Helicobacter pylori infection modulates endogenous hydrogen sulfide production in gastric cancer AGS cells

Taurine ameliorates cellular senescence associated with an increased hydrogen sulfide and a decreased hepatokine, IGFBP-1, in CCl4-induced hepatotoxicity in mice

This study investigated the protective effects of taurine against cellular senescence and hepatokine secretion in a mouse model of carbon tetrachloride (CCl4)-induced chronic liver injury. Oral taurine administration by tap water containing 3 % taurine significantly attenuated liver damage, as evidenced by reduced serum AST, ALT level and hepatic lipid peroxidation. Importantly, hepatic taurine level is reduced in CCl4-induced injury model, while taurine administration recovered it. Moreover, taurine administration decreased the numbers of p21-positive senescent cells in liver tissue of CCl4-treated mice. Taurine increases hydrogen sulfide (H2S) in liver of normal mice, suggesting anti-oxidative role through H2S production by taurine. Furthermore, inhibition of CTH, which is an enzyme responsible for H2S production from cysteine, by propagylglycine attenuated malondialdehyde-lowering effect of taurine in liver of CCl4-treated mice. Moreover, we found taurine treatment lowers insulin-like growth factor binding protein-1 (IGFBP-1) in liver of normal mice. Importantly, while chronic CCl4 injection caused an induction of IGFBP-1, taurine administration blocked it. These findings suggest that taurine exerts its protective effects by attenuating cellular senescence, which is associated with enhancing H2S production and inhibiting IGFBP-1 expression. This study highlights the potential of taurine as a therapeutic strategy for mitigating chronic liver injury by producing H2S and targeting IGFBP1.

Selective G6PDH inactivation for Helicobacter pylori eradication with transformed polysulfide

Alternative treatment for the highly prevalent Helicobacter pylori infection is imperative due to rising antibiotic resistance. We unexpectedly discovered that the anti-H. pylori component in garlic is hydrogen polysulfide (H2Sn, n⩾2), not organic polysulfides. Studies on the mechanism of action (MoA) show that H2Sn specifically inactivates H. pylori glucose-6-phosphate dehydrogenase (G6PDH) by interfering with electron transfer from glucose-6-phosphate (G6P) to nicotinamide adenine dinucleotide phosphate (NADP+). However, low H2Sn yield makes garlic derivatives hard to be a reliable donor of H2Sn to treat H. pylori infection. To address this challenge, we established a polysulfide transformation process from garlic organosulfur compounds into Fe3S4 that generates H2Sn with a 25-58 times increase in yield. Through chitosan encapsulation, we designed a gastric-adaptive H2Sn microreactor (GAPSR) that eradicates H. pylori with 250 times higher efficiency under gastric conditions. A single GAPSR achieves more rapid H. pylori eradication than combined antibiotics therapy without disturbing the gut microbiota. These findings indicate a distinct MoA transformation mediated by polysulfide as an alternative candidate to treat H. pylori infection.

Computer analysis of abnormal proliferation and transformation cells in gastric mucosa and its clinical significance

To investigate the image computer analysis of abnormally proliferating transformed cells of gastric mucosa and its clinical significance. The pathological pictures of gastric adenomatous polyp cells, abnormally proliferating altered cells, and tubular adenocarcinoma cells in the stomach mucosa were assessed by image computer method on a total of 96 gastroscopic biopsy and ESD resection specimens. The data of cytoplasmic area, nuclear area, nuclear-cytoplasmic ratio, nuclear factor and N-heterotypic index of gastric adenomatous polyps, abnormal proliferative transformation and gastric intramucosal tubular adenocarcinoma were collected, and the mean, standard deviation and variance were calculated respectively. Standard Error, Maximum, Minimum Parameters and Statistical Structure. There were substantial discrepancies between gastric mucosal gastric adenomatous polyp cells and gastric mucosal abnormally proliferating transformed cells, according to the five data in the abnormal cells in the stomach mucosal proliferation area (p < 0.01); There was no significant difference between cells (p > 0.05). Computer analysis of cell images can provide quantitative values for the pathological diagnosis of gastric adenomatous polyp cells, abnormally proliferating transformed cells and tubular adenocarcinoma cells in the gastric mucosa, especially the degree of atypical proliferation. The monitoring of abnormally proliferated and transformed cells in gastric mucosa is of great significance for clinicians to accurately treat and track cell transformation, and to control the occurrence and development of gastric adenocarcinoma.

