“In this review, we discuss the role of the endocannabinoid (eCB) system in regulating energy and metabolic homeostasis. Endocannabinoids, via activating the cannabinoid type-1 receptor (CB1R), are commonly known as mediators of the thrifty phenotype hypothesis due to their activity in the central nervous system, which in turn regulates food intake and underlies the development of metabolic syndrome. Indeed, these findings led to the clinical testing of globally acting CB1R blockers for obesity and various metabolic complications. However, their therapeutic potential was halted due to centrally mediated adverse effects. Recent observations that highlighted the key role of the peripheral eCB system in metabolic regulation led to the preclinical development of various novel compounds that block CB1R only in peripheral organs with very limited brain penetration and without causing behavioral side effects. These unique molecules, which effectively ameliorate obesity, type II diabetes, fatty liver, insulin resistance, and chronic kidney disease in several animal models, are likely to be further developed in the clinic and may revive the therapeutic potential of blocking CB1R once again.”
“Diabetes mellitus is a complex, multifactorial disorder that is attributed to pancreatic β cell dysfunction. Pancreatic β cell dysfunction results in declining utilization of glucose by peripheral tissues as kidney and it leads to nephropathy. Excessive production and accumulation of free radicals and incapable antioxidant defense system lead to impaired redox status. Macromolecular damage may occur due to impaired redox status and also immune imbalance.
Δ9-Tetrahydrocannabinol (THC) is the main active ingredient in cannabis. THC acts as an immunomodulator and an antioxidant agent.
Our aim was to evaluate the effects of THC in the diabetic kidney.
According to our data, THC has ameliorative effects on the impaired redox status of diabetic kidney and also it acts as an immunomodulator. Therefore, THC might be used as a therapeutic agent for diabetic kidneys but its usage in the healthy kidney may show adverse effects.”
“Marijuana Doesn’t Seem to Harm the Kidneys” https://www.webmd.com/mental-health/addiction/news/20180306/marijuana-doesnt-seem-to-harm-the-kidneys
“Pot Won’t Harm Healthy Young People’s Kidneys, Study Suggests” https://www.medicinenet.com/script/main/art.asp?articlekey=206375
“Marijuana doesn’t appear to harm kidneys” https://www.hsph.harvard.edu/news/hsph-in-the-news/marijuana-kidneys/
“Acute kidney injury (AKI) is an increasing problem clinically and is associated with chronic kidney disease progression.
Cannabinoid type 2 receptor activation has been shown to mitigate some of the deleterious tubular effects due to AKI, but its role on the renal vasculature has not been fully described.
In this study, we investigated the effects of our novel cannabinoid CB2 receptor agonist, SMM-295, on renal vasculature by assessing cortical perfusion using laser Doppler flowmetry and changes in luminal diameter using isolated afferent arterioles.
These data provide new insight into the potential benefit of SMM-295 by activating vascular and non-vascular CB2 receptors to promote renal vasodilation, and provide a new therapeutic target to treat renal injuries that impact renal blood flow dynamics.”
“Diabetic nephropathy (DN), a distinct manifestation of diabetic kidney disease, affects approximately 30% of patients with diabetes. While most attention has been focused on glomerular changes related to DN, there is growing evidence that tubulopathy is a key feature in the pathogenesis of this disease. The renal proximal tubule cells (RPTCs) are particularly sensitive to the deleterious effect of chronic hyperglycemia. However, the cellular changes that control the dysfunction of the RPTCs are not fully understood.
Controlling glucose reabsorption in the proximal tubules via inhibition of glucose transporters (GLUT) has emerged as a promising therapeutic in ameliorating DN.
Overactivation of the renal endocannabinoid (eCB) system via the cannabinoid-1 receptor (CB1R) contributes to the development of DN, and its blockade by globally acting or peripherally restricted CB1R antagonists has been shown to ameliorate renal dysfunction in different murine models for diabetes. Recently, we have utilized various pharmacological and genetic tools to show that the eCB/CB1R system contributes to the development of DN via regulating the expression, translocation, and activity of the facilitative GLUT2 located in the RPTCs.
