1.Dynamic changes and function of mitochondria in development of em-bryonic hematopoietic stem cells
Rong ZHANG ; Haixin ZHAO ; Jie ZHOU ; Di LIU ; Yu LAN ; Bing LIU
Chinese Journal of Pathophysiology 2024;40(5):769-776
AIM:To describe the dynamic characteristics of mitochondria in the development of mouse embryonic hematopoietic stem cells,and to explore the function of mitochondria in this process.METHODS:Single-cell transcrip-tomic data of continuous developmental hematopoietic stem cell-related populations were analyzed to describe the dynamic changes of genes related to mitochondrial synthesis and energy metabolism.To explore the dynamic changes in the number and activity of mitochondria during the development of hematopoietic stem cells,we detected the mitochondrial number and mitochondrial membrane potential of the cells in each stage of hematopoietic stem cell development by fluorescent probe staining combined with flow cytometry.We added small molecule inhibitors of mitochondrial synthesis and energy metabolism and used hematopoietic cell colony formation assay to detect the effect of mitochondrial function inhibition on the induction of hematopoietic products in vitro.RESULTS:(1)Single-cell transcriptome analysis showed that genes in-volved in mitochondrial synthesis and oxidative phosphorylation were significantly up-regulated in endothelial cell and type Ⅰ pre-hematopoietic stem cell compared with those involved in glycolysis,and these genes could significantly distinguish continuous dynamic populations.(2)The results of fluorescence staining and flow cytometry analysis showed that mito-chondrial number and mitochondrial membrane potential had an increasing trend during the continuous development of he-matopoietic stem cell,reaching the highest level in the precursor stage of type 2 pre-hematopoietic stem cell,and decreasing in the mature hematopoietic stem cell of fetal liver.(3)Compared with control group,inhibition of mitochondrial respirato-ry chain Ⅰ and Ⅴ significantly reduced the number of hematopoietic colonies(P<0.05).CONCLUSION:(1)Genes re-lated to mitochondrial synthesis and oxidative phosphorylation are highly expressed in hemogenic endothelial cells and type Ⅰpre-hematopoietic stem cells,and can be used to distinguish continuous developing populations.(2)The mitochondrial number and mitochondrial membrane potential increased continuously during hematopoietic stem cell development and reached the highest level in type 2 pre-hematopoietic stem cells.(3)Inhibition of mitochondrial respiratory chain Ⅰ and Ⅴ significantly reduced the production of hematopoietic products in vitro.
2.METTL3 regulates adipogenic differentiation of bone marrow MSCs via YTHDF2/AKT1/PPARγ axis
Zhipeng PAN ; Ling CHEN ; Ruolan YOU ; Huifang HUANG
Chinese Journal of Pathophysiology 2024;40(5):777-785
AIM:To investigate the mechanism by which N6-methyladenosine(m6A)methylase methyltrans-ferase-like protein 3(METTL3)regulates the differentiation of human bone marrow mesenchymal stem cells(MSCs)into adipocytes in vitro.METHODS:Lentiviral vectors of METTL3,AKT serine/threonine kinase 1(AKT1),peroxisome pro-liferator-activated receptor γ(PPARγ)and YTH m6A RNA binding protein F2(YTHDF2)were constructed to package lentiviral particles and used to infect MSCs.A human bone MSC adipogenic differentiation kit was used to induce the MSCs into adipocytes.Additionally,the adipocytes were stained by oil red O.The recombinant vector of METTL3 mutant was constructed using molecular cloning to confirm the regulatory effect of the key site of m6A in METTL3 on the target genes.Actinomycin D was applied to MSCs with overexpression of YTHDF2 to evaluate the effect of YTHDF2 recognition on the mRNA and protein expression of AKT1.The RNA pull-down assay combined with silver staining and Western blot were used to detect the binding of potentially methylated fragments to recognized proteins.RESULTS:METTL3 inhibited the adipogenesis of MSCs in an AKT1/PPARγ-dependent manner,and mediated the protein expression of AKT1 in an m6A-YTHDF2-dependent manner.YTHDF2 recognized and bound to coding sequence(CDS)of m6A-AKT1,and reduced its expression,which inhibited the adipogenesis of MSCs.CONCLUSION:The m6A methylase METTL3 regulates the adipo-genic differentiation of human bone marrow MSCs through YTHDF2/AKT1/PPARγ,providing a theoretical basis for the identification of new targets for acute myeloid leukemia treatment from the perspective of tumor microenvironment.
