Hydrogen sulfide promotes autophagy of hepatocellular carcinoma cells through the PI3K/Akt/mTOR signaling pathway

Sulfide regulation and catabolism in health and disease

The metabolic pathway of sulfur-containing amino acids in organisms begins with methionine, which is metabolized to produce important sulfur-containing biomolecules such as adenosylmethionine, adenosylhomocysteine, homocysteine, cystine, and hydrogen sulfide (H2S). These sulfur-containing biomolecules play a wide range of physiological roles in the body, including anti-inflammation, antioxidant stress, DNA methylation, protein synthesis, etc., which are essential for maintaining cellular function and overall health. In contrast, dysregulation of the metabolic pathway of sulfur-containing amino acids leads to abnormal levels of sulfur-containing biomolecules, which produce a range of pathological consequences in multiple systems of the body, such as neurodegenerative diseases, cardiovascular diseases, and cancer. This review traces the milestones in the development of these sulfur-containing biomolecules from their initial discovery to their clinical applications and describes in detail the structure, physiochemical properties, metabolism, sulfide signaling pathway, physiopathological functions, and assays of sulfur-containing biomolecules. In addition, the paper also explores the regulatory role and mechanism of sulfur-containing biomolecules on cardiovascular diseases, liver diseases, neurological diseases, metabolic diseases and tumors. The focus is placed on donors of sulfur-containing biological macromolecule metabolites, small-molecule drug screening targeting H2S-producing enzymes, and the latest advancements in preclinical and clinical research related to hydrogen sulfide, including clinical trials and FDA-approved drugs. Additionally, an overview of future research directions in this field is provided. The aim is to enhance the understanding of the complex physiological and pathological roles of sulfur-containing biomolecules and to offer insights into developing effective therapeutic strategies for diseases associated with dysregulated sulfur-containing amino acid metabolism.

Quercetin Induces Apoptosis Through Downregulating P4HA2 and Inhibiting the PI3K/Akt/mTOR Axis in Hepatocellular Carcinoma Cells: An In Vitro Study

BACKGROUND

Quercetin is a natural product with multiple activities, which possesses a promising antitumor effect on malignancies. The involvement of proline 4-hydroxylase II (P4HA2) in collagen synthesis is crucial in the growth of tumor cells. Apoptosis is a programmed cell death requisite for the stability of the intracellular environment. However, the relationship between quercetin and cell apoptosis, as well as the impact of P4HA2 in this connection, has not yet been specified in hepatocellular carcinoma(HCC).

AIMS

The present study used HCC cells to investigate how quercetin regulates P4HA2 and influences cell proliferation and apoptosis.

METHODS AND RESULTS

The outcomes reveal that quercetin can impede the viability and growth of HCC cells and generate cell apoptosis in a dose-dependent manner. Additionally, quercetin prompts downregulation of P4HA2, leading to cell apoptosis in HCC cells, and knocking down P4HA2 can enhance this effect. Furthermore, we pretreated HCC cells with inhibitors (Z-VAD-FMK, LY294002) or activators (740Y-P) and found that the PI3K/Akt/mTOR pathway was occupied with quercetin-induced cell apoptosis.

CONCLUSION

This investigation reveals that quercetin compels apoptosis in HCC cells by diminishing P4HA2 and restraining the PI3K/Akt/mTOR axis.

Bimetallic MnZnSX Nanotheranostics for Self-Activatable Chemo-Immunotherapy of Hepatocellular Carcinoma via H₂S-Triggered Arsenic Prodrug Activation and Binary cGAS-STING Pathway Modulation

Arsenic trioxide (As2O3) has long been utilized in traditional Chinese medicine due to its therapeutic properties. While it exhibits potent anticancer activity, its clinical application is hindered by systemic toxicity and limited tissue specificity. In this study, an advanced therapeutic approach is developed using arsenic prodrug-loaded bimetallic sulfide MnZnSX nanorods (As-MnZnSX NRs) to enhance both the efficacy and safety of As2O3 in hepatocellular carcinoma treatment. These nanorods are engineered to release Mn2+ and H2S within the tumor microenvironment, facilitating binary-cooperative activation of the cGAS-STING pathway. This dual activation mechanism enhances immune responses while converting the arsenic prodrug into its cytotoxic form, AsIII. The results demonstrate that Mn2+ amplifies the cGAS-STING pathway by inducing TBK1 phosphorylation and IRF3 activation, leading to dendritic cell maturation and improved tumor antigen cross-presentation. Simultaneously, H2S promotes prodrug conversion and enhances immune activation, collectively driving binary stimulation of the cGAS-STING pathway. This strategy significantly augments the antitumor efficacy of As2O3 by integrating immune modulation with targeted cytotoxic effects. Furthermore, MnZnSX nanorods enable in vivo MRI, allowing real-time monitoring of treatment progression. This study represents a substantial advancement in liver cancer therapy by integrating chemoimmunotherapy with diagnostic imaging, thereby improving therapeutic precision while minimizing systemic toxicity.

Diallyl Trisulfide Attenuates Ischemia-Reperfusion-Induced ER Stress and Kidney Dysfunction in Aged Female Mice

Ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury (AKI) in the aging population. Gender studies show that aging is associated with loss of protection from AKI in the female population. While ER stress contributes to IRI-induced AKI in the young, ER regulation during IR in the aged kidney is unclear. Because current evidence suggests hydrogen sulfide (H2S) modulates ER stress, we investigated whether exogenous supplementation of diallyl trisulfide (DATS), an H2S donor, mitigates AKI in aged female kidneys. Wild-type (WT, C57BL/6J) mice aged 75-78 weeks were treated with or without DATS before and after renal IRI. IRI increased ER stress proteins, inflammation, and fibrosis markers in the IRI kidney compared to the control. DATS mitigated ER stress, and reduced inflammation and fibrosis markers in the IRI kidney. Further, IRI kidneys demonstrated reduced blood flow, vascularity, angiogenesis, increased resistive index (RI), and reduced function. DATS treatment upregulated PI3K, AKT, p-mTOR, and pMAPK signaling to stimulate angiogenesis, which improved vascular density, blood flow, and renal function. Together, our results suggest that DATS rescues the aged female kidney IRI by modulating ER stress and upregulation of angiogenesis.

Microbiota-derived H2S induces c-kit+ cDC1 autophagic cell death and liver inflammation in metabolic dysfunction-associated steatohepatitis

Immune dysregulation-induced inflammation serves as a driving force in the progression of metabolic dysfunction-associated steatohepatitis (MASH), while the underlying cellular and molecular mechanisms remain largely uncharted. A Western diet (WD) is employed to construct mouse models of metabolic dysfunction associated steatotic liver disease (MASLD) or MASH. Mass cytometry identifies a c-kit+ cDC1 subset whose frequency is reduced in the livers of mice and patients with MASH compared with healthy controls. Adoptive cell transfer of c-kit+ cDC1 protects the progression of MASH. Moreover, analysis of gut microbe sequence shows that WD-fed mice and MASLD/MASH patients exhibit gut microbiota dysbiosis, with an elevated abundance of H2S-producing Desulfovibrio_sp. Transplanting of MASH-derived fecal flora, Desulfovibrio_sp., or injecting H2S intraperitoneally into MASLD mice decreases the c-kit+cDC1 population and exacerbates liver inflammation. Mechanistically, H2S induces autophagic cell death of cDC1 in a c-kit-dependent manner in cDC-specific c-kit-/- and Atg5-/- mice. We thus uncover that microbiota-derived H2S triggers the autophagic cell death of c-kit+ cDC1 and ignites the liver inflammatory cascade in MASH.

Dual functional nanoplatforms potentiate osteosarcoma immunotherapy via microenvironment modulation

Osteosarcoma (OS), a highly aggressive bone tumor, presents significant challenges in terms of effective treatment. We identified that cellular autophagy was impaired within OS by comparing clinical OS samples through bioinformatic analyses and further validated the inhibition of mitochondrial autophagy in OS at the transcriptomic level. Based on this finding, we investigated the therapeutic potential of a dual functional metal nanoplatform (MnSx) to facilitate a transition from the protective effect of low-level autophagy in OS to the killing effect of high-level autophagy in OS. MnSx facilitated intracellular H2S generation via endocytosis, leading to the S-sulfhydration of ubiquitin-specific peptidase 8 (USP8) and subsequent promotion of mitochondrial autophagy in vitro. Additionally, MnSx activated the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) pathway, further enhancing the cellular autophagic response and accelerating tumor cell death. Moreover, it was demonstrated in vivo that MnSx, on the one hand, mediated the activation of tumor autophagy by USP8 via intracellular H2S, while Mn2+ promoted the maturation of dendritic cells, activated cytotoxic T lymphocytes and contributed to tumor eradication. Such tumor killing could be suppressed by the autophagy inhibitor chloroquine. Importantly, synergistic combination therapy with immune checkpoint inhibitors showed promise for achieving complete remission of OS. This study highlights the potential of MnSx as a dual-functional therapeutic platform for OS treatment and offers novel directions for future research in this field.