These findings have the potential to be translated into therapy, and support the rationale for the preclinical development of novel renal-specific CB1R and/or GLUT2 inhibitors for the treatment of DN.”
“The cannabinoid receptor type 2 (CB2) is a G protein-coupled seven transmembrane receptor that transmits endogenous cannabinoid signaling. The role of CB2 in the pathogenesis of kidney injury and fibrosis remains poorly understood.
Here we demonstrate that CB2 was induced, predominantly in kidney tubular epithelium, in various models of kidney disease induced by unilateral ureteral obstruction, adriamycin or ischemia/reperfusion injury.
By using in silico screening and medicinal chemistry modifications, we discovered a novel compound, XL-001, that bound to CB2 with high affinity and selectivity and acted as an inverse agonist. Delayed administration of XL-001 was also effective in ameliorating kidney fibrosis and inflammation.
Thus, CB2 is a pathogenic mediator in kidney fibrosis and targeted inhibition with the novel inverse agonist XL-001 may provide a strategy in the fight against fibrotic kidney diseases.”
“Hallmark features of acute kidney injury (AKI) include mobilization of immune and inflammatory mechanisms culminating in tissue injury. Emerging information indicates heterogeneity of neutrophils with pro- and anti-inflammatory functions (N1 and N2, respectively). Also, regulatory T-17 (Treg17) cells curtail Th-17-mediated pro-inflammatory responses. However, the status of Treg17 cells and neutrophil phenotypes in AKI are not established.
Further, cannabidiol exerts immunoregulatory effects but its impact on Treg17 cells and neutrophil subtypes is not established. Thus, we examined the status of Treg17 cells and neutrophil subtypes in AKI and determined whether cannabidiol favors regulatory neutrophils and T cells accompanied with renoprotection.
Importantly, cannabidiol treatment preserved ψm, reduced cell death and KIM-1 accompanied by restoration of N1 and N2 imbalance and preservation of Treg17 cells while decreasing Th-17 cells. The ability of cannabidiol to favor development of Treg17 cells was further established using functional mixed lymphocytic reaction. Subsequent studies showed higher renal blood flow and reduced serum creatinine in cannabidiol-treated IRI animals.
Collectively, our novel observations establish that renal IRI causes neutrophil polarization in favor of N1 and also reduces Treg17 cells in favor of Th-17, effects that are reversed by cannabidiol treatment accompanied with significant renoprotection.”
“LLC-PK1 cells, an immortalized epithelial cell line derived from pig renal proximal tubules, express all the major players of the endocannabinoid system (ECS) such as CB1, CB2 and TRPV1 receptor, as well as the main enzymes involved in the biosynthesis and degradation of the major endocannabinoids named 2-arachidonoylglycerol, 2-AG and anandamide, AEA.
Here we investigated whether the damages caused by ischemic insult either in vitro using LLC-PK1 cells exposed to antimycin A (an inductor of ATP-depletion) or in vivo using Wistar rats in a classic renal ischemia and reperfusion (IR) protocol, lead to changes in AEA and 2-AG levels, as well as altered expression of genes from the main enzymes involved in the regulation of the ECS.
Our data show that the mRNA levels of CB1 receptor gene were downregulated, while the transcript levels of monoacylglycerol lipase (MAGL), the main 2-AG degradative enzyme, are upregulated in LLC-PK1 cells after IR model. Accordingly, IR was accompanied by a significant reduction in the levels of 2-AG and AEA, as well as of the two endocannabinoid related molecules, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in LLC-PK1 cells. In kidney cortex homogenates, the AEA levels were selectively significantly decreased. In addition, we found that both the in vitro and in vivo model of IR caused a reduction in the expression and activity of the Na+/K+ATPase. These changes were reversed by the CB1/CB2 agonist WIN55,212, in a CB1-receptor dependent manner on LLC-PK1 IR model.
In conclusion, the ECS and Na+/K+ ATPase are down-regulated following IR model in LLC-PK1 cells and rat kidney. We suggest that CB1 agonists might represent a potential strategy to reverse the consequences of IR injury in kidney tissues.”
