Regenerating Islet-Derived 3-alpha is a Prognostic Biomarker for Gastrointestinal Chronic Graft-Versus-Host Disease

Prognostic biomarkers used to identify likelihood of disease progression have not been identified for chronic graft-versus-host disease (cGVHD), the leading cause of late non-relapse mortality (NRM) in survivors of allogenic hematopoietic cell transplantation. Gastrointestinal cGVHD (GI-cGVHD) has been particularly challenging to classify. Here, we analyzed three proteomics markers [Regenerating-islet-derived-3-alpha (Reg3α), C-X-C-motif-ligand (CXCL9) and Stimulation-2 (ST2)] in two independent cohorts of patients with cGVHD totaling 289 patients. Plasma concentrations of Reg3α were significantly increased in patients with GI-cGVHD compared to those without (p=0.0012, p=0.01 respectively), CXCL9 and ST2 were not. Patients with high Reg3α (≥72ng/mL) vs. low Reg3α had higher NRM (23% vs. 11%, p=0.015). Since Reg3α has been identified as a lower GI-tract marker in acute GVHD, we correlated Reg3α with lower acute-like GI-cGVHD vs. classical fibrotic-like esophageal manifestations and found Reg3a did not differ between the subtypes. No difference was observed between upper and lower subtypes. Patients with extremely high Reg3α (≥180 ng/mL) had higher GI-scores but not higher lower-GI-scores. In multivariate Cox regression model, patients with high Reg3α were 1.9 times more likely to die without relapse. Our findings demonstrate the utility of Reg3α as a prognostic marker for GI-cGVHD. These data warrant prospective biomarker validation studies.

Cytomegalovirus cell tropism and clinicopathological characteristics in gastrointestinal tract of patients with HIV/AIDS

Background Cytomegalovirus (CMV) has been recognized as one of the frequently occurring opportunistic infections (OIs) reported in the patients having human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). In addition, it has been identified as the factor leading to gastrointestinal (GI) tract disorder among HIV/AIDS population. CMV exhibits broad cell tropism in different organs. This study evaluated the CMV cell tropism and clinicopathological characteristics of CMV infection in the different GI regions in HIV/AIDS cases. Methods Using nucleic acid in situ hybridization (ISH), CMV was detected in the gastrointestinal mucosal biopsy samples. The paraffin-embedded samples were stained with hematoxylin and eosin (HE) and immunohistochemistry (IHC), respectively. Results A total of 32 HIV/AIDS patients were enrolled in this study. Fourteen of these patients underwent gastroscopy, while the remaining eighteen received colonoscopy. CMV-infected cells were observed at 46 GI sites. Among them, the colon was the region with the highest susceptibility to GI CMV infection (n = 12, 26.1%). The CMV giant cell inclusion bodies were detected in epithelial cells and mesenchymal cells, including histiocytes, smooth muscle cells, fibroblasts, and endothelial cells. In the duodenum, there were markedly more positive epithelial cells than mesenchymal cells (p = 0.033). In contrast, in the esophagus (p = 0.030), cardia (p = 0.003), rectum (p = 0.019), colon (p < 0.001), and cecum (p < 0.001), there were notably less positive epithelial cells than mesenchymal cells. The expression levels of PDGFRα and Nrp2 in the mesenchymal cells were higher than the epithelial cells in cardia, cecum, colon, sigmoid, and rectum, especially in the areas with ulcers. However, Nrp2 in the epithelial cells was higher than that in the duodenum. Moreover, the positive CMV DNA in peripheral blood was related to the CMV-positive cell count, as well as the ulceration in GI tract (p = 0.035 and 0.036, respectively). Conclusions The colon has been identified as the GI site with the highest susceptibility to CMV infection. There are different CMV-infected cells in the different sites of the GI that relate to the expression level of PDGFRα and Nrp2. CMV DNA positive in the blood is related to the positive CMV cell count, as well as ulceration in the GI tract.

Positive Effect of Lactobacillus acidophilus EG004 on Cognitive Ability of Healthy Mice by Fecal Microbiome Analysis Using Full-Length 16S-23S rRNA Metagenome Sequencing

Recently, the concept of the “gut-brain axis” has risen and suggested that microbes in the GI tract affect the brain by modulating signal molecules. Although many pieces of research were reported in a short period, a signaling mechanism and the effects of a specific bacterial strain are still unclear.

Single cell immune profiling reveals a developmentally distinct CD4+ GM-CSF+ T cell lineage that induces GI tract GVHD

Gastrointestinal (GI) tract involvement is a major determinant for subsequent morbidity and mortality arising during graft versus host disease (GVHD). CD4+ T cells that produce GM-CSF have emerged as central mediators of inflammation in this tissue site as GM-CSF serves as a critical cytokine link between the adaptive and innate arms of the immune system. However, cellular heterogeneity within the CD4+ GM-CSF+ T cell population due to the concurrent production of other inflammatory cytokines has raised questions as to whether these cells have a common ontology or if there exists a unique CD4+ GM-CSF+ subset that differs from other defined T helper (TH) subtypes. Using single cell RNA sequencing analysis, we identified two CD4+ GM-CSF+ T cell populations that arose during GVHD and were distinguishable by the presence or absence of IFN-γ co-expression. CD4+ GM-CSF+ IFN-γ- T cells which emerged preferentially in the colon had a distinct transcriptional profile, employed unique gene regulatory networks, and possessed a non-overlapping TCR repertoire when compared to CD4+ GM-CSF+ IFN-γ+ T cells as well as all other transcriptionally defined CD4+ T cell populations in the colon. Functionally, this CD4+ GM-CSF+ T cell population contributed to pathological damage in the GI tract which was critically dependent upon signaling through the IL-7 receptor but was independent of type 1 interferon signaling. Thus, these studies help to unravel heterogeneity within CD4+ GM-CSF+ T cells that arise during GVHD and define a developmentally distinct colitogenic TH GM-CSF+ subset that mediates immunopathology.

