Decreased Expression Of MCP-1 Research Articles

Kidney targeting and modulating macrophage polarization through AMPK signaling: Therapeutic mechanism of berberine in uric acid nephropathy

Uric acid nephropathy (UAN), caused by a common metabolic disorder resulting from hyperuricemia (HUA), has an increasing incidence. Previous studies have shown that berberine (BBR) has clear urate-lowering and anti-inflammatory effects in UAN mice, but its mechanism needs to be further clarified. Therefore, Potassium Oxonate (PO) combined with hypoxanthine (HX) induced UAN mice model and MSU induced THP-1 cells polarization model were adopted to investigate the mechanism of BBR on UAN in terms of tissue distribution and molecular pharmacology. Study unveiled that BBR was first found to bind to red blood cells (RBCs), which were recognized and phagocytosed by monocytes, then recruited by the injured kidney. Subsequently, BBR was enriched and functional in damaged kidney. The results of in vivo experiments revealed that, BBR reduced UA, BUN, CRE levels as well as the release of TNF-α, IL-1β, IL-18 and IL-6, and alleviated renal injury in UAN mice, as consistent with previous studies. Additionally, BBR decreased MCP-1 expression, while diminishing macrophage infiltration and decreasing M1 proportion as determined by RT-qPCR. In vitro experiments, demonstrated that MSU promoted inflammatory polarization of THP-1 cells, while BBR reduced synthesis of inflammatory factors and inhibited MSU-induced inflammatory polarization. These effects of BBR were dependent on AMPK activation along with indirect inhibition of NF-κB signaling pathway mediated. However, the anti-inflammatory and macrophage polarization regulation effects of BBR were completely reversed upon administration of Compound C, an AMPK inhibitor. Therefore, BBR ameliorated kidney injury via regulating macrophage polarization through AMPK, which has therapeutic potential for UAN patients.

Baicalein inhibits IL-1β-induced extracellular matrix degradation with decreased MCP-1 expression in primary rat chondrocytes.

The online version contains supplementary material available at 10.1007/s43188-024-00225-4.

Abstract 056: Knockout of Dual-Specificity Protein Phosphatase 5 Protects Against Hypertension Induced Chronic Kidney Disease

Dual-specificity protein phosphatase 5 (Dusp5) is a member of serine-threonine phosphatase family that regulates intracellular signal transduction by dephosphorylating ERK1/2. We previously generated Dusp5 zinc-finger knockout (KO) rats and found that KO of Dusp5 enhances myogenic response of middle cerebral artery and autoregulation of cerebral blood flow. This study investigated whether Dusp5 KO also improves renal hemodynamics and protects against hypertension-induced chronic kidney disease (CKD). Renal tissue expression of Dusp5 was decreased and levels of phosphorylated ERK1/2 (p-ERK1/2) and p-PKC enhanced in KO rats. Blood pressure increased similarly to 180 mmHg in both WT and Dusp5 KO rats treated with DOCA/salt. KO of Dusp5 enhanced autoregulation of renal blood flow (RBF increased by 12.1 ± 4.1% vs. 32.7 ± 4.7% when MAP increased from 100 to 180 mmHg, p<0.05) and reduced renal vascular remodeling compared with WT rats (0.64±0.03 vs. 0.94±0.06 wall-to-lumen ratio, p<0.05). Improvement in renal hemodynamics in hypertensive Dusp5 KO vs. WT rats was associated with decreased proteinuria (226.71 ± 23.82 vs. 337.62 ± 30.41 mg/day, p<0.05) and protein cast formation in the renal corticomedullary region (1.01 ± 0.17% vs. 2.4 ± 0.51%, p<0.05). The degree of glomerular injury was reduced (2.22 ± 0.04 vs. 3.12 ± 0.04, p<0.05) and nephrin expression was greater in hypertensive Dusp5 KO rats vs. WT rats. Hypertension-induced renal fibrosis was attenuated in Dusp5 KO rats (5.32 ± 0.6% vs. 9.90 ± 0.7%, p<0.01) in association with decreased MCP-1 expression, reduced ED-1 + macrophage infiltration, down-regulated TGF-β1 expression, and attenuated fibrosis-related epithelial-mesenchymal transition (EMT) in the kidney (decreased expression of α-SMA and vimentin, and increased expression of E-cadherin). In conclusion, these results indicate that KO of Dusp5 protects against hypertension-induced proteinuria and renal fibrosis by enhancing renal hemodynamics and reducing vascular remodeling, glomerular injury, macrophage infiltration, TGF-β1 expression and EMT in the kidney. Thus, targeting Dusp5 may offer a novel approach for treating or preventing hypertension-induced CKD.