Animal Models of Helicobacter pylori Infection and Vaccines: Current Status and Future Prospects

Helicobacter pylori infection causes chronic gastritis, ulcers, and gastric cancer, making it a threat to human health. Despite the use of antibiotic therapy, the global prevalence of H. pylori infection remains high, necessitating early eradication measures. Immunotherapy, especially vaccine development, is a promising solution in this direction, albeit the selection of an appropriate animal model is critical in efficient vaccine production. Accordingly, we conducted a literature, search and summarized the commonly used H. pylori strains, H. pylori infection-related animal models, and models for evaluating H. pylori vaccines. Based on factors such as the ability to replicate human diseases, strain compatibility, vaccine types, and eliciting of immune responses, we systematically compared the advantages and disadvantages of different animal models, to obtain the informed recommendations. In addition, we have proposed novel perspectives on H. pylori-related animal models to advance research and vaccine evaluation for the prevention and treatment of diseases such as gastric cancer.

Modulation of Gut Microbial Biomarkers and Metabolites in Cancer Management by Tea Compounds

Cancers are causing millions of deaths and leaving a huge clinical and economic burden. High costs of cancer drugs are limiting their access to the growing number of cancer cases. The development of more affordable alternative therapy could reach more patients. As gut microbiota plays a significant role in the development and treatment of cancer, microbiome-targeted therapy has gained more attention in recent years. Dietary and natural compounds can modulate gut microbiota composition while providing broader and more accessible access to medicine. Tea compounds have been shown to have anti-cancer properties as well as modulate the gut microbiota and their related metabolites. However, there is no comprehensive review that focuses on the gut modulatory effects of tea compounds and their impact on reshaping the metabolic profiles, particularly in cancer models. In this review, the effects of different tea compounds on gut microbiota in cancer settings are discussed. Furthermore, the relationship between these modulated bacteria and their related metabolites, along with the mechanisms of how these changes led to cancer intervention are summarized.

The Role of Methionine Restriction in Gastric Cancer: A Summary of Mechanisms and a Discussion on Tumor Heterogeneity

Gastric cancer is ranked as the fifth most prevalent cancer globally and has long been a topic of passionate discussion among numerous individuals. However, the incidence of gastric cancer in society has not decreased, but instead has shown a gradual increase in recent years. For more than a decade, the treatment effect of gastric cancer has not been significantly improved. This is attributed to the heterogeneity of cancer, which makes popular targeted therapies ineffective. Methionine is an essential amino acid, and many studies have shown that it is involved in the development of gastric cancer. Our study aimed to review the literature on methionine and gastric cancer, describing its mechanism of action to show that tumor heterogeneity in gastric cancer does not hinder the effectiveness of methionine-restricted therapies. This research also aimed to provide insight into the inhibition of gastric cancer through metabolic reprogramming with methionine-restricted therapies, thereby demonstrating their potential as adjuvant treatments for gastric cancer.

Neuropathological hallmarks in autopsied cases with mitochondrial diseases caused by the mitochondrial 3243A>G mutation

The mitochondrial (m.) 3243A>G mutation is known to be associated with various mitochondrial diseases including mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Their clinical symptoms have been estimated to occur with an increased mitochondrial DNA (mtDNA) heteroplasmy and reduced activity of oxidative phosphorylation (OXPHOS) complexes, but their trends in the central nervous system remain unknown. Six autopsied mutant cases and three disease control cases without the mutation were enrolled in this study. The mutant cases had a disease duration of 1-27 years. Five of six mutant cases were compatible with MELAS. In the mutant cases, cortical lesions including a laminar necrosis were frequently observed in the parietal, lateral temporal, and occipital lobes; less frequently in the frontal lobe including precentral gyrus; and not at all in the medial temporal lobe. The mtDNA heteroplasmy in brain tissue samples of the mutant cases was strikingly high, ranging from 53.8% to 85.2%. The medial temporal lobe was preserved despite an inhospitable environment having high levels of mtDNA heteroplasmy and lactic acid. OXPHOS complex I was widely decreased in the mutant cases. The swelling of smooth muscle cells in the vessels on the leptomeninges, with immunoreactivity (IR) against mitochondria antibody, and a decreased nuclear/cytoplasmic ratio of choroidal epithelial cells were observed in all mutant cases but in none without the mutation. Common neuropathological findings such as cortical laminar necrosis and basal ganglia calcification were not always observed in the mutant cases. A high level of mtDNA heteroplasmy was observed throughout the brain in spite of heterogeneous cortical lesions. A lack of medial temporal lesion, mitochondrial vasculopathy in vessels on the leptomeninges, and an increased cytoplasmic size of epithelial cells in the choroid plexus could be neuropathological hallmarks helpful in the diagnosis of mitochondrial diseases.

