1.Angiotensin converting enzyme 2 alleviates infectious bronchitis virus-induced cellular inflammation by suppressing IL-6/JAK2/STAT3 signaling pathway.
Xiaoxia JI ; Huanhuan WANG ; Chang MA ; Zhiqiang LI ; Xinyu DU ; Yuanshu ZHANG
Chinese Journal of Biotechnology 2023;39(7):2669-2683
The goal of this study was to investigate the regulatory effect of angiotensin converting enzyme 2 (ACE2) on cellular inflammation caused by avian infectious bronchitis virus (IBV) and the underlying mechanism of such effect. Vero and DF-1 cells were used as test target to be exposed to recombinant IBV virus (IBV-3ab-Luc). Four different groups were tested: the control group, the infection group[IBV-3ab-Luc, MOI (multiplicity of infection)=1], the ACE2 overexpression group[IBV-3ab Luc+pcDNA3.1(+)-ACE2], and the ACE2-depleted group (IBV-3ab-Luc+siRNA-ACE2). After the cells in the infection group started to show cytopathic indicators, the overall protein and RNA in cell of each group were extracted. real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the mRNA expression level of the IBV nucleoprotein (IBV-N), glycoprotein 130 (gp130) and cellular interleukin-6 (IL-6). Enzyme linked immunosorbent assay (ELISA) was used to determine the level of IL-6 in cell supernatant. Western blotting was performed to determine the level of ACE2 phosphorylation of janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). We found that ACE2 was successfully overexpressed and depleted in both Vero and DF-1 cells. Secondly, cytopathic indicators were observed in infected Vero cells including rounding, detaching, clumping, and formation of syncytia. These indicators were alleviated in ACE2 overexpression group but exacerbated when ACE2 was depleted. Thirdly, in the infection group, capering with the control group, the expression level of IBV-N, gp130, IL-6 mRNA and increased significantly (P < 0.05), the IL-6 level was significant or extremely significant elevated in cell supernatant (P < 0.05 or P < 0.01); the expression of ACE2 decreased significantly (P < 0.05); protein phosphorylation level of JAK2 and STAT3 increased significantly (P < 0.05). Fourthly, comparing with the infected group, the level of IBV-N mRNA expression in the ACE2 overexpression group had no notable change (P > 0.05), but the expression of gp130 mRNA, IL-6 level and expression of mRNA were elevated (P < 0.05) and the protein phosphorylation level of JAK2 and STAT3 decreased significantly (P < 0.05). In the ACE2-depleted group, there was no notable change in IBV-N (P > 0.05), but the IL-6 level and expression of mRNA increased significantly (P < 0.05) and the phosphorylation level of JAK2 and STAT3 protein decreased slightly (P > 0.05). The results demonstrated for the first time that ACE2 did not affect the replication of IBV in DF-1 cell, but it did contribute to the prevention of the activation of the IL-6/JAK2/STAT3 signaling pathway, resulting in an alleviation of IBV-induced cellular inflammation in Vero and DF-1 cells.
Animals
;
Chlorocebus aethiops
;
Humans
;
Interleukin-6/genetics*
;
Janus Kinase 2/pharmacology*
;
Infectious bronchitis virus/metabolism*
;
STAT3 Transcription Factor/metabolism*
;
Angiotensin-Converting Enzyme 2/pharmacology*
;
Cytokine Receptor gp130/metabolism*
;
Vero Cells
;
Signal Transduction
;
Inflammation
;
RNA, Messenger
2.Alcohol extract of root and root bark of Toddalia asiatica alleviates CIA in rats through anti-inflammatory and proapoptotic effects.