“The anti-tumor properties of cannabinoids have been investigated in many in vitro and in vivo studies. Many of these anti-tumor effects are mediated via cannabinoid receptor types 1 and 2 (CB1 and CB2), comprising the endocannabinoid system (ECS).
In this study, we investigated the ECS based on CB 1 and CB 2 receptor gene and protein expression in renal cell carcinoma (RCC) cell lines. In view of their further use for potential treatments, we thus investigated the roles of CB1 and CB2 receptors in the anti-proliferative action and signal transduction triggered by synthetic cannabinoid agonists [such as JWH-133 and WIN 55,212-2 (WIN-55)] in RCC cell lines.
The CB1 and CB2 genes expression was shown by real-time PCR and flow cytometric and western blot analysis indicating a higher level of CB2 receptor as compared to CB1 in RCC cells. Immunocytochemical staining also confirmed the expression of the CB1 and CB2 proteins. We also found that the synthetic cannabinoid agonist WIN-55 exerted anti-proliferative and cytotoxic effects by inhibiting the growth of RCC cell lines, while the CB2 agonist JWH-133 did not. Pharmacologically blocking the CB1 and CB2 receptors with their respective antagonists SR141716A and AM-630, followed by the WIN-55 treatment of RCC cells allowed uncovering the involvement of CB2, which led to an arrest in the G0/G1 phase of the cell cycle and apoptosis.
This study elucidated the involvement of CB2 in the in vitro inhibition of RCC cells, and future applications of CB2agonists in the prevention and management of RCC are discussed.
In summary, our study shows the involvement of CB2 receptor in the in vitro inhibition of RCC cells. This knowledge will be useful to unravel the future applications of CB2receptor and its agonists in the prevention and management of RCC.”
“The endogenous cannabinoids anandamide and 2-arachidonoylglycerol bind to the cannabinoid receptors of type 1 and 2. These receptors are also the binding sites for exogenous, both natural and synthetic, cannabinoids that are used for recreation purposes.
Until recently, cannabinoids and cannabinoid receptors have attracted little interest among nephrologists; however, a full endocannabinoid system (ECS) is present in the kidney and it has recently emerged as an important player in the pathogenesis of diabetic nephropathy, drug nephrotoxicity, and progressive chronic kidney disease.
This newly established role of the ECS in the kidney might have therapeutic relevance, as pharmacological modulation of the ECS has renoprotective effects in experimental animals, raising hope for future potential applications in humans.
In addition, over the last years, there has been a number of reported cases of acute kidney injury (AKI) associated with the use of synthetic cannabinoids that appear to have higher potency and rate of toxicity than natural Cannabis. This poorly recognized cause of renal injury should be considered in the differential diagnosis of AKI, particularly in young people.
In this review we provide an overview of preclinical evidence indicating a role of the ECS in renal disease and discuss potential future therapeutic applications.”
“Chronic pain is a major therapeutic problem in kidney transplant patients owing to nephrotoxicity associated with nonsteroidal antiiflammatory drugs.
Benefits in chronic pain treatment with cannabidiol (CBD) have been reported.
This study assesses the effect, safety, and possible drug interactions in kidney transplant patients treated with CBD for chronic pain.
We assessed 7 patients with a mean age of 64.5 years (range, 58-75 years). CBD initial dose was 100 mg/d, CBD dose reduction to 50 mg/d has been done on day 4 to patient 1 for persistent nausea. Tacrolimus dose reduction in patient 3 was undertaken on days 4, 7, and 21 owing to persisting elevated levels (even before CBD) and itching, and on day 21 in patient 5. Tacrolimus levels decreased in patient 2 but were normal in the control 1 week later. Patients on cyclosporine were stable. Adverse effects were nausea, dry mouth, dizziness, drowsiness, and intermittent episodes of heat. CBD dose decrease was required in 2 patients. Two patients had total pain improvement, 4 had a partial response in the first 15 days, and in 1 there was no change.
During this follow-up, CBD was well-tolerated, and there were no severe adverse effects. Plasma levels of tacrolimus were variable. Therefore, longer follow-up is required.”