A look at duodenal mucosal resurfacing: Rationale for targeting the duodenum in type 2 diabetes

Development of a targeted oral pharmacologic duodenal exclusion therapy for the treatment of metabolic diseases

Type 2 diabetes (T2D) and obesity are chronic metabolic diseases with global morbidity and mortality. Decades of evidence from surgical and endoscopic procedures bypassing the duodenum underscore the duodenum's critical role in regulating glycemia and body weight. Although metabolic surgeries and endoscopic procedures are effective, their invasiveness, cost, and scalability limit patient access. We developed an orally administered mucin complexing polymeric (MCP) drug, designed to replicate duodenal exclusion physiology. MCPs, intended to have electrostatic and covalent cross-linkages with mucin glycoproteins, form extended network structures with resulting alteration of mucus barrier properties. Selective targeting of the duodenum is achieved via pH-based activation chemistry. Following screening for physiochemical properties, pharmacokinetics, and efficacy, GLY-200 emerged as the lead drug candidate replicating duodenal exclusion physiology with improved glycemia, reduced body weight, and modulation of gut hormones in rodent models. This targeted oral therapy holds promise for treatment of T2D and obesity by mimicking duodenal exclusion without the invasiveness of surgery or endoscopic procedures.

Cloning and Spatiotemporal Expression Analysis of IGF1R Gene cDNA in Alopex lagopus (Arctic Fox)

This study aimed to clarify the sequence characteristics and spatiotemporal expression patterns of the insulin-like growth factor 1 receptor (IGF1R) gene in Alopex lagopus (Arctic fox), thereby addressing the existing knowledge gap regarding IGF1R-mediated growth regulation in this species. The findings establish a crucial foundation for subsequent investigations into the correlation between this gene and Arctic fox growth traits. Specific primers were designed based on the cDNA sequence of the canine IGF1R gene (Accession No. XM_545828). The full-length coding sequence (CDS) of the Arctic fox IGF1R gene (1617 bp, encoding 538 amino acids) was successfully cloned via RT-PCR. Phylogenetic analysis using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) algorithm revealed a 99% sequence homology in the IGF1R gene between the Arctic fox and canine, confirmed their closest evolutionary relationship. Protein characterization showed that the IGF1R protein has a molecular weight of 60.62 kDa (theoretical isoelectric point pI = 5.15), containing one fibronectin type-III domain and one tyrosine kinase domain, classifying it as an acidic hydrophilic transmembrane protein. Phosphorylation site prediction identified 27 phosphorylation sites, with secondary structures dominated by α-helices (26.39%) and random coils (52.79%). The IGF1R gene displayed significant tissue-specific expression variations across 12 examined tissues in Arctic foxes: highest expression levels in testis, minimal expression in stomach, and no detectable expression in duodenum. Spatiotemporal expression analysis revealed that in 2-, 4-, and 6-month-old individuals, hepatic IGF1R exhibited a progressive increase, testicular expression reached peak levels at 6 months, and skeletal muscle demonstrated transient upregulation peaking at 4 months. These spatiotemporal expression patterns suggest that IGF1R may participate in metabolism and organ developmental processes during critical growth stages of Arctic foxes through tissue-specific regulation.

The 2024 top 10 list of endoscopy topics in medical publishing: an annual review by the American Society for Gastrointestinal Endoscopy Editorial Board

Using a systematic literature search of original articles published during 2024 in Gastrointestinal Endoscopy (GIE) and other high-impact medical and gastroenterology journals, the GIE Editorial Board of the American Society for Gastrointestinal Endoscopy compiled a list of the top 10 most significant topic areas in general and advanced GI endoscopy during the year. Each GIE Editorial Board member was directed to consider 3 criteria in generating candidate topics: significance, novelty, and impact on clinical practice. Subject matter consensus was facilitated by the Chair through electronic voting of the entire GIE Editorial Board. The top 10 identified topics collectively represent advances in the following endoscopic areas: glucagon-like peptide-1 receptor agonists and endoscopy, advances in AI in endoscopy, ergonomics in endoscopy, peroral endoscopic myotomy, bariatric and metabolic endoscopy, endoscopic resection in the colon, gastric intestinal metaplasia and endoscopy, inflammatory bowel disease and endoscopy, GI bleeding risk stratification and endoscopic therapies, and therapeutic EUS. Board members were assigned a topic area and summarized relevant and important articles, thereby generating this overview of the "top 10" endoscopic advances of 2024.

Duodenal mucosal ablation with irreversible electroporation reduces liver lipids in rats with non-alcoholic fatty liver disease

BACKGROUND

Duodenal mucosal ablation (DMA) using irreversible electroporation (IRE) with a glucagon-like peptide-1 receptor agonist has been clinically shown to reduce liver lipid deposition in non-alcoholic fatty liver disease (NAFLD). However, the specific metabolic contributions of DMA using IRE in NAFLD remain unclear.

AIM

To assess the feasibility and effectiveness of DMA using IRE in NAFLD rat models.

METHODS

Seven-week-old male Sprague-Dawley rats underwent DMA using IRE after 8 weeks on a high-fat diet. Two weeks post-treatment, duodenal and liver tissues and blood samples were collected. We evaluated differences in the duodenal wall structure, liver lipid deposition, enteroendocrine, claudin, and zonula ocludens-1 in the duodenal mucosa.

RESULTS

DMA using IRE could be safely performed in rats with NAFLD without duodenal bleeding, perforation, or stenosis. The duodenum healed well 2 weeks after DMA and was characterized by slimmer villi, narrower and shallower crypts, and thicker myenterons compared with the sham-control setting. Liver lipid deposition was reduced and serum lipid index parameters were considerably improved in the DMA setting. However, these improvements were independent of food intake and weight loss. In addition, enteroendocrine parameters, such as claudin, and zonula ocludens-1 levels in the duodenal mucosa, differed between the different settings in the DMA group.

CONCLUSION

By altering enteroendocrine and duodenal permeability, simple DMA using IRE ameliorated liver lipid deposition and improved serum lipid parameters in NAFLD rats.