1.Mechanism of Yizhi Qingxin Prescription in Regulating PKA/CaN Pathway to Improve Cognitive Function in Alzheimer's Disease Model Mice
Xiaochen GUO ; Jiangang LIU ; Dandan SHI ; Ziqi NING ; Yaoyao ZHANG ; Fang LIU ; Meixia LIU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):97-108
ObjectiveTo explore the mechanism by which Yizhi Qingxin prescription improves mitochondrial dysfunction in Alzheimer's disease (AD) through regulating mitochondrial Ca2+ homeostasis and kinetic balance based on the protein kinase A (PKA)/calcineurin (CaN) signaling pathway. MethodsSixty three-month-old amyloid precursor protein (APP)/presenilin 1 (PS1) double transgenic mice were randomly divided into a model group, a donepezil group(0.65 mg·kg-1), a low-dose Yizhi Qingxin prescription group (YQF-L,2.6 g·kg-1), a medium-dose Yizhi Qingxin prescription group (YQF-M,5.2 g·kg-1), and a high-dose Yizhi Qingxin prescription group (YQF-H,10.4 g·kg-1), with 12 mice in each group. Twelve C57BL/6J mice with the same genetic background served as a normal group. Each treatment group received gavage administration daily, with the model and normal groups receiving equal volume of physiological saline. Intervention continued for 12 consecutive weeks. The learning and memory abilities of the mice were assessed using the novel object recognition (NOR) and Morris water maze (MWM) tests. Hematoxylin-eosin (HE)/Nissl staining was used to observe histopathological changes in the hippocampus. Transmission electron microscopy (TEM) was used to observe mitochondrial ultrastructure. Fluo-4 acetoxymethyl ester (Fluo-4 AM) Ca2+ probe was used to measure intracellular Ca2+ concentration in brain tissue. Western blot was used to determine the protein expression of PKA, CaN, sodium/calcium/lithium exchanger (NCLX), mitochondrial calcium uniporter (MCU), calmodulin (CaM), dynamin-related protein 1 (Drp1), and phosphorylated dynamin-related protein 1 (serine 637 site) [p-Drp1(S637)] in the hippocampus. Real-time quantitative polymerase chain reaction (Real-time PCR) was used to measure the expression of PKA, CaN, CaM, NCLX, MCU, and Drp1 mRNAs. ResultsCompared with those in the normal group, the recognition index (RI) of the model group decreased (P0.01), and the number of crossings through the original platform area, the duration of stay in the target quadrant, and the distance were reduced (P0.01). The protein expression of PKA, NCLX, and p-DRP1 (ser637) significantly decreased (P0.05), and the mRNA expression of PKA and NCLX significantly decreased (P0.05). The escape latency (EL) was prolonged (P0.05), and the intracellular Ca2+ level significantly increased (P0.01). The protein expression of CaN, CaM, MCU, and Drp1, as well as the mRNA expression of CaN, MCU, and Drp1, significantly increased (P0.05). After intervention with Donepezil and Yizhi Qingxin prescription, compared with that in the model group, the RI of the treatment group significantly increased (P0.05), and the number of crossings through the platform and the duration of stay in the target quadrant significantly increased (P0.05). The protein expression of PKA, NCLX, and p-Drp1 (ser637) and the mRNA expression of PKA and NCLX significantly increased (P0.05). On the 4th and 5th days, the EL was shortened (P0.05), and the intracellular Ca2+ level decreased (P0.05). The protein expression of CaN, CaM, MCU, and Drp1 and the mRNA expression of CaN, MCU, and Drp1 significantly decreased (P0.05). ConclusionYizhi Qingxin prescription regulates the PKA/CaN pathway, upregulates the expression of PKA, NCLX, and p-Drp1 (ser637) proteins, reduces the expression of CaN, CaM, MCU, and Drp1 proteins, and regulates Ca2+ homeostasis and mitochondrial dynamic balance, thereby enhancing the spatial learning and memory abilities of AD mice.
