Fluid resuscitation via the rectum ameliorates hemodynamic disorders through adjusting aquaporin expression in an experimental severe acute pancreatitis model

FTO attenuates TNF-α-induced damage of proximal tubular epithelial cells in acute pancreatitis-induced acute kidney injury via targeting AQP3 in an N6-methyladenosine-dependent manner

BACKGROUND

Acute kidney injury (AKI) is a frequent complication of severe acute pancreatitis (SAP). Previous investigations have revealed the involvement of FTO alpha-ketoglutarate-dependent dioxygenase (FTO) and aquaporin 3 (AQP3) in AKI. Therefore, the aim of this study is to explore the association of FTO and AQP3 on proximal tubular epithelial cell damage in SAP-induced AKI.

METHODS

An in-vitro AKI model was established in human proximal tubular epithelial cells (PTECs) HK-2 via tumor necrosis factor-α (TNF-α) induction (20 ng/mL), after which FTO and AQP3 expression was manipulated and quantified by quantitative real-time PCR and Western blotting. The viability and apoptosis of PTECs under various conditions, and reactive oxygen species (ROS), superoxide dismutase (SOD), and malonaldehyde (MDA) levels within these cells were measured using commercial assay kits and flow cytometry. Methylated RNA immunoprecipitation and mRNA stability assays were performed to elucidate the mechanism of FTO-mediated N6-methyladenosine (m6A) modification. Western blotting was performed to quantify β-catenin protein levels in the PTECs.

RESULTS

FTO overexpression attenuated the TNF-α-induced decrease in viability and SOD levels, elevated apoptosis, increased levels of ROS and MDA, and diminished TNF-α-induced AQP3 expression and reduced β-catenin expression, but its silencing led to contradictory results. FTO negatively modulates AQP3 levels in RTECs in an m6A-depednent manner and compromises AQP3 stability. In addition, all FTO overexpression-induced effects in TNF-α-induced PTECs were neutralized following AQP3 upregulation.

CONCLUSION

FTO alleviates TNF-α-induced damage to PTECs in vitro by targeting AQP3 in an m6A-dependent manner.

Efficacy and safety of early enteral and intravenous fluid resuscitation in severe acute pancreatitis: a systematic review and meta-analysis

OBJECTIVE

To compare the efficacy and safety of enteral fluid resuscitation (via nasointestinal tube or colorectal tube) and intravenous fluid resuscitation (via intravenous route) in the early treatment of severe acute pancreatitis.

METHODS

In this study, 8 electronic databases (PubMed, Web of Science, Embase, Cochrane Library, Scopus, China HowNet database, Wanfang database, and VIP database) were searched to collect clinical studies from inception to June 12, 2022. After the quality evaluation and data extraction of the included studies, the RevMan 5.3 software was used for analysis.

RESULTS

A total of seven studies including 580 patients were studied in this meta-analysis, in which 291 cases were treated with enteral fluid resuscitation and 289 cases were treated with intravenous fluid resuscitation. Compared with the intravenous route group, the enteral route resuscitation group reduced the incidence of new organ failure (OR = 0.23, 95% CI: 0.12-0.43, P < 0.00001), the incidence of persistent organ failure (OR = 0.38, 95% CI: 0.22-0.64, P = 0.0003), the incidence of mechanical ventilation (OR = 0.15, 95% CI: 0.03-0.69, P = 0.01), the incidence of ICU care (OR = 0.49, 95% CI: 0.27-0.88, P = 0.02), and the incidence of pancreatic infection (OR = 0.38, 95% CI: 0.17-0.83, P = 0.02). There were no statistically significant differences in mortality (OR = 0.77, 95% CI: 0.35-1.66, P = 0.50), surgical intervention rate (OR = 0.47, 95% CI: 0.19-1.18, P = 0.11), and incidence of localized ascites (OR = 0.65, 95% CI: 0.25-1.73, P = 0.39).

CONCLUSION

Early enteral fluid resuscitation is safe and effective for in severe pancreatitis. But this conclusion needs to be verified by more additional multi-centre randomized controlled trials with large samples.

The impact of fluid resuscitation via colon on patients with severe acute pancreatitis

Severe acute pancreatitis (SAP) is a life-threatening disease. Fluid Resuscitation Via Colon (FRVC) may be a complementary therapy for early controlled fluid resuscitation. But its clinical application has not been reported. This study aims to explore the impact of FRVC on SAP. All SAP patients with the first onset within 72 h admitted to the hospital were included from January 2014 to December 2018 through electronic databases of Ruijin hospital and were divided into FRVC group (n = 103) and non-FRVC group (n = 78). The clinical differences before and after the therapy between the two groups were analyzed. Of the 181 patients included in the analysis, the FRVC group received more fluid volume and reached the endpoint of blood volume expansion ahead of the non-FRVC group. After the early fluid resuscitation, the inflammation indicators in the FRVC group were lower. The rate of mechanical ventilation and the incidence of hypernatremia also decreased significantly. Using pure water for FRVC was more helpful to reduce hypernatremia. However, Kaplan–Meier 90-day survival between the two groups showed no difference. These results suggest that the combination of FRVC might benefit SAP patients in the early stage of fluid resuscitation, but there is no difference between the prognosis of SAP patients and that of conventional fluid resuscitation. Further prospective study is needed to evaluate the effect of FRVC on SAP patients.

Aquaporins Involvement in Pancreas Physiology and in Pancreatic Diseases

Aquaporins are a family of transmembrane proteins permeable to water. In mammals, they are subdivided into classical aquaporins that are permeable to water; aquaglyceroporins that are permeable to water, glycerol and urea; peroxiporins that facilitate the diffusion of H2O2 through cell membranes; and so called unorthodox aquaporins. Aquaporins ensure important physiological functions in both exocrine and endocrine pancreas. Indeed, they are involved in pancreatic fluid secretion and insulin secretion. Modification of aquaporin expression and/or subcellular localization may be involved in the pathogenesis of pancreatic insufficiencies, diabetes and pancreatic cancer. Aquaporins may represent useful drug targets for the treatment of pathophysiological conditions affecting pancreatic function, and/or diagnostic/predictive biomarker for pancreatic cancer. This review summarizes the current knowledge related to the involvement of aquaporins in the pancreas physiology and physiopathology.