Adiponectin stimulates angiogenesis by promoting cross-talk between AMP-activated protein kinase and Akt signaling in endothelial cells

A Preliminary Study on Factors That Drive Patient Variability in Human Subcutaneous Adipose Tissues

Adipose tissue is a dynamic regulatory organ that has profound effects on the overall health of patients. Unfortunately, inconsistencies in human adipose tissues are extensive and multifactorial, including large variability in cellular sizes, lipid content, inflammation, extracellular matrix components, mechanics, and cytokines secreted. Given the high human variability, and since much of what is known about adipose tissue is from animal models, we sought to establish correlations and patterns between biological, mechanical, and epidemiological properties of human adipose tissues. To do this, twenty-six independent variables were cataloged for twenty patients, which included patient demographics and factors that drive health, obesity, and fibrosis. A factorial analysis for mixed data (FAMD) was used to analyze patterns in the dataset (with BMI > 25), and a correlation matrix was used to identify interactions between quantitative variables. Vascular endothelial growth factor A (VEGFA) and actin alpha 2, smooth muscle (ACTA2) gene expression were the highest loadings in the first two dimensions of the FAMD. The number of adipocytes was also a key driver of patient-related differences, where a decrease in the density of adipocytes was associated with aging. Aging was also correlated with a decrease in overall lipid percentage of subcutaneous tissue, with lipid deposition being favored extracellularly, an increase in transforming growth factor-β1 (TGFβ1), and an increase in M1 macrophage polarization. An important finding was that self-identified race contributed to variance between patients in this study, where Black patients had significantly lower gene expression levels of TGFβ1 and ACTA2. This finding supports the urgent need to account for patient ancestry in biomedical research to develop better therapeutic strategies for all patients. Another important finding was that TGFβ induced factor homeobox 1 (TGIF1), an understudied signaling molecule, which is highly correlated with leptin signaling, was correlated with metabolic inflammation. Furthermore, this study draws attention to what we define as "extracellular lipid droplets", which were consistently found in collagen-rich regions of the obese adipose tissues evaluated here. Reduced levels of TGIF1 were correlated with higher numbers of extracellular lipid droplets and an inability to suppress fibrotic changes in adipose tissue. Finally, this study indicated that M1 and M2 macrophage markers were correlated with each other and leptin in patients with a BMI > 25. This finding supports growing evidence that macrophage polarization in obesity involves a complex, interconnecting network system rather than a full switch in activation patterns from M2 to M1 with increasing body mass. Overall, this study reinforces key findings in animal studies and identifies important areas for future research, where human and animal studies are divergent. Understanding key drivers of human patient variability is required to unravel the complex metabolic health of unique patients.

From Bone Remodeling to Wound Healing: An miR-146a-5p-Loaded Nanocarrier Targets Endothelial Cells to Promote Angiogenesis

Wound healing is a complex challenge that demands urgent attention in the clinical realm. Efficient angiogenesis is a pivotal factor in promoting wound healing. microRNA-146a (miR-146a) inhibitor has angiogenic potential in the periodontal ligament. However, free microRNAs (miRNAs) are poorly delivered into cells due to their limited tissue specificity and low intracellular delivery efficiency. To address this hurdle, we developed a nanocarrier for targeted delivery of the miR-146a inhibitor into endothelial cells. It is composed of a polyethylenimine (PEI)-modified mesoporous silica nanoparticle (MSN) core and a pentapeptide (YIGSR) layer that recognizes endothelial cells. In vitro, we defined that the miR-146a inhibitor and adiponectin (ADP) can modulate angiogenesis and the remodeling of periodontal tissues by activating the ERK and Akt signaling pathways. Then, we confirm the specificity of YIGSR to endothelial cells, and importantly, the nanocarrier effectively delivers the miR-146a inhibitor into endothelial cells, promoting angiogenesis. In a C57 mouse skin wound model, the miR-146a inhibitor is successfully delivered into endothelial cells at the wound site using the nanocarrier, resulting in the formation of new blood vessels with strong CD31 expression. Additionally, no significant differences are found in the expression levels of inflammatory markers interleukin-6 and tumor necrosis factor-α. This outcome not only brings new strategies for angiogenesis but also exhibits broader implications for bone remodeling and wound healing. The breakthrough holds significance for future research and clinical interventions.

Novel Targets and Potential Mechanisms of Mizuhopecten yessoensis-Derived Tripeptide NCW as Antihypertensive Peptides

SCOPE

Mizuhopecten yessoensis-derived tripeptide Asn-Cys-Trp (NCW) exhibits a potent antihypertensive effect in vivo. However, a lack of knowledge of the antihypertensive mechanism of tripeptide NCW limits its application for functional foods industrialization. The purpose of this study is to elucidate the corresponding targets and mechanisms of tripeptide NCW in hypertension regulation.

METHODS AND RESULTS

Administration of tripeptide NCW for 3 weeks, the blood pressure of spontaneously hypertensive rats (SHRs) is significantly decreased. After sacrifice, the serum sample is analyzed using tandem mass tag (TMT)-based liquid chromatography with tandem mass spectrometry to identify differentially expressed proteins. The proteomic analysis indicates that tripeptide NCW administration alters serum protein profiles in SHR rats, significantly upregulating 106 proteins and downregulating 30 proteins. These proteins enhance the glycolysis, glucose, and TCA cycle, improve amino metabolism, trigger the cAMP/PKA, cGMP/PKG, PI3K/AKT, and AMPK signal pathways, and inhibit Ras-regulated JNK activation, TGF-β/MAPK, and TGF-β/ RhoA/ROCK pathways.

CONCLUSION

Tripeptide NCW supplementation is demonstrated to regulate signal pathways involved in the control of blood pressure and regulate the energy and amino acids metabolic processes in serum, providing important insights into the protective effects of tripeptide NCW on hypertension.

The impact of interval training on adiponectin to leptin ratios and on blood pressures in severely obese adolescent girls: A randomized controlled trial

Interval-training is widely implemented among populations with obesity to decrease metabolic-disorders; however, high-intensity-interval-training (HIIT) has rarely been studied in severely obese adolescent girls. Therefore, the aim of this study was to compare the effects of 8 weeks of (HIIT) or moderate-intensity interval-training (MIIT), on cardiometabolic risk factors and hormonal-ratios in severely-obese-girls. For this aim, 35 female-adolescents (14.4 ± 1.4 years) were assigned randomly into HIIT (n = 12) and MIIT (n = 12), groups and a control group (CG, n = 11). Both training groups significantly improved (p < 0.05): the body-mass, body-mass-index (BMIp95), body-fat (BF%), waist-circumference (WC), mean-arterial-pressure (MAP), with a slight increase in the HIIT group. However, HIIT induced greater improvements on the maximal oxygen uptake (VO2MAX) and the speed related (24.7 and 11.8%) compared to MIIT. Higher improvements occurred in HIIT group related to leptin and adiponectin concentrations and the A/L ratio at (p < 0.001). In conclusion, the findings indicate that both HIIT and MIIT can positively influence body composition and cardio-respiratory fitness. Given the significant correlation noted between the A/L ratio, BMIp95, BF%, and MAP post-HIIT, this training modality may be considered a more advantageous approach over MIIT for mitigating cardio-metabolic issues in severely obese adolescent girls.

The mysterious association between adiponectin and endometriosis

Adiponectin is a pleiotropic cytokine predominantly derived from adipose tissue. In addition to its role in regulating energy metabolism, adiponectin may also be related to estrogen-dependent diseases, and many studies have confirmed its involvement in mediating diverse biological processes, including apoptosis, autophagy, inflammation, angiogenesis, and fibrosis, all of which are related to the pathogenesis of endometriosis. Although many researchers have reported low levels of adiponectin in patients with endometriosis and suggested that it may serve as a protective factor against the development of the disease. Therefore, the purpose of this review was to provide an up-to-date summary of the roles of adiponectin and its downstream cytokines and signaling pathways in the aforementioned biological processes. Further systematic studies on the molecular and cellular mechanisms of action of adiponectin may provide novel insights into the pathophysiology of endometriosis as well as potential therapeutic targets.

