Leptin is a physiological regulator of skeletal muscle angiogenesis and is locally produced by PDGFRα and PDGFRβ expressing perivascular cells

Higher Levels of Serum Leptin Are Linked with a Reduction in Gait Stability: A Sex-Based Association

Gait stability prevents falls and injuries during physical activities. Muscle strength, aging, and co-existing chronic diseases are factors that affect gait stability. Leptin is an adipokine with pro-inflammatory properties. Several reports demonstrated an association between serum leptin and a reduction in muscle strength. Given the above relationships, we hypothesized that serum leptin could be associated with gait stability. To test this, 146 apparently healthy university students were recruited. Data collection involved anthropometric measurements, physical activity (PA) data, gait parameters, and serum leptin levels. A gait instability index was derived from the percentages of double support time and walking asymmetry (WA) collected from smartphones. Females demonstrated higher leptin levels and WA despite a lower body mass index (BMI). Lower PA levels were also observed among females. Leptin levels were negatively correlated with WA, step count, and vigorous PA (p < 0.05). These correlations remained significant following correction for leptin by BMI. Using logistic regression, a higher leptin-to-BMI ratio was associated with high gait instability (OR = 9.97, 95%CI: 4.17-23.84, p < 0.001). After stratification by sex, this association was only evident among females (OR = 6.09, 95%CI: 1.04-35.56, p = 0.045). These findings suggest a sex-based association between serum leptin and gait stability among apparently healthy students.

Do Lifestyle Interventions Mitigate the Oxidative Damage and Inflammation Induced by Obesity in the Testis?

Obesity results from a disproportionate accumulation of fat and has become a global health concern. The increase in adipose tissue is responsible for several systemic and testicular changes including hormone levels (leptin, adiponectin, testosterone, estrogen), inflammatory cytokines (increase in TNF-α and IL-6 and decrease in IL-10), and redox state (increase in reactive oxygen species and reduction in antioxidant enzymes). This results in poor sperm quality and compromised fertility in men with obesity. Lifestyle modifications, particularly diet transition to caloric restriction and physical exercise, are reported to reverse these negative effects. Nevertheless, precise mechanisms mediating these benefits, including how they modulate testicular oxidative stress, inflammation, and metabolism, remain to be fully elucidated. The main pathway described by which these lifestyle interventions reverse obesity-induced oxidative damage is the Nrf2-SIRT1 axis, which modulates the overexpression of antioxidant defenses. Of note, some of the detrimental effects of obesity on the testis are inherited by the descendants of individuals with obesity, and while caloric restriction reverses some of these effects, no significant work has been carried out regarding physical exercise. This review discusses the consequences of obesity-induced testicular oxidative stress on adult and pediatric populations, emphasizing the therapeutic potential of lifestyle to mitigate these detrimental effects.

Crosstalk between fat tissue and muscle, brain, liver, and heart in obesity: cellular and molecular perspectives

A high-fat diet and physical inactivity are key contributors to obesity, predisposing individuals to various chronic diseases, such as cardiovascular disease and diabetes, which involve multiple organs and tissues. To better understand the role of multi-organ interaction mechanisms in the rising incidence of obesity and its associated chronic conditions, treatment and prevention strategies are being extensively investigated. This review examines the signaling mechanisms between different tissues and organs, with a particular focus on the crosstalk between adipose tissue and the muscle, brain, liver, and heart, and potentially offers new strategies for the treatment and management of obesity and its complications.

[The role of leptin in endometrium disorders: literature review]

Leptin is not only the main regulator of energy balance, but also it affects the reproductive and immune systems. Leptin and its receptors are expressed in the endometrium and are actively involved in the embryo implantation. According to numerous studies, expression and level changes of leptin are associated with the inflammatory and autoimmune diseases, including endometriosis and chronic endometritis. Hyperplastic and inflammatory diseases of the uterus are accompanied by a violation of the receptivity of the endometrium due to the dysregulation of many factors involved in proliferation, vascularization and decidualization of cells. Activity of most of these factors is due to the leptin action, however, there are no studies of the direct effect of leptin in the pathogenesis of disorders of the endometrium in hyperplastic and inflammatory diseases.Thus, the purpose of this literature review was to describe the putative molecular mechanisms of the effect of leptin on the development of endometrial pathology.Literature search was carried out from 03/20/2023 to 05/11/2023 using scientific literature databases: NCBI PubMed, Google Scholar (foreign sources), Cyberleninka, Elibrary (domestic sources): references for the period 1995-2023 were analyzed. The following keywords were used for the search: leptin, endometrial dysfunction, endometrial receptivity, inflammation, pelvic inflammatory disease.

Leptin signaling promotes blood vessel formation in the Xenopus tail during the embryo-larval transition

The signals that regulate peripheral blood vessel formation during development are still under investigation. The hormone leptin promotes blood vessel formation, adipose tissue establishment and expansion, tumor growth, and wound healing, but the underlying mechanisms for these actions are currently unknown. We investigated whether leptin promotes angiogenesis in the developing tail fin using embryonic transgenic xflk-1:GFP Xenopus laevis, which express a green fluorescent protein on vascular endothelial cells to mark blood vessels. We found that leptin protein is expressed in endothelial cells of developing blood vessels and that leptin treatment via injection increased phosphorylated STAT3 signaling, which is indicative of leptin activation of its receptor, in blood vessels of the larval tail fin. Leptin administration via media increased vessel length, branching, and reconnection with the cardinal vein, while decreased leptin signaling via immunoneutralization had an opposing effect on vessel development. We also observed disorganization of major vessels and microvessels of the tail fin and muscle when leptin signaling was decreased. Reduced leptin signaling lowered mRNA expression of cenpk, gpx1, and mmp9, markers for cell proliferation, antioxidation, and extracellular matrix remodeling/cell migration, respectively, in the developing tail, providing insight into three possible mechanisms underlying leptin's promotion of angiogenesis. Together these results illustrate that leptin levels are correlated with embryonic angiogenesis and that leptin coordinates multiple aspects of blood vessel growth and development, showing that leptin is an important morphogen during embryonic development.

Genetic analysis of impaired healing responses after periodontal therapy in type 2 diabetes: Clinical and in vivo studies

OBJECTIVE

This study aims to investigate the mechanisms underlying the impaired healing response by diabetes after periodontal therapy.

BACKGROUND

Outcomes of periodontal therapy in patients with diabetes are impaired compared with those in patients without diabetes. However, the mechanisms underlying impaired healing response to periodontal therapy have not been sufficiently investigated.

MATERIALS AND METHODS

Zucker diabetic fatty (ZDF) and lean (ZL) rats underwent experimental periodontitis by ligating the mandibular molars for one week. The gingiva at the ligated sites was harvested one day after ligature removal, and gene expression was comprehensively analyzed using RNA-Seq. In patients with and without type 2 diabetes (T2D), the corresponding gene expression was quantified in the gingiva of the shallow sulcus and residual periodontal pocket after non-surgical periodontal therapy.