Zong-Xing ZHANG ; Lu JIANG ; Dao-Zhong LIU ; Bo-Nan TAO ; Zi-Ming HOU ; Meng-Jie TIAN ; Jia FENG ; Lin YUAN
China Journal of Chinese Materia Medica 2023;48(8):2203-2211
This study aims to investigate the therapeutic effect of alcohol extract of root and root bark of Toddalia asiatica(TAAE) on collagen-induced arthritis(CIA) in rats through phosphatidylinoinosidine-3 kinase/protein kinase B(PI3K/Akt) signaling pathway. To be specific, CIA was induced in rats, and then the rats were treated(oral, daily) with TAAE and Tripterygium Glycoside Tablets(TGT), respectively. The swelling degree of the hind leg joints was scored weekly. After 35 days of administration, the histopathological changes were observed based on hematoxylin and eosin(HE) staining. Enzyme-linked immunosorbent assay(ELISA) was employed to detect the levels of cytokines [tumor necrosis factor-α(TNF-α), interleukin(IL)-6)]. Terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL) staining was performed to detect the apoptosis of synoviocytes in rats. Western blot was used to detect the expression levels of apoptosis-related proteins B-cell lymphoma 2(Bcl-2)-associated X(Bax), Bcl-2, and caspase-3 and pathway-related proteins phosphoinositide 3-kinase(PI3K), phosphorylated(p)-PI3K, protein kinase B(Akt), and p-Akt. RT-qPCR was conducted to examine the mRNA levels of Bax, Bcl-2, caspase-3, TNF-α, IL-6, and IL-1β and pathway-related proteins PI3K, p-PI3K, Akt, and p-Akt. TAAE can alleviate the joint swelling in CIA rats, reduce serum levels of inflammatory cytokines, improve synovial histopathological changes, promote apoptosis of synoviocytes, and inhibit synovial inflammation. In addition, RT-qPCR and Western blot results showed that TAAE up-regulated the level of Bax, down-regulated the level of Bcl-2, and activated caspase-3 to promote apoptosis in synoviocytes. TAAE effectively down-regulated the protein levels of p-PI3K and p-Akt. In this study, TAAE shows therapeutic effect on CIA in rats and reduces the inflammation. The mechanism is that it suppresses PI3K/Akt signaling pathway and promotes synoviocyte apoptosis. Overall, this study provides a new clue for the research on the anti-inflammatory mechanism of TAAE and lays a theoretical basis for the better clinical application of TAAE in the treatment of inflammatory and autoimmune diseases.
Rats
;
Animals
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Caspase 3/genetics*
;
Tumor Necrosis Factor-alpha/metabolism*
;
bcl-2-Associated X Protein/metabolism*
;
Plant Bark
;
Anti-Inflammatory Agents/therapeutic use*
;
Arthritis, Experimental/chemically induced*
;
Inflammation/drug therapy*
;
Cytokines/metabolism*
;
Proto-Oncogene Proteins c-bcl-2
;
Apoptosis
3.Mechanism of Buyang Huanwu Decoction glycosides against atherosclerotic inflammation through NF-κB signaling pathway.
Xin-Ying FU ; Zheng-Ji SUN ; Qing-Yin LONG ; Wei TAN ; Yan-Jun LI ; Lu WU ; Qing-Hu HE ; Wei ZHANG
China Journal of Chinese Materia Medica 2023;48(1):202-210
This study aims to explore the effect of Buyang Huanwu Decoction glycosides on the inflammatory response of apolipoprotein E~(-/-)(ApoE~(-/-)) mice and RAW264.7 cells through nuclear factor kappa-B(NF-κB) signaling pathway. In the in vivo experiment, ApoE~(-/-) mice were fed with high-fat diets for 12 weeks to induce the animal model of atherosclerosis, and 75 μg·mL~(-1) oxidized low-density lipoprotein(Ox-LDL) incubated RAW264.7 cells for 24 h to establish the atherosclerosis cell model. Automatic biochemical analyzer, hematoxylin-eosin(HE) staining, enzyme-linked immunosorbent assay(ELISA), Western blot, and droplet digital polymerase chain reaction(PCR) were used to determine the blood lipid levels, aortic intimal thickness, inflammatory factor content, NF-κB pathway-related proteins, and mRNA expression levels, and evaluate arterial atherosclerotic lesions and anti-atherosclerotic mechanisms of the drug. The model of atherosclerosis was successfully established in ApoE~(-/-) mice after 12 weeks of feeding with high-fat diets. In the model group, the plasma levels of total cholesterol(TC), triglyceride(TG), and low-density lipoprotein cholesterol(LDL-C) were increased(P<0.01), the intima of the blood vessels was thickened, the levels of inflammatory factors tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) were increased, and the protein and mRNA expressions of NF-κB and inhibitor of NF-κB(IκBα) were significantly increased as compared with the control group. Compared with the model group, the high-dose Buyang Huanwu Decoction glycoside group decreased the plasma levels of TC, TG, and LDL-C, reduced the plaque area and thickness and the content of inflammatory factor TNF-α, and inhibited the protein and mRNA expressions of NF-κB and IκBα, with the effect same as Buyang Huanwu Decoction. In the in vivo experiment, 75 μg·mL~(-1) Ox-LDL stimulated RAW264.7 cells for 24 h to successfully establish a foam cell model. As compared with the control group, the nuclear amount of NF-κB and the protein and mRNA expressions of IκBα in the model group increased. Compared with the model group, the middle-dose and high-dose Buyang Huanwu Decoction glycoside groups decreased the nuclear amount of NF-κB and the protein and mRNA expressions of IκBα. The above results show that the glycosides are the main effective substances of Buyang Huanwu Decoction against atherosclerosis, which inhibit the NF-κB pathway and reduce the inflammatory response, thus playing the role against atherosclerotic inflammation same as Buyang Huanwu Decoction.
