Therapeutic effects of micro-RNAs in preclinical studies of acute kidney injury: a systematic review and meta-analysis

MicroRNA-mediated epigenetic regulation of inflammasomes in inflammatory responses and immunopathologies

Inflammation represents the first-line defense mechanism of the host against pathogens and cellular stress. One of the most critical inflammatory responses is characterized by the activation of inflammasomes, intracellular multiprotein complexes that induce inflammatory signaling pathways in response to various pathogen-associated molecular patterns or danger-associated molecular patterns under physiological and pathological conditions. Inflammasomes are tightly regulated in normal cells, and dysregulation of these complexes is observed in various pathological conditions, especially inflammatory diseases and cancers. Epigenetic regulation has been suggested as a key mechanism in modulating inflammasome activity, and microRNAs (miRNAs) have been implicated in the post-transcriptional regulation of inflammasomes. Therefore, miRNA-mediated epigenetic regulation of inflammasomes in pathological conditions has received considerable attention, and current strategies for targeting inflammasomes have been shown to be effective in the treatment of diseases associated with inflammasome activation. This review summarizes recent studies suggesting the roles of miRNAs in the epigenetic control of inflammasomes and highlights the potential of miRNAs as a therapeutic tool for treating human diseases.

The anti-inflammatory activity of resveratrol in acute kidney injury: a systematic review and meta-analysis of animal studies

CONTEXT

Accumulated experimental evidence suggests that resveratrol (RSV) may have an effect on acute kidney injury (AKI) by inhibiting inflammation. However, the credibility of the evidence for this practice is unclear.

OBJECTIVE

This study investigated the effect of RSV on AKI and the underlying mechanism.

METHODS

We searched PubMed, EMBASE, and Web of Science from 2005 to April 2022 for controlled animal trials assessing the effect of conventional resveratrol versus placebo on renal function outcome after AKI. This study was registered within the International Prospective Register of Systematic Reviews (PROSPERO) as number CRD42022329596.

RESULTS

We retrieved 455 studies, 25 studies comprising data of 436 animals that met the inclusion criteria. Our meta-analysis suggested that RSV treatment was significantly associated with lower levels of serum creatinine (Scr) and blood urea nitrogen (BUN). The greatest effects were recorded in low-dose (<20 mg/kg/day) groups rather than in high-dose (> 20 mg/kg/day) groups. For time-response effects, subgroup analysis indicated that intervention duration of RSV can influence the treatment effect, and more beneficial effects were observed when studies had a drug administration time of <2 weeks.

DISCUSSION AND CONCLUSIONS

This systematic review of animal AKI studies showed a consistently favourable effect of RSV as compared to placebo on renal function outcomes that increased with lower TNF-α, IL-6, and IL-1β. RSV has a more beneficial effect on SA-AKI animal models than the others. When the RSV intervention dose was low (< 20 mg/kg/day) and the intervention time was <2 weeks, more benefits could be observed.

MicroRNA-223 downregulation promotes HBx-induced podocyte pyroptosis by targeting the NLRP3 inflammasome

Hepatitis B virus (HBV) and its related protein, HBV X (HBx), play an important role in podocyte injury in HBV-associated glomerulonephritis (HBV-GN). The microRNA MiR-223 is expressed in several diseases, including HBV-associated disease, while the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome plays a major role in pyroptosis. In this study, we investigated the function and mechanism of action of miR-223 in HBx-induced podocyte pyroptosis. A quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay showed that miR-223 was downregulated in HBx-transfected podocytes. Transfection with an miR-223 mimic abolished the expression of the NLRP3 inflammasome and the cytokines that are released as a result of NLRP3 overexpression. Moreover, transfection with HBx and NLRP3 overexpression plasmids increased the expression of pyroptosis-related proteins, especially in the presence of miR-223 inhibitors. Thus, miR-223 downregulation plays an important role in HBx-induced podocyte pyroptosis by targeting the NLRP3 inflammasome, suggesting that miR-223 is a potential therapeutic target for alleviating HBV-GN inflammation.

Analysis of Risk Factors for Perioperative Acute Kidney Injury and Management Strategies

Acute kidney injury (AKI) is a serious clinical syndrome, and one of the common comorbidities in the perioperative period. AKI can lead to complications in surgical patients and is receiving increasing attention in clinical workup. In recent years, the analysis of perioperative risk factors has become more in-depth and detailed. In this review, the definition, diagnosis, and pathophysiological characteristics of perioperative AKI are reviewed, and the main risk factors for perioperative AKI are analyzed, including advanced age, gender, certain underlying diseases, impaired clinical status such as preoperative creatinine levels, and drugs that may impair renal function such as non-steroidal anti-inflammatory drugs (NASIDs), ACEI/ARB, and some antibiotics. Injectable contrast agents, some anesthetic drugs, specific surgical interventions, anemia, blood transfusions, hyperglycemia, and malnutrition are also highlighted. We also propose potential preventive and curative measures, including the inclusion of renal risk confirmation in the preoperative assessment, minimization of intraoperative renal toxin exposure, intraoperative management and hemodynamic optimization, remote ischemic preadaptation, glycemic control, and nutritional support. Among the management measures, we emphasize the need for careful perioperative clinical examination, timely detection and management of AKI complications, administration of dexmedetomidine for renal protection, and renal replacement therapy. We aim that this review can further increase clinicians' attention to perioperative AKI, early assessment and intervention to try to reduce the risk of AKI.