RESULTS

Ligation-induced bone resorption and its recovery after ligature removal were significantly impaired in the ZDF group than in the ZL group. The RNA-Seq analysis revealed 252 differentially expressed genes. Pathway analysis demonstrated the enrichment of downregulated genes involved in the peroxisome proliferator-activated receptor (PPAR) signaling pathway. PPARα and PPARγ were decreased in mRNA level and immunohistochemistry in the ZDF group than in the ZL group. In clinical, probing depth reduction was significantly less in the T2D group than control. Significantly downregulated expression of PPARα and PPARγ were detected in the residual periodontal pocket of the T2D group compared with those of the control group, but not in the shallow sulcus between the groups.

CONCLUSIONS

Downregulated PPAR subtypes expression may involve the impaired healing of periodontal tissues by diabetes.

Muscle quality, physical performance, and comorbidity are predicted by circulating procollagen type III N-terminal peptide (P3NP): the InCHIANTI follow-up study

Sarcopenia is characterized by skeletal muscle quantitative and qualitative alterations. A marker of collagen turnover, procollagen type III N-terminal peptide (P3NP), seems to be related to those conditions. This study aims to assess the predictive role of P3NP in muscle density and physical performance changes. In the InCHIANTI study, a representative sample from the registry lists of two towns in Tuscany, Italy, was recruited. Baseline data was collected in 1998, and follow-up visits were conducted every 3 years. Out of the 1453 participants enrolled at baseline, this study includes 1052 participants. According to P3NP median levels, population was clustered in two groups; 544 (51.7%) of the 1052 subjects included were classified in the low median levels (LM-P3NP); at the baseline, they were younger, had higher muscle density, and performed better at the Short Physical Performance Battery (SPPB), compared to the high-median group (HM-P3NP).LM-P3NP cases showed a lower risk to develop liver chronic diseases, CHF, myocardial infarction, and osteoarthritis. HM-P3NP levels were associated with a longitudinal reduction of muscle density, and this effect was potentiated by the interaction between P3NP and leptin. Moreover, variation in physical performance was inversely associated with high level of P3NP, and directly associated with high fat mass, and with the interaction between P3NP and muscle density. Our data indicate that P3NP is associated with the aging process, affecting body composition, physical performance, and clinical manifestations of chronic degenerative age-related diseases.

MuSCs and IPCs: roles in skeletal muscle homeostasis, aging and injury

Skeletal muscle is a highly specialized tissue composed of myofibres that performs crucial functions in movement and metabolism. In response to external stimuli and injuries, a range of stem/progenitor cells, with muscle stem cells or satellite cells (MuSCs) being the predominant cell type, are rapidly activated to repair and regenerate skeletal muscle within weeks. Under normal conditions, MuSCs remain in a quiescent state, but become proliferative and differentiate into new myofibres in response to injury. In addition to MuSCs, some interstitial progenitor cells (IPCs) such as fibro-adipogenic progenitors (FAPs), pericytes, interstitial stem cells expressing PW1 and negative for Pax7 (PICs), muscle side population cells (SPCs), CD133-positive cells and Twist2-positive cells have been identified as playing direct or indirect roles in regenerating muscle tissue. Here, we highlight the heterogeneity, molecular markers, and functional properties of these interstitial progenitor cells, and explore the role of muscle stem/progenitor cells in skeletal muscle homeostasis, aging, and muscle-related diseases. This review provides critical insights for future stem cell therapies aimed at treating muscle-related diseases.

Interaction between Selected Adipokines and Musculoskeletal and Cardiovascular Systems: A Review of Current Knowledge

Adipokines are substances secreted by adipose tissue that are receiving increasing attention. The approach to adipose tissue has changed in recent years, and it is no longer looked at as just a storage organ but its secretion and how it influences systems in the human body are also looked at. The role of adipokine seems crucial in developing future therapies for pathologies of selected systems. In this study, we look at selected adipokines, leptin, adiponectin, chemerin, resistin, omentin-1, nesfatin, irisin-1, visfatin, apelin, vaspin, heparin-binding EGF-like growth factor (HB-EGF), and TGF-β2, and how they affect systems in the human body related to physical activity such as the musculoskeletal and cardiovascular systems.

Case report: Rapid improvements of anorexia nervosa and probable myalgic encephalomyelitis/chronic fatigue syndrome upon metreleptin treatment during two dosing episodes

A comorbidity of anorexia nervosa (AN) and myalgic encephalomyelitis (ME/CSF) is uncommon. A 17 years-old male adolescent with possible onset of ME/CFS after an Epstein Barr Virus infection (EBV) and later onset of AN during a second period of weight loss was twice treated off-label with metreleptin for 15 and 11 days, respectively. As in previous cases, eating disorder specific cognitions and mood improved. Interestingly, fatigue and post-exertional muscle pain (P-EMP) improved, too. We discuss potential mechanisms. Treatment with metreleptin may prove beneficial in AN and in ME/CSF associated with substantial weight loss.

Role and Mechanism of a Micro-/Nano-Structured Porous Zirconia Surface in Regulating the Biological Behavior of Bone Marrow Mesenchymal Stem Cells

Zirconia as a promising dental implant material has attracted much attention in recent years. Improving the bone binding ability of zirconia is critical for clinical applications. Here, we established a distinct micro-/nano-structured porous zirconia through dry-pressing with addition of pore-forming agents followed by hydrofluoric acid etching (POROHF). Porous zirconia without hydrofluoric acid treatment (PORO), sandblasting plus acid-etching zirconia, and sintering zirconia surface were applied as controls. After human bone marrow mesenchymal stem cells (hBMSCs) were seeded on these four groups of zirconia specimens, we observed the highest cell affinity and extension on POROHF. In addition, the POROHF surface displayed an improved osteogenic phenotype in contrast to the other groups. Moreover, the POROHF surface facilitated angiogenesis of hBMSCs, as confirmed by optimal stimulation of vascular endothelial growth factor B and angiopoietin 1 (ANGPT1) expression. Most importantly, the POROHF group demonstrated the most obvious bone matrix development in vivo. To investigate further the underlying mechanism, RNA sequencing was employed and critical target genes modulated by POROHF were identified. Taken together, this study established an innovative micro-/nano-structured porous zirconia surface that significantly promoted osteogenesis and investigated the potential underlying mechanism. Our present work will improve the osseointegration of zirconia implants and help further clinical applications.

