Anti-Survival and Pro-Apoptotic Effects of 6-Shogaol on SW872 Human Liposarcoma Cells via Control of the Intrinsic Caspase Pathway, STAT-3, AMPK, and ER Stress

ALKBH5 protects against stroke by reducing endoplasmic reticulum stress-dependent inflammation injury via the STAT5/PERK/EIF2α/CHOP signaling pathway in an m6A-YTHDF1-dependent manner

BACKGROUND

Endoplasmic reticulum (ER) stress causes neuroinflammation and neuronal apoptosis during ischemic stroke progression. This study has investigated the role of ALKBH5 in ER stress during ischemic stroke progression.

METHODS

In vivo and in vitro models of ischemic stroke were established by middle cerebral artery occlusion (MCAO) and OGD/R treatment, respectively. Cerebral infarct size was detected using triphenyltetrazolium chloride staining (TTC), and pathological changes were examined using histological staining. The levels of inflammatory factors were analyzed using Enzyme-linked immunosorbent assay. Cell counting kit-8 assay and flow cytometry were used to measure cell viability and apoptosis, respectively. The global m6A level was detected using the commercial kit, and STAT5 mRNA m6A level was determined using methylated RNA binding protein immunoprecipitation (Me-RIP). ALKBH5, YTHDF1, and STAT5 interactions were analyzed using RIP and RNA pull-down assays.

RESULTS

ALKBH5 was upregulated in MCAO animals and OGD/R cell models. ALKBH5 knockdown exacerbated ER stress, neuroinflammation, and neuronal apoptosis in brain tissues and neuronal cells. ALKBH5 inhibited STAT5 mRNA stability and expression in an m6A-YTHDF1-dependent manner. STAT5 promoted ER stress by activating the PERK/eIF2/CHOP signaling pathway. Furthermore, STAT5 knockdown reversed the effects of ALKBH5 knockdown on OGD/R-induced ER stress and neuroinflammation in HT22 cells.

CONCLUSION

ALKBH5 knockdown exacerbated ischemic stroke by increasing ER stress-dependent neuroinflammation and neuronal apoptosis via the STAT5/PERK/EIF2α/CHOP signaling pathway in an m6A-YTHDF1-dependent manner.

An overview of 6-shogaol: new insights into its pharmacological properties and potential therapeutic activities

Ginger (Zingiber officinale Roscoe) has traditionally been used as a cooking spice and herbal medicine for treating nausea and vomiting. More recently, ginger was found to effectively reduce the risk of diseases such as gastroenteritis, migraine, gonarthritis, etc., due to its various bioactive compounds. 6-Shogaol, the pungent phenolic substance in ginger, is the most pharmacologically active among such compounds. The aim of the present study was to review the pharmacological characteristic of 6-shogaol, including the properties of anti-inflammatory, antioxidant and antitumour, and its corresponding molecular mechanism. With its multiple mechanisms, 6-shogaol is considered a beneficial natural compound, and therefore, this review will shed some light on the therapeutic role of 6-shogaol and provide a theoretical basis for the development and clinical application of 6-shogaol.

Anticancer perspective of 6-shogaol: anticancer properties, mechanism of action, synergism and delivery system

Cancer is a malignant disease that has plagued human beings all the time, but the treatment effect of commonly used anticancer drugs in clinical practice is not ideal by reason of their drug tolerance and Strong adverse reactions to patients. Therefore, it is imperative to find effective and low-toxic anticancer drugs. Many research works have shown that natural products in Chinese herbal medicine have great anticancer potential, such as 6-shogaol, a monomer composition obtained from Chinese herbal ginger, which has been confirmed by numerous in vitro or vivo studies to be an excellent anti-cancer active substance. In addition, most notably, 6-shogaol has different selectivity for normal and cancer cells during treatment, which makes it valuable for further research and clinical development. Therefore, this review focus on the anti-cancer attributes, the mechanism and the regulation of related signaling pathways of 6-shogaol. In addition, its synergy with commonly used anticancer drugs, potential drug delivery systems and prospects for future research are discussed. This is the first review to comprehensively summarize the anti-cancer mechanism of 6-shogaol, hoping to provide a theoretical basis and guiding significance for future anti-cancer research and clinical development of 6-shogaol.

