Autophagy Inhibits Inflammation via Down-Regulation of p38 MAPK/mTOR Signaling Cascade in Endothelial Cells

Artemisia Argyi essential oil ameliorates acetaminophen-induced hepatotoxicity via CYP2E1 and γ-glutamyl cycle reprogramming

BACKGROUND

The hepatotoxicity induced by acetaminophen (APAP), a commonly used antipyretic, analgesic and anti-inflammatory drug in clinical practice, has received accumulated attention. Artemisia argyi essential oil (AAEO), a volatile oil component extracted from traditional Chinese medicine Artemisia argyi H.Lév. & Vaniot, has great hepatoprotective effects. However, the potential role of AAEO in APAP-induced hepatotoxicity has not been characterized. The present study aimed to investigate the effects of AAEO on hepatic metabolic changes in mice exposed to APAP.

METHODS

In this study, 300.00 mg/kg acetaminophen was used to establish liver injury model in C57BL/6 J mice. Hepatoprotective effect of AAEO on APAP-induced hepatotoxicity in mice was investigated by detecting liver function enzymes and histopathological examination. Secondly, UPLC-MS/MS was used to analyze the to analyze the small molecule metabolites and metabolic pathways induced by AAEO treatment; In addition, the effect of AAEO on APAP-induced oxidative stress and inflammation were evaluated by detecting the levels of glutathione peroxidase 4, malondialdehyde, reactive oxygen species and inflammatory factors. Finally, the active components of AAEO were preliminarily screened by cellular assays. The hepatoprotective effect of AAEO against APAP-induced hepatotoxicity was examined through the Western blotting, after the CYP2E1 gene was knocked down in AML12 cells by siRNA transfection.

RESULTS

Compared with the APAP group, AAEO could reduce the abnormal increase in the levels of liver function enzymes caused by APAP. AAEO could enhance the antioxidant capacity by down-regulating the biosynthesis pathway of unsaturated fatty acids and promoting the activity of antioxidant enzymes SOD and CAT in liver tissue induced by APAP. Our study revealed that AAEO promoted GSH synthesis and covalently combined to form APAP-GSH conjugates to reduce the accumulation of APAP in liver tissue. In addition, the chemical constituents in AAEO were analyzed by GC-MS/MS, and it was determined to identify that dihydro-beta-ionone and (-)-verbenone in AAEO might have a significant protective effect on hepatocyte survival after APAP exposure. Further studies on the hepatoprotective mechanism of AAEO indicated that it might reduce the production of toxic metabolites by regulating CYP2E1 levels.

CONCLUSION

AAEO exerted hepatoprotective effects on acetaminophen-induced hepatotoxicity in mice via regulating the activity of CYP2E1 and regulating the γ-glutamyl cycle pathway.

Paeoniflorin protects hepatocytes from APAP-induced damage through launching autophagy via the MAPK/mTOR signaling pathway

BACKGROUND

Drug-induced liver injury (DILI) is gradually becoming a common global problem that causes acute liver failure, especially in acute hepatic damage caused by acetaminophen (APAP). Paeoniflorin (PF) has a wide range of therapeutic effects to alleviate a variety of hepatic diseases. However, the relationship between them is still poorly investigated in current studies.

PURPOSE

This work aimed to explore the protective effects of PF on APAP-induced hepatic damage and researched the potential molecular mechanisms.

METHODS

C57BL/6J male mice were injected with APAP to establish DILI model and were given PF for five consecutive days for treatment. Aiming to clarify the pharmacological effects, the molecular mechanisms of PF in APAP-induced DILI was elucidated by high-throughput and other techniques.

RESULTS

The results demonstrated that serum levels of ALP, γ-GT, AST, TBIL, and ALT were decreased in APAP mice by the preventive effects of PF. Moreover, PF notably alleviated hepatic tissue inflammation and edema. Meanwhile, the results of TUNEL staining and related apoptotic factors coincided with the results of transcriptomics, suggesting that PF inhibited hepatocyte apoptosis by regulated MAPK signaling. Besides, PF also acted on reactive oxygen species (ROS) to regulate the oxidative stress for recovery the damaged mitochondria. More importantly, transmission electron microscopy showed the generation of autophagosomes after PF treatment, and PF was also downregulated mTOR and upregulated the expression of autophagy markers such as ATG5, ATG7, and BECN1 at the mRNA level and LC3, p62, ATG5, and ATG7 at the protein level, implying that the process by which PF exerted its effects was accompanied by the occurrence of autophagy. In addition, combinined with molecular dynamics simulations and western blotting of MAPK, the results suggested p38 as a direct target for PF on APAP. Specifically, PF-activated autophagy through the downregulation of MAPK/mTOR signaling, which in turn reduced APAP injury.