Current knowledge of leptin in wound healing: A collaborative review

Efficacious wound healing is still a major concern for global healthcare due to the unsatisfactory outcomes under the current treatments. Leptin, an adipocyte-derived hormone, mainly acts in the hypothalamus and plays crucial roles in various biological processes. Recently, an increasing number of researches have shown that leptin played an important role in the wound healing process. In this review, we presented a first attempt to capture the current knowledge on the association between leptin and wound healing. After a comprehensive review, the molecular mechanisms underlying leptin in wound healing were speculated to be correlated to the regulation of inflammation of the macrophage and lymphocytes, angiogenesis, re-epithelialization, proliferation, and differentiation of fibroblasts. The affected genes and the signal pathways were multiple. For example, leptin was reported to ameliorate wound healing by its anti-inflammatory action, which might be correlated to the activation STAT1 and STAT3 via p38 MAPK or JAK2. However, the understanding of the specific role in each process (e.g., inflammatory, proliferative, and maturation phase) of wound repair is not entirely clear, and further studies are still warranted in both macrostructural and microscale factors. Therefore, identifying and validating the biological mechanisms of leptin in wound healing is of great significance to develop potential therapeutic targets for the treatment of wound healing in clinical practice.

Leptin Promotes Angiogenesis via Pericyte STAT3 Pathway upon Intracerebral Hemorrhage

Angiogenesis is a vital endogenous brain self-repair processes for neurological recovery after intracerebral hemorrhage (ICH). Increasing evidence suggests that leptin potentiates angiogenesis and plays a beneficial role in stroke. However, the proangiogenic effect of leptin on ICH has not been adequately explored. Moreover, leptin triggers post-ICH angiogenesis through pericyte, an important component of forming new blood vessels, which remains unclear. Here, we reported that exogenous leptin infusion dose-dependent promoted vascular endothelial cells survival and proliferation at chronic stage of ICH mice. Additionally, leptin robustly ameliorated pericytes loss, enhanced pericytes proliferation and migration in ICH mice in vivo, and in ICH human brain microvascular pericytes (HBVPC) in vitro. Notably, we showed that pericytes-derived pro-angiogenic factors were responsible for enhancing the survival, proliferation and tube formation followed leptin treatment in human brain microvascular endothelial cells (HCMEC/D3)/HBVPC co-culture models. Importantly, considerable improvements in neurobehavioral function and hostile microenvironment were observed in leptin treatment ICH mice, indicating that better vascular functionality post ICH improves outcome. Mechanistically, this study unveiled that leptin boost post-ICH angiogenesis potentially through modulation of leptin receptor (leptinR)/Signal Transducer and Activator of Transcription 3 (STAT3) signaling pathway in pericyte. Thus, leptin may be a lucrative option for the treatment of ICH.

E-Selectin/AAV2/2 Gene Therapy Alters Angiogenesis and Inflammatory Gene Profiles in Mouse Gangrene Model

For patients with chronic limb-threatening ischemia and limited revascularization options, alternate means for therapeutic angiogenesis and limb salvage are needed. E-selectin is a cell adhesion molecule that is critical for inflammation and neovascularization in areas of wound healing and ischemia. Here, we tested the efficacy of modifying ischemic limb tissue by intramuscular administration of E-selectin/AAV2/2 (adeno-associated virus serotype 2/2) to modulate angiogenic and inflammatory responses in a murine hindlimb gangrene model. Limb appearance, reperfusion, and functional recovery were assessed for 3 weeks after induction of ischemia. Mice receiving E-selectin/AAV2/2 gene therapy had reduced gangrene severity, increased limb and footpad perfusion, enhanced recruitment of endothelial progenitor cells, and improved performance on treadmill testing compared to control group. Histologically, E-selectin/AAV2/2 gene therapy was associated with increased vascularity and preserved myofiber integrity. E-selectin/AAV2/2 gene therapy also upregulated a panel of pro-angiogenic genes yet downregulated another group of genes associated with the inflammatory response. This novel gene therapy did not induce adverse effects on coagulability, or hematologic, hepatic, and renal function. Our findings highlight the potential of E-selectin/AAV2/2 gene therapy for improving limb perfusion and function in patients with chronic limb-threatening ischemia.

Cardiac pericyte reprogramming by MEK inhibition promotes arteriologenesis and angiogenesis of the ischemic heart

Pericytes (PCs) are abundant yet remain the most enigmatic and ill-defined cell population in the heart. Here, we investigated whether PCs can be reprogrammed to aid neovascularization. Primary PCs from human and mouse hearts acquired cytoskeletal proteins typical of vascular smooth muscle cells (VSMCs) upon exclusion of EGF/bFGF, which signal through ERK1/2, or upon exposure to the MEK inhibitor PD0325901. Differentiated PCs became more proangiogenic, more responsive to vasoactive agents, and insensitive to chemoattractants. RNA sequencing revealed transcripts marking the PD0325901-induced transition into proangiogenic, stationary VSMC-like cells, including the unique expression of 2 angiogenesis-related markers, aquaporin 1 (AQP1) and cellular retinoic acid-binding protein 2 (CRABP2), which were further verified at the protein level. This enabled us to trace PCs during in vivo studies. In mice, implantation of Matrigel plugs containing human PCs plus PD0325901 promoted the formation of αSMA+ neovessels compared with PC only. Two-week oral administration of PD0325901 to mice increased the heart arteriolar density, total vascular area, arteriole coverage by PDGFRβ+AQP1+CRABP2+ PCs, and myocardial perfusion. Short-duration PD0325901 treatment of mice after myocardial infarction enhanced the peri-infarct vascularization, reduced the scar, and improved systolic function. In conclusion, myocardial PCs have intrinsic plasticity that can be pharmacologically modulated to promote reparative vascularization of the ischemic heart.

The Prognosis of Leptin rs2167270 G > A (G19A) Polymorphism in the Risk of Cancer: A Meta-Analysis

Background

Although the effect of the LEP G19A (rs2167270) polymorphism on cancers is assumed, the results of its influence have been contradictory. A meta-analysis was conducted to precisely verify the relationships between LEP G19A and the development of digestion-related cancers.

Methods

Investigators systematically searched the literature in PubMed, Embase, and Web of Science and used STATA software 14.0 for the meta-analysis. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the associations. Subgroup analyses stratified by ethnicity, cancer type, and cancer system were further conducted to assess the relationship between the LEP G19A polymorphism and digestion-related cancers.

Results

In the overall population, we found a significant relationship with overall cancer (allele comparison: OR = 0.921, p = 0.000; dominant comparison: OR = 0.923, p = 0.004; recessive comparison: OR = 0.842, p = 0.000; homozygote model: OR = 0.0843, p = 0.001). In a subgroup analysis conducted by ethnicity, we obtained significant results in Asians (Asian allele comparison: OR = 0.885, p = 0.000; dominant comparison: OR = 0.862, p = 0.000; homozygote model: OR = 0.824, p = 0.039; and heterozygote comparison: OR = 0.868, p = 0.000) but not in Caucasians. In a subgroup analysis conducted by cancer type and cancer system, we obtained significant results that the LEP G19A polymorphism may decrease the risk of colorectal cancer, esophageal cancer, digestive system cancer, and urinary system cancer.

