摘要 目的 近年来多项研究提示瘦素可能在帕金森病（PD）患者神经元细胞中发挥保护作用，但相关结果尚不一致，因此本研究采用Meta分析方法系统评估瘦素在PD患者中的作用。方法 在PubMed、Embase、ISI Web of Science和中国国家知识基础设施（CNKI）数据库中系统性检索2020年3月底前的文献研究。为了评估总体效果，采用固定效应模型计算合并效应量、标准化均差（SMD）和95%CI。随后进行了亚组分析、敏感性分析和发表偏倚分析，以揭示纳入研究的稳定性和可信度。结果 本研究纳入了7项研究，包括167例帕金森病患者和141名健康对照者。本研究发现，帕金森病患者的血清瘦素水平显著低于健康对照者（SMD=-0.328，95%CI -0.560~-0.096，P=0.006）。亚组分析显示，白种人PD患者的血清瘦素水平较低（SMD=-0.301，95%CI -0.566~-0.036，P=0.026），而亚洲患者的血清瘦素水平差异无统计学意义（SMD=-0.414，95%CI -0.891~0.063，P=0.089）。敏感性分析显示总体效应量的稳定性。通过观察漏斗图，未发现明显的不对称，Begg检验也未发现显著的发表偏倚。结论 本Meta分析结果表明PD患者血清瘦素水平较健康人群降低，提示血清瘦素可能参与PD的病理过程，其具体机制尚待进一步研究阐明。 Abstract Objective Many studies in recent years have shown that leptin may exert a protective effect on neurons in patients with Parkinson disease（PD），but related research findings remain inconsistent. Therefore， this article systematically reviews the role of leptin in PD patients through a meta-analysis. Methods PubMed，Embase，ISI Web of Science， and CNKI were searched for related articles published up to March 2020. In order to assess the overall effect， the fixed effects model was used to calculate pooled effect size， standardized mean difference （SMD）， and 95% confidence interval（CI）. Subgroup analysis， sensitivity analysis， and publication bias analysis were performed to assess the stability and reliability of the studies included in the meta-analysis. Results A total of 7 studies were included in the meta-analysis according to strict inclusion criteria， involving 167 PD patients and 141 healthy controls. The results showed that the PD patients had a significantly lower serum level of leptin than the healthy controls （SMD=-0.328，95%CI -0.560 to -0.096， P=0.006）. The subgroup analysis showed that Caucasian PD patients had a relatively low serum level of leptin （SMD=-0.301， 95%CI -0.566 to -0.036，P=0.026）， while there was no significant difference in the serum level of leptin among Asian patients （SMD=-0.414， 95%CI -0.891 to 0.063， P=0.089）.The sensitivity analysis showed the stability of overall effect size. The funnel plots showed no significant asymmetry， and no obvious publication bias was observed by the Begg test. Conclusion This meta-analysis shows that PD patients have a lower serum level of leptin than the healthy population， suggesting that serum leptin might be involved in the pathological process of PD， and further studies are needed to clarify the specific mechanism.
Leptin ; Adipokines

OBJECTIVES

In Asia, younger individuals (below age 45) are diagnosed to have type 2 diabetes with increased rates of obesity defined by lower BMI yet with greater visceral adiposity (waist circumference and waisthip ratios). The prevalence data on type 1 diabetes is not well established, considered to be low, but is seen to be increasing as well. This changing phenotype therefore, presents a clinical dilemma in terms of correctly classifying diabetes and deciding on the consequent appropriate treatment. Distinguishing type 1 from type 2 diabetes has become more difficult with type 2 diabetes dramatically increasing in young adults and children. This study aims to define the characteristics of diabetes among young adults in the Philippines to provide a basis for appropriate management amidst changes in diabetes phenotypes seen globally.

