Lipid mediators of insulin signaling in diabetic kidney disease

Crosstalk of Hyperglycaemia and Cellular Mechanisms in the Pathogenesis of Diabetic Kidney Disease

Among all nephropathies, diabetic kidney disease (DKD) is the most common cause of kidney impairment advancement to end-stage renal disease (ESRD). Although DKD has no cure, the disease is commonly managed by strict control of blood glucose and blood pressure, and in most of these cases, kidney function often deteriorates, resulting in dialysis, kidney replacement therapy, and high mortality. The difficulties in finding a cure for DKD are mainly due to a poor understanding of the underpinning complex cellular mechanisms that could be identified as druggable targets for the treatment of this disease. The review is thus aimed at giving insight into the interconnection between chronic hyperglycaemia and cellular mechanistic perturbations of nephropathy in diabetes. A comprehensive literature review of observational studies on DKD published within the past ten years, with 57 percent published within the past three years was carried out. The article search focused on original research studies and reviews published in English. The articles were explored using Google Scholar, Medline, Web of Science, and PubMed databases based on keywords, titles, and abstracts related to the topic. This article provides a detailed relationship between hyperglycaemia, oxidative stress, and various cellular mechanisms that underlie the onset and progression of the disease. Moreover, it also shows how these mechanisms affect organelle dysfunction, resulting in fibrosis and podocyte impairment. The advances in understanding the complexity of DKD mechanisms discussed in this review will expedite opportunities to develop new interventions for treating the disease.

Lipid metabolism disorder in diabetic kidney disease

Diabetic kidney disease (DKD), a significant complication associated with diabetes mellitus, presents limited treatment options. The progression of DKD is marked by substantial lipid disturbances, including alterations in triglycerides, cholesterol, sphingolipids, phospholipids, lipid droplets, and bile acids (BAs). Altered lipid metabolism serves as a crucial pathogenic mechanism in DKD, potentially intertwined with cellular ferroptosis, lipophagy, lipid metabolism reprogramming, and immune modulation of gut microbiota (thus impacting the liver-kidney axis). The elucidation of these mechanisms opens new potential therapeutic pathways for DKD management. This research explores the link between lipid metabolism disruptions and DKD onset.

Triglyceride-glucose index is associated with the risk of chronic kidney disease progression in type 2 diabetes

OBJECTIVE

The study aimed to investigate the association of TyG index with chronic kidney disease (CKD) progression in type 2 diabetes mellitus (T2DM).

METHODS

A total of 179 T2DM patients with CKD were retrospectively included. CKD progression was defined as a doubling of baseline serum creatinine or onset of end-stage kidney disease (ESKD). Internal validation was performed by the Kidney Failure Risk Equation (KFRE) model and Net reclassification improvement (NRI).

RESULTS

The optimal cut-off value of the TyG index was 9.17. The cumulative incidence of kidney outcomes was significantly higher in the high-TyG group (v.s low-TyG group, P = 0.019). In addition, the high-TyG index was associated with a greater risk of CKD progression (HR 1.794, 95% CI 1.026-3.137, P = 0.040). And reclassification analyses confirmed the final adjusted model improved NRI (61.90% v.s model 2, 43.80% v.s model 1). The further RCS curves presented an inverted S-shaped relationship between the TyG index and the risk of CKD progression. Internal validation verified that a higher TyG index was associated with 2.10-fold increased odds of 2-year ESKD risk >10% (95% CI 1.82-8.21). Moreover, subgroup analysis suggested that the association was more pronounced in those at relatively early CKD stages (higher than stage 2) and with no medication history of oral hypoglycemic agents.

CONCLUSION

An elevated TyG index was associated with a higher risk of CKD progression in T2DM patients. Our findings suggested that timely targeting insulin sensitivity at the early stages of T2DM might be associated with declined future risk of CKD development.