3.Lenvatinib modulates tumor immune microenvironment to synergistical-ly enhance immune checkpoint inhibitor treatment of hepatocellular car-cinoma
Jiamin LI ; Ruimeng YANG ; Ruili WEI ; Wang YAO ; Wanli ZHANG ; Xinqing JIANG
Chinese Journal of Pathophysiology 2024;40(5):786-795
AIM:To explore the efficacy of lenvatinib(Len)in enhancing the therapeutic effects of immune checkpoint inhibitor for hepatocellular carcinoma(HCC)and to delve into its immunomodulatory mechanisms within the tumor microenvironment.METHODS:The effects of various concentrations of Len on the migration of human umbilical vein endothelial cells(HUVECs)and the secretion of CXC chemokine ligand 10(CXCL10)were investigated,and the mechanism by which Len modulates CXCL10 secretion was validated.An orthotopic HCC model was established,and the mice bearing tumors were randomly allocated into 4 groups:PBS group,BMS-202(PD-1/PD-L1 inhibitor)group,Len group,and Len/BMS-202 group.The progression of the orthotopic liver tumors was monitored with small animal in vivo im-aging techniques.On the 13th day after the treatment,mice were sacrificed and tumor tissues were harvested for analysis.Immunofluorescence was employed to identify apoptosis,vascular architecture,and hypoxic status within the tumor tis-sue.The expression levels of proliferation marker Ki67,transforming growth factor-β(TGF-β),and the infiltration de-grees of CD4+T cells and CD8+T cells in the tumor tissue were monitored with immunohistochemistry.The secretion of im-mune factors interferon-γ(IFN-γ),CXCL10 and TGF-α in the mouse serum was quantified with ELISA.Above all data were followed by statistical analysis.RESULTS:(1)Len could facilitate endothelial cell migration within a specific range and potentiated the response of tumor cells to IFN-γ by blocking fibroblast growth factor receptor(FGFR),thereby increasing the secretion of CXCL10 from the tumor cells.(2)Compared with PBS group,tumor growth was slower in all treatment groups,with Len/BMS-202 group showing the most significant inhibition of tumor growth in tumor-bearing mice(P<0.05).(3)Compared with PBS group and monotherapy groups,Len/BMS-202 significantly promoted tumor tissue apoptosis and inhibited tumor cell proliferation(P<0.05).(4)Compared with PBS group and BMS-202 group,both Len group and Len/BMS-202 group manifested a substantial enhancement in pericytes coverage rate(P<0.01),concomitantly showing a marked improvement in hypoxic conditions(P<0.01).(5)Compared with PBS group and monotherapy groups,Len/BMS-202 group showed a significant increase in the infiltration of CD4+T cells and CD8+T cells within the tumor(P<0.01),along with a marked decrease in the expression of TGF-β(P<0.01).(6)Compared with PBS group,all treatment groups collectively induced varying degrees of secretion of IFN-γ,CXCL10 and TGF-α in mouse serum(P<0.05),with Len/BMS-202 group demonstrating the most pronounced effects(P<0.01).CONCLUSION:Lenvatinib may augment the therapeutic efficacy of BMS-202 in HCC by facilitating tumor vascular normalization,alleviating hypoxic conditions,and enhancing the secretion of CXCL10,thereby synergistically activating the tumor immune microenvironment.