Abstract WMP84: Immune Response Mediates Brain- Heart Interaction After Subarachnoid Hemorrhage

Background: Cardiac dysfunction is evident after Subarachnoid Hemorrhage (SAH). Patients with cardiovascular complications after SAH have 3.5 times increased risk of death compared with non-cardiac complication SAH patients. The immune system may contribute to the cardiac pathological processes post-SAH.This study investigates the possible role of the immune system in mediating cardiac dysfunction after SAH in mice. Methods: Adult male C57BL/6J mice were subjected to SAH model or sham-control. The experimental groups includes (n=15/group): 1) Sham-control; 2) SAH alone; 3) SAH+splenectomy (SAH+SP). Splenectomy was performed one week before SAH. Cardiac hemodynamics and function were measured by echocardiography at 3 days after SAH. The Garcia behavior score was performed . Mice were sacrificed at the third day after SAH. Cardiac tissue immunostaining (n=10/group) and flow cytometry (n=5/group) were performed. Results: We found that: 1) SAH alone induces significant neurological deficit and vasospasm compared to sham-control. SAH+SP significantly decrease neurological deficit, but no significant improvement in the vasospasm compared to SAH mice (p<0.05). 2) SAH mice exhibit significant cardiac dysfunction identified by a decline cardiac ejection fractions (EF) and fraction shortening (FS) compared to the sham. SAH+SP significantly improves cardiac function by increasing EF and FS compared to SAH mice (P<0.05). 3) SAH significantly increases inflammatory cells (CD11b+/CD45+/F480+ macrophages) infiltration into the heart compared to sham-control (p<0.05). The amount of macrophages within the heart tissue was significantly decreased in SAH+SP group when compared with the SAH group. 4) MCP1 expression in the heart was significantly increased in SAH group compared to sham; SAH+SP significantly decreased MCP1 expression compared to SAH (p<0.05). Conclusions: SAH induces cardiac dysfunction; SAH with splenectomy decreases heart inflammatory cell infiltration, inflammatory factor expression as well as decreases cardiac dysfunction after SAH. Immune response may play an important role in SAH-induced cardiac dysfunction.

Overexpression of Sirtuin2 prevents high glucose-induced vascular endothelial cell injury by regulating the p53 and NF-κB signaling pathways.

To investigate the potential role and underlying mechanism of Sirtuin2 (SIRT2) in regulating high glucose (HG)-induced vascular endothelial cell injury by using human umbilical vein endothelial cells (HUVECs). SIRT2 mRNA and protein expression levels were decreased in HG-treated HUVECs. SIRT2 overexpression increased viability, decreased apoptosis and reduced levels of reactive oxygen species in HG-treated HUVECs. SIRT2 overexpression decreased TNF-α expression (146.5±22.8pg TNF-α ml-1) relative to that in the empty vector group (263.5±18.5pg TNF-α ml-1) and decreased MCP-1 expression (63.8±9.85pg MCP-1ml-1) relative to that in the empty vector group (105.8±8.5pg MCP-1ml-1). SIRT2 overexpression decreased the acetylation of p53 by 33% and decreased the acetylation of NF-κB p65 by 58% in HG-treated HUVECs. SIRT2 prevents HG-induced vascular endothelial cell injury through suppressing the p53 and NF-κB signaling pathways.

Probucol plus cilostazol attenuate hypercholesterolemia‑induced exacerbation in ischemic brain injury via anti-inflammatory effects.

Probucol, a lipid-lowering agent with anti-oxidant properties, is involved in protection against atherosclerosis, while cilostazol, an antiplatelet agent, has diverse neuroprotective properties. In this study, we investigated the anti-inflammatory effects of probucol and cilostazol on focal cerebral ischemia with hypercholesterolemia. Apolipoprotein E (ApoE) knockout (KO) mice were fed a high-fat diet (HFD) with or without 0.3% probucol and/or 0.2% cilostazol for 10 weeks. To assess the protective effects of the combined therapy of probucol and cilostazol on ischemic injury, the mice received 40 min of middle cerebral artery occlusion (MCAO). Infarct volumes, neurobehavioral deficits and neuroinflammatory mediators were subsequently evaluated 48 h after reperfusion. Probucol alone and probucol plus cilostazol significantly decreased total- and low-density lipoprotein (LDL)-cholesterol in ApoE KO with HFD. MCAO resulted in significantly larger infarct volumes in ApoE KO mice provided with HFD compared to those fed a regular diet, although these volumes were significantly reduced in the probucol plus cilostazol group. Consistent with a smaller infarct size, probucol alone and the combined treatment of probucol and cilostazol improved neurological and motor function. In addition, probucol alone and probucol plus cilostazol decreased MCP-1 expression and CD11b and GFAP immunoreactivity in the ischemic cortex. These findings suggested that the inhibitory effects of probucol plus cilostazol in MCP-1 expression in the ischemic brain with hypercholesterolemia allowed the identification of one of the mechanisms responsible for anti-inflammatory action. Probucol plus cilostazol may therefore serve as a therapeutic strategy for reducing the impact of stroke in hypercholesterolemic subjects.

