Proinflammatory CD14+CD16+ Monocytes are Associated with Microinflammation in Patients with Type 2 Diabetes Mellitus and Diabetic Nephropathy Uremia

Abstract

Diabetic nephropathy (DN) is a major cause of type 2 diabetes mellitus (T2DM) mortality. Innate immunity has been shown to be closely associated with the occurrence and progression of T2DM-associated complications. In this study, we investigated the expression of Toll-like receptor 4 (TLR4) and CD14(+)CD16(+) monocytes in patients with T2DM and DN patients with uremia and TLR4 response to lipopolysaccharide (LPS), and to further explore the potential effects of inflammatory immune response in T2DM and DN uremia. Thirty DN patients with uremia, 28 T2DM patients, and 20 healthy volunteers were enrolled for the determination of CD14(+)CD16(+) fluorescence intensity and TLR4 expression on monocytes by using peripheral blood flow cytometry. Serum C-reactive protein (CRP) level was determined by using the immunoturbidimetry. Peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with LPS for 24 h. monocytes were collected to detect NF-κB p65 and phosphorylated STAT5(p-STAT5) expressions by using Western blotting. Supernatants were sampled for the determination of interleukin-6 (IL-6) concentration by using ELISA. Compared to normal control, T2DM patients and DN uremic patients had a significantly higher CD14(+)CD16(+) fluorescence intensity, TLR4 expression, serum IL-6 and CRP level, whilst these biomarkers were more upregulated in DN uremic patients than in T2DM patients. Following the exposure to LPS, PBMCs showed a significant upregulation in NF-κB-p65 and p-STAT5 expression and a remarked increase in Supernatants IL-6 level, in a positive correlation with disease severity. Our results suggest that the disturbance in proinflammatory CD14(+)CD16(+) monocytes occurs in T2DM and DN uremic patients. Such immunological dysfunction may be related to the activation of TLR4/NF-κB and STAT5 signaling pathways underlying the immune abnormalities of CD14(+)CD16(+) monocytes.

Innate immunity in diabetes and diabetic nephropathy

“…The downstream signaling molecules, such as MyD88, IRF3, and TRAM were also markedly increased 143 . In patients with T2DM, fluorescent intensity of CD14 + CD16 + cells, TLR4 expression, and serum levels of IL6 and CRP were higher compared to healthy control subjects 144 . Moreover, these biomarkers were further increased in uraemic patients with diabetic nephropathy, compared to patients with T2DM and healthy controls 144 .…”

Prophylactic vaccinations in chronic kidney disease: Current status

“…14 In uremic patients due to diabetic nephropathy, pro-inflammatory CD14(C)CD16(C) monocytes and TLR4 expression were significantly up-regulated concomitantly with increased serum levels of inflammatory markers -interleukin (IL) ¡6 and C-reactive protein. 15 Immunological dysfunction in this group of patients was attributed to the activation of TLR4/NF-kB and STAT5 signaling pathways. 15 Lipopolysaccharide stimulation of TLR4 on neutrophils activates signal transduction pathway leading to pro-inflammatory cytokine secretion, like tumor necrosis factor a (TNF-a), IL-6 or IL-8, whereas anti-inflammatory IL-10 is decreased.…”

Microinflammation as a Candidate for Diabetic Nephropathy

“…However, new perspectives in activated innate immunity and inflammation appear to be important factors in the pathogenesis of DM and its associated complications. Hence, recent studies disclosed that these conventional mechanisms are only partially responsible for the development and/or progression of DN [8], and that low-grade or subclinical inflammation, termed ''microinflammation'', plays a vital role in the pathogenesis of this diabetic complication [2,[8][9][10]. The relationships between microinflammation and the pre-existing traditional factors during the development and progression of DN involve complex pathways with hyperglycaemia laying at upstream and microinflammation and subsequent evolution of DN representing downstream of these pathways addressed here in brief ( Figure 1).…”

“…Disturbance in proinflammatory CD14(+)CD16(+) monocytes was noted in Type 2DM and DN ureamic patients. Such immunological dysfunction may be related to the activation of TLR4/NF-κB and STAT5 (signal transducer and activator of transcription) signaling pathways [2].…”

“…Diabetic nephropathy (DN) is a major cause of mortality in patients with Type 1 and Type 2 diabetes throughout the world [2] and between 20% and 40% of diabetic patients ultimately develop nephropathy [3]. In human glomeruli, glomerular hypertrophy, expansion of diffuse mesangial matrices, exudative lesions, segmental nodular sclerosis (thickening of the glomerular basement membrane) and/or podocyte loss with compensatory expansion of the remaining podocyte foot processes are the main pathological features of diabetic nephropathy which direct to the ultimate development of glomerulosclerosis, tubulointerstitial fibrosis, impairment of renal function and progression to end-stage renal disease (ESRD) [3,4].…”