Renal Endocannabinoid Dysregulation in Obesity-Induced Chronic Kidney Disease in Humans.

The endocannabinoid system (ECS) regulates various physiological processes, including energy homeostasis and kidney function. ECS upregulation in obese animals and humans suggests a potential link to obesity-induced chronic kidney disease (CKD). However, obesity-induced ECS changes in the kidney are mainly studied in rodents, leaving the impact on obese humans unknown. In this study, a total of 21 lean and obese males (38-71 years) underwent a kidney biopsy. Biochemical analysis, histology, and endocannabinoid (eCB) assessment were performed on kidney tissue and blood samples. Correlations between different parameters were evaluated using a comprehensive matrix. The obese group exhibited kidney damage, reflected in morphological changes, and elevated kidney injury and fibrotic markers. While serum eCB levels were similar between the lean and obese groups, kidney eCB analysis revealed higher anandamide in obese patients. Obese individuals also exhibited reduced expression of cannabinoid-1 receptor (CB1R) in the kidney, along with increased activity of eCB synthesizing and degrading enzymes. Correlation analysis highlighted connections between renal eCBs, kidney injury markers, obesity, and related pathologies. In summary, this study investigates obesity's impact on renal eCB "tone" in humans, providing insights into the ECS's role in obesity-induced CKD. Our findings enhance the understanding of the intricate interplay among obesity, the ECS, and kidney function.

Systemic Changes in Endocannabinoids and Endocannabinoid-like Molecules in Response to Partial Nephrectomy-Induced Ischemia in Humans.

Renal ischemia-reperfusion (IR), a routine feature of partial nephrectomy (PN), can contribute to the development of acute kidney injury (AKI). Rodent studies show that the endocannabinoid system (ECS) is a major regulator of renal hemodynamics and IR injury; however, its clinical relevance remains to be established. Here, we assessed the clinical changes in systemic endocannabinoid (eCB) levels induced by surgical renal IR. Sixteen patients undergoing on-clamp PN were included, with blood samples taken before renal ischemia, after 10 min of ischemia time, and 10 min following blood reperfusion. Kidney function parameters (serum creatinine (sCr), blood urea nitrogen (BUN), and serum glucose) and eCB levels were measured. Baseline levels and individual changes in response to IR were analyzed and correlation analyses were performed. The baseline levels of eCB 2-arachidonoylglycerol (2-AG) were positively correlated with kidney dysfunction biomarkers. Unilateral renal ischemia increased BUN, sCr, and glucose, which remained elevated following renal reperfusion. Renal ischemia did not induce changes in eCB levels for all patients pooled together. Nevertheless, stratifying patients according to their body mass index (BMI) revealed a significant increase in N-acylethanolamines (anandamide, AEA; N-oleoylethanolamine, OEA; and N-palmitoylethanolamine, PEA) in the non-obese patients. No significant changes were found in obese patients who had higher N-acylethanolamines baseline levels, positively correlated with BMI, and more cases of post-surgery AKI. With the inefficiency of 'traditional' IR-injury 'preventive drugs', our data support future research on the role of the ECS and its manipulation in renal IR.

Safety and Efficacy of Oral Human Parathyroid Hormone (1-34) in Hypoparathyroidism: An Open-Label Study.

The standard treatment of primary hypoparathyroidism (hypoPT) with oral calcium supplementation and calcitriol (or an analog), intended to control hypocalcemia and hyperphosphatemia and avoid hypercalciuria, remains challenging for both patients and clinicians. In 2015, human parathyroid hormone (hPTH) (1-84) administered as a daily subcutaneous injection was approved as an adjunctive treatment in patients who cannot be well controlled on the standard treatments alone. This open-label study aimed to assess the safety and efficacy of an oral hPTH(1-34) formulation as an adjunct to standard treatment in adult subjects with hypoparathyroidism. Oral hPTH(1-34) tablets (0.75 mg human hPTH(1-34) acetate) were administered four times daily for 16 consecutive weeks, and changes in calcium supplementation and alfacalcidol use, albumin-adjusted serum calcium (ACa), serum phosphate, urinary calcium excretion, and quality of life throughout the study were monitored. Of the 19 enrolled subjects, 15 completed the trial per protocol. A median 42% reduction from baseline in exogenous calcium dose was recorded (p = .001), whereas median serum ACa levels remained above the lower target ACa levels for hypoPT patients (>7.5 mg/dL) throughout the study. Median serum phosphate levels rapidly decreased (23%, p = .0003) 2 hours after the first dose and were maintained within the normal range for the duration of the study. A notable, but not statistically significant, median decrease (21%, p = .07) in 24-hour urine calcium excretion was observed between the first and last treatment days. Only four possible drug-related, non-serious adverse events were reported over the 16-week study, all by the same patient. A small but statistically significant increase from baseline quality of life (5%, p = .03) was reported by the end of the treatment period. Oral hPTH(1-34) treatment was generally safe and well tolerated and allowed for a reduction in exogenous calcium supplementation, while maintaining normocalcemia in adult patients with hypoparathyroidism. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).