Daidzein regulates proinflammatory adipokines thereby improving obesity‐related inflammation through PPARγ

Daidzein was recently reported to act like an activator of peroxisome proliferator-activated receptor γ (PPARγ) thereby enhancing differentiation of adipocytes. Although PPARγ plays a role in adipokine expression, it has not been well researched whether daidzein affects expression of adipokines. This study aimed to clarify the effects of daidzein on proinflammatory adipokines and adipose inflammation causing insulin resistance in obesity. 3T3-L1 adipocytes were treated with daidzein or genistein. Diet-induced obese C57BL/6J mice were fed high-fat high-sucrose diets with daidzein (1.0 g/kg chow) for 12 wk. The results showed that both isoflavones, especially daidzein, stimulated adipogenic differentiation in 3T3-L1 adipocytes with the activation of PPARγ. Daidzein also increased adiponectin expression and decreased MCP-1 expression with the consistent regulation of their secretion. In obese mice, daidzein inhibited hypertrophy in fat cell size and improved insulin sensitivity, concomitant with upregulation of PPARγ in fat tissue. Decreased expression of MCP-1 and TNF-α, and increased expression of adiponectin were also observed in adipose tissue of daidzein-fed mice. Additionally, daidzein administration significantly inhibited macrophage accumulation in adipose tissue. Daidzein regulates adipokine expression through the PPARγ, thereby improving the adverse effects of adipose inflammation, such as insulin resistance, in obesity.

Anti-inflammatory and anti-thrombotic intervention strategies using atorvastatin, clopidogrel and knock-down of CD40L do not modify radiation-induced atherosclerosis in ApoE null mice

Background and purposeWe previously showed that irradiating the carotid arteries of ApoE−/− mice accelerated the development of macrophage-rich, inflammatory and thrombotic atherosclerotic lesions. In this study we investigated the potential of anti-inflammatory (atorvastatin, CD40L knockout) and anti-thrombotic (clopidogrel) intervention strategies to inhibit radiation-induced atherosclerosis. Material and methodsApoE−/− mice were given 0 or 14Gy to the neck and the carotid arteries were harvested at 4 or 28weeks after irradiation. Atorvastatin (15mg/kg/day) or clopidogrel (20mg/kg/day) was given in the chow; control groups received regular chow. Clopidogrel inhibited platelet aggregation by 50%. CD40L−/−/ApoE−/− and ApoE−/− littermates were also given 0 or 14Gy to the neck and the carotid arteries were harvested after 30weeks. ResultsClopidogrel decreased MCP-1 expression in the carotid artery at 4weeks after irradiation. Expression of VCAM-1, ICAM-1, thrombomodulin, tissue factor and eNOS was unchanged in atorvastatin and clopidogrel-treated mice. Neither drug inhibited either age-related or radiation-induced atherosclerosis. Furthermore, loss of the inflammatory mediator CD40L did not influence the development of age-related and radiation-induced atherosclerosis. ConclusionsThe effects of radiation-induced atherosclerosis could not be circumvented by these specific anti-inflammatory and anti-coagulant therapies. This suggests that more effective drug combinations may be required to overcome the radiation stimulus, or that other underlying mechanistic pathways are involved compared to age-related atherosclerosis.

Sphingosine-1-phosphate receptor-2 deficiency leads to inhibition of macrophage proinflammatory activities and atherosclerosis in apoE-deficient mice

Sphingosine-1-phosphate (S1P) is a biologically active sphingolipid that has pleiotropic effects in a variety of cell types including ECs, SMCs, and macrophages, all of which are central to the development of atherosclerosis. It may therefore exert stimulatory and inhibitory effects on atherosclerosis. Here, we investigated the role of the S1P receptor S1PR2 in atherosclerosis by analyzing S1pr2-/- mice with an Apoe-/- background. S1PR2 was expressed in macrophages, ECs, and SMCs in atherosclerotic aortas. In S1pr2-/-Apoe-/- mice fed a high-cholesterol diet for 4 months, the area of the atherosclerotic plaque was markedly decreased, with reduced macrophage density, increased SMC density, increased eNOS phosphorylation, and downregulation of proinflammatory cytokines compared with S1pr2+/+Apoe-/- mice. Bone marrow chimera experiments indicated a major role for macrophage S1PR2 in atherogenesis. S1pr2-/-Apoe-/- macrophages showed diminished Rho/Rho kinase/NF-κB (ROCK/NF-κB) activity. Consequently, they also displayed reduced cytokine expression, reduced oxidized LDL uptake, and stimulated cholesterol efflux associated with decreased scavenger receptor expression and increased cholesterol efflux transporter expression. S1pr2-/-Apoe-/- ECs also showed reduced ROCK and NF-κB activities, with decreased MCP-1 expression and elevated eNOS phosphorylation. Pharmacologic S1PR2 blockade in S1pr2+/+Apoe-/- mice diminished the atherosclerotic plaque area in aortas and modified LDL accumulation in macrophages. We conclude therefore that S1PR2 plays a critical role in atherogenesis and may serve as a novel therapeutic target for atherosclerosis.