METHODS

In this cross-sectional analytic study, we characterized the demographic, metabolic, and autoimmune features of diabetes among young adult Filipinos aged 18 to 45 years old consulting at a tertiary referral center in Manila, Philippines. Baseline serum A1c, FBS, 75-g oral glucose tolerance test, insulin, serum C-peptide, insulin autoantibodies, leptin, adiponectin, lipid profile, and thyroid function tests were obtained from the participants and analyzed. The homeostasis model assessment (HOMA) was used to estimate the insulin sensitivity.

RESULTS

A total of 348 patients with diabetes were included, with females comprising two-thirds of the participants. The mean age at diagnosis of diabetes was 35.9±7.22 years. The mean BMI was 28.12 kg/m2, with median waist to hip ratio (WHR) of 0·93. Metabolic syndrome was found in 60% of participants and 67.82% were obese by body mass index. The mean A1c was 9.07±2.52%. Good glucose control (A1c less than 7.0%) was seen in 23% of participants  while nearly half (48%) had HbA1c which was >9.0%. The median levels of fasting insulin and C-peptide were 12.62 (range 1.33–90.42) mIU/L and 0.78 ng/mL (range 0–16.2), respectively. 

Included participants were diagnosed with diabetes within a year and as such, majority did not have any micro- or macrovascular complications. The most common diabetes complication was sensory neuropathy detected by monofilament testing, which was found in 28% of participants, followed by non-proliferative diabetic retinopathy in 13%. A history of previous diabetic ketoacidosis was found in 10 patients (2.87%). Glutamic acid decarboxylase (GAD) and insulin auto-antibodies were found in 3.2% and 19.3% of participants, respectively. Approximately half (51.73%) of the participants were insulin resistant by HOMA-IR.

CONCLUSION

In contrast with Caucasians and other Asians, diabetes among young Filipino adults is associated with lower BMI but with a similarly high visceral adiposity as shown by an elevated WHR. Metabolic syndrome with insulin resistance as defined by a variety of indices is predominant. Type 1 diabetes with autoantibodies occur in only a small fraction of this population. Data derived from this work can provide a framework for cluster analysis towards personalized management specific to this population.

Human ; Acids ; Adiponectin ; Adiposity ; Adult ; Aged ; Antibodies ; Asia ; Asian ; Asian Continental Ancestry Group ; Autoantibodies ; Body Mass Index ; C-peptide ; Carboxy-lyases ; Child ; Cluster Analysis ; Demography ; Diabetes Complications ; Diabetes Mellitus ; Diabetes Mellitus, Type 1 ; Diabetes Mellitus, Type 2 ; Diabetic Ketoacidosis ; Diabetic Retinopathy ; Diagnosis ; Fasting ; Female ; Glucose ; Glucose Tolerance Test ; Glutamate Decarboxylase ; Glutamic Acid ; Insulin ; Insulin Resistance ; Ketosis ; Leptin ; Lipids ; Metabolic Syndrome ; Obesity ; Patients ; Peptides ; Phenotype ; Philippines ; Population ; Prevalence ; Serum ; Therapeutics ; Thyroid Gland ; Thyroid Function Tests ; Young Adult

Perimenopausal period is a period with high incidence of female depression, which shows the symptoms of depressed mood and disturbed mind. The pathogenesis of the disease is not clear and it is urgent to search for efficient treatment. Leptin is a hormone secreted by fat cells and plays a role in both metabolism and neuroprotection. In recent years, leptin has been reported to ameliorate perimenopausal depression, and leptin is closely related to estrogen synthesis and secretion. Therefore, leptin may be used as a potential molecular target for the treatment of perimenopausal depression. In this paper, the research on the relationship between leptin and perimenopausal depression is reviewed.
Depression ; Leptin ; Estrogens