Integrity of the Intestinal Barrier: The Involvement of Epithelial Cells and Microbiota—A Mutual Relationship

The gastrointestinal tract, which is constantly exposed to a multitude of stimuli, is considered responsible for maintaining the homeostasis of the host. It is inhabited by billions of microorganisms, the gut microbiota, which form a mutualistic relationship with the host. Although the microbiota is generally recognized as beneficial, at the same time, together with pathogens, they are a permanent threat to the host. Various populations of epithelial cells provide the first line of chemical and physical defense against external factors acting as the interface between luminal microorganisms and immunocompetent cells in lamina propria. In this review, we focus on some essential, innate mechanisms protecting mucosal integrity, thus responsible for maintaining intestine homeostasis. The characteristics of decisive cell populations involved in maintaining the barrier arrangement, based on mucus secretion, formation of intercellular junctions as well as production of antimicrobial peptides, responsible for shaping the gut microbiota, are presented. We emphasize the importance of cross-talk between gut microbiota and epithelial cells as a factor vital for the maintenance of the homeostasis of the GI tract. Finally, we discuss how the imbalance of these regulations leads to the compromised barrier integrity and dysbiosis considered to contribute to inflammatory disorders and metabolic diseases.

Nano/Microrobots Line Up for Gastrointestinal Tract Diseases: Targeted Delivery, Therapy, and Prevention

Nano/microrobots (NMRs) are tiny devices that can convert energy into motion and operate at nano/microscales.54 Especially in biomedical research, NMRs have received much attention over the past twenty years because of their excellent capabilities and great potential in various applications, including on-demand drug delivery, gene and cell transport, and precise microsurgery. Reports published in recent years show that synthetic nano/microrobots have promising potential to function in the gastrointestinal (GI) region, particularly in terms of drug delivery. These tiny robots were able to be designed in such a way that they propel in their surroundings (biological media) with high speed, load cargo (drug) efficiently, transport it safely, and release upon request successfully. Their propulsion, retention, distribution, and toxicity in the GI tract of mice has been evaluated. The results envisage that such nano/microrobots can be further modified and developed as a new-generation treatment of GI tract diseases. In this minireview, we focus on the functionality of micro/nanorobots as a biomedical treatment system for stomach/intestinal diseases. We review the research progress from the first in vivo report in December 2014 to the latest in August 2021. Then, we discuss the treatment difficulties and challenges in vivo application (in general) and possible future development routes.

A case report of duodenal arteriovenous malformation: usefulness of intraoperative indocyanine green angiography for precise identification of the lesion

Background Arteriovenous malformation (AVM) of the gastrointestinal (GI) tract can cause bleeding. The treatment choice for GI tract AVM is surgical resection of the involved bowel segment with complete resection of the nidus. The AVM formed in the duodenum or pancreatic head could also cause gastrointestinal bleeding, and there are several reports of pancreaticoduodenectomy as its treatment. However, if the area of AVM can be accurately identified during surgery, it may be possible to completely resect the AVM while preserving the organ. We report a case of duodenal AVM in a patient successfully treated with a subtotal stomach-preserving duodenal bulb resection using intraoperative indocyanine green (ICG) angiography technique. Case presentation An 18-year-old man was diagnosed with duodenal AVM after several examinations for anemia and was referred to our hospital for further treatment. Preoperative imaging studies showed that the inflow vessels of this duodenal AVM were the inferior pyloric artery and the superior duodenal artery, and the AVM was localized to the duodenal bulb. Thereafter, stomach-preserving duodenal bulb resection preceded by ligation of the inflow vessels was performed. During the surgery, ICG angiography clearly demonstrated the area, where the nidus was distributed, and a duodenal bulb resection with complete resection of the AVM was successfully performed. There was no recurrence at the 6-month follow-up. Conclusions Intraoperative ICG angiography was a useful procedure for precise identification of the AVM of the GI tract.

Scoping Review: Ultrasonographic evidence of intraabdominal manifestations of COVID-19 infection

COVID-19 is an infectious disease caused by the novel SARS-CoV-2 coronavirus that in the majority of patients will only cause mild symptoms. The most common serious complication is COVID-19 pneumonia, however, gastrointestinal (GI) COV-ID-19 is also a frequent presentation and likely due to the high expression of the ACE2 receptor in the GI tract. As diagnostic ultrasound has been frequently used in the management of this patient cohort, we conducted a literature search with the aim to present and review the currently published evidence of using ultrasound examinations in the management of intraabdominal manifestations of COVID-19. Our analysis showed that sonographic abnormalities of the hepatobiliary system are the most commonly reported findings in adults, while gastrointestinal abnormalities are the most common findings in children. The most severe complications are related to thromboembolic complications in the intensive care unit.