Migration inhibition of water stress proteins from Nostoc commune Vauch. via activation of autophagy in DLD-1 cells

Ultrasonic-assisted extraction of a low molecular weight polysaccharide from Nostoc commune Vaucher and its structural characterization and immunomodulatory activity

In the current study, a novel crude polysaccharide (cNCEP) was extracted from N. commune Vaucher utilizing ultrasonic-assisted extraction (UAE) with 60 % ethanol, employing response surface methodology. The optimal yield of cNCEP was determined to be 8.07 ± 0.08 mg/g, achieved through ultrasonic-assisted extraction under the conditions of a material-to-liquid ratio of 1:22, temperature of 56 °C, power of 570 W, and duration of 147 min. Subsequent purification of NCEP via Sephadex G75 resulted in a novel polysaccharide with a molecular weight of 20.466 kDa. NCEP exhibited significant scavenging activites against DPPH and hydroxyl radicals, as well as notable in vitro immunomodulatory properties. Furthermore, the mechanisms underlying the immunomodulatory effects of NCEP, involving enhancement of immunity, were investigated, revealing potential regulation of MAPK and TLR4-IRF7-NF-κB signaling pathways through RNA-Seq and Western blot analyses. These findings highlight the promising potential of NCEP as an organic immunomodulatory agent and functional food ingredient.

Wnt5a-mediated autophagy contributes to the epithelial-mesenchymal transition of human bronchial epithelial cells during asthma

BACKGROUND

The epithelial-mesenchymal transition (EMT) of human bronchial epithelial cells (HBECs) is essential for airway remodeling during asthma. Wnt5a has been implicated in various lung diseases, while its role in the EMT of HBECs during asthma is yet to be determined. This study sought to define whether Wnt5a initiated EMT, leading to airway remodeling through the induction of autophagy in HBECs.

METHODS

Microarray analysis was used to investigate the expression change of WNT5A in asthma patients. In parallel, EMT models were induced using 16HBE cells by exposing them to house dust mites (HDM) or interleukin-4 (IL-4), and then the expression of Wnt5a was observed. Using in vitro gain- and loss-of-function approaches via Wnt5a mimic peptide FOXY5 and Wnt5a inhibitor BOX5, the alterations in the expression of the epithelial marker E-cadherin and the mesenchymal marker protein were observed. Mechanistically, the Ca2+/CaMKII signaling pathway and autophagy were evaluated. An autophagy inhibitor 3-MA was used to examine Wnt5a in the regulation of autophagy during EMT. Furthermore, we used a CaMKII inhibitor KN-93 to determine whether Wnt5a induced autophagy overactivation and EMT via the Ca2+/CaMKII signaling pathway.

RESULTS

Asthma patients exhibited a significant increase in the gene expression of WNT5A compared to the healthy control. Upon HDM and IL-4 treatments, we observed that Wnt5a gene and protein expression levels were significantly increased in 16HBE cells. Interestingly, Wnt5a mimic peptide FOXY5 significantly inhibited E-cadherin and upregulated α-SMA, Collagen I, and autophagy marker proteins (Beclin1 and LC3-II). Rhodamine-phalloidin staining showed that FOXY5 resulted in a rearrangement of the cytoskeleton and an increase in the quantity of stress fibers in 16HBE cells. Importantly, blocking Wnt5a with BOX5 significantly inhibited autophagy and EMT induced by IL-4 in 16HBE cells. Mechanistically, autophagy inhibitor 3-MA and CaMKII inhibitor KN-93 reduced the EMT of 16HBE cells caused by FOXY5, as well as the increase in stress fibers, cell adhesion, and autophagy.

CONCLUSION

This study illustrates a new link in the Wnt5a-Ca2+/CaMKII-autophagy axis to triggering airway remodeling. Our findings may provide novel strategies for the treatment of EMT-related diseases.

High glucose inhibits autophagy and promotes the proliferation and metastasis of colorectal cancer through the PI3K/AKT/mTOR pathway

BACKGROUND

Colorectal cancer (CRC) ranks among the most prevalent malignancies worldwide, characterized by its complex etiology and slow research progress. Diabetes, as an independent risk factor for CRC, has been widely certified. Consequently, this study centers on elucidating the intricacies of CRC cells initiation and progression within a high-glucose environment.