Antitumor activity of gamma-irradiated Rosa canina L. against lung carcinoma in rat model: a proposed mechanism

BACKGROUND

Lung cancer is one of the most prevalent malignancies globally and is the leading cause of cancer-related mortality. Although cisplatin is a widely utilized chemotherapeutic agent, its clinical efficacy is often hampered by significant toxicity and undesirable side effects. Rosa canina, a medicinal plant, has demonstrated a range of beneficial biological activities, including anti-inflammatory, anticancer, immunomodulatory, antioxidant, and genoprotective effects.

METHODS

This study aimed to investigate the potential of Rosa canina to enhance the anticancer efficacy of cisplatin in a dimethyl benz(a)anthracene-induced lung cancer model using female rats. The animals were administered Rosa canina, cisplatin, or a combination of both treatments. The expression levels of critical signaling molecules were evaluated, including phosphoinositide-3-kinase (PI3K), Akt, mammalian target of rapamycin (mTOR), cleaved poly (ADP-ribose) polymerase (PARP-1), myeloid differentiation factor 88 (MyD88), and tumor necrosis factor receptor-associated factor (TRAF), in addition to various autophagic markers. Furthermore, we assessed the levels of toll-like receptor 2 (TLR2), nuclear factor kappa B (NF-κB), and apoptotic markers in lung tissue, complemented by histopathological examinations.

RESULTS

The combined treatment of Rosa canina extract and cisplatin significantly inhibited lung cancer cell proliferation by downregulating PARP-1 and the TLR2/MyD88/TRAF6/NF-κB signaling pathway, as well as the PI3K/Akt/mTOR pathway. Moreover, this combination therapy promoted autophagy and apoptosis, evidenced by elevated levels of autophagic and apoptotic markers.

CONCLUSION

Overall, the findings of this study suggest that Rosa canina enhances the anticancer effects of cisplatin by inhibiting cancer cell proliferation while simultaneously inducing autophagy and apoptosis. Thus, Rosa can be used as adjuvant to cisplatin chemotherapy to overcome its limitations which may be considered a new approach during lung cancer treatment strategy.

Autophagy is involved in the toxicity of the biocontrol agent GC16 against Tetranychus pueraricola (Acari: Tetranychidae) based on transcriptomic and proteomic analyses

BACKGROUND

GC16 is a novel pesticide with acaricidal properties against the spider mite Tetranychus pueraricola (Ehara & Gotoh). Its physiological mechanisms have been described previously, but its molecular mechanisms of action remain unclear. Thus, we aimed to explore the acaricidal mechanisms of GC16 through transcriptomic and proteomic analyses. The results were verified using transmission electron microscopy (TEM), immunofluorescence assay, and western blotting.

RESULTS

Transcriptomic and proteomic analyses revealed 2717 differentially expressed genes (DEGs) and 374 differentially expressed proteins (DEPs) between the GC16-treated and control mites. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that the DEGs and DEPs were enriched in the autophagy pathway. TEM showed that the number of autophagosomes and autolysosomes was higher in the GC16-treated mites than in the control mites. Immunofluorescence assay and western blot results consistently indicated that GC16 treatment significantly enhanced the relative expression of the autophagy protein LC3 in insect Sf9 cells. The intracellular calcium concentration in the GC16-treated Sf9 cells was 2.30 times higher than that in the control cells, suggesting that GC16 disrupted calcium homeostasis and potentially acted as a calcium-driven nerve agent.

CONCLUSIONS

Autophagy is involved in the toxicity of GC16 against T. pueraricola and may be activated by elevated Ca2+ levels. This study reveals the molecular insecticidal mechanisms of GC16 and provides rationale for the field application of GC16 to control pest mites.

Knockdown of RASD1 improves MASLD progression by inhibiting the PI3K/AKT/mTOR pathway

BACKGROUND

There is still no reliable therapeutic targets and effective pharmacotherapy for metabolic dysfunction-associated steatotic liver disease (MASLD). RASD1 is short for Ras-related dexamethasone-induced 1, a pivotal factor in various metabolism processes of Human. However, the role of RASD1 remains poorly illustrated in MASLD. Therefore, we designed a study to elucidate how RASD1 could impact on MASLD as well as the mechanisms involved.

METHODS

The expression level of RASD1 was validated in MASLD. Lipid metabolism and its underlying mechanism were investigated in hepatocytes and mice with either overexpression or knockdown of RASD1.

RESULTS

Hepatic RASD1 expression was upregulated in MASLD. Lipid deposition was significantly reduced in RASD1-knockdown hepatocytes and mice, accompanied by a marked downregulation of key genes in the signaling pathway of de novo lipogenesis. Conversely, RASD1 overexpression in hepatocytes had the opposite effect. Mechanistically, RASD1 regulated lipid metabolism in MASLD through the PI3K/AKT/mTOR signaling pathway.

CONCLUSIONS

We discovered a novel role of RASD1 in MASLD by regulating lipogenesis via the PI3K/AKT/mTOR pathway, thereby identifying a potential treatment target for MASLD.

Hydrogen sulfide inhibits gene expression associated with aortic valve degeneration by inducing NRF2-related pro-autophagy effect in human aortic valve interstitial cells

Aortic valve stenosis (AS) is the most common valvular heart disease but there are currently no effective medical treatments that can delay disease progression due to a lack of knowledge of the precise pathophysiology. The expression of sulfide: quinone oxidoreductase (SQOR) and nuclear factor erythroid 2-related factor 2 (NRF2) was decreased in the aortic valve of AS patients. However, the role of SQOR and NRF2 in the pathophysiology of AS has not been found. We investigated the effects of hydrogen sulfide (H2S)-releasing compounds on diseased aortic valve interstitial cells (AVICs) to explain the cellular mechanism of SQOR and elucidate the medical value of H2S for AS treatment. Sodium hydrosulfide (NaHS) treatment increased the expression of SQOR and NRF2 gene and consequently induced the NRF2 target genes, such as NAD(P)H quinone dehydrogenase 1 and cystathionine γ-lyase. In addition, NaHS dose-dependently decreased the expression level of fibrosis and inflammation-related genes (MMP9, TNF-α, IL6) and calcification-related genes (ALP, osteocalcin, RUNX2, COL1A1) in human AVICs. Furthermore, NaHS activated the AMPK-mTOR pathway and inhibited the PI3K-AKT pathway, resulting in a pro-autophagy effect in human AVICs. An NRF2 inhibitor, brusatol, attenuated NaHS-induced AMPK activation and decreased the autophagy markers Beclin-1 and LC3AB, suggesting that the mechanism of action of H2S is related to NRF2. In conclusion, H2S decreased gene expression levels related to aortic valve degeneration and activated AMPK-mTOR-mediated pro-autophagy function associated with NRF2 in human AVICs. Therefore, H2S could be a potential therapeutic target for the development of AS treatment.

Exogenous sulfide regulates hypoxia/reoxygenation stress through the intrinsic apoptotic pathway in the blood clam (Tegillarca granosa)

The intertidal organism Tegillarca granosa can survive under frequent hypoxia/reoxygenation (H/R) exposure. Sulfides as accompanying products in benthic hypoxic environments, may play an important regulatory role, but the mechanisms are not well understood. This article investigated the physiological and molecular changes of T. granosa after adding different concentrations of sulfides (0.1, 0.5, 1 mM) at 72 h into a 120-h exposure to hypoxia, as well as the recovery state of 24 h of reoxygenation. The results indicated that H/R stress induces ROS production and mild mitochondrial depolarization in clams, and sulfide can participate in its regulation. Among them, a low concentration of sulfide up-regulated glutathione content and alternative oxidase activity, maintained the stability of antioxidant enzymes, and up-regulated the expression of the survival genes XIAP/BCL-xl which mediate cell survival via the NFκB signaling pathway. High concentrations of sulfide had a significant inhibitory effect on the p38/MPAK pathway and inhibited intrinsic apoptosis caused by ROS accumulation during reoxygenation. Taken together, our study suggested that different concentrations of sulfides are involved in regulating the endogenous apoptosis of clams during H/R.

Recent advances in the role of hydrogen sulfide in age-related diseases

In recent years, the impact of age-related diseases on human health has become increasingly severe, and developing effective drugs to deal with these diseases has become an urgent task. Considering the essential regulatory role of hydrogen sulfide (H2S) in these diseases, it is regarded as a promising target for treatment. H2S is a novel gaseous transmitter involved in many critical physiological activities, including anti-oxidation, anti-inflammation, and angiogenesis. H2S also regulates cell activities such as cell proliferation, migration, invasion, apoptosis, and autophagy. These regulatory effects of H2S contribute to relieving and treating age-related diseases. In this review, we mainly focus on the pathogenesis and treatment prospects of H2S in regulating age-related diseases.