Obesity ; Body Mass Index ; Leptin ; Inflammation ; Adipose Tissue

OBJECTIVE: To observe the clinical efficacy of acupoint thread-embedding at fat layer for abdominal obesity and its effects on glucose and lipid metabolism. METHODS: Ninety-six patients with abdominal obesity were randomly divided into an acupoint embedding group (48 cases, 3 cases dropped out) and a sham embedding group (48 cases, 3 cases dropped out). Both groups received lifestyle interventions as basic treatment. The acupoint embedding group underwent thread-embedding at Zhongwan (CV 12), Qihai (CV 6), Guanyuan (CV 4), and bilateral Liangmen (ST 21), Fenglong (ST 40), and Pishu (BL 20), with the thread implanted in the fat layer. The sham embedding group followed the same acupoint selection and procedure but without catgut implantation. Both groups were treated once every two weeks for 12 weeks, for a total of six treatments. Waist circumference, body weight, body mass index (BMI), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) were measured, and appetite was assessed using the visual analogue scale (VAS) before and after treatment and at 12 weeks after treatment completion (follow-up) in the two groups. Visceral fat area (VFA) and subcutaneous fat area (SFA) at abdomen were measured, and blood glucose and lipid metabolism markers, including fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR) index, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), leptin, tumor necrosis factor-α(TNF-α), and interleukin-6 (IL-6), were also tested before and after treatment in the two groups. Clinical efficacy was evaluated two weeks after treatment completion. RESULTS: After treatment and at follow-up, the waist circumference, body weight, BMI, WHR, WHtR, and appetite VAS scores in the acupoint embedding group were decreased compared to those before treatment (P<0.01). In the sham embedding group, waist circumference, body weight, BMI, WHtR, and appetite VAS score were also reduced after treatment compared to those before treatment (P<0.01). Except for body weight after treatment, the acupoint embedding group showed lower waist circumference, body weight, BMI, WHR, and WHtR values after treatment and at follow-up compared to the sham embedding group (P<0.01, P<0.05). Additionally, the appetite VAS score in the acupoint embedding group was lower than that in the sham embedding group after treatment (P<0.01). Both groups showed a reduction in abdominal VFA and SFA after treatment compared to those before treatment (P<0.01, P<0.05). In the acupoint embedding group, serum FBG, FINS, HOMA-IR index, TC, TG, LDL-C, leptin, TNF-α, and IL-6 levels were decreased compared to those before treatment (P<0.01), while HDL-C level was increased (P<0.01). In the sham embedding group, serum FBG and HOMA-IR index were decreased compared to those before treatment (P<0.01, P<0.05). After treatment, the abdominal SFA in the acupoint embedding group was lower than that in the sham embedding group (P<0.01). Additionally, the acupoint embedding group had lower levels of serum FINS, HOMA-IR index, TC, LDL-C, leptin, TNF-α, and IL-6 compared to the sham embedding group (P<0.05, P<0.01). The total effective rate in the acupoint embedding group was 82.2% (37/45), which was significantly higher than 15.6% (7/45) in the sham embedding group (P<0.01). CONCLUSION The acupoint catgut embedding at fat layer could effectively reduce the obesity severity in patients with abdominal obesity, decrease abdominal fat accumulation, suppress appetite, improve glucose and lipid metabolism, reduce inflammatory responses, and has a sustained effect.
Humans ; Obesity, Abdominal/physiopathology* ; Male ; Female ; Acupuncture Points ; Middle Aged ; Adult ; Acupuncture Therapy ; Leptin/blood* ; Young Adult ; Body Mass Index ; Aged