2.Mechanism of Yizhi Qingxin Prescription in Regulating PKA/CaN Pathway to Improve Cognitive Function in Alzheimer's Disease Model Mice
Xiaochen GUO ; Jiangang LIU ; Dandan SHI ; Ziqi NING ; Yaoyao ZHANG ; Fang LIU ; Meixia LIU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):97-108
ObjectiveTo explore the mechanism by which Yizhi Qingxin prescription improves mitochondrial dysfunction in Alzheimer's disease (AD) through regulating mitochondrial Ca2+ homeostasis and kinetic balance based on the protein kinase A (PKA)/calcineurin (CaN) signaling pathway. MethodsSixty three-month-old amyloid precursor protein (APP)/presenilin 1 (PS1) double transgenic mice were randomly divided into a model group, a donepezil group(0.65 mg·kg-1), a low-dose Yizhi Qingxin prescription group (YQF-L,2.6 g·kg-1), a medium-dose Yizhi Qingxin prescription group (YQF-M,5.2 g·kg-1), and a high-dose Yizhi Qingxin prescription group (YQF-H,10.4 g·kg-1), with 12 mice in each group. Twelve C57BL/6J mice with the same genetic background served as a normal group. Each treatment group received gavage administration daily, with the model and normal groups receiving equal volume of physiological saline. Intervention continued for 12 consecutive weeks. The learning and memory abilities of the mice were assessed using the novel object recognition (NOR) and Morris water maze (MWM) tests. Hematoxylin-eosin (HE)/Nissl staining was used to observe histopathological changes in the hippocampus. Transmission electron microscopy (TEM) was used to observe mitochondrial ultrastructure. Fluo-4 acetoxymethyl ester (Fluo-4 AM) Ca2+ probe was used to measure intracellular Ca2+ concentration in brain tissue. Western blot was used to determine the protein expression of PKA, CaN, sodium/calcium/lithium exchanger (NCLX), mitochondrial calcium uniporter (MCU), calmodulin (CaM), dynamin-related protein 1 (Drp1), and phosphorylated dynamin-related protein 1 (serine 637 site) [p-Drp1(S637)] in the hippocampus. Real-time quantitative polymerase chain reaction (Real-time PCR) was used to measure the expression of PKA, CaN, CaM, NCLX, MCU, and Drp1 mRNAs. ResultsCompared with those in the normal group, the recognition index (RI) of the model group decreased (P0.01), and the number of crossings through the original platform area, the duration of stay in the target quadrant, and the distance were reduced (P0.01). The protein expression of PKA, NCLX, and p-DRP1 (ser637) significantly decreased (P0.05), and the mRNA expression of PKA and NCLX significantly decreased (P0.05). The escape latency (EL) was prolonged (P0.05), and the intracellular Ca2+ level significantly increased (P0.01). The protein expression of CaN, CaM, MCU, and Drp1, as well as the mRNA expression of CaN, MCU, and Drp1, significantly increased (P0.05). After intervention with Donepezil and Yizhi Qingxin prescription, compared with that in the model group, the RI of the treatment group significantly increased (P0.05), and the number of crossings through the platform and the duration of stay in the target quadrant significantly increased (P0.05). The protein expression of PKA, NCLX, and p-Drp1 (ser637) and the mRNA expression of PKA and NCLX significantly increased (P0.05). On the 4th and 5th days, the EL was shortened (P0.05), and the intracellular Ca2+ level decreased (P0.05). The protein expression of CaN, CaM, MCU, and Drp1 and the mRNA expression of CaN, MCU, and Drp1 significantly decreased (P0.05). ConclusionYizhi Qingxin prescription regulates the PKA/CaN pathway, upregulates the expression of PKA, NCLX, and p-Drp1 (ser637) proteins, reduces the expression of CaN, CaM, MCU, and Drp1 proteins, and regulates Ca2+ homeostasis and mitochondrial dynamic balance, thereby enhancing the spatial learning and memory abilities of AD mice.