Mice
;
Animals
;
NF-kappa B/metabolism*
;
NF-KappaB Inhibitor alpha/metabolism*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Glycosides/pharmacology*
;
Cholesterol, LDL
;
Atherosclerosis/genetics*
;
Signal Transduction
;
Inflammation/drug therapy*
;
Interleukin-6
;
Apolipoproteins E/pharmacology*
;
RNA, Messenger/metabolism*
4.Effects of Rehmanniae Radix and Rehmanniae Radix Praeparata on proteomics and autophagy in mice with type 2 diabetes mellitus induced by high-fat diet coupled with streptozotocin.
Jing-Ning YAN ; Xiao-Qin LIU ; Xiang-Long MENG ; Ke-le REN ; Xue-Min WU ; Hao ZHANG ; Hai-Qin WANG ; Hong-Liang WANG ; Qi SHENG ; Bin LI ; Ding-Bang ZHANG ; Hong-Zhou CHEN ; Fa-Yun ZHANG ; Ming-Hao LI ; Shuo-Sheng ZHANG
China Journal of Chinese Materia Medica 2023;48(6):1535-1545
To compare the pancreatic proteomics and autophagy between Rehmanniae Radix-and Rehmanniae Radix Praeparata-treated mice with type 2 diabetes mellitus(T2DM). The T2DM mouse model was established by high-fat diet coupled with streptozotocin(STZ, intraperitoneal injection, 100 mg·kg~(-1), once a day for three consecutive days). The mice were then randomly assigned into a control group, low-(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix groups, low-(150 mg·kg~(-1)) and high-dose(300 mg·kg~(-1)) catalpol groups, low-(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix Praeparata groups, low-(150 mg·kg~(-1)) and high-dose(300 mg·kg~(-1)) 5-hydroxymethyl furfuraldehyde(5-HMF) groups, and a metformin(250 mg·kg~(-1)) group. In addition, a normal group was also set and each group included 8 mice. The pancreas was collected after four weeks of administration and proteomics tools were employed to study the effects of Rehmanniae Radix and Rehmanniae Radix Praeparata on protein expression in the pancreas of T2DM mice. The expression levels of proteins involved in autophagy, inflammation, and oxidative stress response in the pancreatic tissues of T2DM mice were determined by western blotting, immunohistochemical assay, and transmission electron microscopy. The results showed that the differential proteins between the model group and Rehmanniae Radix/Rehmanniae Radix Prae-parata group were enriched in 7 KEGG pathways, such as autophagy-animal, which indicated that the 7 pathways may be associated with T2DM. Compared with the control group, drug administration significantly up-regulated the expression levels of beclin1 and phosphorylated mammalian target of rapamycin(p-mTOR)/mTOR and down-regulated those of the inflammation indicators, Toll-like receptor-4(TLR4) and Nod-like receptor protein 3(NLRP3), in the pancreas of T2DM mice, and Rehmanniae Radix showed better performance. In addition, the expression levels of inducible nitric oxide synthase(iNOS), nuclear factor erythroid 2-related factor 2(Nrf2), and heine oxygenase-1(HO-1) in the pancreas of T2DM mice were down-regulated after drug administration, and Rehmanniae Radix Praeparata demonstrated better performance. The results indicate that both Rehmanniae Radix and Rehmanniae Radix Praeparata can alleviate the inflammatory symptoms, reduce oxidative stress response, and increase the autophagy level in the pancreas of T2DM mice, while they exert the effect on different autophagy pathways.
