT3 apoptosis pathways and PI3K/AKT/mTOR and TGF-β/SMAD4 cell autophagy pathways. W. coagulans MZY531 postbiotics had a more significant effect than that of W. coagulans MZY531 alone. Probiotics are expected to become effective natural functional foods for the treatment of colorectal cancer.

Interconnection of CD133 Stem Cell Marker with Autophagy and Apoptosis in Colorectal Cancer.

CD133 protein expression is observable in differentiated cells, stem cells, and progenitor cells within normal tissues, as well as in tumor tissues, including colorectal cancer cells. The CD133 protein is the predominant cell surface marker utilized to detect cancer cells exhibiting stem cell-like characteristics. CD133 alters common abnormal processes in colorectal cancer, such as the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and Wnt/β-catenin pathways. Autophagy is a cellular self-digestion mechanism that preserves the intracellular milieu and plays a dual regulatory role in cancer. In cancer cells, apoptosis is a critical cell death mechanism that can impede cancer progression. CD133 can modulate autophagy and apoptosis in colorectal cancer cells via several signaling pathways; hence, it is involved in the regulation of these intricate processes. This can be an explanation for why CD133 expression is associated with enhanced cellular self-renewal, migration, invasion, and survival under stress conditions in colorectal cancer. The purpose of this review article is to explain the complex relationship between the CD133 protein, apoptosis, and autophagy. We also want to highlight the possible ways that CD133-mediated autophagy may affect the apoptosis of colorectal cancer cells. Targeting the aforementioned mechanisms may have a significant therapeutic role in eliminating CD133-positive stem cell-phenotype colorectal cancer cells, which can be responsible for tumor recurrence.

ATF4/PHGDH mediates the effects of ER stress on cadmium-induced autophagy and glycolysis

Cadmium (Cd) has been classified as a Class I carcinogen, but the mechanism of its carcinogenicity is still unknown. Our previous study demonstrated that 2 μM CdCl2 induced autophagy in A549 cells. In this study, we investigated the role of ATF4/PHGDH in Cd-induced autophagy and increased glycolysis. First, BALB/c mice were subcutaneously injected with A549 cells co-treated with or without Cd and siPHGDH to establish a xenograft tumor model, which demonstrated that PHGDH promotes Cd-induced autophagy in vivo. Cd-exposed A549 cells were treated with siPHGDH and 0.4 mM glycine (Gly), respectively. Western blot analysis and Acridine orange staining revealed that PHGDH promotes Cd-induced autophagy. Using 4-PBA (5 mM), the inhibitor of ER stress, or Tm (0.1 μg/ml), the inducer of ER stress, inhibited Cd-induced PHGDH expression. After co-treatment with siPHGDH, PHGDH was determined to mediate ER stress-induced autophagy. Furthermore, transfection with siATF4 inhibited Tm-induced PHGDH expression. ChIP-qPCR experiments demonstrated the transcription regulatory mechanism of ATF4 on PHGDH. Meanwhile, the role of ER stress/PHGDH/autophagy in Cd-promoted cell migration was explored by scratch assay. Finally, the role of ER stress/PHGDH/autophagy in Cd-induced glycolysis was unveiled. In summary, the transcriptional regulation of PHGDH by ATF4 plays a crucial role in Cd-induced autophagy triggered by ER stress. The axis of ER stress/PHGDH/autophagy is important in Cd-induced cell migration by enhancing glycolysis.

Antiviral effects of Sarcodia suae water extracts against vesicular stomatitis virus infection

ABSTRACT Marine algae, a rich source of bioactive substances, have long been utilized in biomedical and veterinary sciences. This study breaks new ground by assessing the antiviral therapeutic potential of water extracts from four algal species – Colaconema formosanum, Caulerpa microphysa, Gelidium amansii and Sarcodia suae – against vesicular stomatitis virus (VSV) infection. The standout among these was Sarcodia suae water extract (SSWE), which not only significantly repressed VSV replication and enhanced cell survival without cytotoxic effects, but also demonstrated its antiviral activity through interference with viral attachment, entry, RNA replication, and egress, and reduced VSV-induced autophagy in Mv1Lu cells during the late stages of infection. The EC50 of SSWE was 0.422 ± 0.14 mg ml‒1. The cytotoxicity assay confirmed the high biocompatibility of SSWE. This study identifies SSWE as a promising natural antiviral agent and elucidates its mechanisms of action, highlighting the need for further research to optimize its use in controlling VSV-related diseases.

Gynostemma pentaphyllum (Thunb.) Makino Affects Autophagy and Improves Diabetic Peripheral Neuropathy Through TXNIP-Mediated PI3K/AKT/mTOR Signaling Pathway.

TXNIP is closely associated with diabetic peripheral neuropathy (DPN). Gynostemma pentaphyllum (Thunb.) Makino (GP), a perennial herb with five leaves, is considered to have medicinal values. However, it is unknown whether GP alleviates DPN by modulating TXNIP-mediated autophagy. The aim of this study was to evaluate the effect of GP on Schwann cell injury during DPN and to investigate the mechanism of GP in DPN for the first time. High-fat diet-fed GK rats and high-glucose-cultured RSC96 cells were used to establish DPN models. The effects of GP on DPN were investigated by blood glucose assay, neurological function assay, pathology assay, and immunohistochemistry. To investigate the effect of GP on autophagy and upstream PI3K/AKT/mTOR signaling pathway in Schwann cells, Western blot and immunofluorescence assay were performed on RSC96 cells to detect the expression of beclin-1 and LC3. Western blot method was used to detect the expression of PI3K, p-Akt/Akt, p-mTOR/mTOR, and RT-qPCR method and was used to detect the expression of PI3K. Apoptosis was detected by flow cytometry. The effects of TXNIP on the above indicators were also detected in RSC96 cells. Finally, the mechanism of GP regulation of autophagy and apoptosis in RSC96 cells was verified. GP reduced blood glucose level, attenuated peripheral nerve myelin damage, and improved nerve function in DPN rats. In addition, GP enhanced autophagy activity and reduced apoptosis in RSC96 cells. GP promoted autophagy by regulating TXNIP-mediated PI3K/AKT/mTOR signaling pathway, and GP reduced apoptosis in RSC96 cells by promoting cellular autophagy. GP attenuates DPN myelin damage in RSC96 cells by enhancing autophagy, and its mechanism may be related to the inhibition of PI3K/AKT/mTOR signaling pathway by up-regulating the expression of TXNIP.