Recent advances in the role of endogenous hydrogen sulphide in cancer cells

Hydrogen sulphide (H2 S) is a gaseous neurotransmitter that can be self-synthesized by living organisms. With the deepening of research, the pathophysiological mechanisms of endogenous H2 S in cancer have been increasingly elucidated: (1) promote angiogenesis, (2) stimulate cell bioenergetics, (3) promote migration and proliferation thereby invasion, (4) inhibit apoptosis and (5) activate abnormal cell cycle. However, the increasing H2 S levels via exogenous sources show the opposite trend. This phenomenon can be explained by the bell-shaped pharmacological model of H2 S, that is, the production of endogenous (low concentration) H2 S promotes tumour growth while the exogenous (high concentration) H2 S inhibits tumour growth. Here, we review the impact of endogenous H2 S synthesis and metabolism on tumour progression, summarize the mechanism of action of H2 S in tumour growth, and discuss the possibility of H2 S as a potential target for tumour treatment.

Mitochondrial Function in Health and Disease: Responses to Helicobacter pylori Metabolism and Impact in Gastric Cancer Development

Mitochondria are major cellular organelles that play an essential role in metabolism, stress response, immunity, and cell fate. Mitochondria are organized in a network with other cellular compartments, functioning as a signaling hub to maintain cells' health. Mitochondrial dysfunctions and genome alterations are associated with diseases including cancer. Mitochondria are a preferential target for pathogens, which have developed various mechanisms to hijack cellular functions for their benefit. Helicobacter pylori is recognized as the major risk factor for gastric cancer development. H. pylori induces oxidative stress and chronic gastric inflammation associated with mitochondrial dysfunction. Its pro-apoptotic cytotoxin VacA interacts with the mitochondrial inner membrane, leading to increased permeability and decreased ATP production. Furthermore, H. pylori induces mitochondrial DNA damage and mutation, concomitant with the development of gastric intraepithelial neoplasia as observed in infected mice. In this chapter, we present diverse aspects of the role of mitochondria as energy supplier and signaling hubs and their adaptation to stress conditions. The metabolic activity of mitochondria is directly linked to biosynthetic pathways. While H. pylori virulence factors and derived metabolites are essential for gastric colonization and niche adaptation, they may also impact mitochondrial function and metabolism, and may have consequences in gastric pathogenesis. Importantly, during its long way to reach the gastric epithelium, H. pylori faces various cellular types along the gastric mucosa. We discuss how the mitochondrial response of these different cells is affected by H. pylori and impacts the colonization and bacterium niche adaptation and point to areas that remain to be investigated.

Gasotransmitters in the tumor microenvironment: Impacts on cancer chemotherapy (Review)

Nitric oxide, carbon monoxide and hydrogen sulfide are three endogenous gasotransmitters that serve a role in regulating normal and pathological cellular activities. They can stimulate or inhibit cancer cell proliferation and invasion, as well as interfere with cancer cell responses to drug treatments. Understanding the molecular pathways governing the interactions between these gases and the tumor microenvironment can be utilized for the identification of a novel technique to disrupt cancer cell interactions and may contribute to the conception of effective and safe cancer therapy strategies. The present review discusses the effects of these gases in modulating the action of chemotherapies, as well as prospective pharmacological and therapeutic interfering approaches. A deeper knowledge of the mechanisms that underpin the cellular and pharmacological effects, as well as interactions, of each of the three gases could pave the way for therapeutic treatments and translational research.

Metabolome Characteristics of Liver Autophagy Deficiency under Starvation Conditions in Infancy

The liver function is essential for metabolism, detoxification, and bile synthesis, even in the neonatal period. Autophagy plays significance roles in THE adult liver, whereas the role of liver autophagy in the early neonatal period largely remains unclear. To clarify the importance of liver autophagy in the neonatal starvation period, we generated liver-specific autophagy-deficient (Atg5^flox/flox; Albumin-Cre) mice and investigated under starvation conditions comparing with control (Atg5^flox/+; Albumin-Cre) mice, focusing on serum metabolites and liver histopathology. As a result, autophagy in the liver was found to unessential for the survival under postnatal starvation. A metabolomics analysis of serum metabolites by gas chromatography-tandem mass spectrometry showed a significant difference between the groups, especially after 12-h starvation, suggesting the synergistical adaption of metabolic pathways, such as the “malate-aspartate shuttle”, “aspartate metabolism”, “urea cycle”, and “glycine and serine metabolism”. Liver-specific autophagy-deficiency under postnatal starvation conditions can cause a characteristic metabolic alteration suggesting a change of the mitochondrial function. Neonates seemed to maintain ketone production under starvation conditions, even in the autophagy-deficient liver, through a change in the mitochondrial function, which may be an adaptive mechanism for avoiding fatal starvation.