Mice
;
Animals
;
Diabetes Mellitus, Type 2/genetics*
;
Streptozocin/pharmacology*
;
Diet, High-Fat/adverse effects*
;
Proteomics
;
Inflammation
;
TOR Serine-Threonine Kinases
;
Autophagy
;
Mammals
5.10,11-Dehydrocurvularin attenuates inflammation by suppressing NLRP3 inflammasome activation.
Qun ZHAO ; Mengyuan FENG ; Shu JIN ; Xiaobo LIU ; Shengbao LI ; Jian GUO ; Xinran CHENG ; Guangbiao ZHOU ; Xianjun YU
Chinese Journal of Natural Medicines (English Ed.) 2023;21(3):163-171
10,11-Dehydrocurvularin (DCV) is a natural-product macrolide that has been shown to exert anti-inflammatory activity. However, the underlying mechanism of its anti-inflammatory activity remains poorly understood. Aberrant activation of the NLRP3 inflammasome is involved in diverse inflammation-related diseases, which should be controlled. The results showed that DCV specifically inhibited the activation of the NLRP3 inflammasome in association with reduced IL-1β secretion and caspase-1 activation, without effect on the NLRC4 and AIM2 inflammasomes. Furthermore, DCV disturbed the interaction between NEK7 and NLRP3, resulting in the inhibition of NLRP3 inflammasome activation. The C=C double bond of DCV was required for the NLRP3 inflammasome inhibition induced by DCV. Importantly, DCV ameliorated inflammation in vivo through inhibiting the NLRP3 inflammasome. Taken together, our study reveals a novel mechanism by which DCV suppresses inflammation, which indicates the potential role of DCV in NLRP3 inflammasome-driven inflammatory disorders.
Animals
;
Mice
;
Inflammasomes
;
NLR Family, Pyrin Domain-Containing 3 Protein/genetics*
;
Inflammation/drug therapy*
;
Anti-Inflammatory Agents/pharmacology*
;
Interleukin-1beta/genetics*
;
Mice, Inbred C57BL
6.APOE-mediated suppression of the lncRNA MEG3 protects human cardiovascular cells from chronic inflammation.
Hongkai ZHAO ; Kuan YANG ; Yiyuan ZHANG ; Hongyu LI ; Qianzhao JI ; Zeming WU ; Shuai MA ; Si WANG ; Moshi SONG ; Guang-Hui LIU ; Qiang LIU ; Weiqi ZHANG ; Jing QU
Protein & Cell 2023;14(12):908-913
7.Paeonol reduces microbial metabolite α-hydroxyisobutyric acid to alleviate the ROS/TXNIP/NLRP3 pathway-mediated endothelial inflammation in atherosclerosis mice.
Yarong LIU ; Hongfei WU ; Tian WANG ; Xiaoyan SHI ; Hai HE ; Hanwen HUANG ; Yulong YANG ; Min DAI
Chinese Journal of Natural Medicines (English Ed.) 2023;21(10):759-774
Gut microbiota dysbiosis is an avenue for the promotion of atherosclerosis (AS) and this effect is mediated partly via the circulating microbial metabolites. More microbial metabolites related to AS vascular inflammation, and the mechanisms involved need to be clarified urgently. Paeonol (Pae) is an active compound isolated from Paeonia suffruticoas Andr. with anti-AS inflammation effect. However, considering the low oral bioavailability of Pae, it is worth exploring the mechanism by which Pae reduces the harmful metabolites of the gut microbiota to alleviate AS. In this study, ApoE-/- mice were fed a high-fat diet (HFD) to establish an AS model. AS mice were administrated with Pae (200 or 400 mg·kg-1) by oral gavage and fecal microbiota transplantation (FMT) was conducted. 16S rDNA sequencing was performed to investigate the composition of the gut microbiota, while metabolomics analysis was used to identify the metabolites in serum and cecal contents. The results indicated that Pae significantly improved AS by regulating gut microbiota composition and microbiota metabolic profile in AS mice. We also identified α-hydroxyisobutyric acid (HIBA) as a harmful microbial metabolite reduced by Pae. HIBA supplementation in drinking water promoted AS inflammation in AS mice. Furthermore, vascular endothelial cells (VECs) were cultured and stimulated by HIBA. We verified that HIBA stimulation increased intracellular ROS levels, thereby inducing VEC inflammation via the TXNIP/NLRP3 pathway. In sum, Pae reduces the production of the microbial metabolite HIBA, thus alleviating the ROS/TXNIP/NLRP3 pathway-mediated endothelial inflammation in AS. Our study innovatively confirms the mechanism by which Pae reduces the harmful metabolites of gut microbiota to alleviate AS and proposes HIBA as a potential biomarker for AS clinical judgment.