4.Mechanism of protopanaxatriol attenuating paclitaxel resistance in MDA-MB-231 cells
Lingyu LI ; Qianyun YE ; Yan LI ; Li HAN ; Panpan WANG ; Ronghua ZHANG
Chinese Journal of Pathophysiology 2024;40(5):796-805
AIM:To investigate the effect of protopanaxatriol(PPT)on the drug resistance of paclitaxel(PTX)-resistant human breast cancer MDA-MB-231 cells(MB231-PR cells).METHODS:The MB231-PR cells were constructed as cell models.They were treated with PPT,and incubated for a certain period of time according to the experi-mental settings.CellTiter-Glo was used to determine the viability of MB231-PR cells and MDA-MB-231 parental cells(MB231-PT cells).The change of sub-G1 phase was detected by flow cytometry.Western blot was used to evaluate the apoptosis-related proteins,such as cleaved caspase-3,cleaved poly(ADP-ribose)polymerase(PARP),B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax)and survivin.The activity of nuclear factor-κB(NF-κB)was detected by lu-ciferase reporter assay and immunofluorescence assay.The mRNA expression levels of interleukin-6(IL-6),IL-8,chemo-kine CXC motif ligand 1(CXCL1),chemokine CC motif ligand 2(CCL2),CD44,NANOG,octamer-binding transcrip-tion factor 4(OCT4),sex-determining region Y-box 2(SOX2)and aldehyde dehydrogenase 1(ALDH1)were detected by qPCR.The protein levels of IL-6 and IL-8 were measured by ELISA.Tumor sphere formation assay was used to evaluate the characteristics of stem cells.RESULTS:(1)The viability of MB231-PR cells was suppressed by PPT treatment in a dose-dependent manner compared with MB231-PT cells(P<0.01).Besides,the viability of MB231-PR cells was de-creased after combined treatment with PPT and PTX(P<0.01),the accumulation of sub-G1 phase was induced(P<0.01),the ratio of Bax/Bcl-2 was elevated(P<0.01),and the protein levels of survivin,cleaved PARP and cleaved cas-pase-3 were increased(P<0.05).(2)After PPT treatment combined with PTX,the mRNA expression of inflammatory cy-tokines(IL-6,IL-8,CXCL1 and CCL2)and cancer stem cell-related markers(OCT4,SOX2,NANOG,ALDH1 and CD44)was reduced(P<0.05),and the protein levels of IL-6 and IL-8 were decreased(P<0.01).The activity of NF-κB in MB231-PR cells was suppressed(P<0.05),and the growth of tumor spheres from MB231-PR cells was damaged(P<0.05).(3)Immunofluorescence assay showed that PTX induced nuclear p-p65 expression,but this effect was attenuated by PPT.CONCLUSION:Combined treatment with PPT and PTX could attenuate PTX resistance of MB231-PR cells by inhibiting inflammatory cytokines and cancer stem cells.
5.Molecular mechanism of lncRNA SNHG1 regulating ferroptosis and at-tenuating inflammation of microglia induced by HIV-1 gp120 V3 loop
Linlin WANG ; Qin ZUO ; Xinyi LI ; Xueqin YAN ; Rui PAN ; Yongmei FU ; Jun DONG
Chinese Journal of Pathophysiology 2024;40(5):806-814
AIM:To investigate the molecular mechanism of long noncoding RNA(lncRNA)SNHG1 in regu-lating ferroptosis to alleviate inflammation in CHME-5 human microglia induced by HIV-1 gp120 V3 loop.METHODS:CHME-5 human microglia were cultured in vitro,and were divided into 7 groups:blank group,random peptide group,gp120 V3 loop group(HIV-1 gp120 group),HIV-1 gp120+shCon group,HIV-1 gp120+SNHG1 sh2 group,HIV-1 gp120+SNHG1 sh2+ferrostatin-1(Fer-1;ferroptosis inhibitor)group,and HIV-1 gp120+SNHG1 sh2+EX527(Sirt1 in-hibitor)group.Normal CHME-5 cells were treated with random peptide or gp120 V3 loop for 24 h.After pretreatment of SNHG1 sh2 cells with inhibitors for 2 h,the cells were then treated with gp120 V3 loop for 24 h.The levels of inflammato-ry cytokines in the cell supernatants were detected by ELISA.Western blot was used to detect the protein expression levels of solute carrier family 7 member 11(SLC7A11),glutathione peroxidase 4(GPX4),Sirt1 and p53.Microplate reader was used to detect the levels of intracellular ferrous ion(Fe2+)and malondialdehyde(MDA).RESULTS:(1)The results of ELISA showed that the expression levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and IL-1β in HIV-1 gp120 group were significantly higher than those in blank group(P<0.05).Compared with HIV-1 gp120 group,the ex-pression levels of inflammatory cytokines in HIV-1 gp120+SNHG1 sh2 group were significantly decreased(P<0.05).Compared with HIV-1 gp120+SNHG1 sh2 group,the expression levels of inflammatory factors in HIV-1 gp120+SNHG1 sh2+Fer-1 were significantly decreased(P<0.05),but those in HIV-1 gp120+SNHG1 sh2+EX527 group were significant-ly increased(P<0.01).