New Mechanisms to Prevent Heart Failure with Preserved Ejection Fraction Using Glucagon-like Peptide-1 Receptor Agonism (GLP-1 RA) in Metabolic Syndrome and in Type 2 Diabetes: A Review

This review examines the impact of obesity on the pathophysiology of heart failure with preserved ejection fraction (HFpEF) and focuses on novel mechanisms for HFpEF prevention using a glucagon-like peptide-1 receptor agonism (GLP-1 RA). Obesity can lead to HFpEF through various mechanisms, including low-grade systemic inflammation, adipocyte dysfunction, accumulation of visceral adipose tissue, and increased pericardial/epicardial adipose tissue (contributing to an increase in myocardial fat content and interstitial fibrosis). Glucagon-like peptide 1 (GLP-1) is an incretin hormone that is released from the enteroendocrine L-cells in the gut. GLP-1 reduces blood glucose levels by stimulating insulin synthesis, suppressing islet α-cell function, and promoting the proliferation and differentiation of β-cells. GLP-1 regulates gastric emptying and appetite, and GLP-1 RA is currently indicated for treating type 2 diabetes (T2D), obesity, and metabolic syndrome (MS). Recent evidence indicates that GLP-1 RA may play a significant role in preventing HFpEF in patients with obesity, MS, or obese T2D. This effect may be due to activating cardioprotective mechanisms (the endogenous counter-regulatory renin angiotensin system and the AMPK/mTOR pathway) and by inhibiting deleterious remodeling mechanisms (the PKA/RhoA/ROCK pathway, aldosterone levels, and microinflammation). However, there is still a need for further research to validate the impact of these mechanisms on humans.

Crosstalk between obesity and cancer: a role for adipokines

Adipose tissue is a complex organ that is increasingly being recognised as the largest endocrine organ in the body. Adipocytes among multiple cell types of adipose tissue can secrete a variety of adipokines, which are involved in signalling pathways and these can be changed by obesity and cancer. There are proposed mechanisms to link obesity/adiposity to cancer development including adipocytokine dysregulation. Among these adipokines, leptin acts through multiple pathways including the STAT3, MAPK, and PI3K pathways involved in cell growth. Adiponectin has the opposite action from leptin in tumour growth partly because of increased apoptotic responses of p53 and Bax. Visfatin increases cancer cell proliferation through ERK1/2, PI3K/AKT, and p38 which are stimulated by proinflammatory cytokines. Omentin through the PI3K/Akt-Nos pathway is involved in cancer-tumour development. Apelin might be involved through angiogenesis in tumour progressions. PAI-1 via its anti-fibrinolytic activity on cell adhesion and uPA/uPAR activity influence cancer cell growth.

Adipocyte-endothelial cell interplay in adipose tissue physiology

Adipose tissue (AT) expansion through hyperplasia or hypertrophy requires vascular remodeling that involves angiogenesis. There is quite some evidence that obese white AT (WAT) displays altered vasculature. Some studies suggest that this is associated with hypoxia, which is thought to play a role in inducing inflammatory activation of the excessively expanding WAT. Increasing evidence, based on genetic manipulations or treatments with inhibitory or activator pharmaceuticals, demonstrates that AT angiogenesis is crucial for AT metabolic function, and thereby for whole body metabolism and metabolic health. Despite some contradiction between studies, disturbance of WAT angiogenesis in obesity could be an important factor driving WAT dysfunction and the comorbidities of obesity. Endothelial cells (ECs) contribute to healthy WAT metabolism via transport of fatty acids and other plasma components, secretory signaling molecules, and extracellular vesicles (EVs). This communication is crucial for adipocyte metabolism and underscores the key role that the AT endothelium plays in systemic energy homeostasis and healthy metabolism. Adipocytes communicate towards the neighboring endothelium through several mechanisms. The pro-inflammatory status of hypertrophic adipocytes in obesity is reflected in ECs activation, which promotes chronic inflammation. On the other hand, adiponectin secreted by the adipocytes is important for healthy endothelial function, and adipocytes also secrete other pro- or anti-angiogenic effector molecules and a wealth of EVs - however, their detailed roles in signaling towards the endothelium are yet poorly understood. To conclude, targeting AT angiogenesis and promoting the healthy communication between adipocytes and ECs represent potentially promising strategies to treat obesity and its comorbidities.

Adiponectin protects against myocardial ischemia-reperfusion injury: a systematic review and meta-analysis of preclinical animal studies

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) is widespread in the treatment of ischemic heart disease, and its treatment options are currently limited. Adiponectin (APN) is an adipocytokine with cardioprotective properties; however, the mechanisms of APN in MIRI are unclear. Therefore, based on preclinical (animal model) evidence, the cardioprotective effects of APN and the underlying mechanisms were explored.

METHODS

The literature was searched for the protective effect of APN on MIRI in six databases until 16 November 2023, and data were extracted according to selection criteria. The outcomes were the size of the myocardial necrosis area and hemodynamics. Markers of oxidation, apoptosis, and inflammation were secondary outcome indicators. The quality evaluation was performed using the animal study evaluation scale recommended by the Systematic Review Center for Laboratory animal Experimentation statement. Stata/MP 14.0 software was used for the summary analysis.

RESULTS

In total, 20 papers with 426 animals were included in this study. The pooled analysis revealed that APN significantly reduced myocardial infarct size [weighted mean difference (WMD) = 16.67 (95% confidence interval (CI) = 13.18 to 20.16, P < 0.001)] and improved hemodynamics compared to the MIRI group [Left ventricular end-diastolic pressure: WMD = 5.96 (95% CI = 4.23 to 7.70, P < 0.001); + dP/dtmax: WMD = 1393.59 (95% CI = 972.57 to 1814.60, P < 0.001); -dP/dtmax: WMD = 850.06 (95% CI = 541.22 to 1158.90, P < 0.001); Left ventricular ejection fraction: WMD = 9.96 (95% CI = 7.29 to 12.63, P < 0.001)]. Apoptosis indicators [caspase-3: standardized mean difference (SMD) = 3.86 (95% CI = 2.97 to 4.76, P < 0.001); TUNEL-positive cells: WMD = 13.10 (95% CI = 8.15 to 18.05, P < 0.001)], inflammatory factor levels [TNF-α: SMD = 4.23 (95% CI = 2.48 to 5.98, P < 0.001)], oxidative stress indicators [Superoxide production: SMD = 4.53 (95% CI = 2.39 to 6.67, P < 0.001)], and lactate dehydrogenase levels [SMD = 2.82 (95% CI = 1.60 to 4.04, P < 0.001)] were significantly reduced. However, the superoxide dismutase content was significantly increased [SMD = 1.91 (95% CI = 1.17 to 2.65, P < 0.001)].

CONCLUSION

APN protects against MIRI via anti-inflammatory, antiapoptotic, and antioxidant effects, and this effect is achieved by activating different signaling pathways.

Advances in the molecular mechanisms of statins in regulating endothelial nitric oxide bioavailability: Interlocking biology between eNOS activity and L-arginine metabolism

Statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A, are widely used to treat hypercholesterolemia. In addition, statins have been suggested to reduce the risk of cardiovascular events owing to their pleiotropic effects on the vascular system, including vasodilation, anti-inflammation, anti-coagulation, anti-oxidation, and inhibition of vascular smooth muscle cell proliferation. The major beneficial effect of statins in maintaining vascular homeostasis is the induction of nitric oxide (NO) bioavailability by activating endothelial NO synthase (eNOS) in endothelial cells. The mechanisms underlying the increased NO bioavailability and eNOS activation by statins have been well-established in various fields, including transcriptional and post-transcriptional regulation, kinase-dependent phosphorylation and protein-protein interactions. However, the mechanism by which statins affect the metabolism of L-arginine, a precursor of NO biosynthesis, has rarely been discussed. Autophagy, which is crucial for energy homeostasis, regulates endothelial functions, including NO production and angiogenesis, and is a potential therapeutic target for cardiovascular diseases. In this review, in addition to summarizing the molecular mechanisms underlying increased NO bioavailability and eNOS activation by statins, we also discuss the effects of statins on the metabolism of L-arginine.

Sex-Specific Associations between Adiponectin and Leptin Signaling and Pancreatic Cancer Survival

BACKGROUND

Circulating adiponectin and leptin have been associated with risk of pancreatic cancer. However, the relationship between long-term exposure to these adipokines in the prediagnostic period with patient survival has not been investigated.

METHODS

Adipokine levels were measured in prospectively collected samples from 472 patients with pancreatic cancer. Because of sex-specific differences in adipokine levels, associations were evaluated separately for men and women. In a subset of 415 patients, we genotyped 23 SNPs in adiponectin receptor genes (ADIPOR1 and ADIPOR2) and 30 SNPs in the leptin receptor gene (LEPR).

