Renal ischemia reperfusion (IR) presents a common challenge for organ graft and function after transplantation. In the kidney, although there are several mechanisms involved in the IR injury, some studies have pointed to angiogenesis as an important process in the pathophysiology of IR and, therefore, as a possible target mechanism to reduce IR damage. Angiogenesis can be modulated by different molecules and recent evidence has shown that opioids are among these molecules. Angiogenesis preconditioning with opioids is a useful and non-invasive strategy to increase the transplant success rate. Although some results have suggested an interaction between the opioid system and VEGF-mediated angiogenesis, more studies are required to fully elucidate the specific mechanisms involved in these actions. The present review summarizes the recent findings on kidney IR-related mechanisms, with as special emphasis on vascular changes. Finally, the evidence about the modulation of angiogenesis by opioids in a preconditioning scheme will be addressed.

The targeting of transforming growth factor β (TGF-β) has been shown to reduce complications related to ischemia-reperfusion injury (IRI) post-surgically. Pirfenidone (PFD) specifically inhibits TGF-β expression and has been demonstrated to provide protection from IRI in short-term allograft models, though not yet in long-term models. A chronic unilateral IRI model was established using male Wistar rats. The animals were divided into two groups: one with IRI and a pre-treatment of PFD (0.5 mg/kg) followed by 0.5 mg/kg/day of orally administered PFD for 30 days, and a control group without PFD treatment. A sham group was also included. Kidneys and blood samples were collected after 30 days, and the renal function was evaluated by measuring the serum creatinine and KIM-1 levels. RT-PCR was used to analyze fibrosis-related genes, and Luminex to quantify the pro-inflammatory serum IL-18 cytokine. Renal section staining and histological analysis were used to detect collagen deposits. Comparison within the groups showed an increase in serum creatinine and KIM-1 expression after IRI in the control group, while PFD reduced COLL1A1 and TGF-β expression and demonstrated a reduction in fibrosis through histological stains. The treatment group also showed a reduction in IL-18. Our results suggest that PFD exerts protective effects on chronic renal IRI, reducing fibrosis development and inflammation. This study provides new insights into the treatment and management of chronic renal function loss after IRI.

The SARS-CoV-2 virus was first identified at the end of December 2019, causing the disease known as COVID-19, which, due to the high degree of contagion, was declared a global pandemic as of 2020. The end of the isolation was in 2022, thanks to the global multidisciplinary work of the massive vaccination campaigns. Even with the current knowledge about this virus and the COVID-19 disease, there are many questions and challenges regarding diagnosis and therapy in the fight against this virus. One of the big problems is the so-called "long COVID", prolonged symptomatology characterized as a multiorgan disorder manifested as brain fog, fatigue, and shortness of breath, which persist chronically after the disease resolution. Therefore, this review proposes using extracellular vesicles (EVs) as a therapeutic or diagnostic option to confront the sequelae of the disease at the central nervous system level. Development: the review of updated knowledge about SARS-CoV-2 and COVID-19 is generally addressed as well as the current classification of extracellular vesicles and their proposed use in therapy and diagnosis. Through an analysis of examples, extracellular vesicles are highlighted to learn what happens in the central nervous system during and after COVID-19 and as a therapeutic option. Conclusions: even though there are limitations in the knowledge of the neurological manifestations of COVID-19, it is possible to observe the potential use of extracellular vesicles in therapy or as a diagnostic method and even the importance of their study for the knowledge of the pathophysiology of the disease