(2)The results of Western blot showed that compared with blank group,the expression levels of ferroptosis-related proteins SLC7A11 and GPX4 in HIV-1 gp120 group were significantly down-regulated(P<0.01).Com-pared with HIV-1 gp120 group,the expression levels of SLC7A11 and GPX4 in HIV-1 gp120+SNHG1 sh2 group were sig-nificantly up-regulated(P<0.01).Compared with HIV-1 gp120+SNHG1 sh2 group,the expression levels of SLC7A11 and GPX4 in HIV-1 gp120+SNHG1 sh2+Fer-1 group were significantly up-regulated(P<0.05),but the expression levels of SLC7A11 and GPX4 in HIV-1 gp120+SNHG1 sh2+EX527 group were significantly down-regulated(P<0.01),and the expression level of p53 was significantly up-regulated(P<0.05).(3)Compared with blank group,the levels of Fe2+and MDA in HIV-1 gp120 group were significantly increased(P<0.05).Compared with HIV-1 gp120 group,the levels of Fe2+and MDA in HIV-1 gp120+SNHG1 sh2 group were significantly decreased(P<0.01).Compared with HIV-1 gp120+SNHG1 sh2 group,Fe2+and MDA in HIV-1 gp120+SNHG1 sh2+Fer-1 group were significantly decreased(P<0.05),but those in HIV-1 gp120+SNHG1 sh2+EX527 group was significantly increased(P<0.05).CONCLUSION:Knockdown of SNHG1 can attenuate the inflammation in microglia induced by HIV-1 gp120 V3 loop,which may be achieved by regulating ferrop-tosis-related signaling molecules through the Sirt1/p53 signaling pathway.
6.Effect of anterior cingulate cortex-nucleus accumbens GABAergic cir-cuit on irritable bowel syndrome in mice and its underlying mechanisms
Ruixiao GUO ; Shengli GAO ; Xufei FENG ; Hua LIU ; Xing MING ; Jinqiu SUN ; Xinchi LUAN ; Zhenyu LIU ; Weiyi LIU ; Feifei GUO
Chinese Journal of Pathophysiology 2024;40(5):815-826
AIM:To investigate the effects of the γ-aminobutyric acid(GABAergic)neural pathway from the anterior cingulate cortex(ACC)to the nucleus accumbens(NAc)on the regulation of irritable bowel syndrome(IBS)and its underlying mechanisms in mice.METHODS:(1)A C57BL/6J mice model of IBS was established by using chronic acute combing stress(CACS).The mice were divided into a normal group and an IBS group(n=8).The presence of IBS-like symptoms was determined through behavioural tests,an intestinal motility test and abdominal withdrawal reflex scores.(2)Fluorescence gold(FG)retrograde tracing and immunohistochemistry were used to investigate the ACC-NAc GABAergic neural pathway and to examine the activation of GABA in the ACC in IBS mice(n=8).(3)A total of 1.5 μL of normal saline(NS),GABAA receptor antagonist bicuculline(BIC)or agonist isoguvacine hydrochloride(Isog)was ad-ministered via a preburied catheter into the NAc of mice in IBS and normal groups.The mice were randomly divided into three groups(n=8):NS group,BIC group and Isog group.IBS-like symptoms were assessed.(4)The mice were prein-jected with AAV2/9-mDlx-iCre-WPRE-pA in the ACC and AAV2/2Retro Plus-hSyn-DIO-hM3D(Gq)-eGFP-WPRE-pA in the NAc and subsequently divided into four groups(n=8):NS(intraperitoneal injection)+NS(NAc microinjection)group,NS+BIC group,clozapine N-oxide(CNO)+NS group and CNO+BIC group.The mice who received AAV2/2Retro-hSyn-DIO-hM4D(Gi)-EGFP-WPRE-pA in the NAc were randomly divided into three groups(n=8):NS+NS group,NS+BIC group and CNO+NS group.Enzyme-linked immunosorbent assay(ELISA)was employed to estimate the expression levels of histamine and 5-hydroxytryptamine(5-HT)in colon tissue,and the effects of GABAergic neural pathways from ACC to NAc on IBS were studied.RESULTS:CACS induced IBS-like symptoms in mice.The results of FG retrograde tracing combined with fluorescence immunohistochemistry showed that GABA neurons of ACC could project to NAc.The injection of BIC in the NAc was found to significantly reduce anxiety-like behaviours,diarrheal symptoms and visceral hy-persensitivity in the IBS mice(P<0.05).Chemogenetic inhibition of the ACC-NAc GABAergic neurons ameliorated IBS-like symptoms in mice(P<0.05).CONCLUSION:The GABAergic pathway of ACC-NAc might be involved in the regu-lation of IBS in mice,which may be related to the release of histamine and 5-HT in colon tissue.