3.Association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40-89 in selected areas of China
Yufei LUO ; Yuan WEI ; Xiaochen WANG ; Yi ZHANG ; Wenli ZHANG ; Bing WU ; Zhengxiong YANG ; Xiaojie DONG ; Ruiting HAO ; Yifu LU ; Xiaoshuang FU ; Ziyue ZHU ; Ying ZHU ; Yuebin LYU ; Dongqun XU ; Xiaoming SHI
Chinese Journal of Preventive Medicine 2024;58(6):839-846
Objective:To investigate the association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40 to 89 years in selected areas of China.Methods:The research was based on the survey of the impact of soil quality of agricultural land on human health in typical areas conducted in 2019-2020. A total of 5 600 middle-aged and older adults aged 40 to 89 years were included by using a multi-stage stratified random sampling method. Baseline characteristics of the subjects were collected and physical examinations were performed. Random midstream urine was collected to measure urinary cadmium and urinary creatinine and fasting venous blood was collected to measure the leukocyte count, neutrophil count, lymphocyte count, monocyte count and eosinophil count. The linear mixed effect model was used to analyse the association of urinary cadmium levels with leukocyte classification counts, and the dose-response relationship between them was analyzed by using the restricted cubic spline (RCS) function.Results:The age of the subjects was (63.17±12.02) years; 2 851 (50.91%) were males; and the M ( Q 1, Q 3) of urinary creatinine-corrected urinary cadmium levels was 2.69 (1.52, 4.69) μg/g·creatinine. After adjusting for confounding factors, the results of linear mixed effects model analysis showed that for each 1-unit increase in urinary creatinine-corrected urinary cadmium level, the percentage change [% (95% CI)] of leukocyte count and lymphocyte count was -1.70% (-2.61%, -0.79%) and -1.57% (-2.86%, -0.26%), respectively. RCS function showed a negative linear relationship between urinary creatinine-corrected urinary cadmium levels and leukocyte counts and lymphocyte counts, respectively (all Pnon-linear>0.05). Conclusion:Urinary cadmium levels are negatively associated with leukocyte count and lymphocyte count among middle-aged and older adults aged 40 to 89 years in selected areas of China.
4.Association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40-89 in selected areas of China
Yufei LUO ; Yuan WEI ; Xiaochen WANG ; Yi ZHANG ; Wenli ZHANG ; Bing WU ; Zhengxiong YANG ; Xiaojie DONG ; Ruiting HAO ; Yifu LU ; Xiaoshuang FU ; Ziyue ZHU ; Ying ZHU ; Yuebin LYU ; Dongqun XU ; Xiaoming SHI
Chinese Journal of Preventive Medicine 2024;58(6):839-846
Objective:To investigate the association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40 to 89 years in selected areas of China.Methods:The research was based on the survey of the impact of soil quality of agricultural land on human health in typical areas conducted in 2019-2020. A total of 5 600 middle-aged and older adults aged 40 to 89 years were included by using a multi-stage stratified random sampling method. Baseline characteristics of the subjects were collected and physical examinations were performed. Random midstream urine was collected to measure urinary cadmium and urinary creatinine and fasting venous blood was collected to measure the leukocyte count, neutrophil count, lymphocyte count, monocyte count and eosinophil count. The linear mixed effect model was used to analyse the association of urinary cadmium levels with leukocyte classification counts, and the dose-response relationship between them was analyzed by using the restricted cubic spline (RCS) function.Results:The age of the subjects was (63.17±12.02) years; 2 851 (50.91%) were males; and the M ( Q 1, Q 3) of urinary creatinine-corrected urinary cadmium levels was 2.69 (1.52, 4.69) μg/g·creatinine. After adjusting for confounding factors, the results of linear mixed effects model analysis showed that for each 1-unit increase in urinary creatinine-corrected urinary cadmium level, the percentage change [% (95% CI)] of leukocyte count and lymphocyte count was -1.70% (-2.61%, -0.79%) and -1.57% (-2.86%, -0.26%), respectively. RCS function showed a negative linear relationship between urinary creatinine-corrected urinary cadmium levels and leukocyte counts and lymphocyte counts, respectively (all Pnon-linear>0.05). Conclusion:Urinary cadmium levels are negatively associated with leukocyte count and lymphocyte count among middle-aged and older adults aged 40 to 89 years in selected areas of China.