OBJECTIVE: To investigate the effect of Zuogui Jiangtang Jieyu Decoction (ZJJ) on Shh signaling and self-renewal of neural stem cells in the hippocampal dentate gyrus of diabetic rats with depression. METHODS: Diabetic rat models with depression were randomly divided into model group, positive drug (metformin + fluoxetine) group, and low-, medium-, and high-dose ZJJ groups (n=16), with normal SD rats as the control group. The positive drugs and ZJJ were administered by gavage, and the rats in the control and model groups were given distilled water. After the treatment, blood glucose level was detected using test strips, and behavioral changes of the rats were assessed by forced swimming test and water maze test. ELISA was used to examine the serum level of leptin; The expressions of nestin and Brdu proteins in the dentate gyrus of the rats were detected using immunofluorescence assay, and the expressions of self-renewal marker proteins and Shh signaling proteins were detected using Western blotting. RESULTS: The diabetic rats with depression showed significantly increased levels of blood glucose and leptin (P < 0.01) and prolonged immobility time in forced swimming test (P < 0.01) and increased stage climbing time with reduced stage seeking time and stage crossings in water maze test (P < 0.01). The expressions of nestin and Brdu in the dentate gyrus, the expressions of cyclin D1, SOX2, Shh, Ptch1, Smo in the hippocampus and the nuclear expression of Gli-1 were decreased (P < 0.01) while hippocampal Gli-3 expression was increased significantly (P < 0.01) in the rat models. Treatment of rat models with high-dose ZJJ significantly reduced the blood glucose (P < 0.01) and leptin level (P < 0.05) and improved their performance in behavioral tests (P < 0.01). The treatment also obviously increased the expressions of nestin, Brdu, cyclin D1, SOX2, Shh, Ptch1, and Smo and the nuclear expression of Gli-1 in the dentate gyrus (P < 0.01) and reduced hippocampal expression of Gli-3 (P < 0.05) in the rat models. CONCLUSION ZJJ can significantly improve the self-renewal ability of neural stem cells and activate Shh signaling in dentate gyrus of diabetic rats with depression.
Animals ; Rats ; Blood Glucose ; Bromodeoxyuridine ; Cell Self Renewal ; Cyclin D1 ; Dentate Gyrus ; Depression ; Diabetes Mellitus, Experimental ; Hippocampus ; Leptin ; Nestin ; Rats, Sprague-Dawley

Sarcopenia is an age-related disease that mainly involves decreases in muscle mass, muscle strength and muscle function. At the same time, the body fat content increases with aging, especially the visceral fat content. Adipose tissue is an endocrine organ that secretes biologically active factors called adipokines, which act on local and distant tissues. Studies have revealed that some adipokines exert regulatory effects on muscle, such as higher serum leptin levels causing a decrease in muscle function and adiponectin inhibits the transcriptional activity of Forkhead box O3 (FoxO3) by activating peroxisome proliferators-activated receptor-γ coactivator -1α (PGC-1α) and sensitizing cells to insulin, thereby repressing atrophy-related genes (atrogin-1 and muscle RING finger 1 [MuRF1]) to prevent the loss of muscle mass. Here, we describe the effects on muscle of adipokines produced by adipose tissue, such as leptin, adiponectin, resistin, mucin and lipocalin-2, and discuss the importance of these adipokines for understanding the development of sarcopenia.
Humans ; Adipokines ; Leptin ; Adiponectin ; Sarcopenia ; Muscles

