Birth weight and its relationship with endothelial function and pattern of endothelium-derived microparticles during childhood: New insight about early vascular damage.

AIMS: To investigate whether a specific endothelium-derived microparticles (EMPs) phenotype could be associated with birth weight and microvascular endothelial function in children. MATERIALS AND METHODS: A total of 95 children aged 6-14 years were recruited. Anthropometric measurements, blood pressure measurement, microvascular endothelial function testing, and biochemical profile analyses were performed. Standardized flow cytometry methods were used to identify and quantify the circulating CD144+, CD31+/annexin V+, and CD62E+ EMPs. KEY FINDINGS: The circulating number of CD31+/annexin V+ EMPs and CD144+ EMP levels were correlated with birth weight, systolic blood pressure, microvascular endothelial function, total cholesterol, and low-density lipoprotein cholesterol (LDL-C) level. In the multivariable logistic regression models, we identified strong evidence of a higher risk of microvascular endothelial dysfunction among children with low birth weight (LBW) and increased levels of both CD31+/annexin V+ EMPs and LDL-C; LBW and elevated LDL-C levels were independent predictors of high circulating numbers of CD31+/annexin V+ and CD144+ > 75th percentile EMPs. SIGNIFICANCE: Our data provide evidence that children with LBW values showed greater numbers of circulating CD31+/annexin V+ and CD144+ EMPs. In addition, LBW and high levels of CD31+/annexin V+ and LDL-C were significant risk factors for the presence of microvascular endothelial dysfunction.

High circulating levels of CD62E+ and CD31+/Annexin V+ endothelium-derived microparticles in children with overweight/obesity: Evidence of early vascular damage.

BACKGROUND: Obesity perturbs endothelium integrity, leading to endothelial activation, which predisposes the release of endothelium-derived microparticles (EMP). We measured the CD31+/annexin V+ and CD62E+ EMP levels to improve our understanding of their contribution to endothelial damage in children with overweight/obesity. SUBJECT AND METHODS: In this cross-sectional study, 107 children with normal weight and 35 children with overweight/obesity were evaluated. Anthropometric measurement, blood pressure, biochemical profile was performed. Standardized flow cytometry methods were used to identify and quantify circulating CD31+/annexin V+ and CD62E+ EMP. RESULTS: Children with overweight/obesity had significantly higher circulating levels of CD31+/annexin V+ (750 [600]) and CD62E+ (1400 [700]) EMP than those with normal weight (P < 0.001 for both). We found that EMP levels were positively correlated with body mass index (BMI), waist circumference, blood pressure, total cholesterol, low-density lipoprotein cholesterol (LDLc), and triglycerides. The multivariable logistic regression model revealed that the risks of having high EMP levels (> 75th percentile) were high in children with both large waist circumference and elevated LDLc level. Receiver operating characteristic (ROC) curves demonstrated that the LDLc levels showed significantly greater discrimination than waist circumference for both CD31+/annexin V+ (P = 0.031) as CD62E+ EMPs (P = 0.041). CONCLUSIONS: Children with overweight/obesity have high circulating CD31+/annexin V+ and CD62E+ EMP levels, which may be an early sign of endothelial apoptosis and inflammatory activation in response to injury. These EMP levels were positively associated with several cardiometabolic risk factors. Our data underscore the negative influence of high-risk metabolic profiles on endothelial integrity in the early stages of childhood obesity.

Nephropathy in Hypertensive Animals Is Linked to M2 Macrophages and Increased Expression of the YM1/Chi3l3 Protein.

Macrophages contribute to a continuous increase in blood pressure and kidney damage in hypertension, but their polarization status and the underlying mechanisms have not been clarified. This study revealed an important role for M2 macrophages and the YM1/Chi3l3 protein in hypertensive nephropathy in a mouse model of hypertension. Bone marrow cells were isolated from the femurs and tibia of male FVB/N (control) and transgenic hypertensive animals that overexpressed the rat form of angiotensinogen (TGM(rAOGEN)123, TGM123-FVB/N). The cells were treated with murine M-CSF and subsequently with LPS+IFN-γ to promote their polarization into M1 macrophages and IL-4+IL-13 to trigger the M2 phenotype. We examined the kidneys of TGM123-FVB/N animals to assess macrophage polarization and end-organ damage. mRNA expression was evaluated using real-time PCR, and protein levels were assessed through ELISA, CBA, Western blot, and immunofluorescence. Histology confirmed high levels of renal collagen. Cells stimulated with LPS+IFN-γ in vitro showed no significant difference in the expression of CD86, an M1 marker, compared to cells from the controls or the hypertensive mice. When stimulated with IL-4+IL-13, however, macrophages of the hypertensive group showed a significant increase in CD206 expression, an M2 marker. The M2/M1 ratio reached 288%. Our results indicate that when stimulated in vitro, macrophages from hypertensive mice are predisposed toward polarization to an M2 phenotype. These data support results from the kidneys where we found an increased infiltration of macrophages predominantly polarized to M2 associated with high levels of YM1/Chi3l3 (91,89%), suggesting that YM1/Chi3l3 may be a biomarker of hypertensive nephropathy.