Conclusions

This meta-analysis revealed that the LEP G19A polymorphism may decrease the risk of cancer.

Leptin as a Biomarker of Stress: A Systematic Review and Meta-Analysis

BACKGROUND

Leptin is a satiety hormone mainly produced by white adipose tissue. Decreasing levels have been described following acute stress.

OBJECTIVE

To conduct a systematic review and meta-analysis to determine if leptin can be a biomarker of stress, with levels decreasing following acute stress.

METHODS

PubMed, Cochrane Library, Embase, and ScienceDirect were searched to obtain all articles studying leptin levels after acute stress on 15 February 2021. We included articles reporting leptin levels before and after acute stress (physical or psychological) and conducted random effects meta-analysis (DerSimonian and Laird approach). We conducted Meta-regressions and sensitivity analyses after exclusion of groups outside the metafunnel.

RESULTS

We included seven articles-four cohort and three case-control studies-(28 groups) from 27,983 putative articles. Leptin levels decreased after the stress intervention (effect size = -0.34, 95%CI -0.66 to -0.02) compared with baseline levels, with a greater decrease after 60 min compared to mean decrease (-0.45, -0.89 to -0.01) and in normal weight compared to overweight individuals (-0.79, -1.38 to -0.21). There was no difference in the overweight population. Sensitivity analyses demonstrated similar results. Levels of leptin after stress decreased with sex ratio-i.e., number of men/women-(-0.924, 95%CI -1.58 to -0.27) and increased with the baseline levels of leptin (0.039, 0.01 to 0.07).

CONCLUSIONS

Leptin is a biomarker of stress, with a decrease following acute stress. Normal-weight individuals and women also have a higher variation of leptin levels after stress, suggesting that leptin may have implications in obesity development in response to stress in a sex-dependent manner.

Voluntary Wheel Running Exercise Improves Aging-Induced Sarcopenia via Activation of Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1α/Fibronectin Type III Domain-Containing Protein 5/Adenosine Monophosphate-Activated Protein Kinase Signaling Pathway

Purpose

In this study, the protective effect of voluntary wheel running exercise on muscle loss and muscle weakness in gastrocnemius of old rats was investigated. The association of voluntary wheel exercise with the peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α)/fibronectin type III domain-containing protein 5 (FNDC5)/adenosine monophosphate- activated protein kinase (AMPK) signaling pathway and vascular endothelial growth factor (VEGF) expression was also evaluated.

Methods

Six-month-old and 22-month-old male rats were used for this experiment. The rats in voluntary wheel running exercise groups were performed wheel running for 2 months. Weight bearing test for walking strength, rotarod test for motor coordination and balance, hematoxylin and eosin (H&E) staining for histological changes in the muscle tissues, Western blot analysis for PGC-1α, FNDC5, AMPK, immunofluorescence for VEGF were conducted.

Results

Decreased muscle mass, strength, and coordination due to aging were associated with a decrease in the PGC-1α/FNDC5/AMPK signaling pathway in the gastrocnemius. Voluntary wheel running exercise enhanced VEGF expression by activating the PGC-1α/FNDC5/AMPK signaling pathway, then increased muscle mass, strength, and coordination.

Conclusions

It has been suggested that voluntary wheel running exercise alleviates symptoms of urological diseases that are difficult to treat. Wheel running exercise is a good therapeutic strategy to prevent or treat aging-related sarcopenia.

High Glucose Treatment Limits Drosha Protein Expression and Alters AngiomiR Maturation in Microvascular Primary Endothelial Cells via an Mdm2-dependent Mechanism

Diabetes promotes an angiostatic phenotype in the microvascular endothelium of skeletal muscle and skin. Angiogenesis-related microRNAs (angiomiRs) regulate angiogenesis through the translational repression of pro- and anti-angiogenic genes. The maturation of micro-RNA (miRs), including angiomiRs, requires the action of DROSHA and DICER proteins. While hyperglycemia modifies the expression of angiomiRs, it is unknown whether high glucose conditions alter the maturation process of angiomiRs in dermal and skeletal muscle microvascular endothelial cells (MECs). Compared to 5 mM of glucose, high glucose condition (30 mM, 6-24 h) decreased DROSHA protein expression, without changing DROSHA mRNA, DICER mRNA, or DICER protein in primary dermal MECs. Despite DROSHA decreasing, high glucose enhanced the maturation and expression of one angiomiR, miR-15a, and downregulated an miR-15a target: Vascular Endothelial Growth Factor-A (VEGF-A). The high glucose condition increased Murine Double Minute-2 (MDM2) expression and MDM2-binding to DROSHA. Inhibition of MDM2 prevented the effects evoked by high glucose on DROSHA protein and miR-15a maturation in dermal MECs. In db/db mice, blood glucose was negatively correlated with the expression of skeletal muscle DROSHA protein, and high glucose decreased DROSHA protein in skeletal muscle MECs. Altogether, our results suggest that high glucose reduces DROSHA protein and enhances the maturation of the angiostatic miR-15a through a mechanism that requires MDM2 activity.

FAM19A5/S1PR1 signaling pathway regulates the viability and proliferation of mantle cell lymphoma

Several intracellular pathological processes have been reported to be regulated by the FAM19A5/S1PR1 signaling pathway. However, the role of FAM19A5/S1PR1 signaling pathway in the viability and proliferation of mantle cell lymphoma is not been completely understood. The task of this study is to explore the influence of FAM19A5/S1PR1 signaling pathway in affecting the survival and growth of mantle cell lymphoma. shRNAs against FAM19A5 or S1PR1 were transfected into mantle cell lymphom. Cell viability and proliferation were measured through MTT assay and CCK8 assay, respectively. Our results demonstrated that loss of FAM19A5 significantly reduced the viability of mantle cell lymphom, an effect that was followed by a drop in cell proliferation capacity. Besides, inhibition of S1PR1 also impairs cell survival and interrupt mantle cell lymphom proliferation in vitro. Taken together, our results illustrate that FAM19A5/S1PR1 signaling pathway is associated with the regulation of mantle cell lymphom viability and proliferation. This finding will provide a potential target for the treatment of malignant lymphoma in the clinical practice.