Lycopene attenuates D-galactose-induced insulin signaling impairment by enhancing mitochondrial function and suppressing the oxidative stress/inflammatory response in mouse kidneys and livers

Lycopene (LYC) possesses bioactivity to improve the pathogenesis of several chronic diseases via antioxidant-associated mechanisms. The purpose of this study was to investigate whether LYC could attenuate D-galactose (D-gal)-induced mitochondrial dysfunction and insulin signaling impairment in mouse kidneys and livers. Two-month-old CD-1 mice were treated by intraperitoneal injection of 150 mg kg^-1 day^-1D-gal for 8 weeks and received 0.03% LYC (w/w, mixed into diet). The results showed that LYC ameliorated oxidative stress triggered by D-gal by enhancing the Nrf2 antioxidant defense pathway and increasing the expression of the antioxidant response genes HO-1 and NQO1 in mouse kidneys and livers. LYC inhibited the MAPK and NFκB pathways and attenuated renal and hepatic inflammatory responses. Moreover, LYC upregulated the expression of genes related to mitochondrial biosynthesis and oxidative phosphorylation and improved insulin signal transduction through the IRS-1/AKT/GSK3β pathway in mouse kidneys and livers.

Fungus-Derived 3-Hydroxyterphenyllin and Candidusin A Ameliorate Palmitic Acid-Induced Human Podocyte Injury via Anti-Oxidative and Anti-Apoptotic Mechanisms

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease. An elevated fatty acid plasma concentration leads to podocyte injury and DN progression. This study aimed to identify and characterize cellular mechanisms of natural compounds that inhibit palmitic acid (PA)-induced human podocyte injury. By screening 355 natural compounds using a cell viability assay, 3-hydroxyterphenyllin (3-HT) and candidusin A (CDA), isolated from the marine-derived fungus Aspergillus candidus PSU-AMF169, were found to protect against PA-induced podocyte injury, with half-maximal inhibitory concentrations (IC₅₀) of ~16 and ~18 µM, respectively. Flow cytometry revealed that 3-HT and CDA suppressed PA-induced podocyte apoptosis. Importantly, CDA significantly prevented PA-induced podocyte barrier impairment as determined by 70 kDa dextran flux. Reactive oxygen species (ROS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) direct scavenging assays indicated that both compounds exerted an anti-oxidative effect via direct free radical-scavenging activity. Moreover, 3-HT and CDA upregulated the anti-apoptotic Bcl2 protein. In conclusion, 3-HT and CDA represent fungus-derived bioactive compounds that have a novel protective effect on PA-induced human podocyte apoptosis via mechanisms involving free radical scavenging and Bcl2 upregulation.

Integrated lipidomics, transcriptomics and network pharmacology analysis to reveal the mechanisms of Danggui Buxue Decoction in the treatment of diabetic nephropathy in type 2 diabetes mellitus

ETHNOPHARMACOLOGICAL RELEVANCE

Danggui Buxue Decoction (DBT) is classical prescriptions, which contains two Traditional Chinese Medicines of Angelicae sinensis radix and Astragali radix. According to the preliminary work of our laboratory and numerous studies, it has been found that DBT has a therapeutic effect on diabetic nephropathy (DN). However, the mechanisms underlying its action remain unclear.

AIM OF THE STUDY

The aim of this study was to evaluate the impact of DBT on kidney disease in diabetic mice and further explore its protective mechanism.

METHODS

DN mice model was induced by high-fat fodder and streptozotocin (STZ). Qualitative and quantitative analysis of 6 compounds in DBT was carried out by HPLC, including calycosin-7-glucoside, ferulic acid, ononin, calycosin, formononetin, and levostilide A. Hematoxylin-Eosin (HE) staining was used to determine the degree of kidney pathological damage. The UPLC-Q Exactive MS technique was used to analyze the lipids metabolism profile of kidneys samples and multiple statistical analysis methods were used to screen and identify biomarkers. Transcriptomics analyses were carried out using RNAseq. The possible molecular mechanism was unraveled by network pharmacology.

RESULTS

Thirty-one significantly altered lipid metabolites were identified in the model group comparing with the control group. DBT improved aberrant expression of several pathways related to lipidomics, including glycerophospholipid metabolism and sphingolipid metabolism. Comprehensive analysis indicated that DBT intervention reduced the content of Cers, phosphatidylethanolamines and phosphatidylcholines in mouse kidneys by downregulating the transcription level of Degs2 and Cers, reducing lipid accumulation and promoting Akt phosphorylation by upregulating the expression of Acers and Pdk1. Network pharmacology analysis showed that components in DBT, such as kaempferol, ferulic acid and astragaloside IV, could be responsible for the pharmacological activity of DN by regulating the AGE-RAGE, PI3K/Akt, MAPK and NF-κB signaling pathways in diabetic complications.

CONCLUSIONS

These results showed that DBT may improve DN by affecting insulin resistance, chronic inflammation and lipid accumulation.

