Sonic Hedgehog acts as a macrophage chemoattractant during regeneration of the gastric epithelium

Sonic Hedgehog (Shh), secreted from gastric parietal cells, contributes to the regeneration of the epithelium. The recruitment of macrophages plays a central role in the regenerative process. The mechanism that regulates macrophage recruitment in response to gastric injury is largely unknown. Here we tested the hypothesis that Shh stimulates macrophage chemotaxis to the injured epithelium and contributes to gastric regeneration. A mouse model expressing a myeloid cell-specific deletion of Smoothened (LysMcre/+;Smof/f) was generated using transgenic mice bearing loxP sites flanking the Smo gene (Smo loxP) and mice expressing a Cre recombinase transgene from the Lysozyme M locus (LysMCre). Acetic acid injury was induced in the stomachs of both control and LysMcre/+;Smof/f (SmoKO) mice and gastric epithelial regeneration and macrophage recruitment analyzed over a period of 7 days post-injury. Bone marrow-derived macrophages (BM-Mø) were collected from control and SmoKO mice. Human-derived gastric organoid/macrophage co-cultures were established, and macrophage chemotaxis measured. Compared to control mice, SmoKO animals exhibited inhibition of ulcer repair and normal epithelial regeneration, which correlated with decreased macrophage infiltration at the site of injury. Bone marrow chimera experiments using SmoKO donor cells showed that control chimera mice transplanted with SmoKO bone marrow donor cells exhibited a loss of ulcer repair, and transplantation of control bone marrow donor cells to SmoKO mice rescued epithelial cell regeneration. Histamine-stimulated Shh secretion in human organoid/macrophage co-cultures resulted in macrophage migration toward the gastric epithelium, a response that was blocked with Smo inhibitor Vismodegib. Shh-induced macrophage migration was mediated by AKT signaling. In conclusion, Shh signaling acts as a macrophage chemoattractant via a Smo-dependent mechanism during gastric epithelial regeneration in response to injury.

Outcomes of the management of corrosive injuries of the upper digestive tract in a tertiary care center

Summary Esophageal stricture is the most common delayed sequelae of aerodigestive tract corrosive injuries. Early endoscopic dilatation is an integral part of corrosive injury management. Self-dilatation of the esophagus is effective in preventing stricture recurrence. In this prospective study, we included patients with corrosive aerodigestive tract injury from January 2009 to December 2020. We analyzed the outcome of the endoscopic dilatation and self-dilatation treatments administered to patients with a corrosive esophageal stricture. Among 295 patients, 164 had an esophageal injury, 73 had esophago-gastric injury, 55 had a gastric injury, and 3 had the pharyngeal injury. Of the 295 patients, 194 (81.85%) underwent dilatation, and 13 patients with diffuse esophageal injury underwent upfront surgery. Successful dilatation was performed in 169 (87.11%) patients. Of the 68 patients undergoing self-dilatation, 63 patients achieved nutritional autonomy by 28 days. Early endoscopic dilatation effectively prevents surgery, and self-dilatation appears promising to prevent recurrent esophageal stricture.

Potential and beneficial effects of Cinnamomum cassia on gastritis and safety: Literature review and analysis of standard extract

The prevalence of gastritis in South Korea is rapidly increasing owing to the prevalence of Helicobacter pylori infection and fast eating habit. The usual treatment for acute gastritis following a long intake of non-steroidal anti-inflammatory drugs (NSAIDs) or alcohol is to stop the causal factors. Metronidazole and lansoprazole are recommended for the treatment of H. pylori infection gastritis. Omeprazole a proton pump inhibitor, is used to decrease gastric acid production. However, owing to the side effects and refractoriness of the drug, a safe and efficient treatment is required. Plant-derived phytochemicals have emerged as novel agents against chronic disorders. In this study, firstly, to explore the potential of pharmacological activities, including efficacy and mechanisms of Cinnamomum cassia against gastritis, a literature review was performed based on 20 studies out of a total of 749 records obtained using a search strategy. From the literature review, the therapeutic targets of C. cassia extract and cinnamaldehyde, a compound of C. cassia, were found to be related with NFκB activity, and their signaling pathway were verified by experiments. C. cassia extract plays a role in protection of gastric ulcers induced in four ways (immersion stress-induced, ethanol-induced, hydrochloric acid-induced, or NSAIDs-induced ulcer). None of the clinical studies on C. cassia extracts or compounds met our criteria. When the standardized extract of C. cassia (ECC) was orally administered repeatedly to Beagle Dog for 4 weeks, no toxicologically harmful changes were observed. Therefore, under the test condition, the no observed adverse effect level (NOAEL) of ECC was judged to be 1000 mg/kg/day for both sexes, and no toxic target organ was observed. Administration of ECC in the Sprague–Dawley rat model of acute gastric injury caused by indomethacin administration significantly increased gastric mucus volume. Administration of ECC in the acute gastric injury model caused by indomethacin administration is considered effective in improving gastric injury. However, research and efforts to develop a reliable ‘standardization of natural drugs’ by establishing the best quality evaluation system are limited. Despite the pharmacological potential of ECC, further well-designed experimental studies such as in vitro, in vivo, and clinical trials are required to validate these findings and the underlying mechanisms of ECC.