TLR2 and TLR4 play opposite role in autophagy associated with cisplatin-induced acute kidney injury.

Acute kidney injury (AKI) is considered an inflammatory disease in which toll-like receptors (TLRs) signaling pathways play an important role. The activation of TLRs results in production of several inflammatory cytokines leading to further renal damage. In contrast, TLRs are key players on autophagy induction, which is associated with a protective function on cisplatin-induced AKI. Hence, the present study aimed to evaluate the specific participation of TLR2 and TLR4 molecules on the development of cisplatin-induced AKI. Complementarily, we also investigated the link between TLRs and heme oxygenase-1 (HO-1), a promisor cytoprotective molecule. First, we observed that only the absence of TLR2 but not TLR4 in mice exacerbated the renal dysfunction, tissue injury and mortality rate, even under an immunologically privileged microenvironment. Second, we demonstrated that TLR2 knockout (KO) mice presented lower expression of autophagy-associated markers when compared with TLR4 KO animals. Similar parameter was confirmed in vitro, using tubular epithelial cells derived from both KO mice. To test the cross-talking between HO-1 and TLRs, hemin (an HO-1 internal inducer) was administrated in cisplatin-treated TLR2 and TLR4 KO mice and it was detected an improvement in the global renal tissue parameters. However, this protection was less evident at TLR2 KO mice. In summary, we documented that TLR2 plays a protective role in cisplatin-induced AKI progression, in part, by a mechanism associated with autophagy up-regulation, considering that its interplay with HO-1 can promote renal tissue recover.

Nasal Polyp-Derived Mesenchymal Stromal Cells Exhibit Lack of Immune-Associated Molecules and High Levels of Stem/Progenitor Cells Markers.

Mesenchymal stromal cells (MSCs) are considered adult progenitor stem cells and have been studied in a multitude of tissues. In this context, the microenvironment of nasal polyp tissue has several inflammatory cells, but their stroma compartment remains little elucidated. Hence, we isolated MSCs from nasal polyps Polyp-MSCs (PO-MSCs) and compared their molecular features and gene expression pattern with bone marrow-derived MSCs (BM-MSCs). Initially, both PO-MSCs and BM-MSCs were isolated, cultivated, and submitted to morphologic, differentiation, phenotypic, immunosuppressive, and gene expression assays. Compared to BM-MSCs, PO-MSCs showed normal morphology and similar osteogenic/adipogenic differentiation potential, but their immunophenotyping showed lack of immune-associated molecules (e.g., CD117, HLA-DR, PDL-1, and PDL-2), which was linked with less immunoregulatory abilities such as (i) inhibition of lymphocytes proliferation and (ii) regulatory T cell expansion. Furthermore, we detected in the PO-MSCs a distinct gene expression profile in comparison with BM-MSCs. PO-MSC expressed higher levels of progenitor stem cells specific markers (e.g., CD133 and ABCB1), while BM-MSCs showed elevated expression of cytokines and growth factors (e.g., FGF10, KDR, and GDF6). The gene ontology analysis showed that the differentially modulated genes in PO-MSC were related with matrix remodeling process and hexose and glucose transport. For BM-MSCs, the highly expressed genes were associated with behavior, angiogenesis, blood vessel morphogenesis, cell-cell signaling, and regulation of response to external stimulus. Thus, these results suggest that PO-MSCs, while sharing similar aspects with BM-MSCs, express a different profile of molecules, which presumably can be implicated in the development of nasal polyp tissue.

Macrophages During the Fibrotic Process: M2 as Friend and Foe.

Macrophages play essential activities in homeostasis maintenance during different organism's conditions. They may be polarized according to various stimuli, which subsequently subdivide them into distinct populations. Macrophages with inflammatory activity function mainly during pathological context, while those with regulatory activity control inflammation and also remodel the repairing process. Here, we propose to review and to present a concise discuss on the role of different components during tissue repair, including those related to innate immune receptors and metabolic modifications. The scar formation is directly related to the degree of inflammation, but also with the appearance of M2 macrophages. In spite of greater numbers of macrophages in the fibrotic phase, regulatory macrophages present some characteristics related to promotion of fibrosis but also with the control of scar formation. These regulatory macrophages present an oxidative metabolism, and differ from the initial inflammatory macrophages, which in turn, present a glycolytic characteristic, which allow regulatory ones to optimize the oxygen consumption and minimizing their ROS production. We will emphasize the difference in macrophage subpopulations and the origin and plasticity of these cells during fibrotic processes.