RESULTS

Adiponectin levels were inversely associated with survival in women [HR, 1.71; 95% confidence interval (CI), 1.15-2.54]; comparing top with bottom quartile but not in men (HR, 0.89; 95% CI, 0.46-1.70). The SNPs rs10753929 and rs1418445 in ADIPOR1 were associated with survival in the combined population (per minor allele HR, 0.66; 95% CI, 0.51-0.84, and HR, 1.33; 95% CI, 1.12-1.58, respectively). Among SNPs in LEPR, rs12025906, rs3790431, and rs17127601 were associated with survival in the combined population [HRs, 1.54 (95% CI, 1.25-1.90), 0.72 (95% CI, 0.59-0.88), and 0.70 (95% CI, 0.56-0.89), respectively], whereas rs11585329 was associated with survival in men only (HR, 0.39; 95% CI, 0.23-0.66; Pinteraction = 0.0002).

CONCLUSIONS

High levels of adiponectin in the prediagnostic period were associated with shorter survival among women, but not among men with pancreatic cancer. Several polymorphisms in ADIPOR1 and LEPR are associated with patient survival.

IMPACT

Our findings reveal the association between adipokine signaling and pancreatic cancer survival and demonstrate the importance of examining obesity-associated pathways in relation to pancreatic cancer in a sex-specific manner.

Serum adiponectin level is positively associated with vascular reactivity index by digital thermal monitoring in patients with coronary artery disease

Objectives

Adiponectin has anti-inflammatory and antiatherogenic effects and is important in the pathogenesis of cardiovascular diseases. In this cross-sectional study, our objective was to study the potential correlation between serum adiponectin levels and endothelial function in participants with coronary artery disease (CAD).

Materials and Methods

We collected serum specimens from 125 fasting participants with CAD. The endothelial function was measured using the vascular reactivity index (VRI) determined by digital thermal monitoring, and VRI values of >2.0, 1.0-1.9, and <1.0 indicated good, intermediate, and poor vascular reactivity, respectively. A commercially available enzyme immunoassay kit was used to measure serum adiponectin levels.

Results

The cohort included 55, 57, and 13 patients with good, intermediate, and poor vascular reactivity, respectively. Poor vascular reactivity was shown to be associated with older age, higher levels of serum total cholesterol, low-density lipoprotein cholesterol (LDL-C), C-reactive protein, and lower levels of serum albumin and adiponectin. The linear regression analysis with multivariable forward stepwise approach revealed that age (β = -0.232), serum LDL-C (β = -0.264), and serum adiponectin (β = 0.574) were correlated with the VRI in CAD patients significantly.

Conclusion

Fasting serum adiponectin levels were associated with good endothelial function determined using the VRI in patients with CAD.

Excessive Pregestational Weight and Maternal Obstetric Complications: The Role of Adipokines

There is a high frequency of overweight and obesity in women of reproductive age. Women who start pregnancy with overweight or obesity have an increased risk of developing maternal obstetric complications such as gestational hypertension, pre-eclampsia, gestational diabetes mellitus, postpartum hemorrhage, and requiring C-section to resolve the pregnancy with a higher risk of C-section surgical site infection. Excessive weight in pregnancy is characterized by dysregulation of adipokines, the functions of which partly explain the predisposition of pregnant women with overweight or obesity to these maternal obstetric complications. This review compiles, organizes, and analyzes the most recent studies on adipokines in pregnant women with excess weight and the potential pathophysiological mechanisms favoring the development of maternal pregnancy complications.

Myonectin protects against skeletal muscle dysfunction in male mice through activation of AMPK/PGC1α pathway

To maintain and restore skeletal muscle mass and function is essential for healthy aging. We have found that myonectin acts as a cardioprotective myokine. Here, we investigate the effect of myonectin on skeletal muscle atrophy in various male mouse models of muscle dysfunction. Disruption of myonectin exacerbates skeletal muscle atrophy in age-associated, sciatic denervation-induced or dexamethasone (DEX)-induced muscle atrophy models. Myonectin deficiency also contributes to exacerbated mitochondrial dysfunction and reduces expression of mitochondrial biogenesis-associated genes including PGC1α in denervated muscle. Myonectin supplementation attenuates denervation-induced muscle atrophy via activation of AMPK. Myonectin also reverses DEX-induced atrophy of cultured myotubes through the AMPK/PGC1α signaling. Furthermore, myonectin treatment suppresses muscle atrophy in senescence-accelerated mouse prone (SAMP) 8 mouse model of accelerated aging or mdx mouse model of Duchenne muscular dystrophy. These data indicate that myonectin can ameliorate skeletal muscle dysfunction through AMPK/PGC1α-dependent mechanisms, suggesting that myonectin could represent a therapeutic target of muscle atrophy.

Adiponectin as a therapeutic target for diabetic foot ulcer

The global burden of diabetic foot ulcers (DFUs) is a significant public health concern, affecting millions of people worldwide. These wounds cause considerable suffering and have a high economic cost. Therefore, there is a need for effective strategies to prevent and treat DFUs. One promising therapeutic approach is the use of adiponectin, a hormone primarily produced and secreted by adipose tissue. Adiponectin has demonstrated anti-inflammatory and anti-atherogenic properties, and researchers have suggested its potential therapeutic applications in the treatment of DFUs. Studies have indicated that adiponectin can inhibit the production of pro-inflammatory cytokines, increase the production of vascular endothelial growth factor, a key mediator of angiogenesis, and inhibit the activation of the intrinsic apoptotic pathway. Additionally, adiponectin has been found to possess antioxidant properties and impact glucose metabolism, the immune system, extracellular matrix remodeling, and nerve function. The objective of this review is to summarize the current state of research on the potential role of adiponectin in the treatment of DFUs and to identify areas where further research is needed in order to fully understand the effects of adiponectin on DFUs and to establish its safety and efficacy as a treatment for DFUs in the clinical setting. This will provide a deeper understanding of the underlying mechanisms of DFUs that can aid in the development of new and more effective treatment strategies.

The role of adiponectin in cardiovascular disease

Cardiovascular disease (CVD) is a common disease that seriously threatens the health of human beings, especially middle-aged and elderly people over 50 years old. It has the characteristics of high prevalence, high disability rate and high mortality rate. Previous studies have shown that adiponectin has therapeutic effects on a variety of CVDs. As a key adipokine, adiponectin, is an abundant peptide-regulated hormone that is mainly released by adipocytes and cardiomyocytes, as well as endothelial and skeletal cells. Adiponectin can protect against CVD by improving lipid metabolism, protecting vascular endothelial cells and inhibiting foam cell formation and vascular smooth muscle cell proliferation. Further investigation of the molecular and cellular mechanisms underlying the adiponectin system may provide new ideas for the treatment of CVD. Herein, this review aims to describe the structure and function of adiponectin and adiponectin receptors, introduce the function of adiponectin in the protection of cardiovascular disease and analyze the potential use and clinical significance of this hormone in the protection and treatment of cardiovascular disease, which shows that adiponectin can be expected to become a new therapeutic target and biomarker for the diagnosis and treatment of CVD.

Adipose and lipoma stem cells: A donor-matched comparison

Lipomas are slow growing benign fat tumors that develop in soft tissues of the mesoderm. Thus, the specific (dys-)function of mesenchymal stem cells (MSCs) has been suggested in the development of lipomas, but details of the tumor pathogenesis remain unclear. Existing studies comparing stem cells from native adipose (adipose stem cells [ASCs]) and lipomatous tissues (LSCs) have reported contradicting findings. However, harvesting ASCs and LSCs from different individuals might have influenced proper comparison. Therefore, we aimed to characterize donor-matched ASCs and LSCs to investigate metabolic activity, proliferation, capability for tri-linear differentiation (chondrogenesis, adipogenesis, osteogenesis), and the secretome of mature adipocytes and lipomacytes. Both stem cell types did not differ in metabolic activity, but ASCs demonstrated stronger proliferation than LSCs. While there was no difference in proteoglycan accumulation during chondrogenic differentiation, adipogenesis was higher in ASCs, with more lipid vacuole formation. Conversely, LSCs showed increased osteogenesis by higher calcium deposition. Lipomacytes showed stronger secretory activity and released higher levels of certain adipokines. Our findings indicated that LSCs possessed important characteristics of MSCs, including ASCs. However, LSCs' low proliferation and adipogenic differentiation behavior did not appear to account for enhanced tissue proliferation, but the secretome of lipomacytes could contribute to lipomatous neoplasm.