Podocyte Bioenergetics in the Development of Diabetic Nephropathy: The Role of Mitochondria

Diabetic nephropathy (DN) is the leading cause of kidney failure, with an increasing incidence worldwide. Mitochondrial dysfunction is known to occur in DN and has been implicated in the underlying pathogenesis of disease. These complex organelles have an array of important cellular functions and involvement in signaling pathways, and understanding the intricacies of these responses in health, as well as how they are damaged in disease, is likely to highlight novel therapeutic avenues. A key cell type damaged early in DN is the podocyte, and increasing studies have focused on investigating the role of mitochondria in podocyte injury. This review will summarize what is known about podocyte mitochondrial dynamics in DN, with a particular focus on bioenergetic pathways, highlighting key studies in this field and potential opportunities to target, enhance or protect podocyte mitochondrial function in the treatment of DN.

Lysophosphatidylcholine mediates fast decline in kidney function in diabetic kidney disease

Some patients with diabetic kidney disease (DKD) show a fast progression of kidney dysfunction and are known as a "fast decliner" (FD). Therefore, it is critical to understand pathomechanisms specific for fast decline. Here, we performed a comprehensive metabolomic analysis of patients with stage G3 DKD and identified increased urinary lysophosphatidylcholine (LPC) in fast decline. This was confirmed by quantification of urinary LPC using mass spectrometry and identified urinary LPC containing saturated fatty acids palmitic (16:0) and stearic (18:0) acids was increased in FDs. The upsurge in urinary LPC levels was correlated with a decline in estimated glomerular filtration rate after 2.5 years. To clarify a pathogenic role of LPC in FD, we studied an accelerated rat model of DKD and observed an increase in LPC (16:0) and (18:0) levels in the urine and kidney tubulointerstitium as the disease progressed. These findings suggested that local dysregulation of lipid metabolism resulted in excessive accumulation of this LPC species in the kidney. Our in vitro studies also confirmed LPC-mediated lipotoxicity in cultured proximal tubular cells. LPC induced accumulation of lipid droplets via activation of peroxisome proliferator-activated receptor-δ followed by upregulation of the lipid droplet membrane protein perilipin 2 and decreased autophagic flux, thereby inducing organelle stress and subsequent apoptosis. Thus, LPC (16:0) and (18:0) may mediate a fast progression of DKD and may serve as a target for novel therapeutic approaches.

Lipid Disorders in NAFLD and Chronic Kidney Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver dysfunction and is characterized by exaggerated lipid accumulation, inflammation and even fibrosis. It has been shown that NAFLD increases the risk of other chronic diseases, particularly chronic kidney disease (CKD). Lipid in excess could lead to liver and kidney lesions and even end-stage disease through diverse pathways. Dysregulation of lipid uptake, oxidation or de novo lipogenesis contributes to the toxic effects of ectopic lipids which promotes the development and progression of NAFLD and CKD via triggering oxidative stress, apoptosis, pro-inflammatory and profibrotic responses. Importantly, dyslipidemia and release of pro-inflammatory cytokines caused by NAFLD (specifically, nonalcoholic steatohepatitis) are considered to play important roles in the pathological progression of CKD. Growing evidence of similarities between the pathogenic mechanisms of NAFLD and those of CKD has attracted attention and urged researchers to discover their common therapeutic targets. Here, we summarize the current understanding of molecular aberrations underlying the lipid metabolism of NAFLD and CKD and clinical evidence that suggests the relevance of these pathways in humans. This review also highlights the orchestrated inter-organ cross-talk in lipid disorders, as well as therapeutic options and opportunities to counteract NAFLD and CKD.

Characterization of purinergic receptor 2 signaling in podocytes from diabetic kidneys

Growing evidence suggests that renal purinergic signaling undergoes significant remodeling during pathophysiological conditions such as diabetes. This study examined the renal P2 receptor profile and ATP-mediated calcium response from podocytes in glomeruli from kidneys with type 1 or type 2 diabetic kidney disease (DKD), using type 2 diabetic nephropathy (T2DN) rats and streptozotocin-injected Dahl salt-sensitive (type 1 diabetes) rats. A dramatic increase in the ATP-mediated intracellular calcium flux in podocytes was observed in both models. Pharmacological inhibition established that P2X₄ and P2X₇ are the major receptors contributing to the augmented ATP-mediated intracellular calcium signaling in diabetic podocytes. The transition in purinergic receptor composition from metabotropic to ionotropic may disrupt intracellular calcium homeostasis in podocytes resulting in their dysfunction and potentially further aggravating DKD progression.