5.Effects of icariin on BDNF/TkB signaling pathway and synaptic plasticity regulation on fear memory improvement in rats with post-traumatic stress disorder
Xiaochen LIU ; Na JIN ; Yuanze GAO ; Baoxiang SHI ; Wei SHAN
Journal of China Medical University 2024;53(1):27-33
Objective To investigate the effects and mechanisms of icariin on changes in fear memory in post-traumatic stress disorder(PTSD)rats.Methods Thirty male SD rats were used to construct a rat model of single prolonged stress(SPS).The model rats were randomly divided into the SPS,icariin,and icariin + K252a(tyrosine kinase receptor B inhibitor)groups(n= 10 each;another 10 normal rats were used as the control group).The icariin and icariin + K252a groups were administered 20 mg/kg icariin by gavage once per day after SPS,while the control and SPS groups were administered the same dose of normal saline.K252a cells were injected into the lateral ventricles.After 2 weeks,anxiety,depression,and fear memory disorder in rats in each group were detected by the mine experiment,ele-vated cross maze experiment,and conditional fear test.The binding activity of icariin to brain-derived neurotrophic factor(BDNF)and the BDNF and TrkB expressions in the rat amygdala were detected by immunohistochemistry.The relative expressions of BDNF and TrkB pro-teins were detected by Western blotting.The expressions of postsynaptic density protein 95(PSD95)and synaptophysin(SYN)in the rat amygdala were detected using immunofluorescence.Results Icariin showed strong binding to BDNF.Compared with the control group,the times of entering the central area and the percentage of movement distance in the central area in the SPS group and the icariin+K252a group were significantly reduced.The open arm entry(OE)and arm opening time(OT)were significantly reduced,the freezing time and defecation times were significantly increased,and the expressions of the BDNF,TrkB,PSD95,and SYN proteins were significantly reduced(P<0.05).Compared with the SPS group,the icariin group rats had significantly increased times of entering the central area and percentages of movement distance in the central area,significantly increased OE and OT,significantly reduced the time of immobilization and defecation,and significantly increased the expressions of BDNF,TrkB,PSD95,and SYN proteins(P<0.05).Conclusion Icariin effectively alleviated the fear memory impairment induced by SPS in rats.This protective effect is related to BDNF/TrkB signaling pathway activation and upregulated PSD95 and SYN expression.