Role of hormones in bone remodeling in the craniofacial complex: A review

Background

Diseases such as periodontitis and osteoporosis are expected to rise tremendously by 2050. Bone formation and remodeling are complex processes that are disturbed in a variety of diseases influenced by various hormones.

Objective

This study aimed to review and present the roles of various hormones that regulate bone remodeling of the craniofacial complex.

Methods

A literature search was conducted on PubMed and Google Scholar for studies related to hormones and jawbone. Search strategies included the combinations ("name of hormone" + "dental term") of the following terms: "hormones", "oxytocin", "estrogen", "adiponectin", "parathyroid hormone", "testosterone", "insulin", "angiotensin", "cortisol", and "erythropoietin", combined with a dental term "jaw bone", "alveolar bone", "dental implant", "jaw + bone regeneration, healing or repair", "dentistry", "periodontitis", "dry socket", "osteoporosis" or "alveolitis". The papers were screened according to the inclusion criteria from January 1, 2000 to March 31, 2021 in English. Publications included reviews, book chapters, and original research papers; in vitro studies, in vivo animal, or human studies, including clinical studies, and meta-analyses.

Results

Bone formation and remodeling is a complex continuous process involving many hormones. Bone volume reduction following tooth extractions and bone diseases, such as periodontitis and osteoporosis, cause serious problems and require a great understanding of the process.

Conclusion

Hormones are with us all the time, shape our development and regulate homeostasis. Newly discovered effects of hormones influencing bone healing open the possibilities of using hormones as therapeutics to combat bone-related diseases.

The impact of adipokines on vascular networks in adipose tissue

Adipose tissue (AT) is a highly active and plastic endocrine organ. It secretes numerous soluble molecules known as adipokines, which act locally to AT control the remodel and homeostasis or exert pleiotropic functions in different peripheral organs. Aberrant production or loss of certain adipokines contributes to AT dysfunction associated with metabolic disorders, including obesity. The AT plasticity is strictly related to tissue vascularization. Angiogenesis supports the AT expansion, while regression of blood vessels is associated with AT hypoxia, which in turn mediates tissue inflammation, fibrosis and metabolic dysfunction. Several adipokines can regulate endothelial cell functions and are endowed with either pro- or anti-angiogenic properties. Here we address the role of adipokines in the regulation of angiogenesis. A better understanding of the link between adipokines and angiogenesis will open the way for novel therapeutic approaches to treat obesity and metabolic diseases.

Association of Microluminal Structures Assessed by Optical Coherence Tomography With Local Inflammation in Adjacent Epicardial Adipose Tissue and Coronary Plaque Characteristics in Fresh Cadavers

BACKGROUND

Coronary intraplaque microluminal structures (MS) are associated with plaque vulnerability, and the inward progression of vascular inflammation from the adventitia towards the media and intima has also been demonstrated. Therefore, in the present study we investigated the relationships among MS, local inflammation in adjacent epicardial adipose tissue (EAT), and coronary plaque characteristics.Methods and Results: Optical coherence tomography (OCT) revealed MS in the left anterior descending coronary artery in 10 fresh cadaveric hearts. We sampled 30 lesions and subdivided them based on the presence of MS: MS (+) group (n=19) and MS (-) group (n=11). We measured inflammatory molecule levels in the adjacent EAT and percentage lipid volume assessed by integrated backscatter intravascular ultrasound in each lesion. The expression levels of vascular endothelial growth factor B and C-C motif chemokine ligand 2 were significantly higher in the MS (+) group than in the MS (-) group (0.9±0.7 vs. 0.2±0.2 arbitrary units (AU), P=0.04 and 1.5±0.5 vs. 0.6±0.7 AU, P=0.02, respectively). Percentage lipid volume was significantly higher in the MS (+) group than in the MS (-) group (38.7±16.5 vs. 23.7±10.9%, P=0.03).

CONCLUSIONS

Intraplaque MS observed on OCT were associated with lipid-rich plaques and local inflammation in the adjacent EAT. Collectively, these results suggest that local inflammation in the EAT is associated with coronary plaque vulnerability via MS.

The Effect of Metabolites on Mitochondrial Functions in the Pathogenesis of Skeletal Muscle Aging

Sarcopenia is an age-related systemic disease characterized by skeletal muscle aging that generally severely affects the quality of life of elderly patients. Metabolomics analysis is a powerful tool for qualitatively and quantitatively characterizing the small molecule metabolomics of various biological matrices in order to clarify all key scientific problems concerning cell metabolism. The discovery of optimal therapy requires a thorough understanding of the cellular metabolic mechanism of skeletal muscle aging. In this review, the relationship between skeletal muscle mitochondria, amino acid, vitamin, lipid, adipokines, intestinal microbiota and vascular microenvironment has been separately reviewed from the perspective of metabolomics, and a new therapeutic direction has been suggested.

The effect of aerobic exercise on pulse wave velocity in middle-aged and elderly people: A systematic review and meta-analysis of randomized controlled trials

A growing body of research examines the effect of aerobic exercise on pulse wave velocity (PWV) in middle-aged and elderly people, while findings of available studies were conflicting. The aim of this study was to explore the effect of aerobic exercise on PWV in middle-aged and elderly people. Searches were performed in PubMed, Web of Science, and EBSCO databases. Cochrane risk assessment tool was used to evaluate the methodological quality of the included literature. We included studies that satisfied the following criteria: (1) eligible studies should be randomized controlled trials (RCTs); (2) eligible studies should include both an intervention and a control group; (3) eligible studies should use the middle-aged or elderly people as subjects; and (4) eligible studies should use PWV as the outcome measure. From 972 search records initially identified, 11 studies with a total of 12 exercise groups (n = 245) and 11 control groups (n = 239) were eligible for meta-analysis. There was a significant effect of aerobic exercise on reducing PWV in middle-aged and elderly people [weighted mean difference (WMD), –0.75 (95% CI, –1.21 to –0.28), p = 0.002]. Specifically, a higher intensity [vigorous-intensity, –0.74 (–1.34 to –0.14), p = 0.02; moderate-intensity, –0.68 (–1.49 to 0.12), p = 0.10], a younger age [45 years ≤ age < 60 years, –0.57 (–0.78 to –0.37), p < 0.00001; age ≥ 60 years, –0.91 (–2.10 to 0.27), p = 0.13], a better health status [healthy, –1.19 (–2.06 to –0.31), p = 0.008; diseased, –0.32 (–0.64 to –0.01), p = 0.04], and a lower basal body mass index (BMI) [BMI < 25, –1.19 (–2.06 to –0.31), p = 0.008; 25 ≤ BMI < 30, –0.52 (–0.92 to –0.12), p = 0.01; BMI ≥ 30, –0.09 (–0.93 to 0.76), p = 0.84] were associatedwith larger reductions in PWV. Aerobic exercise, especially vigorous-intensity aerobic exercise, contributed to reducing PWV in middle-aged and elderly people. The effect of aerobic exercise on improving PWV was associated with characteristics of the participants. Specifically, a younger age, a better health status, and a lower basal BMI contributed to more significant reductions in PWV.

Adiponectin gene therapy prevents islet loss after transplantation

Significant pancreatic islet dysfunction and loss shortly after transplantation to the liver limit the widespread implementation of this procedure in the clinic. Nonimmune factors such as reactive oxygen species and inflammation have been considered as the primary driving force for graft failure. The adipokine adiponectin plays potent roles against inflammation and oxidative stress. Previous studies have demonstrated that systemic administration of adiponectin significantly prevented islet loss and enhanced islet function at post‐transplantation period. In vitro studies indicate that adiponectin protects islets from hypoxia/reoxygenation injury, oxidative stress as well as TNF‐α‐induced injury. By applying adenovirus mediated transfection, we now engineered islet cells to express exogenous adiponectin gene prior to islet transplantation. Adenovirus‐mediated adiponectin transfer to a syngeneic suboptimal islet graft transplanted under kidney capsule markedly prevented inflammation, preserved islet graft mass and improved islet transplant outcomes. These results suggest that adenovirus‐mediated adiponectin gene therapy would be a beneficial clinical engineering approach for islet preservation in islet transplantation.

