The Transcriptomic Landscape of Age-Induced Changes in Human Visceral Fat and the Predicted Omentum-Liver Connectome in Males.

Aging causes alterations in body composition. Specifically, visceral fat mass increases with age and is associated with age-related diseases. The pathogenic potential of visceral fat accumulation has been associated with its anatomical location and metabolic activity. Visceral fat may control systemic metabolism by secreting molecules that act in distal tissues, mainly the liver, through the portal vein. Currently, little is known about age-related changes in visceral fat in humans. Aiming to identify molecular and cellular changes occurring with aging in the visceral fat of humans, we analyzed publicly available transcriptomic data of 355 omentum samples from the Genotype-Tissue Expression portal (GTEx) of 20-79-year-old males and females. We identified the functional enrichment of genes associated with aging, inferred age-related changes in visceral fat cellularity by deconvolution analysis, profiled the senescence-associated secretory phenotype of visceral adipose tissue, and predicted the connectivity of the age-induced visceral fat secretome with the liver. We demonstrate that age induces alterations in visceral fat cellularity, synchronous to changes in metabolic pathways and a shift toward a pro-inflammatory secretory phenotype. Furthermore, our approach identified candidates such as ADIPOQ-ADIPOR1/ADIPOR2, FCN2-LPR1, and TF-TFR2 to mediate visceral fat-liver crosstalk in the context of aging. These findings cast light on how alterations in visceral fat with aging contribute to liver dysfunction and age-related disease etiology.

A systematic review and meta-analysis demonstrating Klotho as an emerging exerkine.

Klotho is an anti-aging protein with several therapeutic roles in the pathophysiology of different organs, such as the skeletal muscle and kidneys. Available evidence suggests that exercise increases Klotho levels, regardless of the condition or intervention, shedding some light on this anti-aging protein as an emergent and promising exerkine. Development of a systematic review and meta-analysis in order to verify the role of different exercise training protocols on the levels of circulating soluble Klotho (S-Klotho) protein. A systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE through PubMed, EMBASE, CINAHL, CT.gov, and PEDro. Randomized and quasi-randomized controlled trials that investigated effects of exercise training on S-Klotho levels. We included 12 reports in the analysis, comprising 621 participants with age ranging from 30 to 65 years old. Klotho concentration increased significantly after chronic exercise training (minimum of 12 weeks) (Hedge' g [95%CI] 1.3 [0.69-1.90]; P < 0.0001). Moreover, exercise training increases S-Klotho values regardless of the health condition of the individual or the exercise intervention, with the exception of combined aerobic + resistance training. Furthermore, protocol duration and volume seem to influence S-Klotho concentration, since the effect of the meta-analysis changes when subgrouping these variables. Altogether, circulating S-Klotho protein is altered after chronic exercise training and it might be considered an exerkine. However, this effect may be influenced by different training configurations, including protocol duration, volume, and intensity.

Exercise-Induced Circulating microRNAs: Potential Key Factors in the Control of Breast Cancer.

Losses in skeletal muscle mass, strength, and metabolic function are harmful in the pathophysiology of serious diseases, including breast cancer. Physical exercise training is an effective non-pharmacological strategy to improve health and quality of life in patients with breast cancer, mainly through positive effects on skeletal muscle mass, strength, and metabolic function. Emerging evidence has also highlighted the potential of exercise-induced crosstalk between skeletal muscle and cancer cells as one of the mechanisms controlling breast cancer progression. This intercellular communication seems to be mediated by a group of skeletal muscle molecules released in the bloodstream known as myokines. Among the myokines, exercise-induced circulating microRNAs (c-miRNAs) are deemed to mediate the antitumoral effects produced by exercise training through the control of key cellular processes, such as proliferation, metabolism, and signal transduction. However, there are still many open questions regarding the molecular basis of the exercise-induced effects on c-miRNA on human breast cancer cells. Here, we present evidence regarding the effect of exercise training on c-miRNA expression in breast cancer, along with the current gaps in the literature and future perspectives.

Prediction of SARS-CoV Interaction with Host Proteins during Lung Aging Reveals a Potential Role for TRIB3 in COVID-19.