METHODS

A battery of assays was employed to assess the proliferation and metastasis of CRC cells cultured under varying glucose concentrations. Optimal glucose levels conducive to cells' proliferation and migration were identified. Western blot analyses were conducted to evaluate alterations in apoptosis, autophagy, and EMT-related proteins in CRC cells under high-glucose conditions. The expression of PI3K/AKT/mTOR pathway-associated proteins was assessed using western blot. The effect of high glucose on xenograft growth was investigated in vivo by MC38 cells, and changes in inflammatory factors (IL-4, IL-13, TNF-α, IL-5, and IL-12) were measured via serum ELISA.

RESULTS

Our experiments demonstrated that elevated glucose concentrations promoted both the proliferation and migration of CRC cells; the most favorable glucose dose is 20 mM. Western blot analyses revealed a decrease in apoptotic proteins, such as Bim, Bax, and caspase-3 with increasing glucose levels. Concurrently, the expression of EMT-related proteins, including N-cadherin, vimentin, ZEB1, and MMP9, increased. High-glucose cultured cells exhibited elevated levels of PI3K/AKT/mTOR pathway proteins. In the xenograft model, tumor cells stimulated by high glucose exhibited accelerated growth, larger tumor volumes, and heightened KI67 expression of immunohistochemistry. ELISA experiments revealed higher expression of IL-4 and IL-13 and lower expression of TNF-α and IL-5 in the serum of high-glucose-stimulated mice.

CONCLUSION

The most favorable dose and time for tumor cells proliferation and migration is 20 mM, 48 h. High glucose fosters CRC cell proliferation and migration while suppressing autophagy through the activation of the PI3K/AKT/mTOR pathway.

Recent advancement of autophagy in polyploid giant cancer cells and its interconnection with senescence and stemness for therapeutic opportunities

Recurrent chemotherapy-induced senescence and resistance are attributed to the polyploidization of cancer cells that involve genomic instability and poor prognosis due to their unique form of cellular plasticity. Autophagy, a pre-dominant cell survival mechanism, is crucial during carcinogenesis and chemotherapeutic stress, favouring polyploidization. The selective autophagic degradation of essential proteins associated with cell cycle progression checkpoints deregulate mitosis fidelity and genomic integrity, imparting polyploidization of cancer cells. In connection with cytokinesis failure and endoreduplication, autophagy promotes the formation, maintenance, and generation of the progeny of polyploid giant cancer cells. The polyploid cancer cells embark on autophagy-guarded elevation in the expression of stem cell markers, along with triggered epithelial and mesenchymal transition and senescence. The senescent polyploid escapers represent a high autophagic index than the polyploid progeny, suggesting regaining autophagy induction and subsequent autophagic degradation, which is essential for escaping from senescence/polyploidy, leading to a higher proliferative phenotypic progeny. This review documents the various causes of polyploidy and its consequences in cancer with relevance to autophagy modulation and its targeting for therapeutic intervention as a novel therapeutic strategy for personalized and precision medicine.

HERPUD1 promotes ovarian cancer cell survival by sustaining autophagy and inhibit apoptosis via PI3K/AKT/mTOR and p38 MAPK signaling pathways

HERPUD1 is an important early marker of endoplasmic reticulum stress (ERS) and is involved in the ubiquitination and degradation of several unfolded proteins. However, its role in tumorigenesis is seldom studied, and its role in ovarian cancer is unclear. Lewis y antigen is a tumor-associated sugar antigen that acts as an 'antenna' on the cell surface to receive signals from both inside and outside the cell. We previously reported that Lewis y can promote ovarian cancer by promoting autophagy and inhibiting apoptosis. In this study, we detect the expression of HERPUD1 and Lewis y antigens in 119 different ovarian cancer tissues, determine their relationship with clinicopathological parameters, analyze the correlation between these two proteins, and explore the related cancer-promoting mechanisms through MTT, flow cytometry, western blotting, and bioinformatics. HERPUD1 is highly expressed in ovarian cancer, especially in the early stage, and the expression of HERPUD1 and Lewis y antigen was positively correlated. After overexpression of Lewis y antigen, the expression level of HERPUD1 increased. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathways (KEGG) analysis showed that HERPUD1 and its related genes are enriched in regulating immunity, endoplasmic reticulum stress, ubiquitin-dependent degradation, ERS-induced apoptosis, and other key signaling pathways. We also clarified the HERPUD1 network of kinases, microRNA and transcription factor targets, and the impact of HERPUD1 mutations on prognosis. In addition, HERPUD1 promotes the proliferation of ovarian cancer cells, inhibits apoptosis, affects the cell cycle, promotes the occurrence of autophagy, and inhibits EMT and PI3K/AKT/mTOR and p38MAPK pathways. Overall, HERPUD1, regulated by the expression of tumor-associated protein Lewis y, promotes cell survival in the early stages of tumors, suggesting that HERPUD1 may play an important role in the development of ovarian cancer.

