Monocyte chemoattractant protein 1 expression in renal tissue is associated w ith monocyte recruitment and tubulo-interstitial lesions in patients with lup us nephritis

Objective To investigate the pattern of monocyte chemoattractant prolein-1 (MCP-1) distribution in the renal interstitium and evaluate its pathogenic role in tubulo-interstitial lesions in patients with lupus nephritis, the distribution of MCP-1 in renal tissue was observed.Methods Eighteen female patients with biopsy-proven lupus nephritis were enrolled in this study. No intensive immunosuppresive therapy was used in these patients during the 3 months prior to renal biopsy. The distribution of MCP-1, infiltration of CD68+ (macrophage/monocyte), CD4+ and CD8+ cells in the tubulo-interstitium of patients with lupus nephritis was detected using immunohistochemical staining with specific antibodies. Renal specimens from patients with minimal change glomerulonephritis were used as controls. Results MCP-1 protein was widely distributed in the renal tissue of patients with lupus nephritis, mainly located at the baso-lateral surface of tubular epithelial cells (16/18 biopsies), and on the wall of interstitial blood vessels (9/18 biopsies). In contrast, tubular MCP-1 staining was weak and rare in renal tissue from controls (7.4±6.2% vs 26.7±22.8%, P<0.01). Tubulo-interstitial infiltration of CD68+, CD4+ and CD8+ cells was markedly increased in patients with lupus nephritis as compared to controls. The tubular expression of MCP-1 was strongly associated with the amount of CD68+ cell infiltration in the interstitium (r=0.5420, P<0.05) and the extent of interstitial fibrosis. There was no correlation between MCP-1 production in tubules and the degree of urinary protein excretion in patients with lupus nephritis (r=0.0547, P>0.05).Conclusions The expression of MCP-1 in the renal tubules and vascular wall was markedly increased in patients with lupus nephritis. The overproduction of MCP-1 in renal tissue may contribute to monocyte recruitment in the interstitium and thus result in tubulo-interstitial damage in lupus nephritis.

Interleukin-1β,Tumor Necrosis Factor-α and Lipopolysaccharide Induce Expression of Monocyte Chemoattractant Protein-1 in Calf Aortic Smooth Muscle Cells

Summary: To investigate whether interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS) induce expression of monocyte chemoattractant protein-1 (MCP-1 ) mRNA and protein in calf aortic smooth muscle cells(SMCs), calf aortic SMCs were cultured by a substrate-attached explant method. The cultured SMCs were used between the third to the fifth passage. After the cells became confluent, the SMCs were exposed to 2 ng/ml IL-1β, 20ng/ml TNF-1α and 100 ng/ml LPS respectively, and the total RNA of SMCs which were incubated for 4 h at 37℃ were extracted from the cells by using guanidinium isothiocyanate method. The expres- ion of MCP-1 mRNA in SMCs was detected by using dot blotting analysis using a probe of γ-32 P- end-labelled 35-mer oligonucleotide. After a 24-h incubation, the media conditioned by the cul- tured SMCs were collected. The MCP-1 protein content in the conditioned media was determined by using sandwich ELISA. The results were as follows: Dot blotting analysis showed that the cul- tured SMCs could express MCP-1 mRNA. After a 4-h exposure to IL-1β, TNF-α and LPS, the MCP-1 mRNA expression in SMCs was increased (3.6-fold, 2. 3-fold and 1. 6-fold, respectively). ELISA showed that the levels of MCP-1 protein in the conditioned media were also increased (2.9- fold, 1.7-fold and 1.1-fold, respectively). The results suggest that calf aortic SMCs could ex- press MCP-1 mRNA and protein. IL-1β and TNF-α can induce strong expression of MCP-1 mRNA and protein, and the former is more effective than the latter.

Olmesartan inhibits the expression of monocyte chemoattractant protein-1 and tumor necrosis factor-α and improves vascular remodeling after vascular injury in mouse

Objective: To investigate the neointima formation and the expression of monocyte chemoattractant protein 1 (MCP 1) and tumor necrosis factor α (TNF α) in cuff induced vascular injury in mouse model, and to examine the effect of angiotensin II type 1 receptor (AT 1) blocker, olmesartan, on MCP 1 and TNF α expression and consequently vascular remodeling. Methods: Vascular injury was induced by polyethylene cuff placement around the mouse femoral artery. Some mice were treated with AT 1 receptor blocker, olmesartan, at the dose of 3 mg·kg -1 ·day -1 with an osmotic minipump. Neointima formation and the proliferation of vascular smooth muscle cells (VSMCs) were measured by morphometric analysis and bromodeoxyuridine (BrdU) incorporation. MCP 1 and TNF α expression was detected by Western blot and immunohistochemical staining. Results: We observed neointima formation 14 days after cuff placement as well as VSMCs proliferation in the media and neointima. Cuff placement also induced MCP 1 and TNF α expression in the media and neointima that the VSMCs specifically existed. Treatment of mice with olmesartan at a dose of 3 mg·kg -1 ·day -1 , which did not influence systolic blood pressure, significantly decreased neointima formation and the proliferation of VSMCs. Olmesartan also inhibited MCP 1 and TNF α expression in the injured arteries. Conclusions: Our results demonstrate that blockade of AT 1 receptor inhibits MCP 1 and TNF α expression and thereby improves vascular remodeling.

