Vascular endothelial growth factor A (VEGF) is highly expressed in adipose tissue. Its role, however, has not been fully elucidated. Here, we reveal the metabolic role of adipose-VEGF by studying mice with deletion (VEGF(AdΔ)) or doxycycline-inducible overexpression of a VEGF transgene (VEGF(AdTg)) in the adipose tissue. VEGF(AdΔ) mice have reduced adipose vascular density and show adipose hypoxia, apoptosis, inflammation, and metabolic defects on a high-fat diet. In contrast, induction of VEGF expression in VEGF(AdTg) mice leads to increased adipose vasculature and reduced hypoxia. The latter changes are sufficient to counteract an established compromising effect of high-fat diet on the metabolism, indicating that metabolic misbalance is reversible by adipose vessel density increase. Our data clearly show the essential role of VEGF signaling for adequate adipose function. Besides revealing insights into the molecular mechanisms of obesity-related metabolic diseases, this study points to the therapeutic potential of increased adipose angiogenesis.

Objective: Exosomal microRNAs (miRNAs) are potential biomarkers for obesity, in which they regulate biological processes. Bariatric surgery has health benefits for patients with obesity; however, the mechanisms of these benefits are not clear. This study attempted to identify the exosomal miRNA signature associated with obesity and how it changed after bariatric surgery. Methods: Healthy volunteers (HVs) and nondiabetic patients with obesity were prospectively enrolled in the study. The study assessed the serum exosomal miRNA profiles of HVs and patients with obesity using RNA sequencing. To evaluate the effects of bariatric surgery, the study also analyzed exosomal miRNAs in patients 6 months after surgery. Results: RNA sequencing revealed differential expression of 72 exosomal miRNAs in patients with obesity compared with HVs and differential expression of 41 miRNAs in post-versus presurgery blood. Among the differentially expressed miRNAs, the study identified nine surgery-responsive miRNAs that were highly expressed in patients before surgery compared with HVs. Biological pathway analysis of the nine miRNAs indicated that they are likely involved in WNT, neurotrophin, and insulin signaling; the insulin receptor signaling cascade; and focal adhesion. Conclusions: Patients with obesity have a distinct exosomal miRNA expression profile compared with HVs. In addition, weight loss after surgery alters the exosomal miRNA profile of patients with obesity.

Background Diabetic nephropathy (DN) is associated with high risk of cardiovascular disease and mortality. Exosomal microRNAs (miRNAs) regulate gene expression in a variety of tissues and play important roles in the pathology of various diseases. We hypothesized that the exosomal miRNA profile would differ between DN patients and patients without nephropathy. Methods We prospectively enrolled 74 participants, including healthy volunteers (HVs), diabetic patients without nephropathy, and those with DN. The serum exosomal miRNA profiles of participants were examined using RNA sequencing. Results The expression levels of 107 miRNAs differed between HVs and patients without DN, whereas the expression levels of 95 miRNAs differed between HVs and patients with DN. Among these miRNAs, we found 7 miRNAs (miR-1246, miR-642a-3p, let-7c-5p, miR-1255b-5p, let-7i-3p, miR-5010-5p, miR-150-3p) that were uniquely up-regulated in DN patients compared to HVs, and miR-4449 that was highly expressed in DN patients compared to patients without DN. A pathway analysis revealed that these eight miRNAs are likely involved in MAPK signaling, integrin function in angiogenesis, and regulation of the AP-1 transcription factor. Moreover, they were all significantly correlated with the degree of albuminuria. Conclusions Patients with DN have a different serum exosomal miRNA profile compared to HVs. These miRNAs may be promising candidates for the diagnosis and treatment of DN and cardiovascular disease. Electronic supplementary material The online version of this article (10.1186/s12967-019-1983-3) contains supplementary material, which is available to authorized users.

Senescent cells accumulate in various tissues over time, and contribute to tissue dysfunction and aging-associated phenotypes. Accumulating evidence suggests that cellular senescence can be inhibited through pharmacological intervention, as well as through treatment with soluble factors derived from embryonic stem cells (ESCs). In an attempt to investigate the anti-senescence factors secreted by ESCs, we analyzed mouse ESC-derived extracellular miRNAs in conditioned medium (CM) via miRNA array analysis. We selected mmu-miR-291a-3p as a putative anti-senescence factor via bioinformatics analysis. We validated its inhibitory effects on replicative, adriamycin-induced, and ionizing radiation-induced senescence in human dermal fibroblasts. Treatment of senescent cells with mmu-miR-291a-3p decreased senescence-associated-β-galactosidase activity, enhanced proliferative potential, and reduced mRNA and protein expression of TGFBR2, p53, and p21. Mmu-miR-291a-3p in CM was enclosed in ESC-derived exosomes and exosomes purified from ESC-CM inhibited cellular senescence. The inhibitory effects of mmu-miR-291a-3p were mediated through the TGFBR2 signaling pathway. Hsa-miR-371a-3p and hsa-miR-520e, the human homologs of mmu-miR-291a-3p, showed similar anti-senescence activity. Furthermore, mmu-miR-291a-3p accelerated the excisional skin wound healing process in aged mice. Our results indicate that the ESC-derived mmu-miR-291a-3p is a novel candidate agent that can be utilized for cell-free therapeutic intervention against aging and aging-related diseases.

