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Bioorganic Chemistry Jun 2024Osteoporosis is particularly prevalent among postmenopausal women and the elderly. In the present study, we investigated the effect of the novel small molecule E0924G...
The novel small molecule E0924G dually regulates bone formation and bone resorption through activating the PPARδ signaling pathway to prevent bone loss in ovariectomized rats and senile mice.
Osteoporosis is particularly prevalent among postmenopausal women and the elderly. In the present study, we investigated the effect of the novel small molecule E0924G (N-(4-methoxy-pyridine-2-yl)-5-methylfuran-2-formamide) on osteoporosis. E0924G significantly increased the protein expression levels of osteoprotegerin (OPG) and runt-related transcription factor 2 (RUNX2), and thus significantly promoted osteogenesis in MC3T3-E1 cells. E0924G also significantly decreased osteoclast differentiation and inhibited bone resorption and F-actin ring formation in receptor activator of NF-κB ligand (RANKL)-induced osteoclasts from RAW264.7 macrophages. Importantly, oral administration of E0924G in both ovariectomized (OVX) rats and SAMP6 senile mice significantly increased bone mineral density and decreased bone loss compared to OVX controls or SAMR1 mice. Further mechanistic studies showed that E0924G could bind to and then activate peroxisome proliferator-activated receptor delta (PPARδ), and the pro-osteoblast effect and the inhibition of osteoclast differentiation induced by E0924G were significantly abolished when PPARδ was knocked down or inhibited. In conclusion, these data strongly suggest that E0924G has the potential to prevent OVX-induced and age-related osteoporosis by dual regulation of bone formation and bone resorption through activation of the PPARδ signaling pathway.
Topics: Animals; Mice; Bone Resorption; Rats; PPAR delta; Ovariectomy; Female; Osteogenesis; Signal Transduction; Structure-Activity Relationship; Molecular Structure; RAW 264.7 Cells; Osteoporosis; Dose-Response Relationship, Drug; Small Molecule Libraries; Rats, Sprague-Dawley; Osteoclasts; Cell Differentiation
PubMed: 38636434
DOI: 10.1016/j.bioorg.2024.107364 -
European Journal of Pharmacology Jun 2024Blockade of PD-1/PD-L1 immune checkpoint is wildly used for multiple types of cancer treatment, while the low response rate for patients is still completely unknown. As...
Blockade of PD-1/PD-L1 immune checkpoint is wildly used for multiple types of cancer treatment, while the low response rate for patients is still completely unknown. As nuclear hormone receptor, PPARδ (peroxisome-proliferator-activated receptor) regulates cell proliferation, inflammation, and tumor progression, while the effect of PPARδ on tumor immune escape is still unclear. Here we found that PPARδ antagonist GSK0660 significantly reduced colon cancer cell PD-L1 protein and gene expression. Luciferase analysis showed that GSK0660 decreased PD-L1 gene transcription activity. Moreover, reduced PD-L1 expression in colon cancer cells led to increased T cell activity. Further analysis showed that GSK0660 decreased PD-L1 expression in a PPARδ dependent manner. Implanted tumor model analysis showed that GSK0660 inhibited tumor immune escape and the combined PD-1 antibody with GSK0660 effectively enhanced colorectal cancer immunotherapy. These findings suggest that GSK0660 treatment could be an effective strategy for cancer immunotherapy.
Topics: B7-H1 Antigen; Humans; Animals; Immunotherapy; Mice; Cell Line, Tumor; PPAR delta; Gene Expression Regulation, Neoplastic; Colonic Neoplasms; T-Lymphocytes; Tumor Escape; Mice, Inbred BALB C
PubMed: 38599309
DOI: 10.1016/j.ejphar.2024.176565 -
Fluids and Barriers of the CNS Apr 2024The blood-brain barrier (BBB) is pivotal for the maintenance of brain homeostasis and it strictly regulates the cerebral transport of a wide range of endogenous...