COVID-19 is prevalent in the elderly. Old individuals are more likely to develop pneumonia and respiratory failure due to alveolar damage, suggesting that lung senescence may increase the susceptibility to SARS-CoV-2 infection and replication. Considering that human coronavirus (HCoVs; SARS-CoV-2 and SARS-CoV) require host cellular factors for infection and replication, we analyzed Genotype-Tissue Expression (GTEx) data to test whether lung aging is associated with transcriptional changes in human protein-coding genes that potentially interact with these viruses. We found decreased expression of the gene tribbles homolog 3 (TRIB3) during aging in male individuals, and its protein was predicted to interact with HCoVs nucleocapsid protein and RNA-dependent RNA polymerase. Using publicly available lung single-cell data, we found TRIB3 expressed mainly in alveolar epithelial cells that express SARS-CoV-2 receptor ACE2. Functional enrichment analysis of age-related genes, in common with SARS-CoV-induced perturbations, revealed genes associated with the mitotic cell cycle and surfactant metabolism. Given that TRIB3 was previously reported to decrease virus infection and replication, the decreased expression of TRIB3 in aged lungs may help explain why older male patients are related to more severe cases of the COVID-19. Thus, drugs that stimulate TRIB3 expression should be evaluated as a potential therapy for the disease.

Acute/Chronic Responses of Combined Training on Serum Pro-thermogenic/Anti-inflammatory Inducers and Its Relation With Fed and Fasting State in Overweight Type 2 Diabetic Individuals.

Concentrations of pro-thermogenic/anti-inflammatory inductors are influenced by fed/fasting, sedentary/trained states, and metabolic pattern. However, there is a lack of information on the interactions of these conditions, especially in humans. Thus, the present study aimed to evaluate the chronic and acute training responses as well as the fed/fasted states of serum pro-thermogenic/anti-inflammatory inducers in overweight type 2 diabetics individuals. Fifteen individuals with type 2 diabetes [body mass index (BMI): 29.61 ± 3.60 kg/m2; age: 50.67 ± 3.97 years] participated in the study. In the pre- and post-experimental periods, baseline clinical parameters analyses were performed. Pro-thermogenic/anti-inflammatory inductors were evaluated pre/post-baseline and before, shortly after, and after 30' and 60' in the first and last sessions of a 16-week combined training (CT) period. These inducers were also compared for fasting and feeding before and after the training period. CT has improved baseline physical fitness, metabolic pattern, and it has also increased interleukin (IL)33 and FNDC5/irisin. In the first training session, there was a decrease in IL4, IL13, and IL33, besides an increase in FNDC5/irisin, and natriuretic peptides. In the last training session, there was an increase in natriuretic peptides and bone morphogenic protein 4 (BMP4). Differences in responses between the first and last training sessions were observed at certain post-session times for IL4, IL33, and natriuretic peptides, always with higher concentrations occurring in the last session. In evaluating the area under the curve (AUC) of the first and last training session, FNDC5/irisin, natriuretics peptides, and meteorin-like showed increased areas in the last training session. The pre-training fed state showed an increase in IL4 and IL33, while in fasting there was an increase in meteorin-like, natriuretic peptides, and FNDC5/irisin. In the post-training, IL4, IL13, and IL33 were increased in the fed state, while meteorin-like, natriuretic peptides, and FNDC5/irisin remained increased in the fast. Adaptation to physical training and a better metabolic pattern favor an improvement in the acute secretory pattern in part of pro-thermogenic and anti-inflammatory substances analyzed. The fed and fasting states also interfere differently in these substances, where fasting interferes with the increase of myokines, while the fed state induces an increase in interleukins. Clinical Trial Registration: [http://www.ensaiosclinicos.gov.br/rg/RBR-62n5qn/], identifier [U1111-1202-1476].

Diversity of polymyxin resistance mechanisms among Acinetobacter baumannii clinical isolates.

Polymyxins have become drugs of last resort for treatment of multi-drug resistant (MDR) Gram-negative infections. However, the mechanisms of resistance to this compound have not been completely elucidated. In this study, we evaluated the mechanisms of resistance to this antimicrobial in two A. baumannii clinical isolates, respectively, susceptible (A027) and resistant (A009) to polymyxin B before and after polymyxin B exposure (A027ind and A009ind). The pmrAB and lpxACD were sequenced and their transcriptional levels were analyzed by qRT-PCR. The bacterial cell morphology was evaluated by transmission electronic microscopy (TEM) and the membrane potential was measured using Zeta-potential analyzer. The virulence of strains was studied using a Caenorhabditis elegans model. Both clinical isolates exhibited an elevation of the polymyxin B MIC after exposure to this compound. On the other hand, A027ind showed decreased values of MIC for ß-lactams, aminoglycosides, vancomycin, teicoplanin, oxacillin and erythromycin. A027ind harbored two mutations in pmrB and the ISAba125 disrupting the lpxA. In contrast, A009ind strain exhibited increase of pmrB transcriptional level, after polymyxin B exposure, despite the absence of mutations in the pmrAB genes. The TEM images revealed a thicker and more electron-dense peptidoglycan layer for A009 than that of A027. The exposure to polymyxin B induced a strong condensation and darkening of intracellular material, mainly in A009ind. In addition, the surface charge of A009 was significantly less negative than the one of A027. Using the C. elegans model, only A027ind strain showed a reduction on virulence. The diversity of polymyxin B resistance mechanisms among A. baumannii strains evaluated in this study confirms the complexity of these mechanisms, which may vary depending of the background of each strain.

