MiR-155 deletion reduces ischemia-induced paralysis in an aortic aneurysm repair mouse model: Utility of immunohistochemistry and histopathology in understanding etiology of spinal cord paralysis.

Spinal cord paralysis is relatively common after surgical repair of thoraco-abdominal aortic aneurysm (TAAA) and its etiology is unknown. The present study was designed to examine the histopathology of the disease and investigate whether miR-155 ablation would reduce spinal cord ischemic damage and delayed hindlimb paralysis induced by aortic cross-clamping (ACC) in our mouse model. The loss of locomotor function in ACC-paralyzed mice correlated with the presence of extensive gray matter damage and central cord edema, with minimal white matter histopathology. qRTPCR and Western blotting showed that the spinal cords of wild-type ACC mice that escaped paralysis showed lower miR-155 expression and higher levels of transcripts encoding Mfsd2a, which is implicated in the maintenance of blood-brain barrier integrity. In situ based testing demonstrated that increased miR-155 detection in neurons was highly correlated with the gray matter damage and the loss of one of its targets, Mfsd2a, could serve as a good biomarker of the endothelial cell damage. In vitro, we demonstrated that miR-155 targeted Mfsd2a in endothelial cells and motoneurons and increased endothelial cell permeability. Finally, miR-155 ablation slowed the progression of central cord edema, and reduced the incidence of paralysis by 40%. In sum, the surgical pathology findings clearly indicated that the epicenter of the ischemic-induced paralysis was the gray matter and that endothelial cell damage correlated to Mfsd2a loss is a good biomarker of the disease. MiR-155 targeting therefore offers new therapeutic opportunity for edema caused by traumatic spinal cord injury and diagnostic pathologists, by using immunohistochemistry, can clarify if this mechanism also is important in other ischemic diseases of the CNS, including stroke.

Different patterns of esophageal motility disorders among patients with dysphagia and normal endoscopy: A 2-center experience.

Esophageal motility disorders (EMDs) are the main etiology of nonobstructive dysphagia (NOD), but they are underestimated in Egypt. High-resolution manometry (HRM) with Chicago Classification version 3.0 (CC v3.0) is the current gold standard diagnostic modality to assess EMD in patients with NOD. In this HRM-based study, we aimed to classify EMD among Egyptian patients and explore the relationship between the severity of symptoms and the various groups of EMD. From January 2020 to January 2021, patients with dysphagia were subjected to diagnostic workup, which included symptom questionnaire for Eckardt score, esophagogastroduodenoscopy, barium esophagogram, and HRM. All patients were categorized based on the HRM results using CC version 3.0 after exclusion of those with obstructive esophageal lesions. Of 252 patients with dysphagia, 55 patients with NOD were analyzed according to CC version 3.0. Achalasia was diagnosed in 31 patients (56.4%) (type I: 18 [58.06%]; type II: 9 [29.03%], and type III: 4 [12.9%]), 3 patients (5.5%) with esophagogastric junction outflow obstruction, 2 patients (3.6%) with absent contractility, 4 patients (7.3%) with distal esophageal spasm, 7 patients (12.7%) with ineffective esophageal motility, and 8 patients (14.5%) with normal manometry. Patients with achalasia experienced significantly high regurgitation (96.8% vs 70.8%; P = .016) compared with those without achalasia. Achalasia was the most common EMD in Egyptian patients with NOD. Eckardt score was higher in patients with outflow obstruction and major motor disorder, but it could not differentiate different categories of CC of EMD. HRM is effective in characterization of EMD.