Application of composite coating of Nostoc commune Vauch polysaccharides and sodium carboxymethyl cellulose for preservation of salmon fillets

The spoilage of fish products and the growth of pathogenic bacteria cause great economic loss and serious harm to human health, so fish preservation is very important issue. In this study, Nostoc commune Vauch polysaccharides (NVP) was added into sodium carboxymethyl cellulose (CMC) to form a mixed coating to prepare an active packaging material. The antibacterial and antioxidant activities of NVP, physicochemical properties of the mixed coating, and preservative effects of the coating on salmon fillets were evaluated. The results showed that NVP had good antibacterial and antioxidant activities. Physical characterization of the coating solution showed that when the ratio of NVP to CMC was 1:3, the coating had the best dispersion, denser structure and strongest hydrogen bond. On this basis, NVP/CMC coating can significantly prolong the shelf life of salmon fillets during cold storage by reducing pH, improving the color and texture, delaying the oxidation of fat and protein, inhibiting the growth of microorganisms. At the same time, the coated salmon fillets had good sensory acceptance. The results showed that the edible coating has a broad application prospect in the preservation of fish products.

Ubiquitination-Proteasome System (UPS) and Autophagy Two Main Protein Degradation Machineries in Response to Cell Stress

In response to environmental stimuli, cells make a series of adaptive changes to combat the injury, repair the damage, and increase the tolerance to the stress. However, once the damage is too serious to repair, the cells will undergo apoptosis to protect the overall cells through suicidal behavior. Upon external stimulation, some intracellular proteins turn into unfolded or misfolded protein, exposing their hydrophobic regions to form protein aggregation, which may ultimately produce serious damage to the cells. Ubiquitin plays an important role in the degradation of these unnatural proteins by tagging with ubiquitin chains in the ubiquitin-proteasome or autophagy system. If the two processes fail to eliminate the abnormal protein aggregates, the cells will move to apoptosis and death. Dysregulation of ubiquitin-proteasome system (UPS) and autophagy may result in the development of numerous diseases. This review focuses on the molecular mechanisms of UPS and autophagy in clearance of intracellular protein aggregates, and the relationship between dysregulation of ubiquitin network and diseases.

Autophagy modulates FSS-induced epithelial-mesenchymal transition in hepatocellular carcinoma cells

Hepatocellular carcinoma is a highly fatal disease and threatens human health seriously. Fluid shear stress (FSS), which is caused by the leakage of plasma from abnormally permeable tumor blood vessels and insufficient lymphatic drainage, has been identified as contributing pathologically to cancer metastasis. Autophagy and epithelial-mesenchymal transition (EMT) are both reported to be involved in cancer cell migration and invasion, but little has been revealed about the interaction between autophagy and EMT under a tumor mechanical microenvironment. Here, we identified that exposure to 1.4 dyne/cm² FSS could promote the formation of autophagosomes and significantly increase the expressions of autophagy-related markers of beclin1 and ATG7, and the ratio of LC3Ⅱ/Ⅰ in both of HepG2 and QGY-7703 cells. The FSS loading also elevated the levels of mesenchymal markers N-cadherin, Vimentin, Twist, Snail, and β-catenin, while the epithelial markers E-cadherin showed a decrease. Once the autophagy was blocked by 3-methyladenine (3-MA) or knocking ATG5 down, the occurrence of FSS-induced EMT was inhibited dramatically according to the expression and translocation of E-cadherin, N-cadherin, and β-catenin. Given the effect of EMT on cell migration, we observed that inhibition of autophagy could impede FSS-induced cell migration. Collectively, this study demonstrated that autophagy played a crucial role in FSS-induced EMT and cell migration in hepatocellular carcinoma.