Aldehyde dehydrogenase 2 augments adiponectin signaling in coronary angiogenesis in HFpEF associated with diabetes

4-hydroxy-2-nonenal (4HNE), an oxidative stress byproduct, is elevated in diabetes which decreases coronary angiogenesis, and this was rescued by the 4HNE detoxifying enzyme, aldehyde dehydrogenase 2 (ALDH2). Adiponectin (APN), an adipocytokine, has pro-angiogenic properties and its loss of function is critical in diabetes and its complications. Coronary endothelial cell (CEC) damage is the initiating step of diabetes-mediated heart failure with preserved ejection fraction (HFpEF) pathogenesis. Thus, we hypothesize that ALDH2 restores 4HNE-induced downregulation of APN signaling in CECs and subsequent coronary angiogenesis in diabetic HFpEF. Treatment with disulfiram, an ALDH2 inhibitor, exacerbated 4HNE-mediated decreases in APN-induced increased coronary angiogenesis and APN-signaling cascades, whereas pretreatment with alda1, an ALDH2 activator, rescued the effect of 4HNE. We employed control mice (db/m), spontaneous type-2 diabetic mice (db/db), ALDH2*2 knock-in mutant mice with intrinsic low ALDH2 activity (AL), and diabetic mice with intrinsic low ALDH2 activity (AF) mice that were created by crossing db/db and AL mice to test our hypothesis in vivo. AF mice exhibited heart failure with preserved ejection fraction (HFpEF)/severe diastolic dysfunction at 6 months with a preserved systolic function compared with db/db mice as well as 3 months of their age. Decreased APN-mediated coronary angiogenesis, along with increased circulatory APN levels and decreased cardiac APN signaling (index of APN resistance) were higher in AF mice relative to db/db mice. Alda1 treatment improved APN-mediated angiogenesis in AF and db/db mice. In summary, 4HNE-induces APN resistance and a subsequent decrease in coronary angiogenesis in diabetic mouse heart which was rescued by ALDH2.

Time-dependent relationships between exercise training-induced changes in nitric oxide production and hormone regulation

Aerobic exercise training (AT) reduces aging-induced deterioration of arterial stiffness and is associated with arterial nitric oxide (NO) production via changes in apelin and adropin as NO-upregulating hormones, and asymmetric dimethylarginine (ADMA) as a NO-downregulating hormone. However, the time-dependent effects of AT on NO production via NO-regulating hormones remain unclear. This study aimed to determine whether AT-induced changes in the time course of NO production via NO-regulating hormones, participate in the AT-induced improvement in central arterial stiffening with advancing age. Methods: Thirty-three healthy Japanese middle-aged and older subjects (67 ± 1 years) were randomly divided into two groups: AT intervention and sedentary controls. Subjects in the training group completed 8-week of AT. Carotid-femoral pulse wave velocity as an index of central arterial stiffness and plasma nitrate/nitrite levels significantly changed from baseline at weeks 6 (P < 0.05) and 8 (P < 0.01). Interestingly, circulating apelin and adropin levels gradually increased during AT intervention and significantly increased from baseline at weeks 4, 6, and 8 (P < 0.01). Additionally, plasma ADMA levels significantly decreased at 8-week AT intervention (P < 0.01). These results suggest that AT-induced changes in the time course of NO production via NO-regulating hormones may participate in AT-induced improvements of central arterial stiffening with advancing age.

Estrogen-related receptor alpha is an AMPK-regulated factor that promotes ischemic muscle revascularization and recovery in diet-induced obese mice

Obesity and type II diabetes are leading causes of peripheral arterial disease (PAD), which is characterized by vascular insufficiency and ischemic damage in the limb skeletal muscle. Glycemic control is not sufficient to prevent progression of PAD, and molecular targets that can promote muscle neo-angiogenesis in obesity and diabetes remain poorly defined. Here, we have investigated whether nuclear receptor estrogen-related receptor alpha (ERRα) can promote ischemic revascularization in the skeletal muscles of diet-induced obese (DIO) mice. Using muscle-specific ERRα transgenic mice, we found that ERRα overexpression promotes revascularization, marked by increased capillary staining and muscle perfusion in DIO mice after hindlimb ischemic injury. Furthermore, ERRα facilitates repair and restoration of skeletal muscle myofiber size after limb ischemia in DIO mice. The ameliorative effects of ERRα overexpression did not involve the prevention of weight gain, hyperglycemia or glucose/insulin intolerance, suggesting a direct role for ERRα in promoting angiogenesis. Interestingly, levels of endogenous ERRα protein are suppressed in the skeletal muscles of DIO mice compared to lean controls, coinciding with the suppression of angiogenic gene expression, and reduced AMPK signaling in the DIO skeletal muscles. Upon further investigating the link between AMPK and ERRα, we found that AMPK activation increases the expression and recruitment of ERRα protein to specific angiogenic gene promoters in muscle cells. Further, the induction of angiogenic factors by AMPK activators in muscle cells is blocked by repressing ERRα. In summary, our results identify an AMPK/ERRα-dependent angiogenic gene program in the skeletal muscle, which is repressed by DIO, and demonstrate that forced ERRα activation can promote ischemic revascularization and muscle recovery in obesity.

Adiponectin Ameliorates Hyperglycemia-Induced Retinal Endothelial Dysfunction, Highlighting Pathways, Regulators, and Networks

Background

The pathophysiology of diabetic retinopathy (DR) is multifaced. A low level of circulating adiponectin (APN) in type 2 diabetes is associated with microvasculature complications, and its role in the evolution of DR is complex.

Aim

This study is designed to explore the potential impact of APN in the pathogenesis of DR, linking the changes in cellular and biological processes with the pathways, networks, and regulators involved in its actions.

Methods

Human microvascular retinal endothelial cells (HMRECs) were exposed to 30mM glucose (HG) and treated with globular adiponectin (30μg/mL) for 24 hours. The cells were evaluated for reactive oxidative stress (ROS) and apoptosis. RT-PCR profile arrays were utilized to evaluate the profile of genes involved in endothelial functions, angiogenesis, extracellular matrix, and adhesion molecules for hyperglycemic HMRECs treated with adiponectin. In addition, the barrier function, leukocyte migration, and angiogenesis were evaluated. The differential expressed genes (DEGs) were outlined, and bioinformatic analysis was applied.

Results

Adiponectin suppresses ROS production and apoptosis in HMRECs under HG conditions. Adiponectin improved migration and barrier functions in hyperglycemic cells. The bioinformatic analysis highlighted that the signaling pathways of integrin, HMGB1, and p38 AMPK, are mainly involved in the actions of APN on HMRECs. APN significantly affects molecular functions, including the adhesion of cells, chemotaxis, migration of WBCs, and angiogenesis. STAT3, NFKB, IKBKB, and mir-8 are the top upstream regulators, which affect the expressions of the genes of the data set, while TNF and TGFB1 are the top regulators.

Conclusion

Adiponectin significantly counteracts hyperglycemia at various cellular and molecular levels, reducing its impact on the pathophysiological progression towards DR in vitro using HMRECs. Adiponectin ameliorates inflammatory response, oxidative stress, and endothelial barrier dysfunction using a causal network of NFBk complex, TNF, and HMGB1 and integrin pathways.

Understanding the Pathobiology of Pulmonary Hypertension Due to Left Heart Disease

The development of pulmonary hypertension (PH) is common and has adverse prognostic implications in patients with heart failure due to left heart disease (LHD), and thus far, there are no known treatments specifically for PH-LHD, also known as group 2 PH. Diagnostic thresholds for PH-LHD, and clinical classification of PH-LHD phenotypes, continue to evolve and, therefore, present a challenge for basic and translational scientists actively investigating PH-LHD in the preclinical setting. Furthermore, the pathobiology of PH-LHD is not well understood, although pulmonary vascular remodeling is thought to result from (1) increased wall stress due to increased left atrial pressures; (2) hemodynamic congestion-induced decreased shear stress in the pulmonary vascular bed; (3) comorbidity-induced endothelial dysfunction with direct injury to the pulmonary microvasculature; and (4) superimposed pulmonary arterial hypertension risk factors. To ultimately be able to modify disease, either by prevention or treatment, a better understanding of the various drivers of PH-LHD, including endothelial dysfunction, abnormalities in vascular tone, platelet aggregation, inflammation, adipocytokines, and systemic complications (including splanchnic congestion and lymphatic dysfunction) must be further investigated. Here, we review the diagnostic criteria and various hemodynamic phenotypes of PH-LHD, the potential biological mechanisms underlying this disorder, and pressing questions yet to be answered about the pathobiology of PH-LHD.