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Diabetic podocytes have sustained intracellular Ca²⁺ signaling in response to ATP

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Podocyte purinergic receptor signaling is predominantly ionotropic in diabetes

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Both type 1 and 2 diabetic podocytes have similar purinergic receptor remodeling

New insights into renal lipid dysmetabolism in diabetic kidney disease

Lipid dysmetabolism is one of the main features of diabetes mellitus and manifests by dyslipidemia as well as the ectopic accumulation of lipids in various tissues and organs, including the kidney. Research suggests that impaired cholesterol metabolism, increased lipid uptake or synthesis, increased fatty acid oxidation, lipid droplet accumulation and an imbalance in biologically active sphingolipids (such as ceramide, ceramide-1-phosphate and sphingosine-1-phosphate) contribute to the development of diabetic kidney disease (DKD). Currently, the literature suggests that both quality and quantity of lipids are associated with DKD and contribute to increased reactive oxygen species production, oxidative stress, inflammation, or cell death. Therefore, control of renal lipid dysmetabolism is a very important therapeutic goal, which needs to be archived. This article will review some of the recent advances leading to a better understanding of the mechanisms of dyslipidemia and the role of particular lipids and sphingolipids in DKD.

Nicotine, smoking, podocytes, and diabetic nephropathy

Diabetic nephropathy (DN) is the leading cause of end-stage kidney disease. Besides glycemic and blood pressure control, environmental factors such as cigarette smoking (CS) adversely affect the progression of DN. The effects of CS on DN progression have been attributed to combustion-generated molecules without consideration to the role of nicotine (NIC), responsible for the addictive properties of both CS and electronic cigarettes (ECs). Podocytes are essential to preserve the structure and function of the glomerular filtration barrier, and strong evidence indicates that early podocyte loss promotes DN progression. We performed experiments in human podocytes and in a mouse model of diabetes that develops nephropathy resembling human DN. We determined that NIC binding to podocytes in concentrations achieved with CS and ECs activated NADPH oxidase, which sets in motion a dysfunctional molecular network integrated by cyclooxygenase 2, known to induce podocyte injury; downregulation of AMP-activated protein kinase, important for maintaining cellular energy stores and antioxidation; and upregulation of CD36, which increased lipid uptake and promoted apoptosis. In diabetic mice, NIC increased proteinuria, a recognized marker of chronic kidney disease progression, accompanied by reduced glomerular podocyte synaptopodin, a crucial stabilizer of the podocyte cytoskeleton, and increased fibronectin expression. This novel study critically implicates NIC itself as a contributor to DN progression in CS and EC users.NEW & NOTEWORTHY In this study, we demonstrate that nicotine increases the production of reactive oxygen species, increases cyclooxygenase-2 expression, and upregulates Cd36 while inducing downregulation of AMP-activated protein kinase. In vivo nicotine increases proteinuria and fibronectin expression in diabetic mice. This study demonstrates that effects of nicotine on podocytes are responsible, at least in part, for the deleterious effects of smoking in the progression of chronic kidney disease, including diabetic nephropathy.

Podocyte Lipotoxicity in CKD

CKD represents the ninth most common cause of death in the United States but, despite this large health burden, treatment options for affected patients remain limited. To remedy this, several relevant pathways have been identified that may lead to novel therapeutic options. Among them, altered renal lipid metabolism, first described in 1982, has been recognized as a common pathway in clinical and experimental CKD of both metabolic and nonmetabolic origin. This observation has led many researchers to investigate the cause of this renal parenchyma lipid accumulation and its downstream effect on renal structure and function. Among key cellular components of the kidney parenchyma, podocytes are terminally differentiated cells that cannot be easily replaced when lost. Clinical and experimental evidence supports a role of reduced podocyte number in the progression of CKD. Given the importance of the podocytes in the maintenance of the glomerular filtration barrier and the accumulation of TG and cholesterol-rich lipid droplets in the podocyte and glomerulus in kidney diseases that cause CKD, understanding the upstream cause and downstream consequences of lipid accumulation in podocytes may lead to novel therapeutic opportunities. In this review, we hope to consolidate our understanding of the causes and consequences of dysregulated renal lipid metabolism in CKD development and progression, with a major focus on podocytes.