BACKGROUND
The blood-brain barrier (BBB) is pivotal for the maintenance of brain homeostasis and it strictly regulates the cerebral transport of a wide range of endogenous compounds and drugs. While fasting is increasingly recognized as a potential therapeutic intervention in neurology and psychiatry, its impact upon the BBB has not been studied. This study was designed to assess the global impact of fasting upon the repertoire of BBB transporters.
METHODS
We used a combination of in vivo and in vitro experiments to assess the response of the brain endothelium in male rats that were fed ad libitum or fasted for one to three days. Brain endothelial cells were acutely purified and transcriptionaly profiled using RNA-Seq. Isolated brain microvessels were used to assess the protein expression of selected BBB transporters through western blot. The molecular mechanisms involved in the adaptation to fasting were investigated in primary cultured rat brain endothelial cells. MCT1 activity was probed by in situ brain perfusion.
RESULTS
Fasting did not change the expression of the main drug efflux ATP-binding cassette transporters or P-glycoprotein activity at the BBB but modulated a restrictive set of solute carrier transporters. These included the ketone bodies transporter MCT1, which is pivotal for the brain adaptation to fasting. Our findings in vivo suggested that PPAR δ, a major lipid sensor, was selectively activated in brain endothelial cells in response to fasting. This was confirmed in vitro where pharmacological agonists and free fatty acids selectively activated PPAR δ, resulting in the upregulation of MCT1 expression. Moreover, dosing rats with a specific PPAR δ antagonist blocked the upregulation of MCT1 expression and activity induced by fasting.
CONCLUSIONS
Altogether, our study shows that fasting affects a selected set of BBB transporters which does not include the main drug efflux transporters. Moreover, we describe a previously unknown selective adaptive response of the brain vasculature to fasting which involves PPAR δ and is responsible for the up-regulation of MCT1 expression and activity. Our study opens new perspectives for the metabolic manipulation of the BBB in the healthy or diseased brain.
Topics: Rats; Male; Animals; Blood-Brain Barrier; PPAR delta; Endothelial Cells; Membrane Transport Proteins; Brain; Fasting
PubMed: 38589879
DOI: 10.1186/s12987-024-00526-8 -
ACS Infectious Diseases May 2024MicroRNA-mediated metabolic reprogramming recently has been identified as an important strategy for (Mtb) to evade host immune responses. However, it is unknown what...
MicroRNA-mediated metabolic reprogramming recently has been identified as an important strategy for (Mtb) to evade host immune responses. However, it is unknown what role microRNA-144-3p (miR-144-3p) plays in cellular metabolism during Mtb infection. Here, we report the meaning of miR-144-3p-mediated lipid accumulation for Mtb-macrophage interplay. Mtb infection was shown to upregulate the expression of miR-144-3p in macrophages. By targeting peroxisome proliferator-activated receptor α (PPARα) and ATP-binding cassette transporter A1 (ABCA1), miR-144-3p overexpression promoted lipid accumulation and bacterial survival in Mtb-infected macrophages, while miR-144-3p inhibition had the opposite effect. Furthermore, reprogramming of host lipid metabolism by miR-144-3p suppressed autophagy in response to Mtb infection. Our findings uncover that miR-144-3p regulates host metabolism and immune responses to Mtb by targeting PPARα and ABCA1, suggesting a potential host-directed tuberculosis therapy by targeting the interface of miRNA and lipid metabolism.
Topics: Animals; Humans; Mice; ATP Binding Cassette Transporter 1; Autophagy; Host-Pathogen Interactions; Lipid Metabolism; Macrophages; MicroRNAs; Mycobacterium tuberculosis; PPAR alpha; Tuberculosis
PubMed: 38578697
DOI: 10.1021/acsinfecdis.3c00731 -
Brain, Behavior, and Immunity Jul 2024Decreased hippocampal tropomyosin receptor kinase B (TrkB) level is implicated in the pathophysiology of stress-induced mood disorder and cognitive decline. However, how...
