Longitudinal microbiome investigation throughout prion disease course reveals pre- and symptomatic compositional perturbations linked to short-chain fatty acid metabolism and cognitive impairment in mice.

Commensal intestinal bacteria shape our microbiome and have decisive roles in preserving host metabolic and immune homeostasis. They conspicuously impact disease development and progression, including amyloid-beta (Aß) and alpha (α)-synuclein pathology in neurodegenerative diseases, conveying the importance of the brain-gut-microbiome axis in such conditions. However, little is known about the longitudinal microbiome landscape and its potential clinical implications in other protein misfolding disorders, such as prion disease. We investigated the microbiome architecture throughout prion disease course in mice. Fecal specimens were assessed by 16S ribosomal RNA sequencing. We report a temporal microbiome signature in prion disease and uncovered alterations in Lachnospiraceae, Ruminococcaceae, Desulfovibrionaceae, and Muribaculaceae family members in this disease. Moreover, we determined the enrichment of Bilophila, a microorganism connected to cognitive impairment, long before the clinical manifestation of disease symptoms. Based on temporal microbial abundances, several associated metabolic pathways and resulting metabolites, including short-chain fatty acids, were linked to the disease. We propose that neuroinflammatory processes relate to perturbations of the intestinal microbiome and metabolic state by an interorgan brain-gut crosstalk. Furthermore, we describe biomarkers possibly suitable for early disease diagnostics and anti-prion therapy monitoring. While our study is confined to prion disease, our discoveries might be of equivalent relevance in other proteinopathies and central nervous system pathologies.

Respiratory exposure to agricultural dust extract promotes increased intestinal Tnfα expression, gut barrier dysfunction, and endotoxemia in mice.

Concentrated animal feeding operations (CAFOs) are responsible for the production of global greenhouse gases and harmful environmental pollutants including hydrogen sulfide, ammonia, and particulate matter. Swine farmers are frequently exposed to organic dust that is proinflammatory in the lung and are thus at greater risk of developing pneumonia, asthma, and other respiratory conditions. In addition to respiratory disease, air pollutants are directly associated with altered gastrointestinal (GI) physiology and the development of GI diseases, thereby highlighting the gut-lung axis in disease progression. Instillation of hog dust extract (HDE) for 3 wk has been reported to promote the development of chronic airway inflammation in mice, however, the impact of HDE exposure on intestinal homeostasis is poorly understood. We report that 3-wk intranasal exposure of HDE is associated with increased intestinal macromolecule permeability and elevated serum endotoxin concentrations in C57BL/6J mice. In vivo studies also indicated mislocalization of the epithelial cell adhesion protein, E-cadherin, in the colon as well as an increase in the proinflammatory cytokine, Tnfα, in the proximal colon. Moreover, mRNA expression of the Paneth cell-associated marker, Lyz1, was increased the proximal colon, whereas the expression of the goblet cell marker, Muc2, was unchanged in the epithelial cells of the ileum, cecum, and distal colon. These results demonstrate that airway exposure to CAFOs dusts promote airway inflammation and modify the gastrointestinal tract to increase intestinal permeability, induce systemic endotoxemia, and promote intestinal inflammation. Therefore, this study identifies complex physiological consequences of chronic exposure to organic dusts derived from CAFOs on the gut-lung axis.NEW & NOTEWORTHY Agricultural workers have a higher prevalence of occupational respiratory symptoms and are at greater risk of developing respiratory diseases. However, gastrointestinal complications have also been reported, yet the intestinal pathophysiology is understudied. This work is novel because it emphasizes the role of an inhaled environmental pollutant on the development of intestinal pathophysiological outcomes. This work will provide foundation for other studies evaluating how agricultural dusts disrupts host physiology and promotes debilitating gastrointestinal and systemic disorders.

PTPN2 Is a Critical Regulator of Ileal Paneth Cell Viability and Function in Mice.