Vascular inflammation, atherosclerosis, and lipid metabolism and the occurrence of non-high albuminuria diabetic kidney disease: A cross-sectional study

AIM

Atherosclerosis involves vascular endothelial damage and lipid metabolism disorder, which is closely related to the occurrence and development of diabetic kidney disease (DKD). However, studies on non-high albuminuria DKD (NHADKD) with an albumin to creatinine ratio (ACR) <30 mg/g are rare. This study is to investigate the relationship between atherogenic factors and the occurrence of NHADKD.

METHODS

Serum lipid indicators, lipoprotein-associated phospholipase A2 (Lip-PLA2) and homocysteine levels were measured in 1116 subjects to analyze their relationship with NHADKD.

RESULTS

Among all subjects, Lip-PLA2 had the closest but relatively weak correlation with ACR (r = 0.297, p < 0.001) and only homocysteine was moderately correlated with eGFR (r = -0.465, p < 0.001). However, in patients with NHADKD, these atherosclerotic factors were weakly correlated or uncorrelated with eGFR (max. |r| = 0.247). Stratified risk analysis showed that when ACR was <10 mg/g, homocysteine [OR = 6.97(4.07-11.95)], total cholesterol (total-Chol) [OR = 6.04(3.03-12.04)], and high-density lipoprotein cholesterol (HDL-Chol) [OR = 5.09(2.99-8.64)] were risk factors for NHADKD. There was no significant difference of OR between these three factors (Z = 0.430-1.044, all p > 0.05). When ACR was ⩾10mg/g, homocysteine [OR = 17.26(9.67-30.82)] and total-Chol [OR = 5.63(2.95-10.76)] were risk factors for NHADKD, and ORhomocysteine was significantly higher than ORtotal-Chol (Z = 3.023, p < 0.05).

CONCLUSIONS

The occurrence of NHADKD may be related to the levels of homocysteine, total-Chol, HDL-Chol, and Lip-PLA2 in blood. Among them, homocysteine may be most closely related to NHADKD.

Subtypes of Type 2 Diabetes Determined From Clinical Parameters

Type 2 diabetes (T2D) is defined by a single metabolite, glucose, but is increasingly recognized as a highly heterogeneous disease, including individuals with varying clinical characteristics, disease progression, drug response, and risk of complications. Identification of subtypes with differing risk profiles and disease etiologies at diagnosis could open up avenues for personalized medicine and allow clinical resources to be focused to the patients who would be most likely to develop diabetic complications, thereby both improving patient health and reducing costs for the health sector. More homogeneous populations also offer increased power in experimental, genetic, and clinical studies. Clinical parameters are easily available and reflect relevant disease pathways, including the effects of both genetic and environmental exposures. We used six clinical parameters (GAD autoantibodies, age at diabetes onset, HbA_1c, BMI, and measures of insulin resistance and insulin secretion) to cluster adult-onset diabetes patients into five subtypes. These subtypes have been robustly reproduced in several populations and associated with different risks of complications, comorbidities, genetics, and response to treatment. Importantly, the group with severe insulin-deficient diabetes (SIDD) had increased risk of retinopathy and neuropathy, whereas the severe insulin-resistant diabetes (SIRD) group had the highest risk for diabetic kidney disease (DKD) and fatty liver, emphasizing the importance of insulin resistance for DKD and hepatosteatosis in T2D. In conclusion, we believe that subclassification using these highly relevant parameters could provide a framework for personalized medicine in diabetes.

Role of Sphingolipid Signaling in Glomerular Diseases: Focus on DKD and FSGS

Sphingolipids are well-recognized as major players in the pathogenesis of many human diseases, including chronic kidney disease. The kidney is a very sensitive organ to alterations in sphingolipid metabolism. The critical issues to be addressed in this review relate to the role of sphingolipids and enzymes involved in sphingolipid metabolism in the pathogenesis of glomerular diseases with a special focus on podocytes, a key cellular component of the glomerular filtration barrier. Among several sphingolipids, we will highlight the role of ceramide, sphingosine, sphingosine-1-phosphate and ceramide-1-phosphate. Additionally, we will summarize the current knowledge with regard to the use of sphingolipids as therapeutic agents for the treatment of podocyte injury in kidney disease.