Decreased hippocampal tropomyosin receptor kinase B (TrkB) level is implicated in the pathophysiology of stress-induced mood disorder and cognitive decline. However, how TrkB is modified and mediates behavioral responses to chronic stress remains largely unknown. Here the effects and mechanisms of TrkB cleavage by asparagine endopeptidase (AEP) were examined on a preclinical murine model of chronic restraint stress (CRS)-induced depression. CRS activated IL-1β-C/EBPβ-AEP pathway in mice hippocampus, accompanied by elevated TrkB 1-486 fragment generated by AEP. Specifi.c overexpression or suppression of AEP-TrkB axis in hippocampal CaMKIIα-positive cells aggravated or relieved depressive-like behaviors, respectively. Mechanistically, in addition to facilitating AMPARs internalization, TrkB 1-486 interacted with peroxisome proliferator-activated receptor-δ (PPAR-δ) and sequestered it in cytoplasm, repressing PPAR-δ-mediated transactivation and mitochondrial function. Moreover, co-administration of 7,8-dihydroxyflavone and a peptide disrupting the binding of TrkB 1-486 with PPAR-δ attenuated depression-like symptoms not only in CRS animals, but also in Alzheimer's disease and aged mice. These findings reveal a novel role for TrkB cleavage in promoting depressive-like phenotype.
Topics: Animals; Hippocampus; Mice; Depression; Male; Stress, Psychological; Receptor, trkB; Disease Models, Animal; Mice, Inbred C57BL; Behavior, Animal; Signal Transduction; Alzheimer Disease; Membrane Glycoproteins
PubMed: 38555992
DOI: 10.1016/j.bbi.2024.03.048 -
Asian Pacific Journal of Cancer... Mar 2024The aim of the present study was to examine whether GLUT1 was involved in the antiproliferative activity of curcumin and doxorubicin by understanding mechanistically how...
OBJECTIVE
The aim of the present study was to examine whether GLUT1 was involved in the antiproliferative activity of curcumin and doxorubicin by understanding mechanistically how curcumin regulated GLUT1.
METHODS
Expression level of GLUT1 in MCF-7 and MDA-MB-231 cells were quantitated using quantitative real-time PCR and western blot. GLUT1 activity was inhibited in MDA-MB-231 cells with the pharmacological inhibitor WZB117 to assess the anti-proliferative effects of doxorubicin using MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). To examine cell proliferation, trypan blue assay was used in cells transfected with GLUT1 siRNA or plasmid overexpressing GLUT1 with doxorubicin and/or commercially available curcumin. The role of PPARδ and Akt on the regulation of GLUT1 by curcumin was examined by overexpressing these proteins and western blot was employed to examine their protein expression.
RESULTS
The data revealed that there was a 1.5 fold increase in GLUT1 mRNA and protein levels in MDA-MB-231 compared to MCF-7. By inhibiting GLUT1 in triple negative breast cancer cell line, MDA-MB-231 with either the pharmacological inhibitor WZB117 or with GLUT1 siRNA, we observed the enhanced antiproliferative effects of doxorubicin. Additional observations indicated these effects can be reversed by the overexpression of GLUT1. Treatment of MDA-MB-231 with curcumin also revealed downregulation of GLUT1, with further growth suppressive effects when combined with doxorubicin. Overexpression of GLUT1 blocked the growth suppressive role of curcumin and doxorubicin (p< 0.05). Mechanistically, we also observed that the regulation of GLUT1 by curcumin was mediated by the Peroxisome proliferator-activated receptor (PPAR) δ/Akt pathway.
CONCLUSION
Our study demonstrates that regulation of GLUT1 by curcumin via the PPARδ/Akt signaling improves the efficacy of doxorubicin by promoting its growth inhibitory effects in MDA-MB-231 cells.