Dissecting the multifaceted roles of autophagy in cancer initiation, growth, and metastasis: from molecular mechanisms to therapeutic applications

Autophagy is a cytoplasmic defense mechanism that cells use to break and reprocess their intracellular components. This utilization of autophagy is regarded as a savior in nutrient-deficient and other stressful conditions. Hence, autophagy keeps contact with and responds to miscellaneous cellular tensions and diverse pathways of signal transductions, such as growth signaling and cellular death. Importantly, autophagy is regarded as an effective tumor suppressor because regular autophagic breakdown is essential for cellular maintenance and minimizing cellular damage. However, paradoxically, autophagy has also been observed to promote the events of malignancies. This review discussed the dual role of autophagy in cancer, emphasizing its influence on tumor survival and progression. Possessing such a dual contribution to the malignant establishment, the prevention of autophagy can potentially advocate for the advancement of malignant transformation. In contrast, for the context of the instituted tumor, the agents of preventing autophagy potently inhibit the advancement of the tumor. Key regulators, including calpain 1, mTORC1, and AMPK, modulate autophagy in response to nutritional conditions and stress. Oncogenic mutations like RAS and B-RAF underscore autophagy's pivotal role in cancer development. The review also delves into autophagy's context-dependent roles in tumorigenesis, metastasis, and the tumor microenvironment (TME). It also discusses the therapeutic effectiveness of autophagy for several cancers. The recent implication of autophagy in the control of both innate and antibody-mediated immune systems made it a center of attention to evaluating its role concerning tumor antigens and treatments of cancer.

Hydrogen sulfide and its role in female reproduction

Hydrogen sulfide (H2S) is a gaseous signaling molecule produced in the body by three enzymes: cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST). H2S is crucial in various physiological processes associated with female mammalian reproduction. These include estrus cycle, oocyte maturation, oocyte aging, ovulation, embryo transport and early embryo development, the development of the placenta and fetal membranes, pregnancy, and the initiation of labor. Despite the confirmed presence of H2S-producing enzymes in all female reproductive tissues, as described in this review, the exact mechanisms of H2S action in these tissues remain in most cases unclear. Therefore, this review aims to summarize the knowledge about the presence and effects of H2S in these tissues and outline possible signaling pathways that mediate these effects. Understanding these pathways may lead to the development of new therapeutic strategies in the field of women's health and perinatal medicine.

Dermaseptin B2 bioactive gene's potential for anticancer and anti-proliferative effect is linked to the regulation of the BAX/BBC3/AKT pathway

Dermaseptin B2 (DrsB2) is an antimicrobial peptide with anticancer and angiostatic properties. We aimed to assess the in vitro inhibitory effect of pDNA/DrsB2 on the growth of breast cancer cells and its impact on the expression of genes involved in the BAX/BBC3/AKT pathway. The nucleic acid sequence of DrsB2 was artificially synthesized and inserted into the pcDNA3.1( +) Mammalian Expression Plasmid. PCR testing and enzyme digesting procedures evaluated the accuracy of cloning. The vectors were introduced into cells using LipofectamineTM2000 transfection reagent. The breast cancer cells were assessed by flow cytometry, MTT assessment, soft agar colony method, and wound healing investigation. The gene's transcription was evaluated using real-time PCR with a significance level of P < 0.05. The recombinant plasmid harboring the pDNA/DrsB2 vector was effectively produced, and the gene sequence showed absolute homogeneity (100% similarity) with the DrsB2 gene. The transfection effectiveness of MCF-7 and MCF-10A cells was 79% and 68%, respectively. The findings are measured using the growth inhibition 50% (GI50) metric, which indicates the concentration of pDNA/DrsB2 that stops 50% of cell growth. The proportions of early apoptosis, late apoptosis, necrosis, and viable MCF-7 cells in the pDNA/DrsB2 group were 40.50%, 2.31%, 1.69%, and 55.50%, respectively. The results showed a 100% increase in gene expression in programmed cell death following treatment with pDNA/DrsB2 (**P < 0.01). To summarize, the results described in this work offer new possibilities for treating cancer by targeting malignancies via pDNA/DrsB2 and activating the BAX/BBC3/AKT signaling pathways.

Cold atmospheric plasma sensitizes head and neck cancer to chemotherapy and immune checkpoint blockade therapy

Head and neck cancer (HNC) is the seventh most prevalent cancer globally, often characterized by chemo-resistance and immunosuppression, which significantly hampers treatment efficacy. Cold atmospheric plasma (CAP) has recently emerged as a promising adjuvant oncotherapy with substantial potential and advantages. In this study, Piezobrush® PZ2, a handheld CAP unit based on the piezoelectric direct discharge technology, was used to generate and deliver non-thermal plasma. We aimed to investigate the effects of CAPPZ2 on various types of HNC cells and elucidate the underlying mechanisms. In addition, we endeavored to examine the efficacy of combining CAPPZ2 with chemotherapy drugs (i.e., cisplatin) or immune checkpoint blockade (ICB, i.e., PD1 antibody) in HNC treatment. Firstly, the results demonstrated that CAPPZ2 exerted anti-neoplastic functions through inhibiting cell proliferation, migration and invasion, and promoting apoptosis and autophagy. Secondly, using transcriptomic sequencing, Western blotting, and quantitative real-time PCR, the mechanisms underlying CAPPZ2 treatment in vitro was presumed to be a multitargeted blockade of major cancer survival pathways, such as redox balance, glycolysis, and PI3K/AKT/mTOR/HIF-1α signaling. Lastly, combinatorial thearpy containing CAPPZ2 and cisplatin or PD-1 antibody significantly suppressed tumor growth and prolonged recipient survival in vivo. Collectively, the synergistic effects of CAPPZ2 and cisplatin or PD-1 antibody could serve as a promising solution to enhance head and neck tumor elimination.

Hydrogen Sulfide and Liver Health: Insights into Liver Diseases

Significance: Hydrogen sulfide (H2S) is a recently recognized gasotransmitter involved in physiological and pathological conditions in mammals. It protects organs from oxidative stress, inflammation, hypertension, and cell death. With abundant expression of H2S-production enzymes, the liver is closely linked to H2S signaling. Recent Advances: Hepatic H2S comes from various sources, including gut microbiota, exogenous sulfur salts, and endogenous production. Recent studies highlight the importance of hepatic H2S in liver diseases such as nonalcoholic fatty liver disease (NAFLD), liver injury, and cancer, particularly at advanced stages. Endogenous H2S production deficiency is associated with severe liver disease, while exogenous H2S donors protect against liver dysfunction. Critical Issues: However, the roles of H2S in NAFLD, liver injury, and liver cancer are still debated, and its effects depend on donor type, dosage, treatment duration, and cell type, suggesting a multifaceted role. This review aimed to critically evaluate H2S production, metabolism, mode of action, and roles in liver function and disease. Future Direction: Understanding H2S's precise roles and mechanisms in liver health will advance potential therapeutic applications in preclinical and clinical research. Targeting H2S-producing enzymes and exogenous H2S sources, alone or in combination with other drugs, could be explored. Quantifying endogenous H2S levels may aid in diagnosing and managing liver diseases. Antioxid. Redox Signal. 40, 122-144.

Fusobacterium nucleatum and its metabolite hydrogen sulfide alter gut microbiota composition and autophagy process and promote colorectal cancer progression

IMPORTANCE

Colorectal cancer (CRC) is the second most common cancer in the world; the main treatment for CRC is immunosuppressive therapy, but this therapy is only effective for a small percentage of CRC patients, so there is an urgent need for a treatment with fewer side effects and higher efficacy. This study demonstrated that Fusobacterium nucleatum with increased abundance in CRC can regulate the autophagy process and disrupt normal intestinal microbiota by producing hydrogen sulfide, factors that may be involved in the development and progression of CRC. This study may provide a reference for future CRC treatment options that are efficient and have fewer side effects.

The double-edged sword role of hydrogen sulfide in hepatocellular carcinoma

With an increasing worldwide prevalence, hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver in the world. It is also the primary reason for cancer-related death in the world. The pathogenesis of HCC is complex, such as DNA methylation changes, immune regulatory disorders, cell cycle disorders, chromosomal instability, and so on. Although many studies have been conducted on HCC, the molecular mechanisms of HCC are not completely understood. At present, there is no effective treatment for HCC. Hydrogen sulfide (H2S) has long been regarded as a toxic gas with the smell of rotten eggs, but recent studies have shown that it is an important gasotransmitter along with carbon monoxide (CO) and nitric oxide (NO). Increasing evidence indicates that H2S has multiple biological functions, such as anti-inflammation, anti-apoptosis, anti-oxidative stress, and so on. Recently, a lot of evidence has shown that H2S has a "double-edged sword" effect in HCC, but the mechanism is not fully understood. Here, we reviewed the progress on the role and mechanism of H2S in HCC in recent years, hoping to provide a theoretical reference for future related research.