Cyanidin-3-O-glucoside attenuates high glucose-induced podocyte dysfunction by inhibiting apoptosis and promoting autophagy via activation of SIRT1/AMPK pathway

Diabetic nephropathy (DN) is a common and complicated chronic kidney disease around the world. To elucidate and find effective therapies of DN is of vital importance. In this paper, we have discovered that cyanidin-3-O-glucoside (C3G), which is one of the anthocyanins, could alleviate high glucose-induced podocyte dysfunction. MTT, flow cytometry assay, and Western blot analysis showed that C3G could reverse the increase of cell apoptosis under high glucose treatment in MPC5 cells by upregulation of Bcl2 and downregulation of Bax and cleaved caspase-3. Moreover, C3G improved the autophagy decrease that was induced by high glucose through regulating the expression level of LC3-II/LC3-I, Beclin1, and p62. In addition, C3G inhibited epithelial-mesenchymal transition (EMT) by increasing E-cadherin and reducing Vimentin. By further study of the mechanisms, we found C3G activated the SIRT1 and AMPK which were inhibited in high glucose condition. Silencing SIRT1 blocked the effect of C3G on regulating cell apoptosis, autophagy, and EMT. In summary, our current findings suggest the protective effect of C3G against high glucose-induced podocyte dysfunction is by improving autophagy and reducing apoptosis and EMT via activating SIRT1/AMPK pathway. It might be a new insight for the treatment of DN.

Cross talk between autophagy and oncogenic signaling pathways and implications for cancer therapy

Autophagy is a highly conserved metabolic process involved in the degradation of intracellular components including proteins and organelles. Consequently, it plays a critical role in recycling metabolic energy for the maintenance of cellular homeostasis in response to various stressors. In cancer, autophagy either suppresses or promotes cancer progression depending on the stage and cancer type. Epithelial-mesenchymal transition (EMT) and cancer metastasis are directly mediated by oncogenic signal proteins including SNAI1, SLUG, ZEB1/2, and NOTCH1, which are functionally correlated with autophagy. In this report, we discuss the crosstalk between oncogenic signaling pathways and autophagy followed by possible strategies for cancer treatment via regulation of autophagy. Although autophagy affects EMT and cancer metastasis, the overall signaling pathways connecting cancer progression and autophagy are still illusive. In general, autophagy plays a critical role in cancer cell survival by providing a minimum level of energy via self-digestion. Thus, cancer cells face nutrient limitations and challenges under stress during EMT and metastasis. Conversely, autophagy acts as a potential cancer suppressor by degrading oncogenic proteins, which are essential for cancer progression, and by removing damaged components such as mitochondria to enhance genomic stability. Therefore, autophagy activators or inhibitors represent possible cancer therapeutics. We further discuss the regulation of autophagy-dependent degradation of oncogenic proteins and its functional correlation with oncogenic signaling pathways, with potential applications in cancer therapy.

Antiangiogenic effect of arsenic trioxide in HUVECs by FoxO3a-regulated autophagy

Arsenic trioxide (ATO) has been shown to have antitumor effect in different tumors, although the underlying mechanisms are not fully understood. Autophagy plays a critical role in tumorigenesis and cancer therapy and has been found to be activated by ATO in different cells. However, the role of autophagy in the antitumor effect of ATO has not yet been elucidated. In this study, we investigated the role of autophagy in the antiangiogenic effect of ATO in human umbilical vein endothelial cells (HUVECs) in vitro and its underlying mechanism. Our data showed that ATO suppresses angiogenesis and induces autophagy in HUVECs through upregulation of forkhead box protein O3 (FoxO3a). Co-incubated with autophagy inhibitor or knockdown of FoxO3a effectively inhibited ATO-induced autophagy and reversed the antiangiogenic effect of ATO, indicating that ATO-induced autophagy plays an antiangiogenic role in HUVECs. Our results highlight the importance of autophagy in the antiangiogenic effect of ATO and provide an improved understanding of the function of ATO.