BACKGROUND & AIMS: Loss-of-function variants in the PTPN2 gene are associated with increased risk of inflammatory bowel disease. We recently showed that Ptpn2 is critical for intestinal epithelial cell (IEC) barrier maintenance, IEC-macrophage communication, and modulation of the gut microbiome in mice, restricting expansion of a small intestinal pathobiont associated with inflammatory bowel disease. Here, we aimed to identify how Ptpn2 loss affects ileal IEC subtypes and their function in vivo. METHODS: Constitutive Ptpn2 wild-type, heterozygous, and knockout (KO) mice, as well as mice with inducible deletion of Ptpn2 in IECs, were used in the study. Investigation was performed using imaging techniques, flow cytometry, enteroid culture, and analysis of gene and protein levels of IEC markers. RESULTS: Partial transcriptome analysis showed that expression of Paneth cell-associated antimicrobial peptides Lyz1, Pla2g2a, and Defa6 was down-regulated markedly in Ptpn2-KO mice compared with wild-type and heterozygous. In parallel, Paneth cell numbers were reduced, their endoplasmic reticulum architecture was disrupted, and the endoplasmic reticulum stress protein, C/EBP-homologous protein (CHOP), was increased in Ptpn2-KO mice. Despite reduced Paneth cell number, flow cytometry showed increased expression of the Paneth cell-stimulatory cytokines interleukin 22 and interferon γ+ in CD4+ T cells isolated from Ptpn2-KO ileum. Key findings in constitutive Ptpn2-KO mice were confirmed in epithelium-specific Ptpn2ΔIEC mice, which also showed impaired lysozyme protein levels in Paneth cells compared with Ptpn2fl/fl control mice. CONCLUSIONS: Constitutive Ptpn2 deficiency affects Paneth cell viability and compromises Paneth cell-specific antimicrobial peptide production. The observed effects may contribute to the increased susceptibility to intestinal infection and dysbiosis in these mice.

Increased visceral sensitivity, elevated anxiety, and depression levels in patients with functional esophageal disorders and non-erosive reflux disease.

BACKGROUND: Little is known about possible underlying psychological abnormalities and physiology of reflux hypersensitivity (RH) as defined in the recent Rome IV classification. We aimed to assess markers of psychological comorbidity as well as gastro-esophageal reflux measurements in RH patients compared to controls and also in patients with functional heartburn (FH) and non-erosive reflux disease (NERD) versus controls. METHODS: Data of 304 patients visiting our Functional Diagnostics Centre from 2016 to 2018 were analyzed. We focused on a psychological assessment using validated questionnaires (visceral sensitivity index; VSI, hospital anxiety and depression score; HADS) as well as multichannel intraluminal impedance (MII) and pH-metry data from the diagnostic work-up. KEY RESULTS: We found a decreased VSI of 57.8 ± 15.4 points (pts) among RH patients (n = 45) indicating higher visceral sensitivity compared to 85.7 ± 2.0 pts in the control group (n = 31, P < 0.001). Furthermore, a significant difference in VSI was found between the FH (60.8 ± 23.3 pts, n = 59, P < 0.001) and between the NERD (61.9 ± 20.8 pts, n = 67, P < 0.001) both compared to the control group. The HADS also displayed a significant difference between the RH (11.9 ± 6.0 pts, P < 0.001), FH (11.0 ± 7.4 pts, P < 0.001), respectively, NERD (11.3 ± 8.9 pts, P < 0.001) as compared to the control group (2.0 ± 1.4 pts). CONCLUSIONS AND INFERENCES: Increased sensation to visceral stimuli as well as anxiety and depression appears to play an important role not only in reflux hypersensitivity and functional heartburn as defined by Rome IV but also in NERD. These findings are in line with the disease concept of disorders of gut-brain interaction in which psychological comorbidities and visceral hypersensitivity play a major role.

Efficacy and side effects of immune checkpoint inhibitors in the treatment of colorectal cancer.

Colorectal cancers (CRCs) remain one of the most common and challenging neoplasia in the Western world. The response rate of immunotherapeutic treatment approaches in a subset of advanced CRCs is remarkable and has sustainably changed treatment regimens. Unfortunately, currently available immunotherapeutics only displayed significant antitumoral activity - in terms of progression free survival (PFS) and objective response rate (ORR) - in microsatellite instability-high (MSI-H)/DNA mismatch repair deficient (dMMR) CRCs. Subsequently, these remarkable results had led to the US Food and Drug Administration's approval of both immune checkpoint inhibitors (ICIs) pembrolizumab and nivolumab in the treatment of advanced MSI-H/dMMR CRCs. However, in microsatellite stable (MSS)/DNA mismatch repair proficient (pMMR) CRCs, ICIs have clearly failed to meet their expectations and are therefore not considered effective. As the vast majority of CRCs display a molecular MSS/pMMR profile, current treatment approaches endeavor to improve tumor immunogenicity that consecutively leads to increased proinflammatory cytokine levels as well as tumor infiltrating T-cells, which in turn may be targeted by various immunotherapeutic agents. Therefore, ongoing studies are investigating novel synergistic therapy modalities and approaches to overcome a "cold" to "hot" tumor conversion in MSS/pMMR CRCs. In this review, we summarize the efficacy and possible immune-related adverse events as well as novel therapeutic approaches of ICIs in the treatment of MSI-H/dMMR and MSS/pMMR CRCs.