Thromboinflammatory Processes at the Nexus of Metabolic Dysfunction and Prostate Cancer: The Emerging Role of Periprostatic Adipose Tissue

Simple Summary

As overweight and obesity increase among the population worldwide, a parallel increase in the number of individuals diagnosed with prostate cancer was observed. There appears to be a relationship between both diseases where the increase in the mass of fat tissue can lead to inflammation. Such a state of inflammation could produce many factors that increase the aggressiveness of prostate cancer, especially if this inflammation occurred in the fat stores adjacent to the prostate. Another important observation that links obesity, fat tissue inflammation, and prostate cancer is the increased production of blood clotting factors. In this article, we attempt to explain the role of these latter factors in the effect of increased body weight on the progression of prostate cancer and propose new ways of treatment that act by affecting how these clotting factors work.

Abstract

The increased global prevalence of metabolic disorders including obesity, insulin resistance, metabolic syndrome and diabetes is mirrored by an increased incidence of prostate cancer (PCa). Ample evidence suggests that these metabolic disorders, being characterized by adipose tissue (AT) expansion and inflammation, not only present as risk factors for the development of PCa, but also drive its increased aggressiveness, enhanced progression, and metastasis. Despite the emerging molecular mechanisms linking AT dysfunction to the various hallmarks of PCa, thromboinflammatory processes implicated in the crosstalk between these diseases have not been thoroughly investigated. This is of particular importance as both diseases present states of hypercoagulability. Accumulating evidence implicates tissue factor, thrombin, and active factor X as well as other players of the coagulation cascade in the pathophysiological processes driving cancer development and progression. In this regard, it becomes pivotal to elucidate the thromboinflammatory processes occurring in the periprostatic adipose tissue (PPAT), a fundamental microenvironmental niche of the prostate. Here, we highlight key findings linking thromboinflammation and the pleiotropic effects of coagulation factors and their inhibitors in metabolic diseases, PCa, and their crosstalk. We also propose several novel therapeutic targets and therapeutic interventions possibly modulating the interaction between these pathological states.

Diabetes Mellitus and Heart Failure With Preserved Ejection Fraction: Role of Obesity

Heart failure with preserved ejection fraction is a growing epidemic and accounts for half of all patients with heart failure. Increasing prevalence, morbidity, and clinical inertia have spurred a rethinking of the pathophysiology of heart failure with preserved ejection fraction. Unlike heart failure with reduced ejection fraction, heart failure with preserved ejection fraction has distinct clinical phenotypes. The obese-diabetic phenotype is the most often encountered phenotype in clinical practice and shares the greatest burden of morbidity and mortality. Left ventricular remodeling plays a major role in its pathophysiology. Understanding the interplay of obesity, diabetes mellitus, and inflammation in the pathophysiology of left ventricular remodeling may help in the discovery of new therapeutic targets to improve clinical outcomes in heart failure with preserved ejection fraction. Anti-diabetic agents like glucagon-like-peptide 1 analogs and sodium-glucose co-transporter 2 are promising therapeutic modalities for the obese-diabetic phenotype of heart failure with preserved ejection fraction and aggressive weight loss via lifestyle or bariatric surgery is still key to reverse adverse left ventricular remodeling. This review focuses on the obese-diabetic phenotype of heart failure with preserved ejection fraction highlighting the interaction between obesity, diabetes, and coronary microvascular dysfunction in the development and progression of left ventricular remodeling. Recent therapeutic advances are reviewed.

Transdermal Photothermal-Pharmacotherapy to Remodel Adipose Tissue for Obesity and Metabolic Disorders

Despite the increasing prevalence of obesity, the current medications, which act indirectly on the central nervous system to suppress appetite or on the gastrointestinal tract to inhibit fat absorption, suffer from poor effectiveness and side effects. Here, we developed a transdermal mild photothermal therapy directly acting on the root of evil (subcutaneous white adipose depot) to induce its ameliorating remodeling (browning, lipolysis, and apoptosis), based on the injectable thermoresponsive hydrogel encapsulated with copper sulfide nanodots. Further, combining pharmaceutical therapy with codelivery of mirabegron leads to a strong therapeutic synergy. This method not only ensures high effectiveness and low side effects due to localized and targeted application but also remotely creates significant improvements in systemic metabolism. Specifically, as compared to the untreated group, it totally inhibits obesity development in high-fat-diet fed mice (15% less in body weight) with decreased masses of both subcutaneous (40%) and visceral fats (54%), reduced serum levels of cholesterol (54%)/triglyceride (18%)/insulin (74%)/glucose (45%), and improved insulin sensitivity (65% less in insulin resistance index). This self-administrable method is amenable for long-term home-based treatment. Finally, multiple interconnected signaling pathways are revealed, providing mechanistic insights to develop effective strategies to combat obesity and associated metabolic disorders.

Natural AMPK Activators in Cardiovascular Disease Prevention

Cardiovascular diseases (CVD), as a life-threatening global disease, is receiving worldwide attention. Seeking novel therapeutic strategies and agents is of utmost importance to curb CVD. AMP-activated protein kinase (AMPK) activators derived from natural products are promising agents for cardiovascular drug development owning to regulatory effects on physiological processes and diverse cardiometabolic disorders. In the past decade, different therapeutic agents from natural products and herbal medicines have been explored as good templates of AMPK activators. Hereby, we overviewed the role of AMPK signaling in the cardiovascular system, as well as evidence implicating AMPK activators as potential therapeutic tools. In the present review, efforts have been made to compile and update relevant information from both preclinical and clinical studies, which investigated the role of natural products as AMPK activators in cardiovascular therapeutics.

Crosstalk Between Adipose and Lymphatics in Health and Disease

Adipose tissue, once thought to be an inert receptacle for energy storage, is now recognized as a complex tissue with multiple resident cell populations that actively collaborate in response to diverse local and systemic metabolic, thermal, and inflammatory signals. A key participant in adipose tissue homeostasis that has only recently captured broad scientific attention is the lymphatic vasculature. The lymphatic system's role in lipid trafficking and mediating inflammation makes it a natural partner in regulating adipose tissue, and evidence supporting a bidirectional relationship between lymphatics and adipose tissue has accumulated in recent years. Obesity is now understood to impair lymphatic function, whereas altered lymphatic function results in aberrant adipose tissue deposition, though the molecular mechanisms governing these phenomena have yet to be fully elucidated. We will review our current understanding of the relationship between adipose tissue and the lymphatic system here, focusing on known mechanisms of lymphatic-adipose crosstalk.

Vascular endothelial adiponectin signaling across the life span

Cardiovascular disease risk increases with age regardless of sex. Some of this risk is attributable to alterations in natural hormones throughout the life span. The quintessential example of this being the dramatic increase in cardiovascular disease following the transition to menopause. Plasma levels of adiponectin, a "cardioprotective" adipokine released primarily by adipose tissue and regulated by hormones, also fluctuate throughout one's life. Plasma adiponectin levels increase with age in both men and women, with higher levels in both pre- and postmenopausal women compared with men. Younger cohorts seem to confer cardioprotective benefits from increased adiponectin levels yet elevated levels in the elderly and those with existing heart disease are associated with poor cardiovascular outcomes. Here, we review the most recent data regarding adiponectin signaling in the vasculature, highlight the differences observed between the sexes, and shed light on the apparent paradox regarding increased cardiovascular disease risk despite rising plasma adiponectin levels over time.

AdipoRon negatively regulates proliferation and migration of ARPE-19 human retinal pigment epithelial cells

Adiponectin is an adipokine playing important roles in metabolic, inflammatory and proliferative processes. At the time of surgery for rhegmatogenous retinal detachment, an altered expression of adipokines has been associated with the development of future proliferative vitreoretinopathy (PVR); this evidence as well as the presence of adiponectin receptors in ocular tissues and cell lines suggests a role of adiponectin in the physio-pathology of ocular conditions. Here, we investigated the effects of AdipoRon, an adiponectin agonist, on ARPE-19, a human retinal pigment epithelial cell line after confirming the expression of AdipoR1, AdipoR2, T-cadherin receptors. We evaluated the effects of AdipoRon in terms of vitality, survival, and migration; furthermore, we investigated the potential effects of AdipoRon on the inflammatory state of ARPE-19 cells analysing the levels of IL-10, VEGF, MCP-1 and IL-6 cytokines. Our findings indicated that AdipoRon, in a time and dose-dependent manner, reduces cell proliferation, migration, and colony formation of ARPE-19 cells. On the contrary, AdipoRon administration does not affect the expression of the tested cytokines. In conclusion, our results indicated that AdipoRon, may constitute an endogenous inhibitor of retinal pigment epithelial cell proliferation and migration, both processes deeply involved in development of PVR. Since PVR are characterized by an aberrant growth, migration and dedifferentiation of retinal pigment epithelial cells, our data contribute to open new fields of research to develop innovative therapeutic targets. Further studies are needed to clarify the effects of AdipoRon and of other small-molecule adiponectin analogs on retinal epithelium to clarify the functional role of adiponectin.