Animals
;
Mice
;
Atherosclerosis/drug therapy*
;
Diet, High-Fat
;
Endothelial Cells
;
Inflammation/drug therapy*
;
Mice, Inbred C57BL
;
NLR Family, Pyrin Domain-Containing 3 Protein/genetics*
;
Reactive Oxygen Species
8.The association between Helicobacter pylori virulence factor genotypes and gastroduodenal diseases in children.
Jing Jing YING ; Xiao Li SHU ; Gao LONG ; Mi Zu JIANG
Chinese Journal of Pediatrics 2023;61(9):827-832
Objective: To investigate the association between Helicobacter pylori (Hp) virulence factor genotypes and the degree and activity of gastric mucosa pathological changes in pediatric gastroduodenal diseases. Methods: This retrospective cohort study was conducted from May 2020 to October 2020. The frozen strains of Hp, which were cultured with the gastric mucosa of 68 children with gastroscopy confirmed gastroduodenal diseases who visited the children's hospital of Zhejiang University School of Medicine from April 2012 to December 2014, were resuscitated. After extracting DNA from these Hp strains, PCR amplification and agarose gel electrophoresis were performed to determine the detection rate of cytotoxin-associated protein A (cagA),vacuolating cytotoxin A (vacA)(s1a、s1b/s2,m1/m2), outer inflammatory protein A (oipA),blood group antigen binding adhesin (babA),duodenal ulcer promoting protein A (dupA) genes; oipA genes were sequenced to determine the gene status. The patients were divided into different groups according to the findings of gastroscopy and gastric mucosa pathology. The detection rates of various virulence factor genotypes among different groups were compared using χ2 tests or Fisher's exact tests. Results: The 68 Hp strains all completed genetic testing. According to the diagnostic findings of gastroscopy, the 68 cases were divided into 47 cases of superficial gastritis and 21 cases of peptic ulcer. Regarding the pathological changes of gastric mucosa, 8 cases were mild, and 60 cases were moderate and severe according to the degree of inflammation; 61 cases were active and 7 cases inactive according to the activity of inflammation. The overall detection rates of cagA, vacA, vacA s1/m2, functional oipA, babA2, and dupA virulence factor genes were 100% (68/68), 100% (68/68), 94% (64/68), 99% (67/68), 82% (56/68), and 71% (48/68), respectively. In the superficial gastritis group, their detection rates were 100% (47/47), 100% (47/47), 96% (45/47), 98% (46/47), 81% (38/47), and 70% (33/47), respectively; in the peptic ulcer group, their detection rates were 100% (21/21), 100% (21/21), 90% (19/21), 100% (21/21), 86% (18/21), and 71% (15/21), respectively. There was no statistically significant difference between the two groups (all P>0.05). In the mild gastric mucosa inflammation group, the detection rates of the above six genotypes were 8/8, 8/8, 8/8, 7/8, 7/8, and 5/8, respectively; and in the moderate to severe inflammation groups, the detection rates were 100% (60/60), 100% (60/60), 93% (56/60), 100% (60/60), 82% (49/60), and 72% (43/60), respectively, with no statistically significant difference between the two groups (all P>0.05). In the active inflammation group, the detection rate of six genotypes were 100% (61/61), 100% (61/61), 93% (57/61), 98% (60/61), 82% (50/61), and 72% (44/61), respectively; and in the inactive inflammation group, they were 7/7, 7/7, 7/7, 7/7, 6/7, and 4/7, respectively. Again, there was no statistically significant difference between the two groups (all P>0.05). There was no statistically significant difference in the detection rate of combinations of 4 or 5 virulence factor genes among the different groups (all P>0.05). Conclusions: CagA, vacA, vacA s1/m2, functional oipA, babA2, and dupA genes are not associated with superficial gastritis and peptic ulcer in children, or with the degree and activity of gastric mucosa pathological inflammation. Different gene combinations of cagA, vacA, oipA, babA2, and dupA have no significant effects on predicting the clinical outcome of Hp infection in children.