Sirt6 deficiency aggravates angiotensin II-induced cholesterol accumulation and injury in podocytes

Disturbed renal lipid metabolism, especially cholesterol dysregulation plays a crucial role in the pathogenesis of chronic kidney disease (CKD). We recently reported that angiotensin (Ang) II could induce cholesterol accumulation and injury in podocytes. However, the underlying mechanisms for these alterations remain unknown. Methods: Bioinformatics analysis of renal biopsy specimens from patients with hypertensive nephropathy (HN) suggests the involvement of Sirtuin 6 (Sirt6) in Ang II-induced dysregulation of glomerular cholesterol. Using a podocyte-specific Sirt6 knockout mouse model, the effects of Sirt6 on Ang II-induced cholesterol accumulation in podocytes and the therapeutic efficacies of cholesterol-lowering agents were evaluated. Results: Cholesterol accumulation was detected in the podocytes of Ang II-infused mice, whereas selective deletion of Sirt6 in podocytes not only increased cholesterol accumulation in these cells but also exacerbated Ang II-induced kidney injury. Deletion of Sirt6 also attenuated the protective effect of cyclodextrin (CD) on Ang II-induced urinary albumin excretion, glomerulosclerosis and podocyte injury. In addition, we demonstrated that Sirt6 affected cholesterol efflux in podocytes by regulating the expression of ATP-binding cassette transporter G1 (ABCG1). Conclusions: These findings provide evidence that Sirt6 is a potential target for renin-angiotensin system (RAS)-associated podocyte injury and provide a rationale for the application of cholesterol-lowering agents in patients with CKD.

Modulation of radiation-induced damage of human glomerular endothelial cells by SMPDL3B

The intracellular molecular pathways involved in radiation-induced nephropathy are still poorly understood. Glomerular endothelial cells are key components of the structure and function of the glomerular filtration barrier but little is known about the mechanisms implicated in their injury and repair. The current study establishes the response of immortalized human glomerular endothelial cells (GEnC) to ionizing radiation (IR). We investigated the role of sphingolipids and the lipid-modifying enzyme sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b) in radiation-induced GEnC damage. After delivering a single dose of radiation, long and very-long-chain ceramide species, and the expression levels of SMPDL3b were elevated. In contrast, levels of ceramide-1-phosphate (C1P) dropped in a time-dependent manner although mRNA and protein levels of ceramide kinase (CERK) remained stable. Treatment with C1P or knocking down SMPDL3b partially restored cell survival and conferred radioprotection. We also report a novel role for the NADPH oxidase enzymes (NOXs), namely NOX1, and NOX-derived reactive oxygen species (ROS) in radiation-induced GEnC damage. Subjecting cultured endothelial cells to radiation was associated with increased NOX activity and superoxide anion generation. Silencing NOX1 using NOX1-specific siRNA mitigated radiation-induced oxidative stress and cellular injury. In addition, we report a novel connection between NOX and SMPDL3b. Treatment with the NOX inhibitor, GKT, decreased radiation-induced cellular injury and restored SMPDL3b basal levels of expression. Our findings indicate the importance of SMPDL3b as a potential therapeutic target in radiation-induced kidney damage.

Lipotoxicity and Diabetic Nephropathy: Novel Mechanistic Insights and Therapeutic Opportunities

Lipotoxicity is characterized by the ectopic accumulation of lipids in organs different from adipose tissue. Lipotoxicity is mainly associated with dysfunctional signaling and insulin resistance response in non-adipose tissue such as myocardium, pancreas, skeletal muscle, liver, and kidney. Serum lipid abnormalities and renal ectopic lipid accumulation have been associated with the development of kidney diseases, in particular diabetic nephropathy. Chronic hyperinsulinemia, often seen in type 2 diabetes, plays a crucial role in blood and liver lipid metabolism abnormalities, thus resulting in increased non-esterified fatty acids (NEFA). Excessive lipid accumulation alters cellular homeostasis and activates lipogenic and glycogenic cell-signaling pathways. Recent evidences indicate that both quantity and quality of lipids are involved in renal damage associated to lipotoxicity by activating inflammation, oxidative stress, mitochondrial dysfunction, and cell-death. The pathological effects of lipotoxicity have been observed in renal cells, thus promoting podocyte injury, tubular damage, mesangial proliferation, endothelial activation, and formation of macrophage-derived foam cells. Therefore, this review examines the recent preclinical and clinical research about the potentially harmful effects of lipids in the kidney, metabolic markers associated with these mechanisms, major signaling pathways affected, the causes of excessive lipid accumulation, and the types of lipids involved, as well as offers a comprehensive update of therapeutic strategies targeting lipotoxicity.