Increased bone loss and amount of osteoclasts in kinin B1 receptor knockout mice.

AIM: The pathophysiology of periodontal diseases involves aspects of immunity and bone remodelling. Considering the role of the kinin B1 receptor (Bdkrb1) in inflammation and healing, the purpose of this study was to evaluate the contribution of Bdkrb1 to the pathogenesis of periodontitis. MATERIAL AND METHODS: We used a model of ligature-induced experimental periodontitis (LIEP) in mice lacking Bdkrb1 (Bdkrb1(-/-) ) to test the role of this receptor in bone loss and cytokine secretion by lymph nodes cells. Angiotensin-converting enzyme inhibitor (ACEi) was used as a pharmacological strategy to support the genetic model. Also, autonomous effect of Bdkrb1 deletion was evaluated in osteoclasts precursors from bone marrow. RESULTS: Bdkrb1(-/-) mice exhibit increased bone loss and IL-17 secretion in response to LIEP when compared to wild type. LIEP does not modify TNF-α, IFN-γ and IL-10 levels in Bdkrb1(-/-) mice after 21 days. Bone marrow cells from Bdkrb1(-/-) displayed increased differentiation into functional osteoclasts with consistent artificial calcium phosphate degradation. Furthermore, treatment of mice with ACEi prevented bone destruction. CONCLUSION: Bdkrb1 participates in the pathogenesis of LIEP bone loss possibly through mechanisms that involve modulation of the TH 17 response, thereby demonstrating its role in the development of periodontitis.

Genetically altered animals in the study of the metabolic functions of peptide hormone systems.

PURPOSE OF REVIEW: Here we review the use of genetically altered animals to address the roles of peptide hormone systems in the modulation of energy homeostasis. Despite the disseminated use of transgenic techniques to establish the functional relevance of several peptide hormone systems, we focus on two multifunctional systems, the renin-angiotensin and the kallikrein-kinin systems. Initially, we explored the background information supporting the functional aspects of these systems, followed by novel knowledge obtained with the phenotypic characterization of genetically altered animals. RECENT FINDINGS: A role for the renin-angiotensin system in the regulation of adiposity and glucose metabolism has been suggested. Studies using genetically altered animals not only confirmed the physiological relevance of angiotensin II in the control of energy homeostasis, but also revealed that the adipose tissue renin-angiotensin system participates in the endocrine modulation of cardiovascular and renal function. On the other hand, the involvement of the kallikrein-kinin system with metabolic processes was not so obvious. Recent reports using genetically altered animals, however, provided strong evidence to support an important role for kinins in the control of glucose homeostasis and energy balance. SUMMARY: Here we present examples of how genetically altered animals contribute to a final postulation of the physiological roles of certain hormone systems, bringing new insights into the field.

Leptin deficiency leads to the regulation of kinin receptors expression in mice.

Kinins are vasoactive and pro-inflammatory peptides generated by the cleavage of the kininogen by kallikreins. Two kinin receptors have been described and denominated B1 and B2. Obesity frequently accompanies other pathologies, such as diabetes and hypertention. The clustering of these pathologies is usually known as "metabolic syndrome". Mice lacking leptin gene (ob/ob) are severely obese and hyperphagic. Using quantitative RT-PCR analysis of B1 and B2 mRNAs expression, we described for the first time a correlation between the kallikrein-kinin system (KKS) and severe obesity in mice. The ob/ob mice presented lower expression of B2 mRNA in the white adipose tissue (WAT) and hypothalamus, both primary sites for neuroendocrine regulation of the energetic metabolism. B1 mRNA, however, is overexpressed in these tissues of ob/ob mice. An upregulation of the B1 mRNA has also been seen in liver, abdominal aorta and stomach fundus. However, different from the lean mice, the expression of the B1 mRNA in brown adipose tissue (BAT) and heart is completely abolished. Our data show that kinin receptors are differently modulated in distinct tissues in obesity. These findings suggest a connection between the KKS and obesity, and suggest that kinin receptors could be involved in the ethiopathogenesis of the metabolic syndrome.