6.Exploration on the Mechanism of Renshen Yimai Prescription in Preventing Vascular Aging Based on Oxidative Stress Pathway
Dandan SHI ; Ziqi NING ; Xiaochen GUO ; Yaoyao ZHANG ; Yuanchun ZHANG ; Haiyan ZHANG ; Meixia LIU ; Jiangang LIU
Chinese Journal of Information on Traditional Chinese Medicine 2024;31(7):63-68
Objective To observe the effects of Renshen Yimai Prescription on oxidative stress and vascular aging in ApoE-/-mice;To explore its mechanism of intervention in vascular aging.Methods Forty ApoE-/-mice were divided into model group,Western medicine group(rosuvastatin,2.6 mg/kg),TCM low-and high-dosage group(Renshen Yimai Prescription,4.29,8.58 g/kg),with 10 mice in each group.Another 10 C57BL/6J mice were set as normal group.A vascular aging model was established by ApoE-/-mice fed with a Western diet.Each medication group was given corresponding drugs by gavage for 12 consecutive weeks,the normal group and model group were given equivalent volume of pure water.HE staining and Masson staining were used to observe the morphological changes of aortic tissue,and ox-LDL content in serum was detected by ELISA,the contents of ROS,GSH,GPX and NAD+in serum were detected by colorimetric method,the expressions of SIRT1,p53,p21 and NOX4 protein in aortic tissue were detected by Western blot.Results Compared with the normal group,the model group mice showed significant fat deposition in the aorta,thickening of the intima and media,a significant decrease in elastic fibers,and an increase in collagen fibers;the serum contents of ox-LDL and ROS significantly increased(P<0.01),while the contents of GSH,GPX and NAD+significantly decreased(P<0.01);the expression of SIRT1 protein in the aortic tissue significantly decreased(P<0.05),the expressions of p21 and p53 protein significantly increased(P<0.01,P<0.05).Compared with the model group,a small amount of lipid deposition was observed in the intima of aorta in each medication group,with clearer membrane structures in each layer and reduced collagen fiber;the serum contents of ox-LDL and ROS in each medication group were significantly decreased(P<0.01),while the GSH content significantly increased(P<0.05,P<0.01),the NAD+content in TCM low-dosage group significantly increased(P<0.05);the expressions of p21 and NOX4 protein in aortic tissue of the TCM high-dosage group significantly increased(P<0.05,P<0.01).Compared with the Western medicine group,the TCM high-dosage group showed a significant decrease in ROS content(P<0.01)and a significant decrease in p53 protein expression(P<0.05).Compared with the TCM low-dosage group,the TCM high-dosage group showed a significant decrease in p21 protein expression(P<0.01)and a significant increase in NOX4 protein expression(P<0.01).Conclusion Renshen Yimai Prescription may reduce vascular endothelial damage by regulating oxidative stress levels and related protein expression,thereby playing a role in improving vascular aging.
7.Analysis of clinicopathological characteristics in 20 cases of primary gastric adenosquamous carcinoma
Yayun HE ; Xiaochen SHI ; Yisha GAO
Chongqing Medicine 2023;52(23):3572-3576
Objective To investigate the clinical manifestations,pathological diagnosis,treatment meth-od and prognosis of primary gastric adenosquamous carcinoma.Methods The clinical data of 20 patients with primary gastric adenosquamous carcinoma receiving the treatment in this hospital from January 1,2013 to No-vember 30,2022 were retrospectively analyzed,and their clinicopathological characteristics and prognosis were analyzed.Results Among the 20 patients,14 cases were male and 6 cases were female,with a median age of 59(36,74)years old.Upper abdominal discomfort,pain and weight loss were the main clinical symptoms.Ser-um carbohydrate antigen 19-9(CA19-9)levels were elevated in some patients.The image examination indica-ted the gastric occupation.Among 20 cases,the tumors were most common in the lower third of the stomach(14 cases),followed by the upper third(1 case)and the middle third(5 cases).The most common tumors were in the lower one-third(14 cases)of the stomach,followed by the middle one-third(5 cases)and upper one-third(1 case).In histomorphology,the gastric tumor cells contained two components,adenocarcinoma and squamous cell carcinoma,and squamous cell carcinoma accounted for more than 25%of tumor cells.Immuno-histochemistry showed that the partial tumor cells of adenocarcinoma expressed CK8/18 and partial tumor cells of squamous cell carcinoma expressed p40.All 20 cases performed the surgical treatment.Only 6 cases survived and the others died of tumor recurrence or metastasis.The adenosquamous carcinoma proportion and Ki-67 were correlated with the prognosis in the patients with gastric adenosquamous carcinoma(P<0.05).The survival curve constructed by the Kaplan-Meier method showed that when the proportion of squamous carcinoma was more than 35%,the prognosis of the patients was good.Conclusion Primary gastric adenosquamous carcinoma,mainly composed of adenocarcinoma,may be correlated with a higher risk of metastasis.