Effects of leptin-modified human placenta-derived mesenchymal stem cells on angiogenic potential and peripheral inflammation of human umbilical vein endothelial cells (HUVECs) after X-ray radiation

Combined radiation-wound injury (CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angiogenesis and inflammation. We established a sustained and stable leptin expression system to study the mechanism. A lentivirus method was employed to explore the angiogenic potential and peripheral inflammation of irradiated human umbilical vein endothelial cells (HUVECs). Leptin was transfected into human placenta-derived mesenchymal stem cells (HPMSCs) with lentiviral vectors. HUVECs were irradiated by X-ray at a single dose of 20 Gy. Transwell migration assay was performed to assess the migration of irradiated HUVECs. Based on the Transwell systems, co-culture systems of HPMSCs and irradiated HUVECs were established. Cell proliferation was measured by cell counting kit-8 (CCK-8) assay. The secretion of pro-inflammatory cytokines (human granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin (IL)-1α, IL-6, and IL-8) was detected by enzyme-linked immunosorbent assay (ELISA). The expression of pro-angiogenic factors (vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF)) mRNA was detected by real-time quantitative polymerase chain reaction (RT-qPCR) assay. Relevant molecules of the nuclear factor-κB (NF-κB) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways were detected by western blot assay. Results showed that leptin-modified HPMSCs (HPMSCs/ leptin) exhibited better cell proliferation, migration, and angiogenic potential (expressed more VEGF and bFGF). In both the single HPMSCs/leptin and the co-culture systems of HPMSCs/leptin and irradiated HUVECs, the increased secretion of pro-inflammatory cytokines (human GM-CSF, IL-1α, and IL-6) was associated with the interaction of the NF-κB and JAK/STAT signaling pathways. We conclude that HPMSCs/leptin could promote angiogenic potential and peripheral inflammation of HUVECs after X-ray radiation.

Elevated serum leptin levels are associated with low muscle strength and muscle quality in male patients undergoing chronic hemodialysis

Objectives:

Low muscle strength and poor muscle quality are highly prevalent in patients with chronic hemodialysis (HD), which lead to an increased risk of poor clinical outcomes. Leptin dysregulation is common in HD patients. Given that leptin receptors are abundant in skeletal muscle, there may be a link between leptin and muscle strength. The cross-sectional study aimed to explore the correlation of serum leptin levels with muscle strength and muscle quality in patients with chronic HD.

Materials and Methods:

A total of 118 chronic HD patients were included in this study. Basic characteristics, handgrip strength, body composition were assessed, and blood samples for serum leptin levels and other biochemical test were obtained. We defined skeletal muscle index (SMI) as skeletal muscle mass/height² (kg/m²) and muscle quality as handgrip strength divided by mid-arm muscle circumference (MAMC). Patients were classified into tertile groups, according to sex-specific leptin levels.

Results:

We observed that patients in the higher leptin tertile tend to have a higher body weight, body mass index (BMI), body fat mass, MAMC, and SMI, while the handgrip strength and muscle quality were significantly lower. Bodyweight (r = 0.30; P = 0.001), BMI (r = 0.45; P = 0.001), body fat mass (r = 0.57;P < 0.001), and SMI (r = 0.22; P = 0.018) were positively and handgrip strength (r = −0.27; P = 0.003) and muscle quality (r = −0.35;P < 0.001) were negatively correlated with serum leptin levels, respectively. After adjusting multiple confounding factors, logarithmically transformed serum leptin levels were independently associated with handgrip strength (β = −3.29, P = 0.005) and muscle quality (β = −0.14, P = 0.009). However, gender-stratified models showed the associations were observed only in male, but not in female.

Conclusion:

We concluded that higher serum leptin levels are associated with low handgrip strength and poor muscle quality in male patients on chronic HD. Further studies are needed to clarify the gender differences and to evaluate the casual relationship between circulating leptin levels and muscle strength.

Deletion of SREBF1, a Functional Bone-Muscle Pleiotropic Gene, Alters Bone Density and Lipid Signaling in Zebrafish

Through a genome-wide analysis of bone mineral density (BMD) and muscle mass, identification of a signaling pattern on 17p11.2 recognized the presence of sterol regulatory element-binding factor 1 (SREBF1), a gene responsible for the regulation of lipid homeostasis. In conjunction with lipid-based metabolic functions, SREBF1 also codes for the protein, SREBP-1, a transcription factor known for its role in adipocyte differentiation. We conducted a quantitative correlational study. We established a zebrafish (ZF) SREBF1 knockout (KO) model and used a targeted customized lipidomics approach to analyze the extent of SREBF1 capabilities. For lipidomics profiling, we isolated the dorsal muscles of wild type (WT) and KO fishes, and we performed liquid chromatography-tandem mass spectrometry screening assays of these samples. In our analysis, we profiled 48 lipid mediators (LMs) derived from various essential polyunsaturated fatty acids to determine potential targets regulated by SREBF1, and we found that the levels of 11,12 epoxyeicosatrienoic acid (11,12-EET) were negatively associated with the number of SREBF1 alleles (P = 0.006 for a linear model). We also compared gene expression between KO and WT ZF by genome-wide RNA-sequencing. Significantly enriched pathways included fatty acid elongation, linoleic acid metabolism, arachidonic acid metabolism, adipocytokine signaling, and DNA replication. We discovered trends indicating that BMD in adult fish was significantly lower in the KO than in the WT population (P < 0.03). These studies reinforce the importance of lipidomics investigation by detailing how the KO of SREBF1 affects both BMD and lipid-signaling mediators, thus confirming the importance of SREBF1 for musculoskeletal homeostasis.

Matrine attenuates cardiomyocyte ischemia-reperfusion injury through activating AMPK/Sirt3 signaling pathway

Matrine has been found to affect cell viability and function. In the present study, we explored the cardioprotective role of matrine in cardiomyocyte damage under hypoxia/reoxygenation. In vitro, cardiomyocyte hypoxia/reoxygenation was used to mimic ischemia/reperfusion injury in the presence of matrine. After exposure to hypoxia/reoxygenation, cardiomyocyte viability was reduced and cell apoptosis was increased; this alteration was inhibited by matrine. At the molecular levels, Sirt3 and AMPK were significantly downregulated by hypoxia/reoxygenation injury whereas matrine administration was able to upregulate Sirt3 and AMPK expression and activity in the presence of hypoxia/reoxygenation. Interestingly, inhibition of Sirt3/AMPK pathway abolished the cardioprotective action of matrine on cardiomyocyte in the presence of hypoxia/reoxygenation injury, resulting into cardiomyocyte viability reduction and cell death augmentation. Altogether, our results demonstrated a novel role played by matrine in regulating cardiomyocyte viability and death in the presence of hypoxia/reoxygenation, with a potential application in the clinical practice for the treatment of patients with myocardial infarction.