7.Honokiol,an SIRT3 activator,alleviates postoperative cognitive dysfunc-tion via inhibiting hippocampal neuronal ferroptosis in mice
Tao HUANG ; Tiantian HAN ; Qianqian XU ; Zhen ZHANG ; Pengchao HU ; Xudong DING ; Huiyu LUO ; Lian ZENG
Chinese Journal of Pathophysiology 2024;40(5):827-835
AIM:To investigate the impact of honokiol(HKL),an activator of silent information regulator 3(SIRT3),on postoperative cognitive dysfunction(POCD)in mice,and to explore the potential mechanisms.METHODS:Ten-month-old male C57/BL6 mice were randomly divided into control(Con)group,surgical(Sur)group and Sur+HKL group(n=10).The mice in Sur+HKL group were intraperitoneally injected with HKL for 7 d before modeling.The mice in Sur and Sur+HKL groups underwent tibial fracture open reduction and internal fixation to establish the POCD model.The assessment of cognitive function was conducted using the open-field test(OFT),novel object recognition test(NORT),Morris water maze test(MWMT),and Y-maze test(YMT).Nissl staining was employed to assess the morphology,struc-ture and vitality of hippocampal and cortical neurons in mice.The protein expression of glutathione peroxidase 4(GPX4),solute carrier family 7 member 11(SLC7A11),acyl coenzyme A synthetase long-chain family member 4(ACSL4),SIRT3 and nuclear factor E2-related factor 2(NRF2)in the mouse hippocampus was detected by Western blot,while im-munofluorescence staining was utilized to determine GPX4 level in mouse neurons.RESULTS:No statistically signifi-cant differences were observed among the groups in terms of total distance moved and central zone exploration during the OFT(P>0.05).However,the results from the NORT and YMT indicated that the mice in Sur group exhibited significant-ly lower recognition indexes,reduced alternation rates(P<0.01),and decreased percentages of entries and crossing time into the new arm after side arm blockade(P<0.01),when compared with Con group.Furthermore,the mice in Sur group demonstrated a slower decrease in latency during the learning period of MWMT,while significantly lower latency,fewer crossing number and lower percentage of time in the target quadrant were observed during the testing period of MWMT(P<0.01).The above indicators were obviously enhanced in Sur+HKL group compared with Sur group(P<0.01).The results of Nissl staining indicated lighter neuronal staining in the hippocampal CA1 region and medial prefrontal cortex in Sur group,accompanied by a significant reduction in the number of Nissl-stained positive neurons(P<0.01).Notably,HKL pretreatment demonstrated a significant improvement in neuronal vitality.Analysis of Western blot revealed that compared with Con group,the expression of SIRT3,GPX4,SLC7A11 and NRF2 in Sur group was significantly reduced,while the expression of ACSL4 was significantly increased(P<0.05).However,these alterations were reversed after treatment with HKL(P<0.05).Immunofluorescence staining of hippocampal neurons corroborated the findings from Western blot analy-sis,demonstrating a notable decrease in GPX4 expression in hippocampal neurons of Sur group,which was significantly restored after HKL pretreatment(P<0.01).CONCLUSION:Treatment with HKL attenuates POCD in mice,potentially through its inhibitory effect on hippocampal neuronal ferroptosis.