Association of NFkB1 Gene Polymorphism with Inflammatory Markers in Patients of Type 2 Diabetes Mellitus with or without Renal Involvement in Eastern India

Aims: To evaluate the association of Nuclear factor kappa B1(NFkB1) gene polymorphism with inflammatory markers Urinary Monocyte Chemoattractant Protein 1 (UMCP1) and Tumor Necrosis Factor alfa (TNF alfa) in Patients of diabetes mellitus with or without renal involvement in Eastern India. Material and Methods: Consecutive Patients of Type 2 Diabetes Mellitus (DM) with or without microalbuminuria attending SCB MEDICAL COLLEGE and HOSPITAL Medical OPDs in between September 2018 to September 2019 were recruited in this study. Patients were subjected to blood and urine investigations. DNA extraction and Restriction fragment Length Polymorphism (RFLP) was done in Department of Biochemistry. Controls were unrelated healthy attendants with no history of Diabetes Mellitus, HTN, Chronic Kidney Disease (CKD). Results: Mean Systolic BP, Fasting Blood Glucose, Post Prandial Blood Glucose, HBA1c, Total Cholesterol were significantly higher in diabetes mellitus and diabetic nephropathy groups than control group. Estimated Glomerular Filtration Rate was significantly lower in diabetic nephropathy (p value < 0.001). UMCP1, Urinary Albumin Creatinine Ratio, TNF alfa were higher in diabetes mellitus and nephropathy with p value (<0.001, 0.006 < 0.001) respectively. In between DM and Diabetic Nephropathy groups nfkb1 gene expression, umcp1 and tnf alfa levels were significantly increased in Diabetic nephropathy with p value 0.019, <0.01, 0.001 respectively. Insertion/insertion NFkB1 gene polymorphisms were more in diabetic nephropathy group and were positively correlated with inflammatory markers UMCP1 (r = 0.517, p < 0.01) and TNF alfa (r = 0.172, p = 0.19). Conclusion: insertion/insertion NFkB1 gene polymorphism increases the risk of nephropathy by 2.52 times (OR = 2.52, 95% CI: 0.04 - 0.63, p value = 0.019) in diabetes patients in eastern India.

Spinal CCL2 Promotes Central Sensitization, Long-Term Potentiation, and Inflammatory Pain via CCR2： Further Insights into Molecular, Synaptic, and Cellular Mechanisms

Mounting evidence supports an important role of chemokines, produced by spinal cord astrocytes, in promoting central sensitization and chronic pain. In particular, CCL2 （C-C motif chemokine ligand 2） has been shown to enhance N-methyl-D-aspartate （NMDA）-induced currents in spinal outer lamina II （Iio） neurons. However, the exact molecular, synaptic, and cellular mechanisms by which CCL2 modulates central sensitization are still unclear. We found that spinal injection of the CCR2 antagonist RS504393 attenuated CCL2- and inflammation-induced hyperalgesia. Single-cell RT-PCR revealed CCR2 expres- sion in excitatory vesicular glutamate transporter subtype 2-positive （VGLUT2＋） neurons. CCL2 increased NMDA- induced currents in CCR2＋/VGLUT2＋ neurons in lamina IIo; it also enhanced the synaptic NMDA currents evoked by dorsal root stimulation; and furthermore, it increased the total and synaptic NMDA currents in somatostatin- expressing excitatory neurons. Finally, intrathecal RS504393 reversed the long-term potentiation evoked in the spinal cord by C-fiber stimulation. Our findings suggest that CCL2 directly modulates synaptic plasticity in CCR2- expressing excitatory neurons in spinal lamina Iio, and this underlies the generation of central sensitization in patho- logical pain.

Spinal CCL2 Promotes Pain Sensitization by Rapid Enhancement of NMDA-Induced Currents Through the ERK-GluN2B Pathway in Mouse Lamina Ⅱ Neurons

Previous studies have shown that CCL2(C-C motif chemokine ligand 2)induces chronic pain,but the exact mechanisms are still unknown.Here,we established models to explore the potential mechanisms.Behavioral experiments revealed that an antagonist of extracellular signal-regulated kinase(ERK)inhibited not only CCL2-induced inflammatory pain,but also pain responses induced by complete Freund’s adjuvant.We posed the question of the intracellular signaling cascade involved.Subsequent experiments showed that CCL2 up-regulated the expression of phosphorylated ERK(pERK)and N-methyl D-aspartate receptor[NMDAR]subtype 2B(GluN2B);meanwhile,antagonists of CCR2 and ERK effectively reversed these phenomena.Whole-cell patchclamp recordings revealed that CCL2 enhanced the NMDAR-induced currents via activating the pERK pathway,which was blocked by antagonists of GluN2B and ERK.In summary,we demonstrate that CCL2 directly interacts with CCR2 to enhance NMDAR-induced currents,eventually leading to inflammatory pain mainly through the CCL2-CCR2-pERK-GluN2B pathway.