Revisiting the multiple roles of T-cadherin in health and disease

As a non-canonical member of cadherin superfamily, T-cadherin was initially described as a molecule involved in homophilic recognition in the nervous and vascular systems. The ensuing decades clearly demonstrated that T-cadherin is a remarkably multifunctional molecule. It was validated as a bona fide receptor for both: LDL exerting adverse atherogenic action and adiponectin mediating many protective metabolic and cardiovascular effects. Motivated by the latest progress and accumulated data unmasking important roles of T-cadherin in blood vessel function and tissue regeneration, here we revisit the original function of T-cadherin as a guidance receptor for the growing axons and blood vessels, consider the recent data on T-cadherin-induced exosomes' biogenesis and their role in myocardial regeneration and revascularization. The review expands upon T-cadherin contribution to mesenchymal stem/stromal cell compartment in adipose tissue. We also dwell upon T-cadherin polymorphisms (SNP) and their possible therapeutic applications. Furthermore, we scrutinize the molecular hub of insulin and adiponectin receptors (AdipoR1 and AdipoR2) conveying signals to their downstream targets in quest for defining a putative place of T-cadherin in this molecular circuitry.

Obesity, Diabetes, and Increased Cancer Progression

Rates of obesity and diabetes have increased significantly over the past decades and the prevalence is expected to continue to rise further in the coming years. Many observations suggest that obesity and diabetes are associated with an increased risk of developing several types of cancers, including liver, pancreatic, endometrial, colorectal, and post-menopausal breast cancer. The path towards developing obesity and diabetes is affected by multiple factors, including adipokines, inflammatory cytokines, growth hormones, insulin resistance, and hyperlipidemia. The metabolic abnormalities associated with changes in the levels of these factors in obesity and diabetes have the potential to significantly contribute to the development and progression of cancer through the regulation of distinct signaling pathways. Here, we highlight the cellular and molecular pathways that constitute the links between obesity, diabetes, cancer risk and mortality. This includes a description of the existing evidence supporting the obesity-driven morphological and functional alternations of cancer cells and adipocytes through complex interactions within the tumor microenvironment.

Medical and Surgical Obesity Treatments and Atherosclerosis: Mechanisms beyond Typical Risk Factors

PURPOSE OF REVIEW

This study aims to discuss the mechanisms by which GLP-1 agonists and bariatric surgery improve cardiovascular outcomes in severely obese patients.

RECENT FINDINGS

Recent studies have demonstrated that both GLP-1 agonist use and bariatric surgery reduce adverse cardiovascular outcomes. Improvements in traditional atherosclerosis risk factors in association with weight loss likely contribute, but weight loss-independent mechanisms are also suggested to have roles. We review the clinical and preclinical evidence base for cardiovascular benefit of LP-1 agonists and bariatric surgery beyond traditional risk factors, including improvements in endothelial function, direct impacts on atherosclerotic plaques, and anti-inflammatory effects.

Effects of Obesity on Adiponectin System Skin Expression in Dogs: A Comparative Study

Simple Summary

Adipokines are biologically active molecules with hormonal action, produced mainly by white adipose tissue and related to the individual’s nutritional status. Adiponectin with its receptors (ADIPOR1, ADIPOR2) intervenes in the control of energy metabolism, as well as in the regulation of peripheral tissue functions. Adiponectin has a primary role in the skin in both physiological and pathological conditions, in addition, this molecule is greatly affected by nutritional status, and its serum level is lowered in the obese. In this work, the adiponectin system was evaluated in the skin of obese dogs along with adiponectin serum levels. Results were compared to normal weight dogs to evidence modifications in the obesity condition. Obesity is a widespread phenomenon in dogs, with a growing trend, as well, in humans; this condition may interfere with the local functionality of tissues, including the skin. The evaluation performed evidenced that adiponectin and ADIPOR2 skin expression is negatively correlated with the serum adiponectin level and accordingly with obesity. These findings evidence that the adiponectin system changes in the skin of obese dogs; this study also explores the role of adipokines in skin biology.

Abstract

Obesity is an important health issue in dogs since it influences a plethora of associated pathologies, including dermatological disorders. Considering the scarcity of information in pets, this work aimed to evaluate the localization and expression of adiponectin (ADIPOQ) and its two receptors (ADIPOR1 and ADIPOR2) in the skin of 10 obese dogs, compared with serum ADIPOQ level. Through immunohistochemistry, ADIPOQ and ADIPOR2 were observed in the adipose tissue, sweat and sebaceous glands, endothelium, and some connective cells. Both receptors were observed in the epidermis and the hair follicles, other than in the sweat and sebaceous glands. Real-time PCR evidenced that the ADIPOQ and ADIPOR2 transcripts were expressed 5.4-fold (p < 0.01) and 2.3-fold less (p < 0.01), respectively, in obese than in normal weight dogs, while ADIPOR1 expression did not change. Obese dogs showed lower serum ADIPOQ levels than the normal weight group. Accordingly, ADIPOQ and ADIPOR2 expression in the skin appear negatively correlated with obesity in the same way as the serum ADIPOQ level. These findings evidence that ADIPOQ system changes in the skin of obese dogs and suggest that the ADIPOQ effect on the skin is at least in part regulated by the reduced expression of ADIPOR2.

Excess adiponectin in eyes with progressive ocular vascular diseases

Anti-vascular endothelial growth factor (VEGF) therapies are now the first-line treatment for many ocular diseases, but some patients are non-responders to these therapies. The purpose of this study was to determine whether the level of adiponectin increased the pathogenesis of retinal edema and neovascularization in the retina of progressive ocular vascular diseases. We examined the role played by adiponectin in two types of cells and animal models which are retinal vein occlusion (RVO) and oxygen-induced retinopathy (OIR) mice. Our results showed that an injection of anti-adiponectin antibody ameliorated the retinal edema and ischemia through the depression of the expression level of VEGF-related factors and tight junction-related proteins in the retina of RVO mice. The intravitreal injection of anti-adiponectin antibody also decreased the degree of retinal neovascularization in an OIR mice. In addition, exposure of human retinal microvascular endothelial cells and human brain microvascular pericytes in culture to adiponectin increased both the vascular permeability and neovascularization through the increase of inflammatory factor and the dropout of the pericytes. These findings indicate that adiponectin plays a critical role in retinal edema and neovascularization, and adiponectin is a potential therapeutic target for the treatment of diabetic macular edema, proliferative diabetic retinopathy, and RVO.

Adiponectin and Leptin Exert Antagonizing Effects on HUVEC Tube Formation and Migration Modulating the Expression of CXCL1, VEGF, MMP-2 and MMP-9

Adiponectin and leptin are two abundant adipokines with different properties but both described such as potent factors regulating angiogenesis. AdipoRon is a small-molecule that, binding to AdipoRs receptors, acts as an adiponectin agonist. Here, we investigated the effects of AdipoRon and leptin on viability, migration and tube formation on a human in vitro model, the human umbilical vein endothelial cells (HUVEC) focusing on the expression of the main endothelial angiogenic factors: hypoxia-inducible factor 1-alpha (HIF-1α), C-X-C motif chemokine ligand 1 (CXCL1), vascular endothelial growth factor A (VEGF-A), matrix metallopeptidase 2 (MMP-2) and matrix metallopeptidase 9 (MMP-9). Treatments with VEGF-A were used as positive control. Our data revealed that, at 24 h treatment, proliferation of HUVEC endothelial cells was not influenced by AdipoRon or leptin administration; after 48 h longer exposure time, the viability was negatively influenced by AdipoRon while leptin treatment and the combination of AdipoRon+leptin produced no effects. In addition, AdipoRon induced a significant increase in complete tubular structures together with induction of cell migration while, on the contrary, leptin did not induce tube formation and inhibited cell migration; interestingly, the co-treatment with both AdipoRon and leptin determined a significant decrease of the tubular structures and cell migration indicating that leptin antagonizes AdipoRon effects. Finally, we found that the effects induced by AdipoRon administration are accompanied by an increase in the expression of CXCL1, VEGF-A, MMP-2 and MMP-9. In conclusion, our data sustain the active role of adiponectin and leptin in linking adipose tissue with the vascular endothelium encouraging the further deepening of the role of adipokines in new vessel’s formation, to candidate them as therapeutic targets.