8.Study of 68Ga-NODAGA-RGD PET/CT in predicting short-term efficacy of tyrosine kinase inhibitor in the treatment of distant metastatic differentiated thyroid cancer
Jun WANG ; Jingjing FU ; Xiaowei TANG ; Xiaochen YAO ; Liang SHI ; Shaohua LI ; Feng WANG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2023;43(8):459-464
Objective:To investigate the clinical application of 68Ga-cyclo( L-arginylglycyl- L-α-aspartyl- D-tyrosyl-N6-(((4, 7-bis(carboxymethyl)-1, 4, 7-triazonan-1-yl)acetyl))- L-lysyl) (NODAGA-RGD) PET/CT to evaluate short-term efficacy of tyrosine kinase inhibitor (TKI) in distant metastatic differentiated thyroid cancer (dmDTC). Methods:From October 2019 to March 2023, 13 dmDTC patients (5 males, 8 females; age: 68(65, 69) years) from Nanjing First Hospital were retrospectively enrolled, of which 9 were clinically confirmed as radioactive iodine-refractory differentiated thyroid cancer (RAIR-DTC) and 4 were dmDTC without radioactive iodine treatment. All patients underwent 68Ga-NODAGA-RGD PET/CT to assess neovascularization of the target lesions (TL), and the SUV max and target background ratio (T/B) were recorded. After 3 months of TKI treatment (anrotinib ( n=9) or apatinib ( n=4)), change rates of the maximum diameter of TL and thyroglobulin (Tg) were measured. The correlation of SUV max, T/B and the change rate of the maximum diameter of TL were analyzed by Spearman rank correlation analysis. ROC curve analysis was performed for the effectiveness of the T/B and TKI therapy, and the difference of the remission rate of lesions was analyzed by Fisher exact test. Results:In 13 patients, 36 TL were measured by 68Ga-NODAGA-RGD PET/CT with SUV max of 5.44(3.43, 7.56) and T/B of 5.25(4.50, 7.23). The change rate of the maximum diameter of TL was -30%(-39%, -21%) and the change rate of Tg was -68%(-96%, -52%). T/B was negatively correlated with the change rate of the maximum diameter of TL after TKI therapy ( rs=-0.46, P=0.005), while SUV max was not correlated with the change rate of the maximum diameter of TL ( rs=0.03, P=0.883). ROC curve analysis showed that the optimal cut-off value for T/B was 4.95, with the AUC of 0.698, the sensitivity of 87.5%, and the specificity of 60.0%. Compared to lesions with T/B<4.95, those with T/B≥4.95 showed higher remission rate (2/14 vs 63.6%(14/22); P=0.006). After 3 months of TKI treatment, the disease control rate was 12/13. Conclusion:68Ga-NODAGA-RGD PET/CT can effectively reflect tumor neovascularization, predict efficacy of TKI therapy, and provide powerful imaging evidence for TKI therapy in dmDTC.