Topics: Humans; Female; Curcumin; MDA-MB-231 Cells; PPAR delta; Proto-Oncogene Proteins c-akt; Glucose Transporter Type 1; Doxorubicin; Cell Proliferation; RNA, Small Interfering; Breast Neoplasms; Cell Line, Tumor; Hydroxybenzoates
PubMed: 38546086
DOI: 10.31557/APJCP.2024.25.3.1035 -
Biomedicines Mar 2024Three peroxisome proliferator-activated receptor subtypes, PPARα, PPAR(ß/)δ, and PPARγ, exert ligand-dependent transcriptional control in concert with retinoid X...
Three peroxisome proliferator-activated receptor subtypes, PPARα, PPAR(ß/)δ, and PPARγ, exert ligand-dependent transcriptional control in concert with retinoid X receptors (RXRs) on various gene sets harboring PPAR response elements (PPREs) in their promoter regions. Ligand-bound PPAR/RXR complexes do not directly regulate transcription; instead, they recruit multiprotein coactivator complexes to specific genomic regulatory loci to cooperatively activate gene transcription. Several coactivators are expressed in a single cell; however, a ligand-bound PPAR can be associated with only one coactivator through a consensus LXXLL motif. Therefore, altered gene transcription induced by PPAR subtypes/agonists may be attributed to the recruitment of various coactivator species. Using a time-resolved fluorescence resonance energy transfer assay, we analyzed the recruitment of four coactivator peptides (PGC1α, CBP, SRC1, and TRAP220) to human PPARα/δ/γ-ligand-binding domains (LBDs) using eight PPAR dual/pan agonists (bezafibrate, fenofibric acid, pemafibrate, pioglitazone, elafibranor, lanifibranor, saroglitazar, and seladelpar) that are/were anticipated to treat nonalcoholic fatty liver disease. These agonists all recruited four coactivators to PPARα/γ-LBD with varying potencies and efficacy. Only five agonists (bezafibrate, pemafibrate, elafibranor, lanifibranor, and seladelpar) recruited all four coactivators to PPARδ-LBD, and their concentration-dependent responses differed from those of PPARα/γ-LBD. These results indicate that altered gene expression through consensus PPREs by different PPAR subtypes/agonists may be caused, in part, by different coactivators, which may be responsible for the unique pharmacological properties of these PPAR agonists.
PubMed: 38540237
DOI: 10.3390/biomedicines12030624 -
Biomedicines Feb 2024Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) that is characterized by hepatic inflammation and steatosis....
Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) that is characterized by hepatic inflammation and steatosis. Currently, limited data exist regarding the risk of NASH in transgender women and the treatment options for this particular population. The use of testosterone supplementation is unfavorable for transgender women, and estrogen supplementation is linked to an increased risk of breast cancer; thus, an isoflavone derivative compound known as "genistein" could serve as a viable substitute for a hormone supplement in this context. The purpose of this study was to investigate the treatment effects and mechanisms of actions of genistein and sex hormones in orchidectomized (ORX) rats with nonalcoholic steatohepatitis induced via a high-fat high-fructose diet (HFHF) model. Male rats (n = 42) were randomly assigned into seven groups; control, ORX + standard diet, HFHF, ORX + HFHF, ORX + HFHF diet + testosterone (50 mg/kg body weight (BW) once weekly), ORX + HFHF diet + estradiol (1.6 mg/kg BW daily), and ORX + HFHF diet + genistein (16 mg/kg BW daily). The duration of the study was 6 weeks. Some parts of liver tissue were used for histological examination by H&E staining. The determination of fat accumulation was performed using Oil Red O staining. and gene expression were quantified using real-time PCR technique. The levels of all types of peroxisome proliferator-activated receptors (PPARs; α, δ, γ), proteins, and signal transducer and activator of transcription 1 (STAT1) signaling pathway were determined by both immunoblotting and immunohistochemistry. Rats in the ORX + HFHF group had the highest degree of hepatic steatosis, lobular inflammation, and hepatocyte ballooning, and showed higher levels of genes related to de novo lipogenesis, including and . The expression of PPARγ and STAT1 were upregulated, while the expression of PPARα and PPARδ were downregulated in the ORX + HFHF group. Testosterone, estradiol and genistein treatments improved NASH histopathology together with the reversal of all types of PPAR protein expressions. Interestingly, genistein decreased the levels of STAT1 protein expression more than those of testosterone and estradiol treatment. Genistein and sex hormone treatment could ameliorate NASH through the upregulation of PPARα, and PPARδ, and the suppression of PPARγ and STAT1 expression.