Enhanced NAMPT-Mediated NAD Salvage Pathway Contributes to Psoriasis Pathogenesis by Amplifying Epithelial Auto-Inflammatory Circuits

Dysregulated cross-talk between immune cells and epithelial compartments is responsible for the onset and amplification of pathogenic auto-inflammatory circuits occurring in psoriasis. NAMPT-mediated NAD salvage pathway has been recently described as an immunometabolic route having inflammatory function in several disorders, including arthritis and inflammatory bowel diseases. To date, the role of NAD salvage pathway has not been explored in the skin of patients affected by psoriasis. Here, we show that NAD content is enhanced in lesional skin of psoriatic patients and is associated to high NAMPT transcriptional levels. The latter are drastically reduced in psoriatic skin following treatment with the anti-IL-17A biologics secukinumab. We provide evidence that NAMPT-mediated NAD⁺ metabolism fuels the immune responses executed by resident skin cells in psoriatic skin. In particular, intracellular NAMPT, strongly induced by Th1/Th17-cytokines, acts on keratinocytes by inducing hyper-proliferation and impairing their terminal differentiation. Furthermore, NAMPT-mediated NAD⁺ boosting synergizes with psoriasis-related cytokines in the upregulation of inflammatory chemokines important for neutrophil and Th1/Th17 cell recruitment. In addition, extracellular NAMPT, abundantly released by keratinocytes and dermal fibroblasts, acts in a paracrine manner on endothelial cells by inducing their proliferation and migration, as well as the expression of ICAM-1 membrane molecule and chemokines important for leukocyte recruitment into inflamed skin. In conclusion, our results showed that NAMPT-mediated NAD salvage pathway contributes to psoriasis pathogenic processes by amplifying epithelial auto-inflammatory responses in psoriasis.

Buxuhuayu decoction accelerates angiogenesis by activating the PI3K-Akt-eNOS signalling pathway in a streptozotocin-induced diabetic ulcer rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Buxuhuayu decoction (BXHYD) has been frequently used to treat patients with diabetic ulcers (DUs), without notable adverse reactions. However, the related molecular mechanism remains unelucidated.

AIM OF THE STUDY

This study assessed the potential mechanism of BXHYD against DUs by using network pharmacology and animal experiments.

MATERIALS AND METHODS

First, high-performance liquid chromatography (HPLC) was used for quality control of BXHYD. Further, the hub compounds and targets were screened from the Active Compound-Targets (ACT) network and the protein and protein interaction (PPI) network. Enrichment analysis was performed using DAVID, and molecular docking technology was used to identify active compounds that may play a key role in pub targets. Finally, a DUs animal model was established and used to elucidate the effect of BXHYD on the PI3K/Akt/eNOS signalling pathway.

RESULTS

(1) Calycosin-7-glucoside, amygdalin, and tanshinone iiA were detected in the freeze-dried powder of BXHYD. (2) Twelve hub compounds and eight hub targets were screened using the ACT and PPI networks. Through molecular docking, it was found that the four hub targets (TP53, IL6, VEGFA, and AKT1) binds luteolin and quercetin more tightly. (3) BXHYD is most likely to promote angiogenesis and wound healing by activating the PI3K/Akt/eNOS signalling pathway.

CONCLUSIONS

This research revealed that BXHYD might activate the PI3K/Akt/eNOS signalling pathway to promote DUs healing. These findings support the clinical use of BXHYD and provide the foundation for its subsequent studies.

Role of Perivascular Adipose Tissue-Derived Adiponectin in Vascular Homeostasis

Studies of adipose tissue biology have demonstrated that adipose tissue should be considered as both passive, energy-storing tissue and an endocrine organ because of the secretion of adipose-specific factors, called adipokines. Adiponectin is a well-described homeostatic adipokine with metabolic properties. It regulates whole-body energy status through the induction of fatty acid oxidation and glucose uptake. Adiponectin also has anti-inflammatory and antidiabetic properties, making it an interesting subject of biomedical studies. Perivascular adipose tissue (PVAT) is a fat depot that is conterminous to the vascular wall and acts on it in a paracrine manner through adipokine secretion. PVAT-derived adiponectin can act on the vascular wall through endothelial cells and vascular smooth muscle cells. The present review describes adiponectin's structure, receptors, and main signaling pathways. We further discuss recent studies of the extent and nature of crosstalk between PVAT-derived adiponectin and endothelial cells, vascular smooth muscle cells, and atherosclerotic plaques. Furthermore, we argue whether adiponectin and its receptors may be considered putative therapeutic targets.

Rapamycin and 3-Methyladenine Influence the Apoptosis, Senescence, and Adipogenesis of Human Adipose-Derived Stem Cells by Promoting and Inhibiting Autophagy: An In Vitro and In Vivo Study

OBJECTIVE

We aimed to clarify the changes in apoptosis, proliferation, senescence, and adipogenesis after promoting and inhibiting autophagy in adipose-derived stem cells (ADSCs) by rapamycin and 3-methyladenine in vitro and in vivo.

METHODS

After rapamycin and 3-methyladenine pretreatment, ADSC autophagy was detected by immunofluorescence for LC3, RT-PCR for ATG genes, and western blotting (WB) for the LC3 II/I and p62 proteins. TUNEL staining, PCR of BAX, and WB of Caspase-3 were preformed to assess ADSC apoptosis. The adipogenesis of ADSCs was evaluated by Oil red O staining and PCR of PPAR-γ. CCK8 assays were conducted to detect proliferation. Senescence was tested by Sa-β-gal staining and PCR of the P16/ 19/21 genes. Moreover, the mass and volume retention rate were determined, and perilipin and CD31 staining were performed in vivo.

RESULTS

Rapamycin and 3-methyladenine pretreatment increased and decreased autophagy of ADSCs, respectively, under normal and oxygen-glucose deprivation conditions. Apoptosis and senescence of ADSCs were decreased, and adipogenesis was increased along with the upregulation of autophagy. However, the proliferation of ADSCs was inhibited after either rapamycin or 3-methyladenine pretreatment. In vivo, the volume and mass retention rate and the angiogenesis of the grafts were also improved after rapamycin pretreatment.

CONCLUSIONS

Rapamycin pretreatment reduced apoptosis, delayed senescence, and promoted adipogenesis of ADSCs. These effects were inhibited by 3-methyladenine, indicating that the changes may be mediated by autophagy. Moreover, the survival rate and angiogenesis of the grafts were increased after upregulation of ADSC autophagy in vivo, which may help improve the efficiency of clinical fat transplantation.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Galactose-NlGr11 inhibits AMPK phosphorylation by activating the PI3K-AKT-PKF-ATP signaling cascade via insulin receptor and Gβγ

As ligands of the sugar gustatory receptors, sugars have been known to activate the insulin/insulin-like growth factor signaling pathway; however, the precise pathways that are activated by the sugar-bound gustatory receptors in insects remain unclear. In this study, we aimed to investigate the signaling cascades activated by NlGr11, a sugar gustatory receptor in the brown planthopper Nilaparvata lugens (Stål), and its ligand. Galactose-bound NlGr11 (galactose-NlGr11) activated the -phosphatidylinositol 3-kinase (PI3K)-AKT signaling cascade via insulin receptor (InR) and Gβγ in vitro. In addition, galactose-NlGr11 inhibited the adenosine monophosphate-activated protein kinase (AMPK) phosphorylation by activating the AKT-phosphofructokinase (PFK)-ATP signaling cascade in vitro. Importantly, the InR-PI3K-AKT-PFK-AKT signaling cascade was activated and the AMPK phosphorylation was inhibited after feeding the brown planthoppers with galactose solution. Collectively, these findings confirm that NlGr11 can inhibit AMPK phosphorylation by activating the PI3K-AKT-PFK-ATP signaling cascades via both InR and Gβγ when bound to galactose. Thus, our study provides novel insights into the signaling pathways regulated by the sugar gustatory receptors in insects.