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

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*

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

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*

OBJECTIVE: To investigate the the effects of leptin on the proliferation, differentiation and PTEN expression of rat retinal progenitor cells (RPCs) cultured under hypoxic condition. METHODS: SD rat RPCs were cultured in normoxic conditions or exposed to hypoxia in the presence of 0, 0.3, 1.0, 3.0, 10, and 30 nmol/L leptin for 12, 48 and 72 h, and the cell viability was assessed using cell counting kit 8 (CCK 8) assay. The RPCs in primary culture were divided into control group, hypoxia group, and hypoxia+leptin group, and after 48 h of culture, the cell medium was replaced with differentiation medium and the cells were further cultured for 6 days. Immunofluorescence staining was employed to detect the cells positive for β-tubulin III and GFAP, and Western blotting was used to examine the expression of PTEN at 48 h of cell culture. RESULTS: The first generation of RPCs showed suspended growth in the medium with abundant and bright cellular plasma and formed mulberry like cell spheres after 2 days of culture. Treatment with low-dose leptin (below 3.0 nmol/L) for 48 h obviously improved the viability of RPCs cultured in hypoxia, while at high concentrations (above 10 nmol/L), leptin significantly suppressed the cell viability (P < 0.05). The cells treated with 3.0 nmol/L leptin for 48 h showed the highest viability (P < 0.05). After treatment with 3.0 nmol/L leptin for 48 h, the cells with hypoxic exposure showed similar GFAP and β-tubulin Ⅲ positivity with the control cells (P>0.05), but exhibited an obvious down-regulation of PTEN protein expression compared with the control cells (P < 0.05). CONCLUSION In rat RPCs with hypoxic exposure, treatment with low dose leptin can promote the cell proliferation and suppress cellular PTEN protein expression without causing significant effects on cell differentiation.
Animals ; Cell Differentiation/drug effects* ; Cell Hypoxia/drug effects* ; Cell Proliferation/drug effects* ; Cells, Cultured ; Leptin/pharmacology* ; PTEN Phosphohydrolase/metabolism* ; Rats ; Rats, Sprague-Dawley ; Retina/metabolism* ; Stem Cells/metabolism* ; Tubulin

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.
Cell Proliferation ; Cells, Cultured ; Cytokines/biosynthesis* ; Female ; Human Umbilical Vein Endothelial Cells/radiation effects* ; Humans ; Inflammation/etiology* ; Leptin/pharmacology* ; Mesenchymal Stem Cells/physiology* ; Neovascularization, Physiologic/physiology* ; Placenta/cytology* ; Pregnancy ; STAT3 Transcription Factor/genetics* ; Transcription Factor RelA/genetics* ; X-Rays