Anti-inflammatory activity of acacia catechu-bark aqueous solution in aspirin induced gastric ulcer in rodents

Background: Aspirin is amongst the most widely used drugs and has many adverse effects on gastric mucosa. Anti-inflammatory properties of Acacia catechu have been established already. Objective was to evaluate the histopathological changes induced by aspirin in the stomach of albino rats and to assess the protective effect of different doses of Acacia catechu.Methods: Experimental study Postgraduate Medical Institute, Lahore for 21 days. Forty-eight adult albino rats, both males and female, were divided into four groups A, B, C and D randomly; each comprising of 12 rats. Group A was control, group B was given aspirin 100 mg/kg and group C and D were given aspirin 100 mg/kg along with Acacia catechu 250 mg/kg and 500 mg/kg respectively by oral route. The rats from individual group were sacrificed on 3rd day, 7th day and 14th day and stomachs were examined under light microscope to observe the inflammatory cells infiltration.Results: Gross and microscopic findings on days 3, 7 and 14 were similar. Control groups A1, A2 and A3 showed normal healthy gastric mucosa and the least number of inflammatory cells. In group B, aspirin produced ulcerations and linear breaks; with highest inflammatory infiltrates. On microscopic examination, numerous inflammatory cells were noted. Group C and D rats had minimum ulcer index and fewer inflammatory cells.Conclusions: Acacia catechu has protective role against gastric injury by inhibiting inflammation.

Preventive Effect of Gonggan (Citrus Reticulata Blanco Var. Gonggan) Peel Extract on Ethanol/HCl-Induced Gastric Injury in Mice via an Anti-oxidative Mechanism

Gonggan (Citrus reticulata Blanco var. gonggan) is one of the most popular citruses. In this study, the effect of Gonggan peel extract (GPE) on gastric injury was investigated. The components in GPE were analysed by HPLC and the gastric injury model in mice was established by ethanol/hydrochloric acid. After treatment by GPE, the pathological changes of gastric tissue were observed by optical microscope. The levels of oxidative stress and inflammation were measure by kit. And the mRNA expression of related gene was determined by qPCR assay. HPLC result showed GPE mainly contained the flavonoids narirutin, hesperidin, nobiletin, tangeretin and 5-demethylnobiletin. Morphological and pathological analysis of gastric tissue revealed that GPE could relieve gastric injury. Also, GPE increased the levels of SOD, GSH-Px, and CAT and decreased the level of MDA. Moreover, GPE decreased the levels of the inflammatory cytokines TNF-α, IFN-γ, IL-1β, and IL-6 to suppress inflammation. In addition, the q-PCR results showed that GPE upregulated the mRNA expression of SOD1, SOD2, γ-GCS, GSH-Px, CAT, and IκBα and downregulated the mRNA expression of NF-κB. In conclusion, GPE alleviated gastric injury caused by ethanol/hydrochloric acid by inhibiting oxidative stress and the inflammatory response. The mechanism by which GPE protects gastric tissues may involve the antioxidative pathway. Therefore, GPE has great potential to be developed as a product to prevent gastric injury.

Therapeutic Potency of Gallium verum Extract on Ethanol-Induced Gastric Ulcer in Rats

Gallium verum, lady's bedstraw is an herbaceous annual plant belonging to the genus Rubiaceae; it possessed antioxidant, cytotoxic for cancer cells, antimicrobial, protective and endocrine effects. This work aimed to investigate the curative effects of G. verum extract on gastric ulcers following absolute ethanol administration in the healthy rat. Eighteen rats were randomly divided into three main groups; rats were fastened for 24 hours before ethanol administration. All groups except control administered ethanol (5 ml/kg body weight; orally). The rats were administrated distilled water (Ulcer group) or G. verum extract (100mg/kg) one hour later. G. verum extract caused a significant decrease in ulcer index, gastric juice volume, malondialdehyde, and nitric oxide, while gastric juice pH, glutathione, glutathione-S-transferase, and catalase increased significantly. The histological lesion score showed a significant enhancement in group G. verum compared to the ulcer group that scored the highest pathological destruction score. Immunohistochemical markers of NF-κB p65 and TNF-α showed a significant decrease in G. verum group. G. verum extract is a promising treatment modality against gastric injury through its powerful antioxidant, acid neutralizing, healing promotion, and ant-inflammation effects.

CD36 maintains the gastric mucosa and associates with gastric disease

The gastric epithelium is often exposed to injurious elements and failure of appropriate healing predisposes to ulcers, hemorrhage, and ultimately cancer. We examined the gastric function of CD36, a protein linked to disease and homeostasis. We used the tamoxifen model of gastric injury in mice null for Cd36 (Cd36−/−), with Cd36 deletion in parietal cells (PC-Cd36−/−) or in endothelial cells (EC-Cd36−/−). CD36 expresses on corpus ECs, on PC basolateral membranes, and in gastrin and ghrelin cells. Stomachs of Cd36−/− mice have altered gland organization and secretion, more fibronectin, and inflammation. Tissue respiration and mitochondrial efficiency are reduced. Phospholipids increased and triglycerides decreased. Mucosal repair after injury is impaired in Cd36−/− and EC-Cd36−/−, not in PC-Cd36−/− mice, and is due to defect of progenitor differentiation to PCs, not of progenitor proliferation or mature PC dysfunction. Relevance to humans is explored in the Vanderbilt BioVu using PrediXcan that links genetically-determined gene expression to clinical phenotypes, which associates low CD36 mRNA with gastritis, gastric ulcer, and gastro-intestinal hemorrhage. A CD36 variant predicted to disrupt an enhancer site associates (p < 10−17) to death from gastro-intestinal hemorrhage in the UK Biobank. The findings support role of CD36 in gastric tissue repair, and its deletion associated with chronic diseases that can predispose to malignancy.