8.Effect of astaxanthin regulating autophagy on cognitive function of rats with intestinal ischemia/reperfusion injury
Wei ZHANG ; Yingbin WANG ; Jingyu ZHANG ; Lu CAO ; Yan LIU ; Li ZHANG
Chinese Journal of Pathophysiology 2024;40(5):836-843
AIM:To evaluate the effect of astaxanthin(AST)on cognitive function of intestinal ischemia/re-perfusion(I/R)injury in rats and the role of autophagy.METHODS:Eight-week-old SPF-grade male Sprague-Dawley(SD)rats were randomly divided into sham group,I/R group,AST group and AST+3-methyladenine(3-MA)group,with 12 animals in each group.The superior mesenteric artery(SMA)of the rats in sham group was only exposed without clamping.The SMA in other 3 groups was clamped for 90 min,and then the arterial clamp was released to restore blood supply and perform reperfusion,thus establishing the intestinal I/R model.The rats in AST group were intraperitoneally in-jected with AST(45 mg·kg-1·d-1)3 d before modeling,and those in AST+3-MA group were intraperitoneally injected with AST(45 mg·kg-1·d-1)+3-MA(1.5 mg·kg-1·d-1)3 d before modeling.Morris water maze was used to evaluate the cogni-tive function of rats 48 h after surgery.Hematoxylin-eosin(HE)staining was used to evaluate intestinal tissue damage.Nissl staining of the frontal cortex was used to evaluate neuronal damage.The levels of interleukin-6(IL-6),IL-1β and tu-mor necrosis factor-α(TNF-α)in the frontal cortex and hippocampus were measured by ELISA kits.The protein levels of beclin-1,microtubule-associated protein 1 light chain 3(LC3)and P62 in the frontal cortex and hippocampus were detected by Western blot.RESULTS:Compared with sham group,the swimming distance of rats in I/R group was increased,with prolonged latency,elevated Chiu's score and decreased number of neurons(P<0.01),while the levels of IL-6,IL-1β and TNF-α in the frontal cortex and hippocampus were increased(P<0.01).Beclin-1 expression and LC3-II/LC3-I ratio in the frontal cortex and hippocampus were increased(P<0.05 or P<0.01).Compared with I/R group,the swimming distance and latency of rats in AST group were shortened,with decreased Chiu's score,increased neuronal number(P<0.01),de-creased IL-6,IL-1β and TNF-α levels in the frontal cortex and hippocampus(P<0.01),and increased beclin-1 expres-sion and decreased of P62 expression in the frontal cortex and hippocampus(P<0.05 or P<0.01).Compared with AST group,the swimming distance of rats in AST+3-MA group was increased,with prolonged latency,elevated Chiu's score,decreased number of neurons(P<0.05),increased levels of IL-6,IL-1β and TNF-α in the frontal cortex and hippocam-pus,and decreased beclin-1 expression and LC3-II/LC3-I ratio and increased P62 expression in the frontal cortex and hip-pocampus(P<0.01).CONCLUSION:Astaxanthin alleviates intestinal I/R-induced cognitive impairment in rats by pro-moting autophagy and inhibiting neuroinflammation.
9.Ginsenoside Rc attenuates cerebral ischemia-reperfusion injury in mice by regulating AMPK pathway-mediated pyroptosis
Liangyong LI ; Li MA ; Yajun LI ; Deng MEI
Chinese Journal of Pathophysiology 2024;40(5):844-851
AIM:To comprehend the mechanism by which ginsenoside Rc protects against cerebral ischemia-reperfusion injury(CIRI),with a particular emphasis on pyroptosis.METHODS:The C57BL/6 mice were randomly di-vided into 6 groups:sham group,middle cerebral artery occlusion/reperfusion(MCAO/R)group,ginsenoside Rc+MCAO/R group(Rc group),AMP-activated protein kinase(AMPK)agonist acadesine/5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside(AICAR)+MCAO/R group(agonist group),and ginsenoside Rc+MCAO/R+AMPK inhibitor Compound C group(Rc+inhibitor group).The mice in agonist group were given 500 mg/kg of AICAR intraperitoneally,while those in Rc+inhibitor group were given 20 mg/kg of Compound C intraperitoneally.Ginsenoside Rc was gavaged into the mice in Rc and Rc+inhibitor groups at a dose of 40 mg/kg once per day for 7 d after modeling,while the mice in sham and MCAO/R groups got the same volume of purified water.With the use of the Zea-Longa score,we determined which mice had neu-rological abnormalities.TTC staining was employed for assessing the cerebral infarct amount in mice,and the dry wet weight technique was utilized for determining the degree of cerebral edema.Moreover,HE staining was used to observe pathological alterations in the brain,and Western blot and RT-qPCR were applied for detecting the expression of AMPK,nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),caspase-1 and gasdermin-D(GSDMD)in the brains of mice.Lastly,ELISA was employed for measuring the levels of inflammatory factors,interleukin-1β(IL-1β)and IL-18.RESULTS:Brain edema,infarct volume and neurological impairments were all diminished in agonist and Rc groups.Additionally,they demonstrated neuronal damage inhibition.The ratio of p-AMPK/AMPK and AMPK mRNA ex-pression in mouse brain tissues was elevated in both Rc and agonist groups.They showed decreased mRNA and protein levels of NLRP3,caspase-1 and GSDMD,as well as the levels of IL-1β and IL-18.Compared with Rc group,there were remarkable decreases in p-AMPK/AMPK ratio and AMPK mRNA expression in the brain tissue of mice in Rc+inhibitor group(P<0.05).The mRNA and protein levels of NLRP3,caspase-1 and GSDMD,and the IL-1β and IL-18 expression levels were significantly increased(P<0.05).Moreover,the neurological deficiency scores and infarct volume were in-creased,and the degrees of cerebral edema and neuronal pathological damage were enhanced(P<0.05).CONCLU-SION:Ginsenoside Rc may inhibit NLRP3/caspase-1/GSDMD-mediated pyroptosis by activating AMPK pathway,thereby reducing CIRI in mice.