RILP inhibits tumor progression in osteosarcoma via Grb10-mediated inhibition of the PI3K/AKT/mTOR pathway

BACKGROUND

Rab-interacting lysosomal protein (RILP) contains an alpha-helical coil with an unexplored biological function in osteosarcoma. This study investigated the expression of RILP in osteosarcoma cells and tissues to determine the effect of RILP on the biological behaviors of osteosarcoma cells and the underlying mechanism.

METHODS

Tumor Immune Estimation Resource (TIMER) database, The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database were used for bioinformatic analysis. Co-immunoprecipitation experiment was used to determine whether the two proteins were interacting. In functional tests, cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay, transwell invasion assay, Immunofluorescence (IF) assay and immunohistochemical (IHC) assay were performed.

RESULTS

Overexpression of RILP significantly inhibited proliferation and impaired metastasis ability of osteosarcoma cells, while silencing of RILP showed the opposite trend. RNA-seq data analysis was applied in 143B cells and pathway enrichment analysis revealed that differentially expressed genes were mainly enriched in the PI3K/AKT pathway. We further verified that overexpression of RILP restrained the PI3K/AKT/mTOR signaling pathway and induced autophagy in osteosarcoma cells, while the opposite trend was observed when PI3K pathway activator 740Y-P was used. 3-Methyladenine (3-MA), a selective autophagy inhibitor, partially attenuated the inhibitory effect of RILP on the migration and invasion ability of osteosarcoma cells, suggesting the involvement of autophagy in epithelial-mesenchymal transition regulation in osteosarcoma cells. Growth factor receptor binding protein-10 (Grb10), an adaptor protein, was confirmed as a potential target of RILP to restrain the PI3K/AKT signaling pathway. We subcutaneously injected stably overexpressing 143B osteosarcoma cells into nude mice and observed that overexpression of RILP inhibited tumor growth by inhibiting the PI3K/AKT/mTOR pathway.

CONCLUSION

Our study revealed that the expression of RILP was associated with favorable prognosis of osteosarcoma and RILP inhibits proliferation, migration, and invasion and promotes autophagy in osteosarcoma cells via Grb10-mediated inhibition of the PI3K/AKT/mTOR signaling pathway. In the future, targeting RILP may be a potential strategy for osteosarcoma treatment.

Therapeutic implications of targeting autophagy and TGF-β crosstalk for the treatment of liver fibrosis

Liver fibrosis is characterized by the excessive deposition and accumulation of extracellular matrix components, mainly collagens, and occurs in response to a broad spectrum of triggers with different etiologies. Under stress conditions, autophagy serves as a highly conserved homeostatic system for cell survival and is importantly involved in various biological processes. Transforming growth factor-β1 (TGF-β1) has emerged as a central cytokine in hepatic stellate cell (HSC) activation and is the main mediator of liver fibrosis. A growing body of evidence from preclinical and clinical studies suggests that TGF-β1 regulates autophagy, a process that affects various essential (patho)physiological aspects related to liver fibrosis. This review comprehensively highlights recent advances in our understanding of cellular and molecular mechanisms of autophagy, its regulation by TGF-β, and the implication of autophagy in the pathogenesis of progressive liver disorders. Moreover, we evaluated crosstalk between autophagy and TGF-β1 signalling and discussed whether simultaneous inhibition of these pathways could represent a novel approach to improve the efficacy of anti-fibrotic therapy in the treatment of liver fibrosis.

Application and value of hydrogen sulfide modulated autophagy in sepsis

Sepsis is is anabnormalhost immune responsecausedbyinfection. Antibiotics, anti-viral drugs, and vasoactive drugs have always been used in the traditional treatment of sepsis, but there are no specific and effective drugs in clinical practice. Autophagy is a highly conservative process in biological evolution, and plays an important role in maintaining intracellular homeostasis and cellular self-renewal. Autophagy can remove and degrade misfolding proteins and damaged organelles in cells, providing materials for cell repair and self-renewal. Hydrogen sulfide (H2S) is a colorless gas that smells likerotteneggs. It is the third endogenous gas signal molecule discovered after nitric oxide and carbon monoxide and has become a research hotspot in recent years. H2S has a variety of biological functions and plays an important role in various physiological and pathological processes. Thereisgrowingevidencethat H2S can regulate autophagy. The intervention of autophagy is a promising therapeutic strategy to improve sepsis organ damage. This article reviews the organ protection of autophagy in sepsis and the role of H2S in regulating autophagy in sepsis, revealing that H2S intervention with autophagy may be a a worthy target in sepsis treatment.

Antitumor activity of miR-188-3p in gastric cancer is achieved by targeting CBL expression and inactivating the AKT/mTOR signaling

BACKGROUND

Altered miR-188-3p expression has been observed in various human cancers.

AIM

To investigate the miR-188-3p expression, its roles, and underlying molecular events in gastric cancer.

METHODS

Fifty gastric cancer and paired normal tissues were collected to analyze miR-188-3p and CBL expression. Normal and gastric cancer cells were used to manipulate miR-188-3p and CBL expression through different assays. The relationship between miR-188-3p and CBL was predicted bioinformatically and confirmed using a luciferase gene reporter assay. A Kaplan-Meier analysis was used to associate miR-188-3p or CBL expression with patient survival. A nude mouse tumor cell xenograft assay was used to confirm the in vitro data.

RESULTS

MiR-188-3p was found to be lower in the plasma of gastric cancer patients, tissues, and cell lines compared to their healthy counterparts. It was associated with overall survival of gastric cancer patients (P < 0.001), tumor differentiation (P < 0.001), lymph node metastasis (P = 0.033), tumor node metastasis stage (I/II vs III/IV, P = 0.024), and American Joint Committee on Cancer stage (I/II vs III/IV, P = 0.03). Transfection with miR-188-3p mimics reduced tumor cell growth and invasion while inducing apoptosis and autophagy. CBL was identified as a direct target of miR-188-3p, with its expression antagonizing the effects of miR-188-3p on gastric cancer (GC) cell proliferation by inducing tumor cell apoptosis and autophagy through the inactivation of the Akt/mTOR signaling pathway. The in vivo data confirmed antitumor activity via CBL downregulation in gastric cancer.

CONCLUSION

The current data provides ex vivo, in vitro, and in vivo evidence that miR-188-3p acts as a tumor suppressor gene or possesses antitumor activity in GC.

Effects of LAIR-1 on hepatocellular carcinoma cell proliferation and invasion via PI3K-AKT-mTOR pathway regulation

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the common malignant tumors. Although surgical resection is the best treatment for HCC, many patients with HCC are found to have metastases at the time of initial diagnosis and lose the opportunity for radical treatment. Therefore, the study of the invasion and metastasis of HCC has always been the focus of HCC research. This study aimed to assess the influence of LAIR-1 on HCC cell proliferation and invasion and the relevant mechanisms involved in this process.

METHODS

Immunocytochemical staining assay, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting (WB) were used to detect the expression of LAIR-1mRNA and protein in healthy human hepatocyte LO2 and the HCC cell lines HepG2, Bel-7402, MHCC97-H, and Huh-7. Then, we evaluated the cell viability, colony formation, and invasion of MHCC97-H and Huh-7 cells in each group by silencing or overexpressing LAIR-1 expression in MHCC97-H and Huh-7 cells, respectively. WB was used to detect the expression levels of PI3K-AKT-mTOR pathway related proteins.

RESULTS

Our findings showed that LAIR-1 can inhibit cell viability, colony formation and invasion in vitro. Meanwhile, LAIR-1 significantly downregulated the expression of PI3K, p-AKT and p-mTOR, which were abolished by the PI3K inhibitor, LY294002.

CONCLUSIONS

Our study revealed that LAIR-1 inhibited cell proliferation and invasion, probably via suppressing the PI3K-AKT-mTOR pathway.

Hydrogen sulfide suppresses H2O2-induced proliferation and migration of HepG2 cells through Wnt/β-catenin signaling pathway

Both H₂S and H₂O₂ affect many cellular events, such as cell differentiation, cell proliferation and cell death. However, there is some controversy about the roles of H₂S and H₂O_2, since the detailed mechanisms they are involved remain unclear. In this study, low concentration of H₂O₂ (40 μM) increased the viability of hepatocellular carcinoma cells HepG2, while both H₂S and high concentration of H₂O₂ decreased the cell viability in a dose-dependent manner. Wound healing assay indicated that 40 μM H₂O₂ promoted migration of HepG2 cells, which was suppressed by exogenous H₂S. Further analysis revealed that administration of exogenous H₂S and H₂O₂ changed the redox status of Wnt3a in HepG2 cells. Altered expression of proteins including Cyclin D1, TCF-4, and MMP7, which are downstream of the Wnt3a/β-catenin signaling pathway, were found after treatment with exogenous H₂S and H₂O₂. Compared with H₂S, low concentration of H₂O₂ showed opposite effects on these protein expression levels in HepG2 cells. These results suggest that H₂S suppressed H₂O₂-induced proliferation and migration of HepG2 through regulating Wnt3a/β-catenin signaling pathway.