Humans
;
Child
;
Helicobacter pylori/genetics*
;
Retrospective Studies
;
Genotype
;
Inflammation
;
Gastritis
;
Cytotoxins
9.Matrine inhibits inflammatory response induced by TNF-α in human umbilical vein endothelial cells through miR-25-3p-mediated Klf4 pathway.
Zi-Ping XIANG ; Yan-Jie LI ; Huan MA ; Xing WANG ; Hui-Xin ZHANG ; Chao WANG
China Journal of Chinese Materia Medica 2023;48(17):4731-4737
This study aimed to analyze the effect of matrine on tumor necrosis factor-α(TNF-α)-induced inflammatory response in human umbilical vein endothelial cells(HUVECs) and explore whether the underlying mechanism was related to the miR-25-3p-mediated Krüppel-like factor 4(Klf4) pathway. The HUVEC cell inflammation model was induced by TNF-α stimulation. After 24 or 48 hours of incubation with different concentrations of matrine(0.625, 1.25, and 2.5 mmol·L~(-1)), CCK-8 assay was used to detect cell proliferation. After treatment with 2.5 mmol·L~(-1) matrine for 48 h, the expression of TNF-α, interleukin-6(IL-6), interleukin-1β(IL-1β), and Klf4 mRNA and miR-25-3p was detected by real-time fluorescence-based quantitative PCR, and the protein expression of TNF-α, IL-6, IL-1β, and Klf4 was detected by Western blot. The anti-miR-25-3p was transfected into HUVECs, and the effect of anti-miR-25-3p on TNF-α-induced cell proliferation and inflammatory factors was detected by the above method. The cells were further transfected with miR-25-3p and incubated with matrine to detect the changes in proliferation and expression of related inflammatory factors, miR-25-3p, and Klf4. The targeting relationship between miR-25-3p and Klf4 was verified by bioinformatics analysis and dual luciferase reporter gene assay. The results displayed that matrine could inhibit TNF-α-induced HUVEC proliferation, decrease the mRNA and protein expression of TNF-α, IL-6, and IL-1β, increase the mRNA and protein expression of Klf4, and reduce the expression of miR-25-3p. Bioinformatics analysis showed that there were specific complementary binding sites between miR-25-3p and Klf4 sequences. Dual luciferase reporter gene assay confirmed that miR-25-3p negatively regulated Klf4 expression in HUVECs by targeting. The inhibition of miR-25-3p expression can reduce TNF-α-induced cell proliferation and mRNA and protein expression of TNF-α, IL-6, and IL-1β. MiR-25-3p overexpression could reverse the effect of matrine on TNF-α-induced cell proliferation and the mRNA and protein expression of TNF-α, IL-6, IL-1β, and Klf4. This study shows that matrine inhibits the inflammatory response induced by TNF-α in HUVECs through miR-25-3p-mediated Klf4 pathway.
Humans
;
Tumor Necrosis Factor-alpha/metabolism*
;
MicroRNAs/metabolism*
;
Human Umbilical Vein Endothelial Cells
;
Matrines
;
Interleukin-6/genetics*
;
Signal Transduction
;
Antagomirs
;
Inflammation/metabolism*
;
Luciferases/pharmacology*
;
RNA, Messenger
;
Apoptosis
10.Melatonin promotes osteogenesis of bone marrow mesenchymal stem cells by improving the inflammatory state in ovariectomized rats.