CONCLUSIONS

Paeoniflorin mitigated liver injury by activating autophagy to suppress oxidative stress and apoptosis via the MAPK/mTOR signaling pathway. Taken together, our findings elucidate the role and mechanism of paeoniflorin in DILI, which is expected to provide a new therapeutic strategy for the development of paeoniflorin.

Nrf2 Connects Cellular Autophagy and Vascular Senescence in Atherosclerosis: A Mini-Review

Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcriptional factor that maintains intracellular redox equilibrium, modulates the expression of antioxidant genes, scavenger receptors, and cholesterol efflux transporters, all of which contribute significantly to foam cell development and plaque formation. Nrf2 has recently emerged as a key regulator that connects autophagy and vascular senescence in atherosclerosis. Autophagy, a cellular mechanism involved in the breakdown and recycling of damaged proteins and organelles, and cellular senescence, a state of irreversible growth arrest, are both processes implicated in the pathogenesis of atherosclerosis. The intricate interplay of these processes has received increasing attention, shedding light on their cumulative role in driving the development of atherosclerosis. Recent studies have revealed that Nrf2 plays a critical role in mediating autophagy and senescence in atherosclerosis progression. Nrf2 activation promotes autophagy, which increases lipid clearance and prevents the development of foam cells. Meanwhile, the activation of Nrf2 also inhibits cellular senescence by regulating the expression of senescence markers to preserve cellular homeostasis and function and delay the progression of atherosclerosis. This review provides an overview of the molecular mechanisms through which Nrf2 connects cellular autophagy and vascular senescence in atherosclerosis. Understanding these mechanisms can provide insights into potential therapeutic strategies targeting Nrf2 to modulate cellular autophagy and vascular senescence, thereby preventing the progression of atherosclerosis.

Will AMPK be a potential therapeutic target for hepatocellular carcinoma?

Cancer is the disease that poses the greatest threat to human health today. Among them, hepatocellular carcinoma (HCC) is particularly prominent due to its high recurrence rate and extremely low five-year postoperative survival rate. In addition to surgical treatment, radiotherapy, chemotherapy, and immunotherapy are the main methods for treating HCC. Due to the natural drug resistance of chemoradiotherapy and targeted drugs, satisfactory results have not been achieved in terms of therapeutic efficacy and cost. AMP-Activated Protein Kinase (AMPK) is a serine/threonine protein kinase. It mainly coordinates the metabolism and transformation of energy between cells, which maintaining a balance between energy supply and demand. The processes of cell growth, proliferation, autophagy, and survival all involve various reaction of cells to energy changes. The regulatory role of AMPK in cellular energy metabolism plays an important role in the occurrence, development, treatment, and prognosis of HCC. Here, we reviewed the latest progress on the regulatory role of AMPK in the occurrence and development of HCC. Firstly, the molecular structure and activation mechanism of AMPK were introduced. Secondly, the emerging regulator related to AMPK and tumors were elaborated. Next, the multitasking roles of AMPK in the occurrence and development mechanism of HCC were discussed separately. Finally, the translational implications and the challenges of AMPK-targeted therapies for HCC treatment were elaborated. In summary, these pieces of information suggest that AMPK can serve as a promising specific therapeutic target for the treatment of HCC.

Skin barrier-inflammatory pathway is a driver of the psoriasis-atopic dermatitis transition

As chronic inflammatory conditions driven by immune dysregulation are influenced by genetics and environment factors, psoriasis and atopic dermatitis (AD) have traditionally been considered to be distinct diseases characterized by different T cell responses. Psoriasis, associated with type 17 helper T (Th17)-mediated inflammation, presents as well-defined scaly plaques with minimal pruritus. AD, primarily linked to Th2-mediated inflammation, presents with poorly defined erythema, dry skin, and intense itching. However, psoriasis and AD may overlap or transition into one another spontaneously, independent of biological agent usage. Emerging evidence suggests that defects in skin barrier-related molecules interact with the polarization of T cells, which forms a skin barrier-inflammatory loop with them. This loop contributes to the chronicity of the primary disease or the transition between psoriasis and AD. This review aimed to elucidate the mechanisms underlying skin barrier defects in driving the overlap between psoriasis and AD. In this review, the importance of repairing the skin barrier was underscored, and the significance of tailoring biologic treatments based on individual immune status instead of solely adhering to the treatment guidelines for AD or psoriasis was emphasized.

