Endothelial progenitor cell-derived extracellular vesicles protect from complement-mediated mesangial injury in experimental anti-Thy1.1 glomerulonephritis

BACKGROUND

Endothelial progenitor cells (EPCs) are known to induce tissue repair by paracrine mechanisms including the release of growth factors and extracellular vesicles (EVs), nanoparticles able to carry proteins and genetic information to target cells. The aim of this study was to evaluate whether EVs derived from EPCs may protect from complement-mediated mesangial injury in experimental anti-Thy1.1 glomerulonephritis.

METHODS

EVs were isolated by serial ultracentrifugation from supernatants of cultured human EPCs and characterized for their protein and RNA content. In vivo, EVs were injected i.v. in the experimental rat model of mesangiolytic anti-Thy1.1 glomerulonephritis evaluating renal function, proteinuria, complement activity and histological lesions. In vitro, the biological effects of EPC-derived EVs were studied in cultured rat mesangial cells incubated with anti-Thy1.1 antibody and rat or human serum as complement source.

RESULTS

After i.v. injection in Thy1.1-treated rats, EVs localized within injured glomeruli and inhibited mesangial cell activation, leucocyte infiltration and apoptosis, decreased proteinuria, increased serum complement haemolytic activity (CH50) and ameliorated renal function. EV treatment decreased intraglomerular deposition of the membrane attack complex (MAC or C5b-9) and expression of smooth muscle cell actin and preserved the endothelial antigen RECA-1 and the podocyte marker synaptopodin. The protective effect of EVs was significantly reduced by pre-treatment with a high dose of RNase (1 U/mL), suggesting a key role for EV-carried RNAs in these mechanisms. Indeed, EPC-derived EVs contained different mRNAs coding for several anti-apoptotic molecules and for the complement inhibitors Factor H, CD55 and CD59 and the related proteins. The in vitro experiments aimed to investigate the mechanisms of EV protection indicated that EVs transferred to mesangial cell mRNAs coding for Factor H, CD55 and CD59 and inhibited anti-Thy1.1 antibody/complement-induced apoptosis and C5b-9/C3 mesangial cell deposition.

CONCLUSIONS

EVs derived from EPCs exert a protective effect in Thy1.1 glomerulonephritis by inhibition of antibody- and complement-mediated injury of mesangial cells.

Resveratrol-poor red wines modulate SIRT1 in human renal cells

The cardioprotective and anti-aging effects of red wine phenols, especially resveratrol (RSV), are well known. One of the most interesting biological properties of RSV and other naturally occurring phenols is the regulation of the expression and activity of SIRT1 (silent mating type information regulation 2 homolog). In view of the role of SIRT1 in acute and chronic renal diseases, we decided to study the effects of RSV-poor red wines on the expression of SIRT1 and HIF-2α (hypoxia-inducible factor 2α) to be compared with a nanomolar concentration of RSV or malvidin in proximal tubular cells of human kidneys (PTEC). Survival signaling systems activation (extracellular signal-regulated kinases, ERK and AMP-activated protein kinase, AMPK) was also investigated in PTEC incubated with wines. PTEC cells were incubated in the presence of RSV-poor wines diluted 1:1,000 for 30', 90', 120' and 24 h. Expression of SIRT1 and HIF-2α, and activation of ERK and AMPK were analyzed by Western Blot. The data obtained show that wine modulates the expression of anti-aging molecular systems even when RSV is present in very small amounts.

The Effectiveness of the Buzzy Device in Reducing Pain in Children Undergoing Venipuncture: A Single-Center Experience

OBJECTIVES

Needle-related procedures are among the most important sources of pain in children in different health care settings. Our study was aimed to evaluate the effectiveness of Buzzy (MMJ Labs, Atlanta, Ga.), a palm-sized bee/ladybug-shaped device combining vibration and cold, as a nonpharmacological strategy to manage needle-related pain in children.

METHODS

In this single-center, randomized (1:1) controlled open-label study, we enrolled patients aged from 1 month to 18 years who had to undergo a planned outpatient blood sampling in Pisa University Hospital's Department of Pediatrics and randomly allocated them to either the BUZZY group (intervention group) or NO BUZZY group (control group). Pain was estimated using proper pain scales according to age.

RESULTS

Between May 2021 and January 2022, 234 children aged 8.8 ± 5.1 years (50.8% girls) were enrolled and 117 were treated with the Buzzy device. In the study population, pain inversely correlated with age (r = -0.52, P < 0.001); the intervention group showed significantly lower pain (2.5 ± 2.4 vs 4.7 ± 2.8, P < 0.001) and no difference was found between boys and girls. Significant reduction in pain scores was confirmed when stratifying children by age (29 days to <3 years, P = 0.002; ≥3 to ≤8 years, P < 0.001; >8 years, P < 0.001).

CONCLUSIONS

The Buzzy device effectively reduces pain caused by percutaneous antecubital venipuncture in children in different age groups and represents a cheap and easy-to-use strategy to manage routine needle-related procedures.