IntroductionObesity is a risk factor for type 2 diabetes mellitus (T2DM) and cardiovascular disease. T2DM increases the risk of cardiovascular-related death. We investigated changes in circulating exosomal microRNA (miRNA) profiles in patients with DM with obesity compared with patients without DM with obesity.Research design and methodsThis prospective study involved 29 patients with obesity (patients without DM=16, patients with DM=13) and healthy volunteers (HVs) (n=18). We measured circulating levels of exosomal miRNAs by next-generation sequencing and compared miRNA levels across the three groups.ResultsThe expression levels of 25 miRNAs (upregulated=14, downregulated=11) differed between patients with obesity with DM and patients with obesity without DM. Compared with HV, patients with DM with obesity had 53 dysregulated miRNAs. Additionally, moving stepwise from HV to patients with obesity without DM to patients with obesity with DM, there was a consistent increase in expression levels of miR-23a-5p and miR-6087 and a consistent decrease in expressions levels of miR-6751-3p.ConclusionsOur data show that the exosomal miRNAs is altered by dysregulated glucose metabolism in patients with obesity. This circulating exosomal miRNA signature in patients with obesity with or without DM is a potential biomarker and therapeutic target in these patients.

Cellular senescence, an irreversible state of growth arrest, underlies organismal aging and agerelated diseases. Recent evidence suggests that aging intervention based on inhibition of cellular senescence might be a promising strategy for treatment of aging and age-related diseases. Embryonic stem cells (ESCs) and ESC conditioned medium (CM) have been suggested as a desirable source for regenerative medicine. However, effects of ESC-CM on cellular senescence remain to be determined. We found that treatment of senescent human dermal fibroblasts with CM from mouse ESCs (mESCs) decreases senescence phenotypes. We found that plateletderived growth factor BB in mESC-CM plays a critical role in antisenescence effect of mESC-CM through upregulation of fibroblast growth factor 2. We confirmed that mESC-CM treatment accelerates the wound-healing process by down-regulating senescence-associated p53 expression in in vivo models. Taken together, our results suggest that mESC-CM has the ability to suppress cellular senescence and maintain proliferative capacity. Therefore, this strategy might emerge as a novel therapeutic strategy for aging and age-related

Tubular injury and fibrosis are associated with progressive kidney dysfunction in advanced glomerular disease. Glomerulotubular crosstalk is thought to contribute to tubular injury. microRNAs (miRNAs) in extracellular vesicles (EVs) can modulate distant cells. We hypothesized that miRNAs in EVs derived from injured podocytes lead to tubular epithelial cell damage. As proof of this concept, tubular epithelial (HK2) cells were cultured with exosomes from puromycin-treated or healthy human podocytes, and damage was assessed. Sequencing analysis revealed the miRNA repertoire of podocyte EVs. RNA sequencing identified 63 upregulated miRNAs in EVs from puromycin-treated podocytes. Among them, five miRNAs (miR-149, -424, -542, -582, and -874) were selected as candidates for inducing tubular apoptosis according to a literature-based search. To validate the effect of the miRNAs, HK2 cells were treated with miRNA mimics. EVs from injured podocytes induced apoptosis and p38 phosphorylation of HK2 cells. The miRNA-424 and 149 mimics led to apoptosis of HK2 cells. These results show that miRNAs in EVs from injured podocytes lead to damage to tubular epithelial cells, which may contribute to the development of tubular injury in glomerular disease.

Aim:  The objective of this study was to investigate toluene‐induced accumulation mechanism of trehalose in a toluene‐tolerant bacterium Pseudomonas sp. BCNU 106. Methods and Results:  The accumulation of trehalose by a toluene‐tolerant bacterium Pseudomonas sp. BCNU 106 was examined at various cultivation time by measuring the total intracellular trehalose content, trehalase activity and mRNA levels of the trehalose‐biosynthetic genes. The pattern of trehalose accumulation corresponded to the mRNA expression pattern of the trehalose‐biosynthetic genes with the maximum level at 12 h or 4 h of cultivation with 10% (v/v) toluene, respectively. The trehalose‐biosynthetic genes were also cloned and sequenced. Furthermore, the effects of toluene addition on the intracellular osmotic pressure and pH were investigated. It was shown that homeostasis was maintained in the bacterial cells. Conclusions:  In a toluene‐tolerant bacterium Pseudomonas sp. BCNU 106, a significant amount of trehalose was accumulated through the toluene‐induced expression of the trehalose‐biosynthetic genes after the exposure to toluene. Significance and Impact of the Study:  The accumulation of the high level of intracellular trehalose was preceded by the expression of otsA/B genes in toluene‐tolerant bacteria, contributing to the elucidation of the tolerance mechanism.