Effects of early high-dose erythropoietin on acute kidney injury following cardiac arrest: exploratory post hoc analyses from an open-label randomized trial

Targeting the innate repair receptor axis via erythropoietin or pyroglutamate helix B surface peptide attenuates hemolytic-uremic syndrome in mice

Hemolytic-uremic syndrome (HUS) can occur as a systemic complication of infections with Shiga toxin (Stx)-producing Escherichia coli and is characterized by microangiopathic hemolytic anemia and acute kidney injury. Hitherto, therapy has been limited to organ-supportive strategies. Erythropoietin (EPO) stimulates erythropoiesis and is approved for the treatment of certain forms of anemia, but not for HUS-associated hemolytic anemia. EPO and its non-hematopoietic analog pyroglutamate helix B surface peptide (pHBSP) have been shown to mediate tissue protection via an innate repair receptor (IRR) that is pharmacologically distinct from the erythropoiesis-mediating receptor (EPO-R). Here, we investigated the changes in endogenous EPO levels in patients with HUS and in piglets and mice subjected to preclinical HUS models. We found that endogenous EPO was elevated in plasma of humans, piglets, and mice with HUS, regardless of species and degree of anemia, suggesting that EPO signaling plays a role in HUS pathology. Therefore, we aimed to examine the therapeutic potential of EPO and pHBSP in mice with Stx-induced HUS. Administration of EPO or pHBSP improved 7-day survival and attenuated renal oxidative stress but did not significantly reduce renal dysfunction and injury in the employed model. pHBSP, but not EPO, attenuated renal nitrosative stress and reduced tubular dedifferentiation. In conclusion, targeting the EPO-R/IRR axis reduced mortality and renal oxidative stress in murine HUS without occurrence of thromboembolic complications or other adverse side effects. We therefore suggest that repurposing EPO for the treatment of patients with hemolytic anemia in HUS should be systematically investigated in future clinical trials.

When the Renal (Function) Begins to Fall: A Mini-Review of Acute Kidney Injury Related to Acute Respiratory Distress Syndrome in Critically Ill Patients

Acute kidney injury (AKI) is one of the most frequent causes of organ failure encountered in patients in the intensive care unit (ICU). Because of its predisposition to occur in the most critically ill patients, it is not surprising to observe a high frequency of AKI in patients with acute respiratory distress syndrome (ARDS). However, few studies have been carried out to assess the epidemiology of AKI in subgroups of ARDS patients using recommended KDIGO criteria. Moreover, the mechanisms involved in the physio-pathogenesis of AKI are still poorly understood, in particular the impact of mechanical ventilation on the kidneys. We carried out a review of the literature, focusing on the epidemiology and physiopathology of AKI in patients with ARDS admitted to the ICU. We addressed the importance of clinical management, focusing on mechanical ventilation for improving outcomes, on AKI. Finally, we also propose candidate treatment strategies and management perspectives. Our literature search showed that AKI is particularly common in ICU patients with ARDS. In association with the classic risk factors for AKI, such as comorbidities and iatrogeny, changes in mechanical ventilation parameters, which have been exclusively evaluated for their outcomes on respiratory function and death, must be considered carefully in terms of their impact on the short-term renal prognosis.

Erythropoietin in Acute Kidney Injury (EAKI): a pragmatic randomized clinical trial

Background

Treatment with erythropoietin is well established for anemia in chronic kidney disease patients but not well studied in acute kidney injury.

Methods

This is a multicenter, randomized, pragmatic controlled clinical trial. It included 134 hospitalized patients with anemia defined as hemoglobin < 11 g/dL and acute kidney injury defined as an increase of serum creatinine of ≥ 0.3 mg/dL within 48 h or 1.5 times baseline. One arm received recombinant human erythropoietin 4000 UI subcutaneously every other day (intervention; n = 67) and the second received standard of care (control; n = 67) during the hospitalization until discharge or death. The primary outcome was the need for transfusion; secondary outcomes were death, renal recovery, need for dialysis.

Results

There was no statistically significant difference in transfusion need (RR = 1.05, 95%CI 0.65,1.68; p = 0.855), in renal recovery full or partial (RR = 0.96, 95%CI 0.81,1.15; p = 0.671), in need for dialysis (RR = 11.00, 95%CI 0.62, 195.08; p = 0.102) or in death (RR = 1.43, 95%CI 0.58,3.53; p = 0.440) between the erythropoietin and the control group.

Conclusions

Erythropoietin treatment had no impact on transfusions, renal recovery or mortality in acute kidney injury patients with anemia.

The trial was registered on ClinicalTrials.gov (NCT03401710, 17/01/2018).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02727-5.

Exosomal‑miR‑1184 derived from mesenchymal stem cells alleviates cisplatin‑associated acute kidney injury

Acute kidney injury (AKI) poses a severe threat to human health. MicroRNAs (miRNAs/miRs) are known to be involved in the progression of AKI; however, the function of miR‑1184 in AKI remains unclear. Thus, the aim of the present study was to examine the role of this miRNA in kidney injury. In order to mimic AKI in vitro, HK‑2 cells were treated with cisplatin. Bioinformatics analysis was performed to explore the differentially expressed miRNAs in AKI. A Cell Counting Kit‑8 assay and flow cytometry were performed to examine cell viability and apoptosis, respectively. mRNA expression levels were detected via reverse transcription‑quantitative PCR, and protein levels were investigated by western blot analysis. ELISA was performed to examine the levels of IL‑1β and TNF‑α in the cell supernatants. The results revealed that miR‑1184 expression was downregulated in AKI. Exosomes derived from miR‑1184 agomir‑treated mesenchymal stem cells (MSCs) significantly reversed cisplatin‑induced cell growth inhibition by inhibiting apoptosis. Moreover, forkhead box O4 (FOXO4) was found to be the direct target of miR‑1184, and exosomes expressing miR‑1184 notably inhibited cisplatin‑induced inflammatory responses in HK‑2 cells via the mediation of IL‑1β and TNF‑α. Furthermore, exosomes derived from miR‑1184 agomir‑treated MSCs significantly induced G1 phase arrest in HK‑2 cells via the regulation of FOXO4, p27 Kip1 and CDK2. In conclusion, the present study demonstrated that exosomal‑miR‑1184 derived from MSCs alleviates cisplatin‑associated AKI. Thus, the findings presented herein may shed new light onto the exploration of novel strategies for the treatment of AKI.

Outcome of acute kidney injury: how to make a difference?

Background

Acute kidney injury (AKI) is one of the most frequent organ failure encountered among intensive care unit patients. In addition to the well-known immediate complications (hydroelectrolytic disorders, hypervolemia, drug overdose), the occurrence of long-term complications and/or chronic comorbidities related to AKI has long been underestimated. The aim of this manuscript is to briefly review the short- and long-term consequences of AKI and discuss strategies likely to improve outcome of AKI.

Main body

We reviewed the literature, focusing on the consequences of AKI in all its aspects and the management of AKI. We addressed the importance of clinical management for improving outcomes AKI. Finally, we have also proposed candidate future strategies and management perspectives.

Conclusion

AKI must be considered as a systemic disease. Due to its short- and long-term impact, measures to prevent AKI and limit the consequences of AKI are expected to improve global outcomes of patients suffering from critical illnesses.