Diminazene aceturate exacerbates renal fibrosis after unilateral ureteral obstruction in female mice

Pharmacokinetics and safety of pirfenidone in individuals with chronic kidney disease stage G2 and G3a: A single-dose, Phase I, bridging study

BACKGROUND AND OBJECTIVE

Pirfenidone is an inhibitor of transforming growth factor-beta 1 (TGF-β1) and is being developed for the treatment of diabetic kidney disease (DKD). We assessed the pharmacokinetics (PK) and safety of a single dose of pirfenidone in individuals with CKD stages G2/G3a.

METHODS

In this phase I bridging study, patients with CKD stages G2 or G3a, aged 18-70 years, with a body mass index of 18-26 kg/m2, and glomerular filtration rate (eGFR) ranging from 45 to 89 ml/min/1.73 m2, received a single oral dose of 400 mg pirfenidone capsules 30 min after a standard breakfast. The pharmacokinetic parameters of the two groups were measured and compared after blood and urine collection. The co-primary endpoints were the area under the plasma concentration-time curve from time zero to 36 h (AUC0-36) and the maximum observed plasma concentration (Cmax) of pirfenidone. Safety was a secondary endpoint. The trial has been registered on ClinicalTrials.gov (ChiCTR2300077297).

RESULTS

A total of 20 subjects participated in this study. There were no significant differences between the control group and the patient group (CKD stages G2/G3a) in terms of plasma Cmax, the time to reach the maximum observed concentration (Tmax), and elimination half-life(t1/2). However, the Vz/F of the patient group (CKD G2 stage) was significantly higher than that of the control group. Renal accumulation rate, renal clearance rate (CLr), and urine drug concentration also showed no significant differences. No severe adverse events occurred during the trial.

CONCLUSIONS

These results indicate that the PK and safety of pirfenidone are not influenced by renal function. Individuals with renal impairment may not require dose adjustments.

Intracellular iron accumulation throughout the progression of sepsis influences the phenotype and function of activated macrophages in renal tissue damage

Sepsis, the most common cause of acute kidney injury, remains a major socioeconomic burden. A dysregulated immune response leads to progressive organ dysfunction. Although numerous inflammatory pathways were described, most are still vague and need to be studied in terms of the mechanisms to improve the therapeutic intervention. We tackled the relationship between intracellular iron overload and macrophage polarization within 6, 24, and 72 h of sepsis induction. In our study, sepsis-induced kidney injury was caused by using the cecal ligation and puncture (CLP) model. Our results indicated severe renal tissue damage with a progressive increase in serum BUN and creatinine with architectural tissue damage and positive PAS staining. There was increased expression of CD8+ CD68+ M1 macrophage markers with upregulation of iNOS and co-expression of CD163+. Alternatively, Arg1+ Fizz1+ M2 macrophage markers were downregulated with increased iNOS/Arg1 ratio. TFR1, cubilin, and DMT1, as iron transport systems, were increased compared to sham but were significant after 72 h, while ZIP8 showed no significant change. There was a correlation between iron overload and M1 macrophage polarization with CD163+ phenotype, together with fibrotic changes. The intracellular iron overload with downregulation of ferritin was strongly related to macrophage polarization that was exaggerated at 72 h. Finally, early introduced therapy to target free iron during sepsis is a proposed novel solution for protecting the renal tissue from acute injury due to macrophage activation that may end up with chronic kidney injury, if not mortality.

Targeting renal damage: The ACE2/Ang-(1-7)/mas axis in chronic kidney disease

The renin-angiotensin system (RAS) is a crucial factor in chronic kidney disease (CKD) progression, affecting renal function and contributing significantly to renal tissue inflammation and fibrosis. Activation of the classical ACE/Ang II/AT1 axis exacerbates renal damage, while the ACE2/Ang-(1-7)/Mas axis has shown promise in reducing CKD progression in numerous animal models. Recently, the ACE2/Ang-(1-7)/Mas axis has emerged as a promising target for CKD interventions. This review provides a comprehensive review of the pivotal role of this axis in CKD pathogenesis and systematically examines various molecules and pharmaceutical agents targeting this pathway. This review aims to elucidate potential strategies for delaying or halting CKD progression, offering patients more effective treatment options.

Nephroprotective effects of diminazene on doxorubicin-induced acute kidney injury in rats

This study aimed to investigate the potential protective effects of diminazene, an activator of angiotensin II converting enzyme (ACE2), on kidney function and structure in rats with acute kidney injury (AKI) induced by the anticancer drug doxorubicin (DOX). The impact of diminazene was compared to that of two other drugs: the ACE inhibitor lisinopril and the angiotensin II type 1 (AT1) receptor blocker valsartan. Rats were subjected to a single intraperitoneal injection of DOX (13.5 mg/kg) on the 5th day, either alone or in combination with diminazene (15 mg/kg/day), lisinopril (10 mg/kg/day), or valsartan (30 mg/kg/day) for 8 consecutive days. Various markers related to kidney function, oxidative stress, and inflammation were measured in plasma and urine. Additionally, kidney tissues were assessed histopathologically. DOX-induced nephrotoxicity was confirmed by elevated levels of plasma urea, creatinine, and neutrophil gelatinase-associated lipocalin (NGAL). DOX also led to increased urinary N-acetyl-β-D-glucosaminidase (NAG) activity and decreased creatinine clearance, albumin levels, and osmolality. Moreover, DOX caused a reduction in renal oxidative stress markers, including superoxide dismutase (SOD), glutathione reductase (GR), and catalase activities, while increasing malondialdehyde (MDA) levels. It also raised plasma inflammatory markers, tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β). Concurrently administering diminazene significantly mitigated these DOX-induced changes, including histopathological alterations like renal tubule necrosis, tubular casts, shrunken glomeruli, and increased renal fibrosis. Similar protective effects were observed with lisinopril and valsartan. These protective effects, at least in part, appear to result from the anti-inflammatory and antioxidant properties of these drugs. In summary, this study suggests that the administration of diminazene, lisinopril, or valsartan had comparable effects in ameliorating the biochemical and histopathological aspects of DOX-induced acute kidney injury in rats.