BACKGROUND: Currently, a significant number of miners are involved in mining operations at the Gejiu tin mine in Yunnan. This occupational setting is associated with exposure to dust particles, heavy metals, polycyclic aromatic hydrocarbons, and radioactive radon, thereby significantly elevating the risk of lung cancer. This study aims to investigate the involvement of leptin-mediated extracellular regulated protein kinase (ERK) signaling pathway in the malignant transformation of rat alveolar type II epithelial cells induced by Yunnan tin mine dust. METHODS: Immortalized rat alveolar cells type II (RLE-6TN) cells were infected with Yunnan tin mine dust at a concentration of 200 μg/mL for nine consecutive generations to establish the infected cell model, which was named R₂₀₀ cells. The cells were cultured normally, named as R cells. The expression of leptin receptor in both cell groups was detected using the Western blot method. The optimal concentration of leptin and mitogen-activated protein kinase kinase (MEK) inhibitor (U0126) on R₂₀₀ cells was determined using the MTT method. Starting from the 20th generation, the cells in the R group were co-cultured with leptin, while the cells in the R₂₀₀ group were co-cultured with the MEK inhibitor U0126. The morphological alterations of the cells in each group were visualized utilizing hematoxylin-eosin staining. Additionally, concanavalin A (ConA) was utilized to detect any morphological differences, and an anchorage-independent growth assay was conducted to assess the malignant transformation of the cells. The changes in the ERK signaling pathway in epithelial cells after the action of leptin were detected using the Western blot method. RESULTS: Both the cells in the R group and R₂₀₀ group express leptin receptor OB-R. Compared to the R₂₀₀ group, the concentration of leptin at 100 ng/mL shows the most significant pro-proliferation effect. The proliferation of R₂₀₀ cells infected with the virus is inhibited by 30 μmol/L U0126, and a statistically significant divergence was seen when compared to the control group (P<0.05). Starting from the 25th generation, the cell morphology of the leptin-induced R₂₀₀ group (R₂₀₀L group) underwent changes, leading to malignant transformation observed at the 30th generation. The characteristics of malignant transformation became evident by the 40th generation in the R₂₀₀L group. In contrast, the other groups showed agglutination of P40 cells, and the speed of cell aggregation increased with an increase in ConA concentration. Notably, the R₂₀₀L group exhibited faster cell aggregation compared to the U0126-induced R₂₀₀ (R₂₀₀LU) group. Additionally, the cells in the R₂₀₀L group were capable of forming clones starting from P30, with a colony formation rate of 2.25‰±0.5‰. However, no clonal colonies were observed in the R₂₀₀LU group and R₂₀₀ group. The expression of phosphorylated extracellular signal-regulated kinase (pERK) was enhanced in cells of the R₂₀₀L group. However, when the cells in the R₂₀₀L group were treated with U0126, a blocking agent, the phosphorylation level of pERK decreased. CONCLUSIONS Leptin can promote the malignant transformation of lung epithelial cells infected by mine dust, and the ERK signaling pathway may be necessary for the transformation of alveolar type II epithelial cells induced by Yunnan tin mine dust.
Rats ; Animals ; Alveolar Epithelial Cells/pathology* ; Dust ; Tin/adverse effects* ; Lung Neoplasms/pathology* ; Leptin/adverse effects* ; Receptors, Leptin ; China ; Signal Transduction ; Epithelial Cells/pathology* ; Mitogen-Activated Protein Kinase Kinases/adverse effects*

