Antibiotics-Induced Intestinal Immunomodulation Attenuates Experimental Autoimmune Neuritis (EAN).

BACKGROUND: The composition of gut microbiota plays a pivotal role in priming the immune system and thus impacts autoimmune diseases. Data on the effects of gut bacteria eradication via systemic antibiotics on immune neuropathies are currently lacking. This study therefore assessed the effects of antibiotics-induced gut microbiota alterations on the severity of experimental autoimmune neuritis (EAN), a rat model of Guillain-Barré Syndrome (GBS). Myelin P0 peptide 180-199 (P0 180-199)-induced EAN severity was compared between adult Lewis rats (12 weeks old) that received drinking water with or without antibiotics (colistin, metronidazole, vancomycin) and healthy rats, beginning antibiotics treatment immediately after immunization (day 0), and continuing treatment for 14 consecutive days. Neuropathy severity was assessed via a modified clinical score, and then related to gut microbiota alterations observed after fecal 16S rRNA gene sequencing at baseline and after EAN induction. Effectors of gut mucosal and endoneurial immunity were assessed via immunostaining. EAN rats showed increased gut mucosal permeability alongside increased mucosal CD8+ T cells compared to healthy controls. Antibiotics treatment alleviated clinical EAN severity and reduced endoneurial T cell infiltration, decreased gut mucosal CD8+ T cells and increased gut bacteria that may be associated with anti-inflammatory mechanisms, like Lactobacillus or Parasutterella. Our findings point out a relation between gut mucosal immunity and the pathogenesis of EAN, and indicate that antibiotics-induced intestinal immunomodulation might be a therapeutic approach to alleviate autoimmunity in immune neuropathies. Further studies are warranted to evaluate the clinical transferability of these findings to patients with GBS.

Morphological, ultrastructural, genetic characteristics and remarkably low prevalence of macroscopic Sarcocystis species isolated from sheep and goats in Kurdistan region, Iraq.

Introduction: Sarcocystis is a genus of cyst-forming parasites that infest both humans and livestock. Some parasites cause clinical and subclinical diseases in their hosts, resulting in economic losses. Methods: Esophagus, diaphragm, and skeletal muscle from slaughtered sheep and goats were examined macroscopically, microscopically, and ultrastructurally and subjected to DNA analysis. Results: We isolated macrocysts of S. gigantea and of S. caprafelis moulei from naturally infected sheep (Ovis aries) and goats (Capra hircus). The macrocyst wall thickness was 18.9 µm in sheep and 15.3 µm in goats, and consisted of an inner Periodic acid Schiff- (PAS) negative primary wall and an outer glycoconjugates containing i.e. PAS-positive secondary wall. The walls inner surface was compartmentalized and filled with bradyzoites. In S. gigantea the bradyzoites were approximently 12.3 x 2.6 µm in size, while in S. caprafelis moulei they were 13.9 x 4.4 µm. Ultrastructurally, both species have nearly identical morphology: cauliflower-like protrusions with numerous microtubules and often dendritic-like filaments, branching from the primary wall. The 18S rRNA gene in S. gigantea was 85.9% identical to that in S. medusiformis and 80.4% to the S. caprafelis moulei gene. The 28S rRNA gene in S. gigantea was 94.6% identical to that in S. medusiformis and 97.3% to the S. caprafelis moulei. Conclusion: This study is the first to (i) detail the ultrastructure of the macrocyst wall of S. caprafelis moulei, (ii) identify S. medusiformis in Iraqi sheep, and (iii) compare the prevalence of macroscopic Sarcocystis at different time periods within the same region. A positive finding was the reduction of macroscopic sarcocystosis occurrences (0.01% in sheep and 0.02% in goats) compared to our previous data from 1992 (4.1%: sheep, 33.6%: goats).

Angiotensin II type 1 receptor localizes at the blood-bile barrier in humans and pigs.

Animal models and clinical studies suggest an influence of angiotensin II (AngII) on the pathogenesis of liver diseases via the renin-angiotensin system. AngII application increases portal blood pressure, reduces bile flow, and increases permeability of liver tight junctions. Establishing the subcellular localization of angiotensin II receptor type 1 (AT1R), the main AngII receptor, helps to understand the effects of AngII on the liver. We localized AT1R in situ in human and porcine liver and porcine gallbladder by immunohistochemistry. In order to do so, we characterized commercial anti-AT1R antibodies regarding their capability to recognize heterologous human AT1R in immunocytochemistry and on western blots, and to detect AT1R using overlap studies and AT1R-specific blocking peptides. In hepatocytes and canals of Hering, AT1R displayed a tram-track-like distribution, while in cholangiocytes AT1R appeared in a honeycomb-like pattern; i.e., in liver epithelia, AT1R showed an equivalent distribution to that in the apical junctional network, which seals bile canaliculi and bile ducts along the blood-bile barrier. In intrahepatic blood vessels, AT1R was most prominent in the tunica media. We confirmed AT1R localization in situ to the plasma membrane domain, particularly between tight and adherens junctions in both human and porcine hepatocytes, cholangiocytes, and gallbladder epithelial cells using different anti-AT1R antibodies. Localization of AT1R at the junctional complex could explain previously reported AngII effects and predestines AT1R as a transmitter of tight junction permeability.

Sensitive asprosin detection in clinical samples reveals serum/saliva correlation and indicates cartilage as source for serum asprosin.

The C-terminal pro-fibrillin-1 propeptide asprosin is described as white adipose tissue derived hormone that stimulates rapid hepatic glucose release and activates hunger-promoting hypothalamic neurons. Numerous studies proposed correlations of asprosin levels with clinical parameters. However, the enormous variability of reported serum and plasma asprosin levels illustrates the need for sensitive and reliable detection methods in clinical samples. Here we report on newly developed biochemical methods for asprosin concentration and detection in several body fluids including serum, plasma, saliva, breast milk, and urine. Since we found that glycosylation impacts human asprosin detection we analyzed its glycosylation profile. Employing a new sandwich ELISA revealed that serum and saliva asprosin correlate strongly, depend on biological sex, and feeding status. To investigate the contribution of connective tissue-derived asprosin to serum levels we screened two cohorts with described cartilage turnover. Serum asprosin correlated with COMP, a marker for cartilage degradation upon running exercise and after total hip replacement surgery. This together with our finding that asprosin is produced by primary human chondrocytes and expressed in human cartilage suggests a contribution of cartilage to serum asprosin. Furthermore, we determined asprosin levels in breast milk, and urine, for the first time, and propose saliva asprosin as an accessible clinical marker for future studies.