Regular Aspirin Use Is Associated with a Reduced Risk of Hepatocellular Carcinoma (HCC) in Chronic Liver Disease: a Systematic Review and Meta-analysis

PURPOSE

Aspirin reduces the incidence of various gastrointestinal (GI) malignancies. This meta-analysis assessed the efficacy and safety of regular aspirin use on the incidence of hepatocellular carcinoma (HCC) in patients with chronic liver disease.

METHODS

Electronic reference databases were searched for studies in patients with chronic liver disease exposed to aspirin. The primary outcome was the incidence of HCC in regular aspirin users compared to non-users. The secondary outcome was the incidence of major GI bleeding events in both groups. The propensity score (PS) and non-PS-adjusted pooled hazard ratio (HR) were calculated using random-effects models.

RESULTS

Six observational studies with 71,211 subjects were included. The median duration of follow-up ranged from 2.7 to 7.9 years. Four studies included patients with viral hepatitis; five studies used aspirin 100 mg/day. All six studies reported the non-PS-matched HR, and there was a 54% reduction in the incidence of HCC among regular aspirin users [HR (95% CI): 0.46(0.31-0.67), p < 0.001]. Four studies reported on the PS-matched HR; this showed a 46% reduced incidence of HCC in those using aspirin [HR (95% CI): 0.54(0.38-0.79), p < 0.001]. Subgroup analysis on studies restricted to viral hepatitis (n = 4) showed a 28% reduction in HCC incidence in aspirin users [HR (95% CI): 0.72(0.64-0.80), p < 0.001]. Four studies reported the incidence of major GI bleeds, there was no significant difference between the two groups [HR (95% CI: 1.00(0.69-1.45), p = 0.90]. All outcome analysis, except the subgroup analysis, had significant inter-study heterogeneity.

CONCLUSION

Regular aspirin use in chronic liver disease is associated with reduced incidence of HCC without increasing the risk of major GI bleeding.

Hepatoid adenocarcinoma-Clinicopathological features and molecular characteristics

Hepatoid adenocarcinoma (HAC) is a rare, malignant, extrahepatic tumor with histologic features similar to those of hepatocellular carcinoma. HAC is most often associated with elevated alpha-fetoprotein (AFP). HAC can occur in multiple organs, including the stomach, esophagus, colon, pancreas, lungs, and ovaries. HAC differs greatly from typical adenocarcinoma in terms of its biological aggression, poor prognosis, and clinicopathological characteristics. However, the mechanisms underlying its development and invasive metastasis remain unclear. The purpose of this review was to summarize the clinicopathological features, molecular traits, and molecular mechanisms driving the malignant phenotype of HAC, in order to support the clinical diagnosis and treatment of HAC.

Hydrogen sulfide and its donors: Novel antitumor and antimetastatic agents for liver cancer

Hepatocellular carcinoma (HCC) is the sixth most frequent human cancer and the world's third most significant cause of cancer mortality. HCC treatment has recently improved, but its mortality continues to increase worldwide due to its extremely complicated and heterogeneous genetic abnormalities. After nitric oxide (NO) and carbon monoxide (CO), the third gas signaling molecule discovered is hydrogen sulfide (H₂S), which has long been thought to be a toxic gas. However, numerous studies have proven that H₂S plays many pathophysiological roles in mammals. Endogenous or exogenous H₂S can decrease cell proliferation, promote apoptosis, block cell cycle, invasion and migration through various cellular signaling pathways. This review analyzes and discusses the recent literature on the function and molecular mechanism of H₂S and H₂S donors in HCC, so as to provide convenience for the scientific research and clinical application of H₂S in the treatment of liver cancer.

Biological impact and therapeutic perspective of targeting PI3K/Akt signaling in hepatocellular carcinoma: Promises and Challenges

Cancer progression results from activation of various signaling networks. Among these, PI3K/Akt signaling contributes to proliferation, invasion, and inhibition of apoptosis. Hepatocellular carcinoma (HCC) is a primary liver cancer with high incidence rate, especially in regions with high prevalence of viral hepatitis infection. Autoimmune disorders, diabetes mellitus, obesity, alcohol consumption, and inflammation can also lead to initiation and development of HCC. The treatment of HCC depends on the identification of oncogenic factors that lead tumor cells to develop resistance to therapy. The present review article focuses on the role of PI3K/Akt signaling in HCC progression. Activation of PI3K/Akt signaling promotes glucose uptake, favors glycolysis and increases tumor cell proliferation. It inhibits both apoptosis and autophagy while promoting HCC cell survival. PI3K/Akt stimulates epithelial-to-mesenchymal transition (EMT) and increases matrix-metalloproteinase (MMP) expression during HCC metastasis. In addition to increasing colony formation capacity and facilitating the spread of tumor cells, PI3K/Akt signaling stimulates angiogenesis. Therefore, silencing PI3K/Akt signaling prevents aggressive HCC cell behavior. Activation of PI3K/Akt signaling can confer drug resistance, particularly to sorafenib, and decreases the radio-sensitivity of HCC cells. Anti-cancer agents, like phytochemicals and small molecules can suppress PI3K/Akt signaling by limiting HCC progression. Being upregulated in tumor tissues and clinical samples, PI3K/Akt can also be used as a biomarker to predict patients' response to therapy.

Hydrogen sulfide attenuates uranium-induced kidney cells pyroptosis via upregulation of PI3K/AKT/mTOR signaling

We have identified that hydrogen sulfide (H₂ S), a gaseous mediator, plays a crucial role in antioxidative, anti-inflammatory, and cytoprotective effects on uranium (U)-triggered rat nephrotoxicity. Pyroptosis is a special mode of inflammation and programmed cell death involved in the activation of inflammasome and Caspase-1 and the release of inflammatory cytokines. This study aims to confirm whether H₂ S can alleviate U-induced rat NRK-52^E cell pyroptosis and to investigate the H₂ S underlying regulatory mechanism. Our results indicate that pretreatment with NaHS (an H₂ S donor) significantly inhibited U-increased reactive oxygen species level, NLRP3, apoptosis-related speck-like protein consisting of a caspase recruitment domain (ASC), and cleaved Caspase-1 proteins expression, gasdermin D messenger RNA (GSDMD mRNA) expression, interleukin (IL)-1β and IL-18 contents, lactate dehydrogenase leakage, and numbers of double-positive dying kidney cells. NaHS application evidently augmented phosphorylated PI3K, AKT, and mTOR expression as well as ratios of their respective phosphorylation to the corresponding total proteins which were downregulated by U treatment. But, LY294002 (a PI3K inhibitor) administration effectively abrogated the consequences of NaHS on the levels of p-PI3K, cleaved Caspase-1, ASC and NLRP3 proteins, GSDMD mRNA expression, and (IL)-1β and IL-18 contents. Simultaneously, LY294002 significantly reversed the effects of NaHS on U-induced pyroptosis rate and cytotoxicity. Taken together, these results indicate that H₂ S ameliorated U-triggered NRK-52^E cells pyroptosis via upregulation of PI3K/AKT/mTOR pathway, suggesting a novel role for H₂ S in the management of nephrotoxicity caused by U exposure.

PI3K/AKT/mTOR pathway and its related molecules participate in PROK1 silence-induced anti-tumor effects on pancreatic cancer

The PI3K/AKT/mTOR (phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin) pathway can be initiated by PROK1 (prokineticin 1), but its effect and mechanism of action in pancreatic carcinoma (PC) are not fully understood. In this study, we elucidated the roles of PROK1 and its related molecules in PC in vivo. PANC-1 cells with PROK1 knockdown were injected into BALB/c nude mice. The growth and weight of the tumor were monitored and measured, which was followed by TUNEL (terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling), immunohistochemical staining, and hematoxylin and eosin staining. The key proteins related to proliferation, apoptosis, and the PI3K/AKT/mTOR pathway were determined by Western blotting. We also used public databases to identify the molecules related to PROK1. The reduction of PROK1 inhibited angiopoiesis and promoted apoptosis in vivo. PCNA-1, cyclin D1, and Bcl-2 decreased considerably, while Bax and cleaved caspase-3 increased significantly after PROK1 inhibition. The PI3K/AKT/mTOR signal inhibition was also closely associated with PROK1 knockdown. The possible related molecules of PROK1, such as von Willebrand factor, were screened and considered to be involved in the aberrant activation of PI3K/AKT. In conclusion, PROK1 knockdown significantly prevented tumor growth and promoted apoptosis of human PC cells in vivo, where the PI3K/AKT/mTOR pathway was probably inhibited. Therefore, PROK1, along with its related molecules, might be important targets for PC therapy.