Cancer Drug Resistance: Targeting Proliferation or Programmed Cell Death

The development of resistance to chemotherapy is one of the main problems for effective cancer treatment. Drug resistance may result from disturbances in two important physiological processes-cell proliferation and cell death. Importantly, both processes characterize alterations in cell metabolism, the level of which is often measured using MTT/MTS assays. To examine resistance to chemotherapy, different cancer cell lines are usually used for the in vitro modulation of developing resistance. However, after the creation of resistant cell lines, researchers often have difficulty in starting investigations of the mechanisms of insensitivity. In the first stage, researchers should address the question of whether the drug resistance results from a depression of cell proliferation or an inhibition of cell death. To simplify the choice of research strategy, we have suggested a combination of different approaches which reveal the actual mechanism. This combination includes rapid and high-throughput methods such as the MTS test, the LIVE/DEAD assay, real-time cell metabolic analysis, and Western blotting. To create chemoresistant tumor cells, we used four different cancer cell lines of various origins and utilized the most clinically relevant pulse-selection approach. Applying a set of methodological approaches, we demonstrated that three of them were more capable of modulating proliferation to avoid the cytostatic effects of anti-cancer drugs. At the same time, one of the studied cell lines developed resistance to cell death, overcoming the cytotoxic action.

Resistin - A Plausible Therapeutic Target in the Pathogenesis of Psoriasis

Resistin, a cytokine hormone predominantly secreted by adipose tissue, is elevated in various metabolic disorders such as obesity, type 2 diabetes, and cardiovascular disease. In addition to its involvement in metabolic regulation, resistin has been implicated in the pathogenesis of psoriasis, a chronic inflammatory skin disorder. Numerous studies have reported increased resistin levels in psoriatic skin lesions, suggesting a possible association between resistin and psoriasis. Recent studies have suggested the potential involvement of resistin in the development and progression of certain cancers. Resistin is overexpressed in breast, colorectal, and gastric cancers. This suggests that it may play a role in the development of these cancers, possibly by inducing inflammation and cell growth. The link between resistin and cancer raises the possibility of shared underlying mechanisms driving the pathogenesis of psoriasis. Chronic inflammation, one such mechanism, is a hallmark of psoriasis and cancer. Further research is needed to fully understand the relationship between resistin and psoriasis. Identifying potential therapeutic targets is crucial for effective management of psoriasis. By doing so, we may be able to develop more effective treatment options for individuals living with psoriasis and ultimately improve their quality of life. Ultimately, a more comprehensive understanding of the mechanisms underlying the impact of resistin on psoriasis is essential for advancing our knowledge and finding new ways to treat and manage this challenging condition.

The obesity-autophagy-cancer axis: Mechanistic insights and therapeutic perspectives

Autophagy, a self-degradative process vital for cellular homeostasis, plays a significant role in adipose tissue metabolism and tumorigenesis. This review aims to elucidate the complex interplay between autophagy, obesity, and cancer development, with a specific emphasis on how obesity-driven changes affect the regulation of autophagy and subsequent implications for cancer risk. The burgeoning epidemic of obesity underscores the relevance of this research, particularly given the established links between obesity, autophagy, and various cancers. Our exploration delves into hormonal influence, notably INS (insulin) and LEP (leptin), on obesity and autophagy interactions. Further, we draw attention to the latest findings on molecular factors linking obesity to cancer, including hormonal changes, altered metabolism, and secretory autophagy. We posit that targeting autophagy modulation may offer a potent therapeutic approach for obesity-associated cancer, pointing to promising advancements in nanocarrier-based targeted therapies for autophagy modulation. However, we also recognize the challenges inherent to these approaches, particularly concerning their precision, control, and the dual roles autophagy can play in cancer. Future research directions include identifying novel biomarkers, refining targeted therapies, and harmonizing these approaches with precision medicine principles, thereby contributing to a more personalized, effective treatment paradigm for obesity-mediated cancer.

Insights into Autophagic Machinery and Lysosomal Function in Cells Involved in the Psoriatic Immune-Mediated Inflammatory Cascade

Impaired autophagy, due to the dysfunction of lysosomal organelles, contributes to maladaptive responses by pathways central to the immune system. Deciphering the immune-inflammatory ecosystem is essential, but remains a major challenge in terms of understanding the mechanisms responsible for autoimmune diseases. Accumulating evidence implicates a role that is played by a dysfunctional autophagy-lysosomal pathway (ALP) and an immune niche in psoriasis (Ps), one of the most common chronic skin diseases, characterized by the co-existence of autoimmune and autoinflammatory responses. The dysregulated autophagy associated with the defective lysosomal system is only one aspect of Ps pathogenesis. It probably cannot fully explain the pathomechanism involved in Ps, but it is likely important and should be seriously considered in Ps research. This review provides a recent update on discoveries in the field. Also, it sheds light on how the dysregulation of intracellular pathways, coming from modulated autophagy and endolysosomal trafficking, characteristic of key players of the disease, i.e., skin-resident cells, as well as circulating immune cells, may be responsible for immune impairment and the development of Ps.