9.Influence of Resolvin D1 on the inflammatory response and expression of NLRP3 in mice with acute lung injury
Jun SHI ; Jingxia ZENG ; Shaodong ZHAO ; Xiaochen HU ; Hongjun MIAO ; Qin ZHANG
Chinese Journal of Applied Clinical Pediatrics 2020;35(21):1668-1671
Objective:To investigate the effects of Resolvin D1 (RvD1) on the inflammatory response and the expression of Nod-like receptor protein 3(NLRP3) inflammasomes in mice with acute lung injury.Methods:The 30 male BALB/c mice weighing 25-30 g were divided into 3 groups(each group with 10 mice). Mice in the normal control group were given normal saline by tail vein injection.Mice in the lipopolysaccharide (LPS) group were given the same volume of LPS (10 mg/kg) via tail vein injection.Mice in the RvD1 group were injected with RvD1 (5 μg/kg) through the tail vein 30 minutes prior to LPS administration.Mice were humanely sacrificed after 6 hours.Histopatholo-gical changes of lung tissue, the levels of pro-inflammatory cytokines interleukin(IL)-18 and IL-1β, and the expression of NLRP3 inflammasomes in lung tissue were measured.Results:After LPS administration, the lung of mice showed pathological damage.The levels of pro-inflammatory factors IL-18 and IL-1β as well as the expression of NLRP3, apoptosis-associated speck-like protein containing a card(ASC)and Caspase-1 in the LPS group were significantly higher than those in the normal control group (all P<0.05). After pretreatment with RvD1, the pathological damage of lung tissue was alleviated.The levels of pro-inflammatory factors IL-18 and IL-1β as well as the expression of NLRP3, ASC and Caspase-1 in the RvD1 group were significantly lower than those in the LPS group (all P<0.05). Conclusions:RvD1 can attenuate the pulmonary inflammation in acute lung injury and inhibit the release of pro-inflammatory factors, which is possibly related to the suppression of NLRP3.
10.Tet2 Regulates Osteoclast Differentiation by Interacting with Runx1 and Maintaining Genomic 5-Hydroxymethylcytosine (5hmC).
Yajing CHU ; Zhigang ZHAO ; David Wayne SANT ; Ganqian ZHU ; Sarah M GREENBLATT ; Lin LIU ; Jinhuan WANG ; Zeng CAO ; Jeanette Cheng THO ; Shi CHEN ; Xiaochen LIU ; Peng ZHANG ; Jaroslaw P MACIEJEWSKI ; Stephen NIMER ; Gaofeng WANG ; Weiping YUAN ; Feng-Chun YANG ; Mingjiang XU
Genomics, Proteomics & Bioinformatics 2018;16(3):172-186
As a dioxygenase, Ten-Eleven Translocation 2 (TET2) catalyzes subsequent steps of 5-methylcytosine (5mC) oxidation. TET2 plays a critical role in the self-renewal, proliferation, and differentiation of hematopoietic stem cells, but its impact on mature hematopoietic cells is not well-characterized. Here we show that Tet2 plays an essential role in osteoclastogenesis. Deletion of Tet2 impairs the differentiation of osteoclast precursor cells (macrophages) and their maturation into bone-resorbing osteoclasts in vitro. Furthermore, Tet2 mice exhibit mild osteopetrosis, accompanied by decreased number of osteoclasts in vivo. Tet2 loss in macrophages results in the altered expression of a set of genes implicated in osteoclast differentiation, such as Cebpa, Mafb, and Nfkbiz. Tet2 deletion also leads to a genome-wide alteration in the level of 5-hydroxymethylcytosine (5hmC) and altered expression of a specific subset of macrophage genes associated with osteoclast differentiation. Furthermore, Tet2 interacts with Runx1 and negatively modulates its transcriptional activity. Our studies demonstrate a novel molecular mechanism controlling osteoclast differentiation and function by Tet2, that is, through interactions with Runx1 and the maintenance of genomic 5hmC. Targeting Tet2 and its pathway could be a potential therapeutic strategy for the prevention and treatment of abnormal bone mass caused by the deregulation of osteoclast activities.
5-Methylcytosine
;
analogs & derivatives
;
chemistry
;
metabolism
;
Animals
;
Cell Differentiation
;
Cells, Cultured
;
Core Binding Factor Alpha 2 Subunit
;
genetics
;
metabolism
;
DNA-Binding Proteins
;
physiology
;
Genome
;
Genomics
;
Mice
;
Mice, Knockout
;
Osteoclasts
;
cytology
;
metabolism
;
Proto-Oncogene Proteins
;
physiology

Result Analysis
Print
Save
E-mail