10.Overexpression of mitoNEET inhibits ferroptosis-induced mitochondrial metabolic dysfunction in brown adipocytes
Hongyu ZHENG ; Zhen TIAN ; Yanxia WANG ; Kun ZHOU ; Zhong REN ; Zhixiang ZHOU ; Wenhao XIONG ; He ZHENG ; Zhisheng JIANG
Chinese Journal of Pathophysiology 2024;40(5):852-861
AIM:To investigate the potential impact of mitoNEET[mitochondrial protein containing Asn-Glu-Glu-Thr(NEET)sequence]on mitochondrial metabolism in brown adipocytes,and to elucidate its underlying mecha-nism.METHODS:An in vitro model of primary mouse brown adipocytes was established.Western blot were utilized to detect relevant proteins,and iron ion and ATP content was measured using kits.Mitochondrial membrane potential and re-active oxygen species(ROS)were assessed by fluorescence microscopy and flow cytometry.RESULTS:The expression of the ferroptosis-related protein ACSL4 increased by 1.13 times in ferroptosis inducer erastin treatment group,whereas the expression of SLC7A11 and GPX4 decreased by 27.33%and 25.33%,respectively,compared with control group(P<0.05).The expression of Nrf1,PGC-1α,MFN2 and UCP1 proteins,related to mitochondrial energy metabolism,de-creased by 20.98%,15.17%,15.03%and 34.22%,respectively(P<0.05).Additionally,the mitoNEET protein con-tent was significantly reduced by 42.14%(P<0.05).The iron ion content in erastin group was substantially increased by 1.80 times compared with control group.However,a notable decrease in ATP content of 14.95%was seen(P<0.05).The results obtained from fluorescence microscopy and flow cytometry demonstrated a significant decrease in the mitochon-drial membrane potential of brown adipocytes in erastin group,with reductions of 52.18%and 61.31%(P<0.05),re-spectively.A substantial increase in mitochondrial ROS content of 80.97%was seen(P<0.05).Western blot analysis of overexpressed stable strains revealed a significant elevation in mitoNEET levels in brown adipocytes following lentivirus transfection,exhibiting an increase of 11.19 times(P<0.05),thus confirming successful transfection.The LV-mitoNEET group exhibited a significant decrease of 37.95%in the expression of ferroptosis-related protein ACSL4 in brown adipose cells compared with control group.Additionally,there was a notable increase of 77.82%and 66.3%in the expression of SLC7A11 and GPX4,respectively(P<0.05).Up-regulation was observed in the expression of MFN2(79.06%),PGC-1α(72.89%),Nrf1(40.14%),and UCP1(31.68%)(P<0.05).The test results demonstrated that the LV-mitoNEET group experienced a reduction of 43.5%in iron ion content compared with control group while exhibiting an increase of 33.5%in ATP content(P<0.05).The results obtained from fluorescence microscopy and flow cytometry demonstrated that mitoNEET overexpression led to a significant increase in the mitochondrial membrane potential of erastin-induced brown adipocytes,with increments of 17.61%and 96.05%,respectively.Additionally,mitoNEET overexpression effec-tively reduced the production of mitochondrial ROS by 24.48%(P<0.05).CONCLUSION:Our findings suggest that mitoNEET overexpression can effectively inhibit the disruption of mitochondrial energy metabolism caused by ferroptosis-induced death of brown adipocytes.

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