PubMed: 38540097
DOI: 10.3390/biomedicines12030483 -
Journal of Neuroimmune Pharmacology :... Mar 2024Neuro-inflammation involves distinct alterations of microglial phenotypes, containing nocuous pro-inflammatory M1-phenotype and neuroprotective anti-inflammatory...
Neuro-inflammation involves distinct alterations of microglial phenotypes, containing nocuous pro-inflammatory M1-phenotype and neuroprotective anti-inflammatory M-phenotype. Currently, there is no effective treatment for modulating such alterations. M1/M2 marker of primary microglia influenced by Melatonin were detected via qPCR. Functional activities were explored by western blotting, luciferase activity, EMSA, and ChIP assay. Structure interaction was assessed by molecular docking and LIGPLOT analysis. ER-stress detection was examined by ultrastructure TEM, calapin activity, and ERSE assay. The functional neurobehavioral evaluations were used for investigation of Melatonin on the neuroinflammation in vivo. Melatonin had targeted on Peroxisome Proliferator Activated Receptor Delta (PPARδ) activity, boosted LPS-stimulated alterations in polarization from the M1 to the M2 phenotype, and thereby inhibited NFκB-IKKβ activation in primary microglia. The PPARδ agonist L-165,041 or over-expression of PPARδ plasmid (ov-PPARδ) showed similar results. Molecular docking screening, dynamic simulation approaches, and biological studies of Melatonin showed that the activated site was located at PPARδ (phospho-Thr256-PPARδ). Activated microglia had lowered PPARδ activity as well as the downstream SIRT1 formation via enhancing ER-stress. Melatonin, PPARδ agonist and ov-PPARδ all effectively reversed the above-mentioned effects. Melatonin blocked ER-stress by regulating calapin activity and expression in LPS-activated microglia. Additionally, Melatonin or L-165,041 ameliorated the neurobehavioral deficits in LPS-aggravated neuroinflammatory mice through blocking microglia activities, and also promoted phenotype changes to M2-predominant microglia. Melatonin suppressed neuro-inflammation in vitro and in vivo by tuning microglial activation through the ER-stress-dependent PPARδ/SIRT1 signaling cascade. This treatment strategy is an encouraging pharmacological approach for the remedy of neuro-inflammation associated disorders.
Topics: Rats; Mice; Animals; Microglia; PPAR delta; Melatonin; Lipopolysaccharides; Sirtuin 1; Molecular Docking Simulation; Inflammation
PubMed: 38530514
DOI: 10.1007/s11481-024-10108-y -
PeerJ 2024Peroxisome proliferator-activated receptors (PPARs) exert multiple functions in the initiation and progression of stomach adenocarcinomas (STAD). This study analyzed the...
BACKGROUND
Peroxisome proliferator-activated receptors (PPARs) exert multiple functions in the initiation and progression of stomach adenocarcinomas (STAD). This study analyzed the relationship between PPARs and the immune status, molecular mutations, and drug therapy in STAD.
METHODS
The expression profiles of three PPAR genes (PPARA, PPARD and PPARG) were downloaded from The Cancer Genome Atlas (TCGA) dataset to analyze their expression patterns across pan-cancer. The associations between PPARs and clinicopathologic features, prognosis, tumor microenvironment, genome mutation and drug sensitivity were also explored. Co-expression between two PPAR genes was calculated using Pearson analysis. Regulatory pathways of PPARs were scored using gene set variation analysis (GSVA) package. