High Glucose-Aggravated Hepatic Insulin Resistance: Role of the NLRP3 Inflammasome in Kupffer Cells

Glycated haemoglobin is a major predictor of disease severity in patients with NAFLD

OBJECTIVES

Currently, non-invasive scoring systems to stage the severity of non-alcoholic fatty liver disease (NAFLD) do not consider markers of glucose control (glycated haemoglobin, HbA1c); this study aimed to define the relationship between HbA1c and NAFLD severity in patients with and without type 2 diabetes.

RESEARCH DESIGN AND METHODS

Data were obtained from 857 patients with liver biopsy staged NAFLD. Generalized-linear models and binomial regression analysis were used to define the relationships between histological NAFLD severity, age, HbA1c, and BMI. Paired biopsies from interventional studies (n = 421) were used to assess the impact of change in weight, HbA1c and active vs. placebo treatment on improvements in steatosis, non-alcoholic steatohepatitis (NASH), and fibrosis.

RESULTS

In the discovery cohort (n = 687), risk of severe steatosis, NASH and advanced fibrosis correlated positively with HbA1c, after adjustment for obesity and age. These data were endorsed in a separate validation cohort (n = 170). Predictive modelling using HbA1c and age was non-inferior to the established non-invasive biomarker, Fib-4, and allowed the generation of HbA1c, age, and BMI adjusted risk charts to predict NAFLD severity. Following intervention, reduction in HbA1c was associated with improvements in steatosis and NASH after adjustment for weight change and treatment, whilst fibrosis change was only associated with weight change and treatment.

CONCLUSIONS

HbA1c is highly informative in predicting NAFLD severity and contributes more than BMI. Assessments of HbA1c must be a fundamental part of the holistic assessment of patients with NAFLD and, alongside age, can be used to identify patients with highest risk of advanced disease.

The role and mechanism of NLRP3 in wasp venom-induced acute kidney injury

BACKGROUND

Inflammation and pyroptosis have crucial impacts on the development of acute kidney injury (AKI) and have been validated in a variety of existing AKI animal models. However, the mechanisms underlying wasp venom-induced AKI are still unclear. The involvement of nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) in some mouse models of AKI has been extensively documented, and its crucial function in controlling inflammation and pyroptosis has been highlighted. The objective of our study was to investigate the role and mechanism of NLRP3 in inflammation and pyroptosis associated with wasp venom-induced AKI.

METHODS

A mouse model of AKI induced by wasp venom pre-injected with an NLRP3 inhibitor was used to study the role and mechanism of NLRP3. To verify the importance of NLRP3, western blotting was performed to assess the expression of NLRP3, caspase-1 p20, and gasdermin D (GSDMD)-N. Additionally, quantitative real-time polymerase was used to determine the expression of NLRP3, caspase-1, and GSDMD. Furthermore, enzyme-linked immunosorbent assay was utilized to measure the levels of interleukin (IL)-1β and IL-18.

RESULTS

NLRP3 was found to be the downstream signal of the stimulator of interferon genes in the wasp sting venom-induced AKI model. The administration of wasp venom in mice significantly upregulated the expression of NLRP3, leading to renal dysfunction, inflammation, and pyroptosis. Treatment with an NLRP3 inhibitor reversed the renal damage induced by wasp venom and attenuated pathological injury, inflammatory response, and pyroptosis.

CONCLUSION

NLRP3 activation is associated with renal failure, inflammatory response and pyroptosis in the hyper early phase of wasp venom-induced AKI. The inhibition of NLRP3 significantly weakened this phenomenon. These findings could potentially offer a viable therapeutic approach for AKI triggered by wasp venom.

Protective Effects of Sitagliptin on Streptozotocin-Induced Hepatic Injury in Diabetic Rats: A Possible Mechanisms

Diabetes is a ubiquitous disease that causes several complications. It is associated with insulin resistance, which affects the metabolism of proteins, carbohydrates, and fats and triggers liver diseases such as fatty liver disease, steatohepatitis, fibrosis, and cirrhosis. Despite the effectiveness of Sitagliptin (ST) as an antidiabetic drug, its role in diabetes-induced liver injury is yet to be fully investigated. Therefore, this study aims to investigate the effect of ST on hepatic oxidative injury, inflammation, apoptosis, and the mTOR/NF-κB/NLRP3 signaling pathway in streptozotocin (STZ)-induced liver injury. Rats were allocated into four groups: two nondiabetic groups, control rats and ST rats (100 mg/kg), and two diabetic groups induced by STZ, and they received either normal saline or ST for 90 days. Diabetic rats showed significant hyperglycemia, hyperlipidemia, and elevation in liver enzymes. After STZ induction, the results revealed remarkable increases in hepatic oxidative stress, inflammation, and hepatocyte degeneration. In addition, STZ upregulated the immunoreactivity of NF-κB/p65, NLRP3, and mTOR but downregulated IKB-α in liver tissue. The use of ST mitigated metabolic and hepatic changes induced by STZ; it also reduced oxidative stress, inflammation, and hepatocyte degeneration. The normal expression of NF-κB/p65, NLRP3, mTOR, and IKB-α were restored with ST treatment. Based on that, our study revealed for the first time the hepatoprotective effect of ST that is mediated by controlling inflammation, oxidative stress, and mTOR/NF-κB/NLRP3 signaling.

Research progress of NLRP3 inflammasome and its inhibitors with aging diseases

In recent years, a new target closely linked to a variety of diseases has appeared in the researchers' vision, which is the NLRP3 inflammasome. With the deepening of the study of NLRP3 inflammasome, it was found that it plays an extremely important role in a variety of physiological pathological processes, and NLRP3 inflammasome was also found to be associated with some age-related diseases. It is associated with the development of insulin resistance, Alzheimer's disease, Parkinson's, cardiovascular aging, hearing and vision loss. At present, the only clinical approach to the treatment of NLRP3 inflammasome-related diseases is to use anti-IL-1β antibodies, but NLRP3-specific inhibitors may be better than the IL-1β antibodies. This article reviews the relationship between NLRP3 inflammasome and aging diseases: summarizes some of the relevant experimental results reported in recent years, and introduces the biological signals or pathways closely related to the NLRP3 inflammasome in a variety of aging diseases, and also introduces some promising small molecule inhibitors of NLRP3 inflammasome for clinical treatment, such as: ZYIL1, DFV890 and OLT1177, they have excellent pharmacological effects and good pharmacokinetics.

Açaí berry ameliorates cognitive impairment by inhibiting NLRP3/ASC/CASP axis in STZ-induced diabetic neuropathy in mice

Diabetes complications such as diabetic peripheral neuropathy (DPN) are linked to morbidity and mortality. Peripheral nerve damages in DPN are accompanied by discomfort, weakness, and sensory loss. Some drugs may demonstrate their therapeutic promise by reducing neuroinflammation, but they have side effects. Based on these considerations, the objective of this study was to examine the beneficial properties of açaí berry in a mouse model of DPN generated by injection of streptozotocin (STZ). Açaí berry was given orally to diabetic and control mice every day beginning 2 wk after STZ injection. The animals were euthanized after 16 wk, and tissues from the spinal cord and sciatic nerve and urine were taken. Our findings showed that daily treatment of açaí berry at a dose of 500 mg/kg was able to prevent behavioral changes as well as mast cell activation and nerve deterioration via NOD-like receptor family pyrin-domain-containing-3 (NLRP3)/apoptosis-associated speck-like protein containing a card (ASC)/caspase (CASP) regulation after diabetes induction.NEW & NOTEWORTHY Our research shows that açaí berry reduces mast cells degranulation and histological damage in diabetic neuropathy, improves physiological defense against reactive oxygen species, modulates the NLRP3/ASC/CASP axis, and ameliorates inflammation and oxidative stress. Diet could help treatment for diabetic peripheral neuropathy.

Role of NLRP3 inflammasome and oxidative stress in hepatic insulin resistance and the ameliorative effect of phytochemical intervention

NLRP3 inflammasome has a key role in chronic low-grade metabolic inflammation, and its excessive activation may contribute to the beginning and progression of several diseases, including hepatic insulin resistance (hIR). Thus, this review aims to highlight the role of NLRP3 inflammasome and oxidative stress in the development of hIR and evidence related to phytochemical intervention in this context. In this review, we will address the hIR pathogenesis related to reactive oxygen species (ROS) production mechanisms, involving oxidized mitochondrial DNA (ox-mtDNA) and thioredoxin interacting protein (TXNIP) induction in the NLRP3 inflammasome activation. Moreover, we discuss the inhibitory effect of bioactive compounds on the insulin signaling pathway, and the role of microRNAs (miRNAs) in the phytochemical target mechanism in ameliorating hIR. Although most of the research in the field has been focused on evaluating the inhibitory effect of phytochemicals on the NLRP3 inflammasome pathway, further investigation and clinical studies are required to provide insights into the mechanisms of action, and, thus, encourage the use of these bioactive compounds as an additional therapeutic strategy to improve hIR and correlated conditions.

Antioxidant hepatic lipid metabolism can be promoted by orally administered inorganic nanoparticles

Accumulation of inorganic nanoparticles in living organisms can cause an increase in cellular reactive oxygen species (ROS) in a dose-dependent manner. Low doses of nanoparticles have shown possibilities to induce moderate ROS increases and lead to adaptive responses of biological systems, but beneficial effects of such responses on metabolic health remain elusive. Here, we report that repeated oral administrations of various inorganic nanoparticles, including TiO₂, Au, and NaYF₄ nanoparticles at low doses, can promote lipid degradation and alleviate steatosis in the liver of male mice. We show that low-level uptake of nanoparticles evokes an unusual antioxidant response in hepatocytes by promoting Ces2h expression and consequently enhancing ester hydrolysis. This process can be implemented to treat specific hepatic metabolic disorders, such as fatty liver in both genetic and high-fat-diet obese mice without causing observed adverse effects. Our results demonstrate that low-dose nanoparticle administration may serve as a promising treatment for metabolic regulation.

Salidroside protects pancreatic β-cells against pyroptosis by regulating the NLRP3/GSDMD pathway in diabetic conditions

The NACHT, LRP, and PYD domains-containing protein 3 (NLRP3) inflammasome-evoked chronic inflammation is involved in the pathogenesis of diabetes mellitus (DM), and the NLRP3/gasdermin D (GSDMD)-mediated canonical pathway of pyroptosis leads to the loss of pancreatic β-cells and failure of pancreatic function in DM. A previous study demonstrated that salidroside (SAL) alleviates the pathological hyperplasia of pancreatic β-cells in db/db mice. However, it is not clear whether the NLRP3/GSDMD pathway-mediated pyroptosis can be regulated by SAL. In addition, the action of SAL on pancreatic β-cells in DM remains poorly understood. Thus, this study aimed to investigate the effects and underlying mechanisms of SAL on pancreatic β-cell pyroptosis. Rat insulinoma (INS-1) cells were cultured in a medium containing either high glucose (HG) or HG plus high insulin (HG-HI), and the effects of SAL on cell viability, AMP-activated protein kinase (AMPK) activity, reactive oxygen species (ROS) generation, NLRP3/GSDMD activation, and pyroptotic body formation were assessed. Streptozocin-induced DM mice were used to further investigate the effects of SAL on pancreatic pyroptosis. The results revealed aberrances on cell viability, AMPK activity, ROS generation, NLRP3/GSDMD activation, and pyroptotic body formation in HG- and HG-HI-exposed INS-1 cells; these abnormal effects were corrected by SAL in both a concentration- and AMPK-dependent manner. Moreover, SAL administration activated AMPK, suppressed NLRP3/GSDMD signaling, and protected pancreatic β-cells against pyroptosis in DM mice. These findings suggest that SAL promotes AMPK activation to suppress NLRP3/GSDMD-related pyroptosis in pancreatic β-cells under DM conditions.

Linking nutrient sensing, mitochondrial function, and PRR immune cell signaling in liver disease

Caloric overconsumption in vertebrates promotes adipose and liver fat accumulation while perturbing the gut microbiome. This triad triggers pattern recognition receptor (PRR)-mediated immune cell signaling and sterile inflammation. Moreover, immune system activation perpetuates metabolic consequences, including the progression of nonalcoholic fatty liver disease (NAFLD) to nonalcoholic hepatic steatohepatitis (NASH). Recent findings show that sensing of nutrient overabundance disrupts the activity and homeostasis of the central cellular energy-generating organelle, the mitochondrion. In parallel, whether caloric excess-initiated PRR signaling and mitochondrial perturbations are coordinated to amplify this inflammatory process in NASH progression remains in question. We hypothesize that altered mitochondrial function, classic PRR signaling, and complement activation in response to nutrient overload together play an integrated role across the immune cell landscape, leading to liver inflammation and NASH progression.

Aqueous extract of Scrophularia ningpoensis improves insulin sensitivity through AMPK-mediated inhibition of the NLRP3 inflammasome

BACKGROUND

Scrophularia ningpoensis Hemsl. is a commonly used medicinal plant in China for the treatment of diabetes mellitus (DM), but its mechanism of action remains poorly described. Type 2 diabetes mellitus (T2DM) accounts for > 90% of all DM cases and is characterized by insulin resistance.

PURPOSE

The aim of this study was to investigate whether the insulin sensitivity can be improved by treatment with aqueous extract of S. ningpoensis (AESN) and further explore its mechanism(s) of activity.

METHODS

Primary mouse hepatocytes and human HepG2 hepatocytes were used to investigate the effects of AESN on cell viability, AMP-activated protein kinase (AMPK) activation and glucose output under normal culture conditions. To mimic hyperglycemia and insulin resistance in vitro, hepatocytes were exposed to high glucose (HG), and the influences of AESN on AMPK phosphorylation, NLRP3 inflammation activation, insulin signaling, lipid accumulation and glucose output were investigated. Increasing doses of AESN (50, 100 and 200 mg/kg/day) were administered by gavage to db/db mice for 8 weeks, and then biochemical analysis and histopathological examinations were performed.

RESULTS

AESN significantly activated AMPK and inhibited glucose output in hepatocytes, but did not impact cell viability under normal culture conditions. Moreover, in HG-treated hepatocytes, AESN protected against aberrant AMPK activity, NLRP3 inflammasome activation, insulin signaling, and lipid accumulation. AMPK inhibition abolished the regulatory effects of AESN on the NLRP3 inflammasome, insulin signaling, lipid accumulation, and glucose output of hepatocytes following HG exposure. Furthermore, AESN administration reduced blood glucose and serum insulin levels, improved lipid profiles and insulin resistance, and corrected the aberrant AMPK activity and NLRP3 inflammasome activation in liver tissues.

CONCLUSION

AESN improves insulin sensitivity via AMPK-mediated NLRP3 inflammasome inhibition.

Cell-specific Deletion of NLRP3 Inflammasome Identifies Myeloid Cells as Key Drivers of Liver Inflammation and Fibrosis in Murine Steatohepatitis

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide. The NLRP3 inflammasome, a platform for caspase-1 activation and release of interleukin 1β, is increasingly recognized in the induction of inflammation and liver fibrosis during NAFLD. However, the cell-specific contribution of NLRP3 inflammasome activation in NAFLD remains unknown.

METHODS

To investigate the role of NLRP3 inflammasome activation in hepatocytes, hepatic stellate cells (HSCs) and myeloid cells, a conditional Nlrp3 knock-out mouse was generated and bred to cell-specific Cre mice. Both acute and chronic liver injury models were used: lipopolysaccharide/adenosine-triphosphate to induce in vivo NLRP3 activation, choline-deficient, L-amino acid-defined high-fat diet, and Western-type diet to induce fibrotic nonalcoholic steatohepatitis (NASH). In vitro co-culture studies were performed to dissect the crosstalk between myeloid cells and HSCs.

RESULTS

Myeloid-specific deletion of Nlrp3 blunted the systemic and hepatic increase in interleukin 1β induced by lipopolysaccharide/adenosine-triphosphate injection. In the choline-deficient, L-amino acid-defined high-fat diet model of fibrotic NASH, myeloid-specific Nlrp3 knock-out but not hepatocyte- or HSC-specific knock-out mice showed significant reduction in inflammation independent of steatosis development. Moreover, myeloid-specific Nlrp3 knock-out mice showed ameliorated liver fibrosis and decreased HSC activation. These results were validated in the Western-type diet model. In vitro co-cultured studies with human cell lines demonstrated that HSC can be activated by inflammasome stimulation in monocytes, and this effect was significantly reduced if NLRP3 was downregulated in monocytes.

CONCLUSIONS

The study provides new insights in the cell-specific role of NLRP3 in liver inflammation and fibrosis. NLRP3 inflammasome activation in myeloid cells was identified as crucial for the progression of NAFLD to fibrotic NASH. These results may have implications for the development of cell-specific strategies for modulation of NLRP3 activation for treatment of fibrotic NASH.

Pyroptosis and inflammasomes in diabetic wound healing

Diabetic wound is one of the complications of diabetes and is not easy to heal. It often evolves into chronic ulcers, and severe patients will face amputation. Compared with normal wounds, diabetic wounds have an increased proportion of pro-inflammatory cytokines that are detrimental to the normal healing response. The burden of this disease on patients and healthcare providers is overwhelming, and practical solutions for managing and treating diabetic wounds are urgently needed. Pyroptosis, an inflammatory type of programmed cell death, is usually triggered by the inflammasome. The pyroptosis-driven cell death process is primarily mediated by the traditional signaling pathway caused by caspase -1 and the non-classical signaling pathways induced by caspase -4/5/11. Growing evidence that pyroptosis promotes diabetic complications, including diabetic wounds. In addition, inflammation is thought to be detrimental to wound healing. It is worth noting that the activation of the NLRP3 inflammasome plays a crucial role in the recovery of diabetic wounds. This review has described the mechanisms of pyroptosis-related signaling pathways and their impact on diabetic wounds. It has discussed new theories and approaches to promote diabetic wound healing, as well as some potential compounds targeting pyroptosis and inflammasome signaling pathways that could be new approaches to treating diabetic wounds.

Salidroside Suppresses the Proliferation and Migration of Human Lung Cancer Cells through AMPK-Dependent NLRP3 Inflammasome Regulation

Inflammatory reactions mediated by the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome contributes to non-small-cell lung cancer (NSCLC) progression, particularly in patients with bacterial infections. Salidroside (SAL) has recently been shown to suppress lipopolysaccharide- (LPS-) induced NSCLC proliferation and migration, but its mechanism of action remains unclear. It has been shown that SAL improves metabolic inflammation in diabetic rodents through AMP-activated protein kinase- (AMPK-) dependent inhibition of the NLRP3 inflammasome. However, whether the NLRP3 inflammasome is regulated by SAL in NSCLC cells and how its underlying mechanism(s) can be determined require clarification. In this study, human lung alveolar basal carcinoma epithelial (A549) cells were treated with LPS, and the effects of SAL on cell proliferation, migration, AMPK activity, reactive oxygen species (ROS) production, and NLRP3 inflammasome activation were investigated. We found that LPS induction increases the proliferation and migration of A549 cells which was suppressed by SAL. Moreover, SAL protected A549 cells against LPS-induced AMPK inhibition, ROS production, and NLRP3 inflammasome activation. Blocking AMPK using Compound C almost completely suppressed the beneficial effects of SAL. In summary, these results indicate that SAL suppresses the proliferation and migration of human lung cancer cells through AMPK-dependent NLRP3 inflammasome regulation.

Bletilla striata Polysaccharide Promotes Diabetic Wound Healing Through Inhibition of the NLRP3 Inflammasome

The aim of this study was to evaluate the therapeutic effects of Bletilla striata polysaccharide (BSP) on wound healing in diabetes mellitus (DM) and to explore the underlying mechanisms. DM mouse models were induced by high fat-diet feeding combined with low-dose streptozocin injection. To establish diabetic foot ulcer (DFU) models, DM mice were wounded on the dorsal surface. Subsequently, mice were treated with vehicle or BSP for 12 days and wound healing was monitored. The effects of BSP on the production of interleukin-1β (IL-1β), tumor necrosis factor-α, macrophages infiltration, angiogenesis, the activation of nucleotide-binding and oligomerization (NACHT) domain, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome, and insulin sensitivity in wound tissues were subsequently evaluated. Separated- and cultured- bone marrow-derived macrophages (BMDMs) and cardiac microvascular endothelial cells (CMECs) were isolated from mice and used to investigate the effects of BSP on cell viability, reactive oxygen species (ROS) generation, NLRP3 inflammasome activation and insulin sensitivity in vitro following exposure to high glucose (HG). BSP administration accelerated diabetic wound healing, suppressed macrophage infiltration, promoted angiogenesis, suppressed NLRP3 inflammasome activation, decreased IL-1β secretion, and improved insulin sensitivity in wound tissues in DM mice. In vitro, co-treatment with BSP protected against HG-induced ROS generation, NLRP3 inflammasome activation, and IL-1β secretion in BMDMs, and improved cell viability and decreased ROS levels in CMECs. Moreover, in HG exposed BMDMs-CMECs cultures, BSP treatment suppressed NLRP3 inflammasome activation and IL-1β secretion in BMDMs, and improved cell viability and insulin sensitivity in CMECs. Furthermore, treatment with IL-1β almost completely suppressed the beneficial effects of BSP on the NLRP3 inflammasome, IL-1β secretion, and insulin sensitivity in HG-treated BMDMs-CMECs. BSP promotes DFU healing through inhibition of the HG-activated NLRP3 inflammasome.

Salidroside alleviates diabetic neuropathic pain through regulation of the AMPK-NLRP3 inflammasome axis

High glucose (HG)-induced nucleotide-binding and oligomerization (NACHT) domain, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome activation leads to diabetic neuropathic pain. We recently showed that salidroside could suppress NLRP3 inflammasome activation in hepatocytes exposed to HG. The aim of this study was to evaluate the analgesic effect of salidroside on diabetic rats and to explore its underlying mechanisms. Rat models with diabetic neuropathic pain were induced by high-fat diet feeding combined with low dose streptozotocin injections. Doses of salidroside at 50 and 100 mg.kg-1.day-1 were administered by gavage to diabetic rats for 6 weeks. Mechanical allodynia test, thermal hyperalgesia test and biochemical analysis were performed to evaluate therapeutic effects. Primary dorsal root ganglion (DRG) cells exposed to HG at 45 mM were used to further study the effects of salidroside on the AMP-activated protein kinase (AMPK)-NLRP3 inflammasome axis and insulin sensitivity in vitro. Salidroside administration improved hyperglycemia, ameliorated insulin resistance, and alleviated neuropathic pain in diabetic rats. Moreover, salidroside induced AMPK activation and suppressed NLRP3 inflammasome activation in the DRGs of diabetic rats. In addition, salidroside treatment relieved oxidative stress, improved insulin sensitivity and regulated the AMPK-NLRP3 inflammasome axis in HG-treated DRGs in vitro. Furthermore, AMPK inhibition in vivo or AMPK silencing in vitro abolished the beneficial effects of salidroside on diabetic neuropathic pain. Together, these results indicate that salidroside alleviates diabetic neuropathic pain through its regulation of the AMPK-NLRP3 inflammasome axis in DRGs.

Adipose tissue and insulin resistance in obese

Currently, obesity has become a global health issue and is referred to as an epidemic. Dysfunctional obese adipose tissue plays a pivotal role in the development of insulin resistance. However, the mechanism of how dysfunctional obese-adipose tissue develops insulin-resistant circumstances remains poorly understood. Therefore, this review attempts to highlight the potential mechanisms behind obesity-associated insulin resistance. Multiple risk factors are directly or indirectly associated with the increased risk of obesity; among them, environmental factors, genetics, aging, gut microbiota, and diets are prominent. Once an individual becomes obese, adipocytes increase in their size; therefore, adipose tissues become larger and dysfunctional, recruit macrophages, and then these polarize to pro-inflammatory states. Enlarged adipose tissues release excess free fatty acids (FFAs), reactive oxygen species (ROS), and pro-inflammatory cytokines. Excess systemic FFAs and dietary lipids enter inside the cells of non-adipose organs such as the liver, muscle, and pancreas, and are deposited as ectopic fat, generating lipotoxicity. Toxic lipids dysregulate cellular organelles, e.g., mitochondria, endoplasmic reticulum, and lysosomes. Dysregulated organelles release excess ROS and pro-inflammation, resulting in systemic inflammation. Long term low-grade systemic inflammation prevents insulin from its action in the insulin signaling pathway, disrupts glucose homeostasis, and results in systemic dysregulation. Overall, long-term obesity and overnutrition develop into insulin resistance and chronic low-grade systemic inflammation through lipotoxicity, creating the circumstances to develop clinical conditions. This review also shows that the liver is the most sensitive organ undergoing insulin impairment faster than other organs, and thus, hepatic insulin resistance is the primary event that leads to the subsequent development of peripheral tissue insulin resistance.