Resveratrol Improves Bnip3-Related Mitophagy and Attenuates High-Fat-Induced Endothelial Dysfunction

Statin treatment reduces cardiovascular risk. However, individuals with well-controlled low-density lipoprotein (LDL) levels may remain at increased risk owing to persistent high triglycerides and low high-density lipoprotein cholesterol. Because resveratrol promotes glucose metabolism and mitigates cardiovascular disorders, we explored its mechanism of protective action on high-fat-induced endothelial dysfunction. Human umbilical venous endothelial cells were treated with oxidized LDL (ox-LDL) in vitro. Endothelial function, cell survival, proliferation, migration, and oxidative stress were analyzed through western blots, quantitative polymerase chain reaction, ELISA, and immunofluorescence. ox-LDL induced endothelial cell apoptosis, proliferation arrest, and mobilization inhibition, all of which resveratrol reduced. ox-LDL suppressed the activities of mitochondrial respiration complex I and III and reduced levels of intracellular antioxidative enzymes, resulting in reactive oxygen species overproduction and mitochondrial dysfunction. Resveratrol treatment upregulated Bnip3-related mitophagy and prevented ox-LDL-mediated mitochondrial respiration complexes inactivation, sustaining mitochondrial membrane potential and favoring endothelial cell survival. We found that resveratrol enhanced Bnip3 transcription through hypoxia-inducible factor 1 (HIF1) and 5' AMP-activated protein kinase (AMPK). Inhibition of AMPK and HIF1 abolished resveratrol-mediated protection of mitochondrial redox balance and endothelial viability. Together, these data demonstrate resveratrol reduces hyperlipemia-related endothelial damage by preserving mitochondrial homeostasis.

SirT3 activates AMPK-related mitochondrial biogenesis and ameliorates sepsis-induced myocardial injury

Sirtuin-3 (SirT3) and AMPK stimulate mitochondrial biogenesis, which increases mitochondrial turnover and cardiomyocyte regeneration. We studied the effects of SirT3, AMPK, and mitochondrial biogenesis on sepsis-induced myocardial injury. Our data showed that after treating cardiomyocytes with lipopolysaccharide, SirT3 and AMPK levels decreased, and this was followed by mitochondrial dysfunction and cardiomyocyte death. Overexpression of SirT3 activated the AMPK pathway and improved mitochondrial biogenesis, which is required to sustain mitochondrial redox balance, maintain mitochondrial respiration, and suppress mitochondrial apoptosis. Inhibition of mitochondrial biogenesis abolished SirT3/AMPK-induced cardioprotection by causing mitochondrial damage. These findings indicate that SirT3 reduces sepsis-induced myocardial injury by activating AMPK-related mitochondrial biogenesis.

Bcl-2-associated athanogene 5 overexpression attenuates catecholamine-induced vascular endothelial cell apoptosis

Bcl-2 associated athanogene 5 (Bag5) is a novel endoplasmic reticulum (ER) regulator. However, its role in catecholamine-induced endothelial cells damage has not been fully understood. In our study, catecholamine was used to mimic hypertension-related endothelial cell damage. Then, western blots, enzyme-linked immunosorbent assay, immunofluorescence, quantitative polymerase chain reaction and pathway analysis were conducted to analyze the role of Bag5 in endothelial cell damage in response to catecholamine. Our results indicated that the endothelial cell viability was impaired by catecholamine. Interestingly, Bag5 overexpression significantly reversed endothelial cell viability. Mechanistically, Bag5 overexpression inhibited ER stress, attenuated oxidative stress and repressed inflammation in catecholamine-treated endothelial cells. These beneficial effects finally contributed to endothelial cell survival under catecholamine treatment. Pathway analysis demonstrated that Bag5 was under the control of the mitogen-activated protein kinase (MAPK)-extracellular-signal-regulated kinase (ERK) signaling pathway. Reactivation of the MAPK-ERK pathway could upregulate Bag5 expression and thus promote endothelial cell survival through inhibiting oxidative stress, ER stress, and inflammation. Altogether, our results illustrate that Bag5 overexpression sustains endothelial cell survival in response to catecholamine treatment. This finding identifies Bag5 downregulation and the inactivated MAPK-ERK pathway as potential mechanisms underlying catecholamine-induced endothelial cell damage.

High-fat diet pre-conditioning improves microvascular remodelling during regeneration of ischaemic mouse skeletal muscle

AIM

Critical limb ischaemia (CLI) is characterized by inadequate angiogenesis, arteriolar remodelling and chronic myopathy, which are most severe in type 2 diabetic patients. Hypertriglyceridaemia, commonly observed in these patients, compromises macrovascular function. However, the effects of high-fat diet-induced increases in circulating lipids on microvascular remodelling are not established. Here, we investigated if high-fat diet would mimic the detrimental effect of type 2 diabetes on post-ischaemia vascular remodelling and muscle regeneration, using a mouse model of hindlimb ischaemia.

METHODS

Male C57Bl6/J mice were fed with normal or high-fat diets for 8 weeks prior to unilateral femoral artery ligation. Laser doppler imaging was used to assess limb perfusion recovery. Vascular recovery, inflammation, myofibre regeneration and fibrosis were assessed at 4 or 14 days post-ligation by histology and RNA analyses. Capillary-level haemodynamics were assessed by intravital microscopy of control and regenerating muscles 14 days post-ligation.

RESULTS

High-fat diet increased muscle succinate dehydrogenase activity and capillary-level oxygen supply. At 4 days post-ligation, no diet differences were detected in muscle damage, inflammatory infiltration or capillary activation. At 14 days post-ligation, high fat-fed mice displayed accelerated limb blood flow recovery, elevated capillary and arteriole densities as well as greater red blood cell supply rates and capillary-level oxygen supply. Regenerating muscles from high fat-fed mice displayed lower interstitial fat and collagen deposition.

CONCLUSION

The muscle-level adaptations to high-fat diet improved multiple aspects of muscle recovery in response to ischaemia and did not recapitulate the worse outcomes seen in diabetic CLI patients.

Melatonin improves mitochondrial biogenesis through the AMPK/PGC1α pathway to attenuate ischemia/reperfusion-induced myocardial damage

Cardiac ischemia/reperfusion injury is associated with reduced mitochondrial turnover and regeneration. There is currently no effective approach to stimulate mitochondrial biogenesis in the reperfused myocardium. In this study, we investigated whether melatonin could increase mitochondrial biogenesis and thus promote mitochondrial homeostasis in cardiomyocytes. Cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) injury with or without melatonin treatment, and various mitochondrial functions were measured. H/R injury repressed mitochondrial biogenesis in cardiomyocytes, whereas melatonin treatment restored mitochondrial biogenesis through the 5’ adenosine monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC1α) pathway. Melatonin enhanced mitochondrial metabolism, inhibited mitochondrial oxidative stress, induced mitochondrial fusion and prevented mitochondrial apoptosis in cardiomyocytes subjected to H/R injury. The melatonin-induced improvement in mitochondrial biogenesis was associated with increased cardiomyocyte survival during H/R injury. On the other hand, silencing of PGC1α attenuated the protective effects of melatonin on cardiomyocyte viability, thereby impairing mitochondrial bioenergetics, disrupting the mitochondrial morphology, and activating mitochondrial apoptosis. Thus, H/R injury suppressed mitochondrial biogenesis, while melatonin activated the AMPK/PGC1α pathway and restored mitochondrial biogenesis, ultimately protecting the reperfused heart.