Anti-adipogenic and Pro-lipolytic Effects on 3T3-L1 Preadipocytes by CX-4945, an Inhibitor of Casein Kinase 2

Casein kinase 2 (CK2) is a ubiquitously expressed serine/threonine kinase and is upregulated in human obesity. CX-4945 (Silmitasertib) is a CK2 inhibitor with anti-cancerous and anti-adipogenic activities. However, the anti-adipogenic and pro-lipolytic effects and the mode of action of CX-4945 in (pre)adipocytes remain elusive. Here, we explored the effects of CX-4945 on adipogenesis and lipolysis in differentiating and differentiated 3T3-L1 cells, a murine preadipocyte cell line. CX-4945 at 15 μM strongly reduced lipid droplet (LD) accumulation and triglyceride (TG) content in differentiating 3T3-L1 cells, indicating the drug’s anti-adipogenic effect. Mechanistically, CX-4945 reduced the expression levels of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and perilipin A in differentiating 3T3-L1 cells. Strikingly, CX-4945 further increased the phosphorylation levels of cAMP-activated protein kinase (AMPK) and liver kinase B-1 (LKB-1) while decreasing the intracellular ATP content in differentiating 3T3-L1 cells. In differentiated 3T3-L1 cells, CX-4945 had abilities to stimulate glycerol release and elevate the phosphorylation levels of hormone-sensitive lipase (HSL), pointing to the drug’s pro-lipolytic effect. In addition, CX-4945 induced the activation of extracellular signal-regulated kinase-1/2 (ERK-1/2), and PD98059, an inhibitor of ERK-1/2, attenuated the CX4945-induced glycerol release and HSL phosphorylation in differentiated 3T3-L1 cells, indicating the drug’s ERK-1/2-dependent lipolysis. In summary, this investigation shows that CX-4945 has strong anti-adipogenic and pro-lipolytic effects on differentiating and differentiated 3T3-L1 cells, mediated by control of the expression and phosphorylation levels of CK2, C/EBP-α, PPAR-γ, FAS, ACC, perilipin A, AMPK, LKB-1, ERK-1/2, and HSL.

Growth-Suppressive and Apoptosis-Inducing Effects of Tetrandrine in SW872 Human Malignant Liposarcoma Cells via Activation of Caspase-9, Down-Regulation of XIAP and STAT-3, and ER Stress

Liposarcoma is a rare and heterogeneous soft tissue malignant tumor and has a significant impact on mortality with a poor prognosis. To date, there is no effective treatment for liposarcoma, whereas surgical resection is only the gold treatment with numerous adverse effects. Here we investigated whether tetrandrine inhibits the growth of SW872 human malignant liposarcoma cells. Of note, tetrandrine at 10 μM vastly inhibited growth and induced apoptosis, as evidenced by increased nuclear DNA fragmentation and sub-G1 population of SW872 cells. Mechanistically, treatment with tetrandrine led to activation of caspase-9/3 in SW872 cells, and z-VAD-fmk, a pan-caspase inhibitor, attenuated the tetrandrine-induced apoptosis and growth suppression in SW872 cells. In addition, tetrandrine treatment resulted in down-regulation of XIAP andSTAT-3 in SW872 cells, and importantly knockdown of STAT-3 caused a significant reduction of the cell survival. Tetrandrine also had abilities to up-regulate not only the expression of GRP78 and ATF-4 but also the phosphorylation of eIF-2α in SW872 cells. In summary, these results demonstrated that tetrandrine has strong growth-suppressive and apoptosis-inducing effects on SW872 cells, which are mediated through control of the intrinsic caspase pathway, down-regulation of XIAP and STAT-3, and triggering ER stress.

Plant-Derived Compounds as Promising Therapeutics for Vitiligo

Vitiligo is the most common depigmenting disorder characterized by white patches in the skin. The pathogenetic origin of vitiligo revolves around autoimmune destruction of melanocytes in which, for instance, oxidative stress is responsible for melanocyte molecular, organelle dysfunction and melanocyte specific antigen exposure as well as melanocyte cell death and thus serves as an important contributor for vitiligo progression. In recent years, natural products have shown a wide range of pharmacological bioactivities against many skin diseases, and this review focuses on the effects and mechanisms of natural compounds against vitiligo models. It is showed that some natural compounds such as flavonoids, phenols, glycosides and coumarins have a protective role in melanocytes and thereby arrest the depigmentation, and, additionally, Nrf2/HO-1, MAPK, JAK/STAT, cAMP/PKA, and Wnt/β-catenin signaling pathways were reported to be implicated in these protective effects. This review discusses the great potential of plant derived natural products as anti-vitiligo agents, as well as the future directions to explore.