Interferon‐gamma Induced Adipose Inflammation Linked to the Impairment of Vascular Function in Type 2 diabetic mice

We hypothesized that IFNγ induces inflammatory cell infiltration and chemoattractant gene expression in mesenteric adipose tissue (MAT) and impairs vascular function of mesenteric arteries (MA) of type 2 diabetic mice. Acetylcholine (ACh)‐induced vasodilation was impaired in Leprdb vs. m Leprdb, but sodium nitroprusside (SNP)‐induced vasodilation was comparable. Both anti‐IFNγ and anti‐MCP‐1 improved endothelial function in Leprdb, while IFNγ induced impaired vascular function in m Leprdb. Mesenteric bed weight and MAT adipocyte size were greatly elevated (P<0.05) in Leprdb vs. m Leprdb. Immunohistochemical staining results revealed that CD3‐positve T‐lymphocytes, Mac‐3 positive macrophages infiltration into the adventitia of small mesenteric arteries was significantly increased in Leprdb and IFNγ‐treated m Leprdb, suggesting the possible crosstalk between adipose inflammation and vascular dysfunction. Western blotting results showed that anti‐IFNγ decreased MAT IFNγ and MCP‐1 protein expression in Leprdb,while IFNγ and MCP‐1 expression was elevated in IFNγ‐treated m Leprdb. Anti‐MCP‐1 treatment only decreased MCP‐1 expression in Leprdb without affecting IFNγ levels, indicating that IFNγ may act as an initiator of MAT inflammation. These results suggest a role for IFNγ in the regulation of visceral adipose inflammatory response and vascular dysfunction in type 2 diabetes.

Abstract 5042: Interferon-gamma Induced Adipose Inflammation Linked to the Impairment of Vascular Function in Type 2 Diabetic Mice

Interferon-gamma (IFN) is the hallmark cytokine of Th1 cells and plays a major role in immuno-mediated inflammation in type 1 diabetes. However, the role of IFN in initiating adipose inflammation and subsequent vascular dysfunction in type 2 diabetes remains to be determined. Accordingly, we hypothesized that IFN induces inflammatory cell infiltration and chemoattractant gene expression in mesenteric adipose tissue (MAT) and impairs vascular function of small mesenteric arteries (MA) of type 2 diabetic mice. To test this, we studied MAT inflammation, and vascular function of MA in control mice (m Lepr db ), diabetic mice (Lepr db ), m Lepr db treated with IFN, Lepr db treated with anti-IFN or anti-monocyte chemoattractant protein (MCP)-1. Acetylcholine (ACh)-induced vasodilation was impaired in Lepr db vs. m Lepr db , but sodium nitroprusside (SNP)-induced vasodilation was comparable. Both anti-IFN and anti-MCP-1 improved endothelial function in Lepr db , while IFN induced impaired vascular function in m Lepr db . Mesenteric bed weight and MAT adipocyte size were greatly elevated (P<0.05) in Lepr db vs. m Lepr db . Immunohistochemical staining results revealed that CD3-positve T-lymphocytes, F4/80 and Mac-3 positive macrophage infiltration into MAT was markedly increased in Lepr db and IFN-treated m Lepr db . It showed reduced MAT macrophages infiltration in Lepr db treated with anti-IFN vs. Lepr db . Interestingly, Mac-3 positive macrophage infiltration into the adventitia of small mesenteric arteries was significantly increased in Lepr db and IFN-treated m Lepr db , suggesting the possible crosstalk between adipose inflammation and vascular dysfunction. Western blotting results showed that anti-IFN decreased MAT IFN and MCP-1 protein expression in Lepr db , while IFN and MCP-1 expression was elevated in IFN-treated m Lepr db . Anti-MCP-1 treatment only decreased MCP-1 expression in Lepr db without affecting IFN levels, indicating that IFN may act as an initiator of MAT inflammation and chemoattractant gene expression. These results suggest a role for IFN in the regulation of visceral adipose inflammatory response and vascular dysfunction in type 2 diabetes. This research has received full or partial funding support from the American Heart Association, Midwest Affiliate (Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, South Dakota & Wisconsin).