Huanshuai GUAN ; Ruomu CAO ; Yiwei ZHAO ; Jiewen ZHANG ; Heng LI ; Xudong DUAN ; Yiyang LI ; Ning KONG ; Run TIAN ; Kunzheng WANG ; Pei YANG
Chinese Journal of Reparative and Reconstructive Surgery 2023;37(8):1011-1020
OBJECTIVE:
To investigate the effects of melatonin (MT) on bone mass and serum inflammatory factors in rats received ovariectomy (OVX) and to investigate the effects of MT on the levels of inflammatory factors in culture medium and osteogenic ability of bone marrow mesenchymal stem cells (BMSCs) stimulated by lipopolysaccharide.
METHODS:
Fifteen 12-week-old Sprague Dawley (SD) rats were randomly divided into 3 groups. The rats in Sham group only received bilateral lateral abdominal incision and suture, the rats in OVX group received bilateral OVX, and the rats in OVX+MT group received 100 mg/(kg·d) MT oral intervention after bilateral OVX. After 8 weeks, the levels of serum inflammatory factors [interleukin-1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α)] were detected using ELISA assay. Besides, the distal femurs were detected by Micro-CT to observe changes in bone mass and microstructure, and quantitatively measured bone volume fraction, trabecular thickness, and trabecular number. The BMSCs were extracted from the femurs of three 3-week-old SD rats using whole bone marrow culture method and passaged. The 3rd-5th passage BMSCs were cultured with different concentrations of MT (0, 1, 10, 100, 1 000 µmol/L), and the cell viability was then detected using cell counting kit 8 (CCK-8) to select the optimal concentration of MT for subsequent experiments. Cells were devided into osteogenic induction group (group A) and osteogenic induction+1/5/10 μg/mL lipopolysaccharide group (group B-D). The levels of inflammatory factors (IL-1β, IL-6 and TNF-α) in cell culture medium were detected using ELISA assay after corresponding intervention. According to the results of CCK-8 method and ELISA detection, the cells were intervened with the most significant concentration of lipopolysaccharide for stimulating inflammation and the optimal concentration of MT with osteogenic induction, defining as group E, and the cell culture medium was collected to detect the levels of inflammatory factors by ELISA assay. After that, alkaline phosphatase (ALP) staining and alizarin red staining were performed respectively in groups A, D, and E, and the expression levels of osteogenic related genes [collagen type Ⅰ alpha 1 chain (Col1a1) and RUNX family transcription factor 2 (Runx2)] were also detected by real time fluorescence quantitative PCR (RT-qPCR).
RESULTS:
ELISA and Micro-CT assays showed that compared with Sham group, the bone mass of the rats in the OVX group significantly decreased, and the expression levels of serum inflammatory factors (IL-1β, IL-6, and TNF-α) in OVX group significantly increased (P<0.05). Significantly, the above indicators in OVX+MT group were all improved (P<0.05). Rat BMSCs were successfully extracted, and CCK-8 assay showed that 100 µmol/L was the maximum concentration of MT that did not cause a decrease in cell viability, and it was used in subsequent experiments. ELISA assays showed that compared with group A, the expression levels of inflammatory factors (IL-1β, IL-6, and TNF-α) in the cell culture medium of groups B-D were significantly increased after lipopolysaccharide stimulation (P<0.05), and in a concentration-dependent manner. Moreover, the expression levels of inflammatory factors in group D were significantly higher than those in groups B and C (P<0.05). After MT intervention, the expression levels of inflammatory factors in group E were significantly lower than those in group D (P<0.05). ALP staining, alizarin red staining, and RT-qPCR assays showed that compared with group A, the percentage of positive area of ALP and alizarin red and the relative mRNA expressions of Col1a1 and Runx2 in group D significantly decreased, while the above indicators in group E significantly improved after MT intervention (P<0.05).
CONCLUSION
MT may affect the bone mass of postmenopausal osteoporosis by reducing inflammation in rats; MT can reduce the inflammation of BMSCs stimulated by lipopolysaccharide and weaken its inhibition of osteogenic differentiation of BMSCs.
Female
;
Rats
;
Animals
;
Tumor Necrosis Factor-alpha
;
Osteogenesis
;
Rats, Sprague-Dawley
;
Core Binding Factor Alpha 1 Subunit
;
Melatonin/pharmacology*
;
Interleukin-6/genetics*
;
Lipopolysaccharides/pharmacology*
;
Coloring Agents
;
Inflammation

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