Dynamin-related protein-1 promotes lung cancer A549 cells apoptosis through the F-actin/bax signaling pathway

Dynamin-related protein-1 (Drp1) has been found to be associated with cell death. The role of Drp1 in A549 cells death has not been explored. In this study, adenovirus-mediated Drp1 overexpression was used to investigate the influence of Drp1 on A549 cell viability with a focus on F-actin and Bax. Cell viability, protein expression, oxygen consumption, energy metabolism, and growth rate were measured through ELISA, qPCR, western blots and pathway analysis. Our results indicated that Drp1 overexpression promoted A549 cell death through apoptosis. Mechanistically, cytoskeletal F-actin was impaired and Bax expression was elevated in response to Drp1 overexpression. Besides, energy metabolism was reduced and oxygen consumption was interrupted. Therefore, our results demonstrated that A549 cell viability, apoptosis and growth were regulated by the Drp1/F-actin/Bax signaling pathways. These data explain a new role played by Drp1 in regulating cell viability and also provide a potential target to affect the progression of lung cancer through induction of cell death.

The impact of a high-fat diet in mice is dependent on duration and age, and differs between muscles

Prolonged high-fat diets (HFDs) can cause intramyocellular lipid (IMCL) accumulation that may negatively affect muscle function. We investigated the duration of a HFD required to instigate these changes, and whether the effects are muscle specific and aggravated in older age. Muscle morphology was determined in the soleus, extensor digitorum longus (EDL) and diaphragm muscles of female CD-1 mice from 5 groups: young fed a HFD for 8 weeks (YS-HFD, n=16), young fed a HFD for 16 weeks (YL-HFD, n=28) and young control (Y-Con, n=28). The young animals were 20 weeks old at the end of the experiment. Old (70 weeks) female CD-1 mice received either a normal diet (O-Con, n=30) or a HFD for 9 weeks (OS-HFD, n=30). Body mass, body mass index and intramyocellular lipid (IMCL) content increased in OS-HFD (P≤0.003). In the young mice, this increase was seen in YL-HFD and not YS-HFD (P≤0.006). The soleus and diaphragm fibre cross-sectional area (FCSA) in YL-HFD was larger than that in Y-Con (P≤0.004) while OS-HFD had a larger soleus FCSA compared with that of O-Con after only 9 weeks on a HFD (P<0.001). The FCSA of the EDL muscle did not differ significantly between groups. The oxidative capacity of fibres increased in young mice only, irrespective of HFD duration (P<0.001). High-fat diet-induced morphological changes occurred earlier in the old animals than in the young, and adaptations to HFD were muscle specific, with the EDL being least responsive.

Metabolic Coordination of Pericyte Phenotypes: Therapeutic Implications

Pericytes are mural vascular cells found predominantly on the abluminal wall of capillaries, where they contribute to the maintenance of capillary structural integrity and vascular permeability. Generally quiescent cells in the adult, pericyte activation and proliferation occur during both physiological and pathological vascular and tissue remodeling. A considerable body of research indicates that pericytes possess attributes of a multipotent adult stem cell, as they are capable of self-renewal as well as commitment and differentiation into multiple lineages. However, pericytes also display phenotypic heterogeneity and recent studies indicate that lineage potential differs between pericyte subpopulations. While numerous microenvironmental cues and cell signaling pathways are known to regulate pericyte functions, the roles that metabolic pathways play in pericyte quiescence, self-renewal or differentiation have been given limited consideration to date. This review will summarize existing data regarding pericyte metabolism and will discuss the coupling of signal pathways to shifts in metabolic pathway preferences that ultimately regulate pericyte quiescence, self-renewal and trans-differentiation. The association between dysregulated metabolic processes and development of pericyte pathologies will be highlighted. Despite ongoing debate regarding pericyte classification and their functional capacity for trans-differentiation in vivo, pericytes are increasingly exploited as a cell therapy tool to promote tissue healing and regeneration. Ultimately, the efficacy of therapeutic approaches hinges on the capacity to effectively control/optimize the fate of the implanted pericytes. Thus, we will identify knowledge gaps that need to be addressed to more effectively harness the opportunity for therapeutic manipulation of pericytes to control pathological outcomes in tissue remodeling.

Functional Relationship between Leptin and Nitric Oxide in Metabolism

Leptin, the product of the ob gene, was originally described as a satiety factor, playing a crucial role in the control of body weight. Nevertheless, the wide distribution of leptin receptors in peripheral tissues supports that leptin exerts pleiotropic biological effects, consisting of the modulation of numerous processes including thermogenesis, reproduction, angiogenesis, hematopoiesis, osteogenesis, neuroendocrine, and immune functions as well as arterial pressure control. Nitric oxide (NO) is a free radical synthesized from L-arginine by the action of the NO synthase (NOS) enzyme. Three NOS isoforms have been identified: the neuronal NOS (nNOS) and endothelial NOS (eNOS) constitutive isoforms, and the inducible NOS (iNOS). NO mediates multiple biological effects in a variety of physiological systems such as energy balance, blood pressure, reproduction, immune response, or reproduction. Leptin and NO on their own participate in multiple common physiological processes, with a functional relationship between both factors having been identified. The present review describes the functional relationship between leptin and NO in different physiological processes.

Tanshinone IIA attenuates cardiac microvascular ischemia-reperfusion injury via regulating the SIRT1-PGC1α-mitochondrial apoptosis pathway

Cardiac microvascular ischemia-reperfusion (IR) injury has been a neglected topic in recent decades. In the current study, we investigated the mechanism underlying microvascular IR injury, with a focus on mitochondrial homeostasis. We also explored the protective role of tanshinone IIA (Tan IIA) in microvascular protection in the context of IR injury. Through animal studies and cell experiments, we demonstrated that IR injury mediated microvascular wall destruction, lumen stenosis, perfusion defects, and cardiac microvascular endothelial cell (CMEC) apoptosis via inducing mitochondrial damage. In contrast, Tan IIA administration had the ability to sustain CMEC viability and microvascular homeostasis, finally attenuating microvascular IR injury. Function studies have confirmed that the SIRT1/PGC1α pathway is responsible for the microvascular protection from the Tan IIA treatment. SIRT1 activation by Tan IIA sustained the mitochondrial potential, alleviated the mitochondrial pro-apoptotic factor leakage, reduced the mPTP opening, and blocked mitochondrial apoptosis, providing a survival advantage for CMECs and preserving microvascular structure and function. By comparison, inhibiting SIRT1 abrogated the beneficial effects of Tan IIA on mitochondrial function, CMEC survival, and microvascular homeostasis. Collectively, this study indicated that Tan IIA should be considered a microvascular-protective drug that alleviates acute cardiac microcirculation IR injury via activating the SIRT1/PGC1α pathway and thereby blocking mitochondrial damage.