The double-edged role of hydrogen sulfide in the pathomechanism of multiple liver diseases

In mammalian systems, hydrogen sulfide (H2S)-one of the three known gaseous signaling molecules in mammals-has been found to have a variety of physiological functions. Existing studies have demonstrated that endogenous H2S is produced through enzymatic and non-enzymatic pathways. The liver is the body's largest solid organ and is essential for H2S synthesis and elimination. Mounting evidence suggests H2S has essential roles in various aspects of liver physiological processes and pathological conditions, such as hepatic lipid metabolism, liver fibrosis, liver ischemia‒reperfusion injury, hepatocellular carcinoma, hepatotoxicity, and acute liver failure. In this review, we discuss the functions and underlying molecular mechanisms of H2S in multiple liver pathophysiological conditions.

Cystathionine γ-lyase mediates cell proliferation, migration, and invasion of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelia-derived malignancy with a distinctive geographic distribution. Cystathionine γ-lyase (CSE) is involved in cancer development and progression. Nevertheless, the role of CSE in the growth of NPC is unknown. In this study, we found that CSE levels in human NPC cells were higher than those in normal nasopharyngeal cells. CSE overexpression enhanced the proliferative, migrative, and invasive abilities of NPC cells and CSE downregulation exerted reverse effects. Overexpression of CSE decreased the expressions of cytochrome C, cleaved caspase (cas)-3, cleaved cas-9, and cleaved poly-ADP-ribose polymerase, whereas CSE knockdown exhibited reverse effects. CSE overexpression decreased reactive oxygen species (ROS) levels and the expressions of phospho (p)-extracellular signal-regulated protein kinase 1/2, p-c-Jun N-terminal kinase, and p-p38, but promoted the expressions of p-phosphatidylinositol 3-kinase (PI3K), p-AKT, and p-mammalian target of rapamycin (mTOR), whereas CSE knockdown showed oppose effects. In addition, CSE overexpression promoted NPC xenograft tumor growth and CSE knockdown decreased tumor growth by modulating proliferation, angiogenesis, cell cycle, and apoptosis. Furthermore, DL-propargylglycine (an inhibitor of CSE) dose-dependently inhibited NPC cell growth via ROS-mediated mitogen-activated protein kinase (MAPK) and PI3K/AKT/mTOR pathways without significant toxicity. In conclusion, CSE could regulate the growth of NPC cells through ROS-mediated MAPK and PI3K/AKT/mTOR cascades. CSE might be a novel tumor marker for the diagnosis and prognosis of NPC. Novel donors/drugs that inhibit the expression/activity of CSE can be developed in the treatment of NPC.

Hydrogen Sulfide Attenuates Lymphedema Via the Induction of Lymphangiogenesis Through a PI3K/Akt‐Dependent Mechanism

Background

Accumulating evidence suggests that hydrogen sulfide ( H 2 S ), an endogenously produced gaseous molecule, plays a critical role in the regulation of cardiovascular homeostasis. However, little is known about its role in lymphangiogenesis. Thus, the current study aimed to investigate the involvement of H 2 S in lymphatic vessel growth and lymphedema resolution using a murine model and assess the underlying mechanisms.

Methods and Results

A murine model of tail lymphedema was created both in wild‐type mice and cystathionine γ‐lyase–knockout mice, to evaluate lymphedema up to 28 days after lymphatic ablation. Cystathionine γ‐lyase–knockout mice had greater tail diameters than wild‐type mice, and this phenomenon was associated with the inhibition of reparative lymphangiogenesis at the site of lymphatic ablation. In contrast, the administration of an H 2 S donor, diallyl trisulfide, ameliorated lymphedema by inducing the formation of a considerable number of lymphatic vessels at the injured sites in the tails. In vitro experiments using human lymphatic endothelial cells revealed that diallyl trisulfide promoted their proliferation and differentiation into tube‐like structures by enhancing Akt (protein kinase B) phosphorylation in a concentration‐dependent manner. The blockade of Akt activation negated the diallyl trisulfide–induced prolymphangiogenic responses in lymphatic endothelial cells. Furthermore, the effects of diallyl trisulfide treatment on lymphangiogenesis in the tail lymphedema model were also negated by the inhibition of phosphoinositide 3'‐kinase (P13K)/Akt signaling.

Conclusions

H 2 S promotes reparative lymphatic vessel growth and ameliorates secondary lymphedema, at least in part, through the activation of the Akt pathway in lymphatic endothelial cells. As such, H 2 S donors could be used as therapeutics against refractory secondary lymphedema.

Hydrogen Sulfide and Its Donors: Keys to Unlock the Chains of Nonalcoholic Fatty Liver Disease

Hydrogen sulfide (H2S) has emerged as the third “gasotransmitters” and has a crucial function in the diversity of physiological functions in mammals. In particular, H2S is considered indispensable in preventing the development of liver inflammation in the case of excessive caloric ingestion. Note that the concentration of endogenous H2S was usually low, making it difficult to discern the precise biological functions. Therefore, exogenous delivery of H2S is conducive to probe the physiological and pathological roles of this gas in cellular and animal studies. In this review, the production and metabolic pathways of H2S in vivo, the types of donors currently used for H2S release, and study evidence of H2S improvement effects on nonalcoholic fatty liver disease are systematically introduced.

Function of gaseous hydrogen sulfide in liver fibrosis

Over the past few years, hydrogen sulfide (H2S) has been shown to exert several biological functions in mammalian. The endogenous production of H2S is mainly mediated by cystathione β-synthase, cystathione γ-lyase and 3-mercaptopyruvate sulfur transferase. These enzymes are broadly expressed in liver tissue and regulates liver function by working on a variety of molecular targets. As an important regulator of liver function, H2S is critically involved in the pathogenesis of various liver diseases, such as non-alcoholic steatohepatitis and liver cancer. Targeting H2S-generating enzymes may be a therapeutic strategy for controlling liver diseases. This review described the function of H2S in liver disease and summarized recent characterized role of H2S in several cellular process of the liver. [BMB Reports 2022; 55(10): 481-487].

Vascular smooth muscle cell-derived hydrogen sulfide promotes atherosclerotic plaque stability via TFEB (transcription factor EB)-mediated autophagy

Vascular smooth muscle cells (VSMCs) contribute to plaque stability. VSMCs are also a major source of CTH (cystathionine gamma-lyase)-hydrogen sulfide (H₂S), a protective gasotransmitter in atherosclerosis. However, the role of VSMC endogenous CTH-H₂S in pathogenesis of plaque stability and the mechanism are unknown. In human carotid plaques, CTH expression in ACTA2⁺ cells was dramatically downregulated in lesion areas in comparison to non-lesion areas. Intraplaque CTH expression was positively correlated with collagen content, whereas there was a negative correlation with CD68⁺ and necrotic core area, resulting in a rigorous correlation with vulnerability index (r = -0.9033). Deletion of Cth in VSMCs exacerbated plaque vulnerability, and were associated with VSMC autophagy decline, all of which were rescued by H₂S donor. In ox-LDL treated VSMCs, cth deletion reduced collagen and heightened apoptosis association with autophagy reduction, and vice versa. For the mechanism, CTH-H₂S mediated VSMC autophagosome formation, autolysosome formation and lysosome function, in part by activation of TFEB, a master regulator for autophagy. Interference with TFEB blocked CTH-H₂S effects on VSMCs collagen and apoptosis. Next, we demonstrated that CTH-H₂S sulfhydrated TFEB at Cys212 site, facilitating its nuclear translocation, and then promoting transcription of its target genes such as ATG9A, LAPTM5 or LDLRAP1. Conclusively, CTH-H₂S increases VSMC autophagy by sulfhydration and activation of TFEB, promotes collagen secretion and inhibits apoptosis, thereby attenuating atherogenesis and plaque vulnerability. CTH-H₂S may act as a warning biomarker for vulnerable plaque.Abbreviations ATG9A: autophagy related 9A; CTH: cystathionine gamma-lyase; CQ: chloroquine; HASMCs: human aortic smooth muscle cells; H₂S: hydrogen sulfide; LAMP1: lysosomal associated membrane protein 1; LAPTM5: lysosomal protein transmembrane 5; NaHS: sodium hydrosulfide hydrate; ox-LDL: oxidized-low density lipoprotein; PPG: DL- propagylglycine; TFEB: transcription factor EB; 3-MA: 3-methyladenine; VSMCs: vascular smooth muscle cells.