OBJECTIVES: Acute kidney injury (AKI) can be caused by ischemia/reperfusion (I/R), nephrotoxin, and sepsis, with poor prognosis and high mortality. Leptin is a protein molecule that regulates the body's energy metabolism and reproductive activities via binding to its specific receptor. Leptin can inhibit cardiomyocyte apoptosis caused by I/R, but its effect on I/R kidney injury and the underlying mechanisms are still unclear. This study aims to investigate the effect and mechanisms of leptin on renal function, renal histopathology, apoptosis, and autophagy during acute I/R kidney injury. METHODS: Healthy adult male mice were randomly divided into 4 groups: a sham+wild-type mice (ob/+) group, a sham+leptin gene-deficient mice (ob/ob) group, an I/R+ob/+ group, and an I/R+ob/ob group (n=8 per group). For sham operation, a longitudinal incision was made on the back of the mice to expose and separate the bilateral kidneys and renal arteries, and no subsequent treatment was performed. I/R treatment was ischemia for 30 min and reperfusion for 48 h. The levels of BUN and SCr were detected to evaluate renal function; HE staining was used to observe the pathological changes of renal tissue; TUNEL staining was used to observe cell apoptosis, and apoptosis-positive cells were counted; Western blotting was used to detect levels of apoptosis-related proteins (caspase 3, caspase 9), autophagy-related proteins [mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), LC3 I, LC3 II], mTOR-dependent signaling pathway proteins [phosphate and tension homology (PTEN), adenosine monophosphate-activated protein kinase (AMPK), protein kinase B (AKT), extracellular regulated protein kinase (ERK), phosphorylated PTEN (p-PTEN), phosphorylated AMPK (p-AMPK), phosphorylated AKT (p-AKT), phosphorylated ERK (p-ERK)]. RESULTS: There was no significant difference in the levels of BUN and SCr between the sham+ob/+ group and the sham+ob/ob group (both P>0.05). The levels of BUN and SCr in the I/R+ob/+ group were significantly higher than those in the sham+ob/+ group (both P<0.05). Compared with the mice in the sham+ob/ob group or the I/R+ob/+ group, the levels of BUN and SCr in the I/R+ob/ob group were significantly increased (all P<0.05). There was no obvious damage to the renal tubules in the sham+ob/+ group and the sham+ob/ob group. Compared with sham+ob/+ group and sham+ob/ob group, both the I/R+ob/+ group and the I/R+ob/ob group had cell damage such as brush border shedding, vacuolar degeneration, and cast formation. Compared with the I/R+ob/+ group, the renal tubules of the mice in the I/R+ob/ob group were more severely damaged. The pathological score of renal tubular injury showed that the renal tubular injury was the most serious in the I/R+ob/ob group (P<0.05). Compared with the sham+ob/+ group, the protein levels of caspase 3, caspase 9, PTEN, and LC3 II were significantly up-regulated, the ratio of LC3 II to LC3 I was significantly increased, and the protein levels of p-mTOR, p-PTEN, p-AMPK, p-AKT, and p-ERK were significantly down-regulated in the I/R+ob/+ group (all P<0.05). Compared with the sham+ob/ob group, the protein levels of caspase 3, caspase 9, PTEN, and LC3 II were significantly up-regulated, and the ratio of LC3 II to LC3 I was significantly increased, while the protein levels of p-mTOR, p-PTEN, p-AMPK, p-AKT, and p-ERK were significantly down-regulated in the I/R+ob/ob group (all P<0.05). Compared with the I/R+ob/+ group, the levels of p-mTOR, p-PTEN, p-AMPK, p-AKT were more significantly down-regulated, while the levels of caspase 3, caspase 9, PTEN, and LC3 II were more significantly up-regulated, and the ratio of LC3 II to LC3 I was more significantly increase in the I/R+ob/ob group (all P<0.05). CONCLUSIONS Renal function and tubular damage, and elevated levels of apoptosis and autophagy are observed in mice kidneys after acute I/R. Leptin might relieve I/R induced AKI by inhibiting apoptosis and autophagy that through a complex network of interactions between mTOR-dependent signaling pathways.
AMP-Activated Protein Kinases/metabolism* ; Acute Kidney Injury/pathology* ; Animals ; Apoptosis ; Apoptosis Regulatory Proteins/pharmacology* ; Autophagy ; Caspase 3/metabolism* ; Caspase 9/metabolism* ; Female ; Humans ; Ischemia ; Kidney/pathology* ; Leptin/pharmacology* ; Male ; Mammals/metabolism* ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; Reperfusion/adverse effects* ; Reperfusion Injury/metabolism* ; TOR Serine-Threonine Kinases/metabolism*

Leptin, an adipocyte-derived peptide hormone, has been shown to facilitate breathing. However, the central sites and circuit mechanisms underlying the respiratory effects of leptin remain incompletely understood. The present study aimed to address whether neurons expressing leptin receptor b (LepRb) in the nucleus tractus solitarii (NTS) contribute to respiratory control. Both chemogenetic and optogenetic stimulation of LepRb-expressing NTS (NTS^LepRb) neurons notably activated breathing. Moreover, stimulation of NTS^LepRb neurons projecting to the lateral parabrachial nucleus (LPBN) not only remarkably increased basal ventilation to a level similar to that of the stimulation of all NTS^LepRb neurons, but also activated LPBN neurons projecting to the preBötzinger complex (preBötC). By contrast, ablation of NTS^LepRb neurons projecting to the LPBN notably eliminated the enhanced respiratory effect induced by NTS^LepRb neuron stimulation. In brainstem slices, bath application of leptin rapidly depolarized the membrane potential, increased the spontaneous firing rate, and accelerated the Ca²⁺ transients in most NTS^LepRb neurons. Therefore, leptin potentiates breathing in the NTS most likely via an NTS-LPBN-preBötC circuit.
Leptin/pharmacology* ; Membrane Potentials ; Neurons/metabolism* ; Solitary Nucleus/metabolism*