Proinflammation effect of Mst1 promotes BV-2 cell death via augmenting Drp1-mediated mitochondrial fragmentation and activating the JNK pathway

Inflammation has been increasingly studied as part of the pathophysiology of neurodegenerative diseases. Mammalian Ste20-like kinase 1 (Mst1), a key factor of the Hippo pathway, is connected to cell death. Unfortunately, little study has been performed to detect the impact of Mst1 in neuroninflammation. The results indicated that Mst1 expression was upregulated because of LPS treatment. However, the loss of Mst1 sustained BV-2 cell viability and promoted cell survival in the presence of LPS treatment. Molecular investigation assay demonstrated that Mst1 deletion was followed by a drop in the levels of mitochondrial fission via repressing Drp1 expression. However, Drp1 adenovirus transfection reduced the protective impacts of Mst1 knockdown on mitochondrial stress and neuronal dysfunction. Finally, our results illuminated that Mst1 affected Drp1 content and mitochondrial fission in a JNK-dependent mechanism. Reactivation of the JNK axis inhibited Mst1 knockdown-mediated neuronal protection and mitochondrial homeostasis. Altogether, our results indicated that Mst1 upregulation and the activation of JNK-Drp1-mitochondrial fission pathway could be considered as the novel mechanism regulating the progression of neuroninflammation. This finding would pave a new road for the treatment of neurodegenerative diseases via modulating the Mst1-JNK-Drp1-mitochondrial fission axis.

Caveolin-1 knockdown increases the therapeutic sensitivity of lung cancer to cisplatin-induced apoptosis by repressing Parkin-related mitophagy and activating the ROCK1 pathway

Chemotherapy is the first-line treatment option for patients with lung cancer. However, therapeutic resistance occurs through an incompletely understood mechanism. Our research wants to investigate the influence of Caveolin-1 (Cav-1) on the therapeutic sensitivity of lung cancer in vitro. Results in this study demonstrated that Cav-1 levels were markedly inhibited in A549 lung cancer cells after exposure to cisplatin. Knockdown of caveolin further enhanced cisplatin-triggered cancer death in A549 cells. The functional investigation demonstrated that Cav-1 inhibition amplified the mitochondrial stress signaling induced by cisplatin, as evidenced by the mitochondrial reactive oxygen species burst, cellular metabolic disruption, mitochondrial membrane potential reduction, and mitochondrial caspase-9-related apoptosis activation. At the molecular level, cav-1 augmented cisplatin-mediated mitochondrial damage by inhibiting Parkin-related mitochondrial autophagy. Mitophagy activation effectively attenuated the promotive impact of Cav-1 knockdown on mitochondrial damage and cell death. Furthermore, our data indicated that Cav-1 affected Parkin-related mitophagy by activating the Rho-associated coiled-coil kinase 1 (ROCK1) pathway; inhibition of the ROCK1 axis prevented cav-1 knockdown-mediated cell death and mitochondrial damage. Taken together, our results provide ample data illuminate the necessary action exerted by Cav-1 on affecting cisplatin-related therapeutic resistance. Silencing of Cav-1 inhibited Parkin-related mitophagy, thus amplifying cisplatin-mediated mitochondrial apoptotic signaling. This finding identifies the Cav-1/ROCK1/Parkin/mitophagy axis as a potential target to overcome cisplatin-related resistance in lung cancer cells.

Leptin rs7799039 (G2548A) polymorphism is associated with cancer risk: a meta-analysis involving 25,799 subjects

Background: Leptin (LEP) is a human analogous form of the mouse obese gene and plays a critical role in energy expenditure as well as the progression of carcinogenesis. Many studies exploring the relationship between the LEP rs7799039 (G2548A) polymorphism and cancer risk have observed controversial results. To extensively evaluate this potential association, we conducted this meta-analysis.

Methods: All eligible studies published up to August 2018 on the relationship between the LEP rs7799039 G>A polymorphism and cancer risk were obtained by searching PubMed, EMBASE, and the China Biology Medicine databases. The association of LEP rs7799039 G>A polymorphism with cancer risk was evaluated by crude ORs together with their 95% CI's.

Results: Thirty-one case–control studies involving 25,799 subjects were included for meta-analysis. We identify a significant correlation with an overall cancer risk when these eligible case–control studies were pooled for analysis: for AA vs GG: an OR = 1.22, 95% CI = 1.01–1.48, P = 0.042 and for AA/GA vs GG: an OR = 1.16, 95% CI = 1.02–1.33, P = 0.026. A significant association was also detected in Asians, prostate cancer, other cancers, and hematopoietic malignancy subgroups. Sensitivity analysis was conducted by deleting an individual study in turn and calculation of the pooled ORs and CIs of the remainders. The results of sensitivity analyses indicated that no eligible study influenced the pooled ORs and CIs materially. Begg’s and Egger’s tests revealed that there was no evidence of publication bias.

Conclusion: In conclusion, our study suggests that the LEP rs7799039 G>A polymorphism might contribute to the development of cancer. In order to further verify or refute our findings, large and well-designed epidemiological studies are needed.

Anti-tumor effect of LATS2 on liver cancer death: Role of DRP1-mediated mitochondrial division and the Wnt/β-catenin pathway

Large tumor suppressor 2 (LATS2), an important mediator of the cell apoptotic response pathway, has been linked to the progression of several cancers. Here, we described the molecular feature of LATS2 as a novel antitumor factor in liver cancer cells in vitro. Western blotting was used to detect the expression of LATS2 and its downstream factors. ELISA, immunofluorescence, and flow cytometry were used to evaluate the alterations of mitochondrial function in response to LATS2 overexpression. Adenovirus-loaded LATS2 and siRNA against DRP1 were transfected into liver cancer cells to overexpress LATS2 and knockdown DRP1 expression, respectively. The results of the present study demonstrated that overexpression of LATS2 was closely associated with more liver cancer cell death. Mechanistically, LATS2 overexpression increased the expression of DRP1, and DRP1 elevated mitochondrial division, an effect that was accompanied by mitochondrial dysfunction, including mitochondrial membrane potential reduction, mitochondrial respiratory complex downregulation, mitochondrial cyt-c release into the nucleus and mitochondrial oxidative injury. Moreover, LATS2 overexpression also initiated mitochondrial apoptosis, and this process was highly dependent on DRP1-related mitochondrial division. Molecular investigations demonstrated that LATS2 modulated DRP1 expression via the Wnt/β-catenin pathway. Inhibition of the Wnt/β-catenin pathway pregented LATS2-mediated DRP1 upregulation, ultimately sustaining mitochondrial function and cell viability in the presence of LATS2 overexpression. Altogether, the above data identify LATS2-Wnt/β-catenin/DRP1/mitochondrial division as a novel anticancer signaling pathway promoting cancer cell death, which might be an attractive therapeutic target for the treatment of hepatocellular carcinoma.