Analysis of the Mechanism of GuizhiFuling Wan in Treating Adenomyosis Based on Network Pharmacology Combined with Molecular Docking and Experimental Verification

Background

The effect of GuizhiFuling Wan (GFW) on adenomyosis (AM) is definite. This study aimed to explore the mechanism and key therapeutic targets of GFW in treating AM through network pharmacology combined with molecular docking and experimental verification.

Materials and Methods

In network pharmacology, firstly, the active components of GFW, its drug, and disease targets were screened through several related public databases, and GFW-AM common targets were obtained after the intersection. Then, the biological function (Gene Ontology, GO) and pathway (Kyoto Encyclopedia of Genes and Genomes, KEGG) of GFW in treating AM were enriched and analyzed. Finally, the interaction and binding force between key components and key targets of GFW were verified by molecular docking. In the animal part, the effect of GFW on the expression of matrix metallopeptidase 2 (MMP-2), matrix metallopeptidase 9 (MMP-9), and vascular endothelial growth factor (VEGF) in mice with AM was observed by HE staining, ELISA, and immunohistochemistry.

Results

In this study, 89 active components of GFW, 102 related targets, and 291 targets of AM were collected. After the intersection, 26 common targets were finally obtained. The key active compounds were baicalein, sitosterol, and β-sitosterol, and the key targets were MMP-2, MMP-9, and VEGF. GO and KEGG enrichment analyses showed that biological processes such as the positive regulation of vascular endothelial migration and signaling pathways such as TNF and HIF-1 were involved in regulating angiogenesis, invasion, and metastasis in AM. The molecular docking results showed that baicalein, β-sitosterol, and stigmasterol had better binding potential with MMP-2, MMP-9, and VEGF. The results of in vivo analysis showed that GFW could decrease the serum content and protein expression of MMP-2, MMP-9, and VEGF in mice with AM.

Conclusions

GFW could reduce the expression of MMP-2, MMP-9, and VEGF, which might be an essential mechanism for GFW to inhibit the invasion and metastasis of ectopic tissues of AM.

Mitochondria-targeted hydrogen sulfide donors versus acute oxidative gastric mucosal injury

Hydrogen sulfide (H2S) as a gaseous molecule prevents gastrointestinal (GI)-tract against various injuries. This study aimed to evaluate for the first time the detailed molecular mechanism of mitochondria-targeting H2S-prodrugs, AP39 and RT01 in gastroprotection against ischemia/reperfusion (I/R)-induced lesions. Wistar rats exposed to I/R were pretreated i.g. with vehicle, AP39 (0.004-2 mg/kg), RT01 (0.1 mg/kg), or with AP219 (0.1 mg/kg) as structural control without ability to release H2S. AP39 was also administered with mTOR1 inhibitor, rapamycin (1 mg/kg i.g.). Gastric damage area was assessed micro-/macroscopically, gastric blood flow (GBF) by laser flowmetry, mRNA level of HIF-1α, GPx, SOD1, SOD2, annexin-A1, SOCS3, IL-1RA, IL-1β, IL-1R1, IL-1R2, TNFR2, iNOS by real-time PCR. Gastric mucosal and/or serum content of IL-1β, IL-4, IL-5, IL-10, G-CSF, M-CSF, VEGFA, GRO, RANTES, MIP-1α, MCP1, TNF-α, TIMP1, FABP3, GST-α, STAT3/5 and phosphorylation of mTOR, NF-κB, ERK, Akt was evaluated by microbeads-fluorescent assay. Mitochondrial complexes activities were measured biochemically. RNA damage was assessed as 8-OHG by ELISA. AP39 and RT01 reduced micro-/macroscopic gastric I/R-injury increasing GBF. AP39-gastroprotection was accompanied by maintained activity of mitochondrial complexes, prevented RNA oxidation and enhanced mRNA/protein expression of SOCS3, IL-1RA, annexin-A1, GST-α, HIF-1α. Rapamycin reversed AP-39-gastroprotection. AP39-gastroprotection was followed by decreased NF-κB, ERK, IL-1β and enhanced Akt and mTOR proteins phosphorylation. AP39-prevented gastric mucosal damage caused by I/R-injury, partly by mitochondrial complex activity maintenance. AP39-mediated attenuation of gastric mucosal oxidation, hypoxia and inflammation involved mTOR1 and Akt pathways activity and modulation of HIF-1α, GST-α, SOCS3, IL1RA and TIMP1 molecular interplay.

Hydrogen Sulfide Biology and Its Role in Cancer

Hydrogen sulfide (H2S) is an endogenous biologically active gas produced in mammalian tissues. It plays a very critical role in many pathophysiological processes in the body. It can be endogenously produced through many enzymes analogous to the cysteine family, while the exogenous source may involve inorganic sulfide salts. H2S has recently been well investigated with regard to the onset of various carcinogenic diseases such as lung, breast, ovaries, colon cancer, and neurodegenerative disorders. H2S is considered an oncogenic gas, and a potential therapeutic target for treating and diagnosing cancers, due to its role in mediating the development of tumorigenesis. Here in this review, an in-detail up-to-date explanation of the potential role of H2S in different malignancies has been reported. The study summarizes the synthesis of H2S, its roles, signaling routes, expressions, and H2S release in various malignancies. Considering the critical importance of this active biological molecule, we believe this review in this esteemed journal will highlight the oncogenic role of H2S in the scientific community.

Metformin exerts an antitumor effect by inhibiting bladder cancer cell migration and growth, and promoting apoptosis through the PI3K/AKT/mTOR pathway

Background

To observe and explore the effect of metformin on the migration and proliferation of bladder cancer T24 and 5637 cells in vitro.

Methods

Bladder cancer T24 and 5637 cell lines were cultured in vitro, and were divided into group A (blank control group) and group B (metformin group: 5, 10, 15, and 20 mmol/L); both groups were plated on 6-well plates at the same time. Culture in 24-well plates was used for wound healing assays and in 96-well plates for Transwell migration and invasion, and Cell Counting Kit-8 proliferation experiments. We observed and detected the cell migration and proliferation ability of each group at 48 h, and calculated the cell migration area and survival rate. Flow cytometry was used to detect cell apoptosis in the groups. The apoptosis-related proteins, cleaved-caspase 3, cleaved-PARP, and the PI3K/AKT/mTOR signaling pathway member proteins PI3K, phosphorylated (p)-PI3K, AKT, p-AKT, mTOR, and p-mTOR were detected using western blotting.

Results

After 48 h of treatment with different concentrations of metformin, the cell migration and proliferation capabilities were significantly lower than those in the blank control group. The proliferation and migration abilities of T24 and 5637 cells decreased in a metformin concentration-dependent manner (P < 0.05). The apoptosis rate under different concentrations of metformin, as detected by flow cytometry, showed a significantly higher rate in the metformin group than in the control group (P < 0.05). Compared with that in the control group, the level of cleaved-caspase 3 and cleaved-PARP protein in the metformin group was increased in each treatment group, and the levels of p-mTOR, p-AKT, and p-PI3K decreased significantly compared with those in the control group (P < 0.05).

Conclusion

Metformin inhibited bladder cancer T24 and 5637 cell migration and proliferation, and induced their apoptosis. The mechanism might involve inhibition of the activation of the PI3K/AKT/mTOR signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-01027-2.

Emerging roles of cystathionine β-synthase in various forms of cancer

The expression of the reverse transsulfuration enzyme cystathionine-β-synthase (CBS) is markedly increased in many forms of cancer, including colorectal, ovarian, lung, breast and kidney, while in other cancers (liver cancer and glioma) it becomes downregulated. According to the clinical database data in high-CBS-expressor cancers (e.g. colon or ovarian cancer), high CBS expression typically predicts lower survival, while in the low-CBS-expressor cancers (e.g. liver cancer), low CBS expression is associated with lower survival. In the high-CBS expressing tumor cells, CBS, and its product hydrogen sulfide (H₂S) serves as a bioenergetic, proliferative, cytoprotective and stemness factor; it also supports angiogenesis and epithelial-to-mesenchymal transition in the cancer microenvironment. The current article reviews the various tumor-cell-supporting roles of the CBS/H₂S axis in high-CBS expressor cancers and overviews the anticancer effects of CBS silencing and pharmacological CBS inhibition in various cancer models in vitro and in vivo; it also outlines potential approaches for biomarker identification, to support future targeted cancer therapies based on pharmacological CBS inhibition.