Presence of PTPN2 SNP rs1893217 Enhances the Anti-inflammatory Effect of Spermidine.

BACKGROUND: The single nucleotide polymorphism (SNP) rs1893217 within the gene locus encoding PTPN2 represents a risk factor for inflammatory bowel disease (IBD). Our previous work demonstrated reduced PTPN2 activity and subsequently increased inflammatory signaling upon presence of SNP rs1893217. The naturally occurring polyamine spermidine reduces pro-inflammatory signaling via induction of PTPN2 activity; however, the effect of SNP rs1893217 on the anti-inflammatory potential of spermidine is still unknown. Here, we investigated how presence of SNP rs1893217 affects treatment efficacy of spermidine and whether it might serve as a potential biomarker for spermidine treatment. METHODS: Human T84 (wild-type [WT] for PTPN2 SNP rs1893217) and HT29 (heterozygous for PTPN2 SNP rs1893217) intestinal epithelial cells (IECs) were treated with several polyamines from the putrescine-spermidine pathway. T84 and HT29 IECs, THP-1 monocytes (WT and transfected with a lentiviral vector expressing PTPN2 SNP rs1893217) and genotyped, patient-derived peripheral blood mononuclear cells were challenged with IFN-γ and/or spermidine. RESULTS: Among the analyzed polyamines, spermidine was the most efficient activator of PTPN2 phosphatase activity, regardless of the PTPN2 genotype. Spermidine suppressed IFN-γ-induced STAT1 and STAT3 phosphorylation, along with decreased mRNA expression of ICAM-1, NOD2, and IFNG in IECs and monocytes. Of note, these effects were clearly more pronounced when the disease-associated PTPN2 C-variant in SNP rs1893217 was present. CONCLUSIONS: Our data demonstrate that spermidine is the most potent polyamine in the putrescine-spermine axis for inducing PTPN2 enzymatic activity. The anti-inflammatory effect of spermidine is potentiated in the presence of SNP rs1893217, and this SNP might thus be a useful biomarker for possible spermidine-treatment in IBD patients.

Bilateral Anterior Shoulder Dislocation in the Elderly - A Case Report and Review of the Literature.

INTRODUCTION: Bilateral shoulder dislocations are rare and a diagnostic as well as a therapeutic challenge. CASE REPORT: We report the case of a 67-year-old male who fell while skiing and suffered a bilateral anterior shoulder dislocation associated with a four-part proximal humerus fracture on the left side and an osseous avulsion of the rotator cuff, a Pulley lesion, and a Hill-Sachs lesion on the right side. In addition, we searched the PubMed database using the terms "bilateral shoulder dislocation" and also "bilateral glenohumeral dislocation". All retrieved matches were browsed for reports of bilateral anterior shoulder dislocations in patients aged 40 years or older. We identified and analyzed 35 case reports, including our own, regarding 20 male and 15 female patients with an average age of 58.9 years (female: 59.2 years, male: 58.6 years). CONCLUSION: Elderly patients with a bilateral shoulder dislocation are at special risk for late diagnosis (five of 35 cases were not detected on the same day, but up to nine months later), concomitant pathologies (proximal humerus fractures were present in 19 cases; rotator cuff pathologies in seven cases), and insufficient diagnostic soft-tissue imaging (only four cases performed ultrasound/magnetic resonance imaging). Our reported case assembles a variety of possible concomitant pathologies. Through careful and comprehensive diagnostics all accompanying lesions were detected and subsequently addressed. The patient's outcome shows that even in older patients with a combination of various bony, cartilaginous, muscular and ligamentous pathologies, good-to-excellent post-reductive and post-operative results are possible if diagnostics are comprehensive and treatment is prompt.