Multifaceted WNT Signaling at the Crossroads Between Epithelial-Mesenchymal Transition and Autophagy in Glioblastoma

Tumor cells can employ epithelial-mesenchymal transition (EMT) or autophagy in reaction to microenvironmental stress. Importantly, EMT and autophagy negatively regulate each other, are able to interconvert, and both have been shown to contribute to drug-resistance in glioblastoma (GBM). EMT has been considered one of the mechanisms that confer invasive properties to GBM cells. Autophagy, on the other hand, may show dual roles as either a GBM-promoter or GBM-suppressor, depending on microenvironmental cues. The Wingless (WNT) signaling pathway regulates a plethora of developmental and biological processes such as cellular proliferation, adhesion and motility. As such, GBM demonstrates deregulation of WNT signaling in favor of tumor initiation, proliferation and invasion. In EMT, WNT signaling promotes induction and stabilization of different EMT activators. WNT activity also represses autophagy, while nutrient deprivation induces β-catenin degradation via autophagic machinery. Due to the importance of the WNT pathway to GBM, and the role of WNT signaling in EMT and autophagy, in this review we highlight the effects of the WNT signaling in the regulation of both processes in GBM, and discuss how the crosstalk between EMT and autophagy may ultimately affect tumor biology.

H19/let‑7/Lin28 ceRNA network mediates autophagy inhibiting epithelial‑mesenchymal transition in breast cancer

Long non‑coding RNA (lncRNA) H19 and Lin28 protein have been shown to participate in various pathophysiological processes, including cellular proliferation, autophagy and epithelial‑mesenchymal transition (EMT). A number of studies have investigated lncRNAs, microRNAs and mRNAs, and their roles in the initiation and progression of cancer, in doing so identifying competitive endogenous RNA (ceRNA) networks, including the H19/let‑7/Lin28 network. However, whether the H19/let‑7/Lin28 ceRNA network is involved in autophagy and EMT in breast cancer (BC) remains unclear. The present study demonstrated that the H19/let‑7/Lin28 loop was required for the downregulation of autophagy in BC cells via western blot analysis, reverse transcription‑quantitative PCR and autophagy flux monitoring. Using wound healing, migration and invasion assays, and morphological assays, the H19/let‑7/Lin28 loop was revealed to promote EMT in BC cells. Moreover, the H19/let‑7/Lin28 network was found to contribute to autophagy by inhibiting EMT in BC cells. To the best of our knowledge, the present study is the first to suggest the important roles of the H19/let‑7/Lin28 ceRNA network in BC autophagy and EMT, thus providing insight for the use of these molecules as prognostic biomarkers and therapeutic targets in BC metastasis.

Crosstalk between autophagy and epithelial-mesenchymal transition and its application in cancer therapy

Autophagy is a highly conserved catabolic process that mediates degradation of pernicious or dysfunctional cellular components, such as invasive pathogens, senescent proteins, and organelles. It can promote or suppress tumor development, so it is a “double-edged sword” in tumors that depends on the cell and tissue types and the stages of tumor. The epithelial-mesenchymal transition (EMT) is a complex biological trans-differentiation process that allows epithelial cells to transiently obtain mesenchymal features, including motility and metastatic potential. EMT is considered as an important contributor to the invasion and metastasis of cancers. Thus, clarifying the crosstalk between autophagy and EMT will provide novel targets for cancer therapy. It was reported that EMT-related signal pathways have an impact on autophagy; conversely, autophagy activation can suppress or strengthen EMT by regulating various signaling pathways. On one hand, autophagy activation provides energy and basic nutrients for EMT during metastatic spreading, which assists cells to survive in stressful environmental and intracellular conditions. On the other hand, autophagy, acting as a cancer-suppressive function, is inclined to hinder metastasis by selectively down-regulating critical transcription factors of EMT in the early phases. Therefore, the inhibition of EMT by autophagy inhibitors or activators might be a novel strategy that provides thought and enlightenment for the treatment of cancer. In this article, we discuss in detail the role of autophagy and EMT in the development of cancers, the regulatory mechanisms between autophagy and EMT, the effects of autophagy inhibition or activation on EMT, and the potential applications in anticancer therapy.