Sulfane Sulfur Posttranslationally Modifies the Global Regulator AdpA to Influence Actinorhodin Production and Morphological Differentiation of Streptomyces coelicolor

The transcription factor AdpA is a key regulator controlling both secondary metabolism and morphological differentiation in Streptomyces. Due to its critical functions, its expression undergoes multilevel regulations at transcriptional, posttranscriptional, and translational levels, yet no posttranslational regulation has been reported. Sulfane sulfur, such as hydro polysulfide (HS_nH, n ≥ 2) and organic polysulfide (RS_nH, n ≥ 2), is common inside microorganisms, but its physiological functions are largely unclear. Here, we discovered that sulfane sulfur posttranslationally modifies AdpA in Streptomyces coelicolor via specifically reacting with Cys⁶² of AdpA to form a persulfide (Cys⁶²-SSH). This modification decreases the affinity of AdpA to its self-promoter P_adpA, allowing increased expression of adpA, further promoting the expression of its target genes actII-4 and wblA. ActII-4 activates actinorhodin biosynthesis, and WblA regulates morphological development. Bioinformatics analyses indicated that AdpA-Cys⁶² is highly conserved in Streptomyces, suggesting the prevalence of such modification in this genus. Thus, our study unveils a new type of regulation on the AdpA activity and sheds a light on how sulfane sulfur stimulates the production of antibiotics in Streptomyces.

Prediction of overall survival based upon a new ferroptosis-related gene signature in patients with clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the most common and lethal renal cell carcinoma (RCC) histological subtype. Ferroptosis is a newly discovered programmed cell death and serves an essential role in tumor occurrence and development. The purpose of this study is to analyze ferroptosis-related gene (FRG) expression profiles and to construct a multi-gene signature for predicting the prognosis of ccRCC patients.

METHODS

RNA-sequencing data and clinicopathological data of ccRCC patients were downloaded from The Cancer Genome Atlas (TCGA). Differentially expressed FRGs between ccRCC and normal tissues were identified using 'limma' package in R. GO and KEGG enrichment analyses were conducted to elucidate the biological functions and pathways of differentially expressed FRGs. Consensus clustering was used to investigate the relationship between the expression of FRGs and clinical phenotypes. Univariate and the least absolute shrinkage and selection operator (LASSO) Cox regression analysis were used to screen genes related to prognosis and construct the optimal signature. Then, a nomogram was established to predict individual survival probability by combining clinical features and prognostic signature.

RESULTS

A total of 19 differentially expressed FRGs were identified. Consensus clustering identified two clusters of ccRCC patients with distinguished prognostic. Functional analysis revealed that metabolism-related pathways were enriched, especially lipid metabolism. A 7-gene ferroptosis-related prognostic signature was constructed to stratify the TCGA training cohort into high- and low-risk groups where the prognosis was significantly worse in the high-risk group. The signature was identified as an independent prognostic indicator for ccRCC. These findings were validated in the testing cohort, the entire cohort, and the International Cancer Genome Consortium (ICGC) cohort. We further demonstrated that the signature-based risk score was highly associated with the ccRCC progression. Further stratified survival analysis showed that the high-risk group had a significantly lower overall survival (OS) rate than those in the low-risk group. Moreover, we constructed a nomogram that had a strong ability to forecast the OS of the ccRCC patients.

CONCLUSIONS

We constructed a ferroptosis-related prognostic signature, which might provide a reliable prognosis assessment tool for the clinician to guide clinical decision-making and outcomes research.

The Role of Hydrogen Sulfide Regulation of Autophagy in Liver Disorders

Autophagy is a complex process of degradation of senescent or dysfunctional organelles in cells. Dysfunctional autophagy is associated with many diseases such as cancers, immune dysfunction, and aging. Hydrogen sulfide (H₂S) is considered to be the third gas signal molecule after nitrous oxide and carbon monoxide. In recent years, H₂S has been found to have a variety of important biological functions, and plays an important role in a variety of physiological and pathological processes. In this review, we review the recent role and mechanism of H₂S in regulating autophagy in liver disorders, in order to provide a basis for further research in the future.

Hepatic stellate cell mediates transcription of TNFSF14 in hepatocellular carcinoma cells via H2S/CSE-JNK/JunB signaling pathway

Hepatic stellate cells (HSC) and hydrogen sulfide (H2S) both play important roles in the development of hepatocellar carcinoma (HCC). Whereas, in the microenvironment of HCC, whether HSC participate in regulating the biological process of HCC cells by releasing H2S remains elusive. In vitro, Flow cytometry (FCM), CCK-8, RNA-sequencing, Western blotting, RT-qPCR, immunofluorescence and ChIP assays were carried out in the HCC cells to investigate the effect of H2S on biological functions and JNK/JunB-TNFSF14 signaling pathway. Specimens from HCC patients were analyzed by RT-qPCR and Western blotting assays for evaluating the expression of TNFSF14 and CSE. Statistical analysis was used to analyze the correlation between TNFSF14 expression and clinical data of HCC patients. Based on the FCM and CCK-8 results, we found the LX-2 cells were able to induce HCC cells apoptosis through releasing H2S. RNA-sequencing, RT-qPCR, and Western blotting results showed that TNFSF14 gene was upregulated in both LX-2 and NaHS group. NaHS treated in HCC cells led to JNK/JunB signaling pathway activating and greater binding of p-JunB to its responsive elements on TNFSF14 promoter. Impairment of TNFSF14 induction alleviated LX-2 and NaHS induced apoptosis of HepG2 and PLC/PRF/5 cells. Furthermore, TNFSF14 expression in HCC tissues was lower than the adjacent tissue. HCC patients with low expression of TNFSF14 had higher malignant degree and poor prognosis. In summary, demonstration of the involvement of HSC-derived H2S in JNK/JunB mediated expression of TNFSF14 gene strongly indicates H2S palys an important role in the regulation of HCC apoptosis.

Genome-Wide Analyses of Heat Shock Protein Superfamily Provide New Insights on Adaptation to Sulfide-Rich Environments in Urechis unicinctus (Annelida, Echiura)

The intertidal zone is a transitional area of the land-sea continuum, in which physical and chemical properties vary during the tidal cycle and highly toxic sulfides are rich in sediments due to the dynamic regimes. As a typical species thriving in this habitat, Urechis unicinctus presents strong sulfide tolerance and is expected to be a model species for sulfide stress research. Heat shock proteins (HSPs) consist of a large group of highly conserved molecular chaperones, which play important roles in stress responses. In this study, we systematically analyzed the composition and expression of HSPs in U. unicinctus. A total of eighty-six HSP genes from seven families were identified, in which two families, including sHSP and HSP70, showed moderate expansion, and this variation may be related to the benthic habitat of the intertidal zone. Furthermore, expression analysis revealed that almost all the HSP genes in U. unicinctus were significantly induced under sulfide stress, suggesting that they may be involved in sulfide stress response. Weighted gene co-expression network analysis (WGCNA) showed that 12 HSPs, including 5 sHSP and 4 HSP70 family genes, were highly correlated with the sulfide stress response which was distributed in steelblue and green modules. Our data indicate that HSPs, especially sHSP and HSP70 families, may play significant roles in response to sulfide stress in U. unicinctus. This systematic analysis provides valuable information for further understanding of the function of the HSP gene family for sulfide adaptation in U. unicinctus and contributes a better understanding of the species adaptation strategies of marine benthos in the intertidal zone.

Hydrogen Sulfide: A Key Role in Autophagy Regulation from Plants to Mammalians

Autophagy is a degradative conserved process in eukaryotes to recycle unwanted cellular protein aggregates and damaged organelles. Autophagy plays an important role under normal physiological conditions in multiple biological processes, but it is induced under cellular stress. Therefore, it needs to be tightly regulated to respond to different cellular stimuli. In this review, the regulation of autophagy by hydrogen sulfide is described in both animal and plant systems. The underlying mechanism of action of sulfide is deciphered as the persulfidation of specific targets, regulating the pro- or anti-autophagic role of sulfide with a cell survival outcome. This review aims to highlight the importance of sulfide and persulfidation in autophagy regulation comparing the knowledge available in mammals and plants.

Hydrogen sulfide regulates autophagy in nucleus pulposus cells under hypoxia

OBJECTIVE

Hydrogen sulfide (H2S) has been found to act as an important gasotransmitter to regulate cell activities. This study aimed to investigate the effect of H2S on autophagy of nucleus pulposus (NP) cells under hypoxia and possible mechanism.

MATERIALS AND METHODS

NP cells were isolated from rat caudal discs. Cobalt chloride was used to mimic hypoxia, sodium hydrosulfide was used to emulate exogenous H2S and 3-methyladenine was used to block cell autophagy. Cell viability was assessed by phase contrast microscope and Cell Counting Kit-8 method. Moreover, expression of key autophagic proteins was analyzed via western blotting, and transmission electron microscopy was performed to detect autophagosomes.

RESULTS

Hypoxia markedly impaired NP cell proliferation compared with control. Whereas H2S provided pro-proliferation and pro-autophagy effects on hypoxic NP cells. However, these beneficial impact of H2S on hypoxic NP cells were reversed by autophagy inhibitor.

CONCLUSIONS

Our results showed that H2S played a cytoprotective role in NP cells exposed to hypoxia in an autophagy-dependent manner.