Deceleration of Fusion–Fission Cycles Improves Mitochondrial Quality Control during Aging

Mitochondrial dynamics and mitophagy play a key role in ensuring mitochondrial quality control. Impairment thereof was proposed to be causative to neurodegenerative diseases, diabetes, and cancer. Accumulation of mitochondrial dysfunction was further linked to aging. Here we applied a probabilistic modeling approach integrating our current knowledge on mitochondrial biology allowing us to simulate mitochondrial function and quality control during aging in silico. We demonstrate that cycles of fusion and fission and mitophagy indeed are essential for ensuring a high average quality of mitochondria, even under conditions in which random molecular damage is present. Prompted by earlier observations that mitochondrial fission itself can cause a partial drop in mitochondrial membrane potential, we tested the consequences of mitochondrial dynamics being harmful on its own. Next to directly impairing mitochondrial function, pre-existing molecular damage may be propagated and enhanced across the mitochondrial population by content mixing. In this situation, such an infection-like phenomenon impairs mitochondrial quality control progressively. However, when imposing an age-dependent deceleration of cycles of fusion and fission, we observe a delay in the loss of average quality of mitochondria. This provides a rational why fusion and fission rates are reduced during aging and why loss of a mitochondrial fission factor can extend life span in fungi. We propose the ‘mitochondrial infectious damage adaptation’ (MIDA) model according to which a deceleration of fusion–fission cycles reflects a systemic adaptation increasing life span

Histological Evaluation of Diabetic Neurodegeneration in the Retina of Zucker Diabetic Fatty (ZDF) Rats

In diabetes, retinal dysfunctions exist prior to clinically detectable vasculopathy, however the pathology behind these functional deficits is still not fully established. Previously, our group published a detailed study on the retinal histopathology of type 1 diabetic (T1D) rat model, where specific alterations were detected. Although the majority of human diabetic patients have type 2 diabetes (T2D), similar studies on T2D models are practically absent. To fill this gap, we examined Zucker Diabetic Fatty (ZDF) rats - a model for T2D - by immunohistochemistry at the age of 32 weeks. Glial reactivity was observed in all diabetic specimens, accompanied by an increase in the number of microglia cells. Prominent outer segment degeneration was detectable with changes in cone opsin expression pattern, without a decrease in the number of labelled elements. The immunoreactivity of AII amacrine cells was markedly decreased and changes were detectable in the number and staining of some other amacrine cell subtypes, while most other cells examined did not show any major alterations. Overall, the retinal histology of ZDF rats shows a surprising similarity to T1D rats indicating that despite the different evolution of the disease, the neuroretinal cells affected are the same in both subtypes of diabetes

EUS-Guided Choledocho-duodenostomy Using Lumen Apposing Stent Versus ERCP With Covered Metallic Stents in Patients With Unresectable Malignant Distal Biliary Obstruction: A Multicenter Randomized Controlled Trial (DRA-MBO Trial)

International audienceBackground Liver cirrhosis and esophageal cancer share several risk factors, such as alcohol intake and excess weight. Endoscopic resection is the gold standard treatment for superficial tumors. Portal hypertension and coagulopathy may increase the bleeding risk in these patients. This study aimed to assess the safety and efficacy of endoscopic resection for early esophageal neoplasia in patients with cirrhosis or portal hypertension. Methods This retrospective multicenter international study included consecutive patients with cirrhosis or portal hypertension who underwent endoscopic resection in the esophagus from January 2005 to March 2021. Results 134 lesions in 112 patients were treated, including by endoscopic submucosal dissection in 101 cases (75 %). Most lesions (128/134, 96 %) were in patients with liver cirrhosis, with esophageal varices in 71 procedures. To prevent bleeding, 7 patients received a transjugular intrahepatic portosystemic shunt, 8 underwent endoscopic band ligation (EBL) before resection, 15 received vasoactive drugs, 8 received platelet transfusion, and 9 underwent EBL during the resection procedure. Rates of complete macroscopic resection, en bloc resection, and curative resection were 92 %, 86 %, and 63 %, respectively. Adverse events included 3 perforations, 8 delayed bleedings, 8 sepsis, 6 cirrhosis decompensations within 30 days, and 22 esophageal strictures; none required surgery. In univariate analysis, cap-assisted endoscopic mucosal resection was associated with delayed bleeding (P = 0.01). Conclusions In patients with liver cirrhosis or portal hypertension, endoscopic resection of early esophageal neoplasia appeared to be effective and should be considered in expert centers with choice of resection technique, following European Society of Gastrointestinal Endoscopy guidelines to avoid undertreatment

Counterdiffusion protein crystallisation in microgravity and its observation with PromISS (Protein Microscope for the International Space Station)

SCOPUS: cp.jinfo:eu-repo/semantics/publishe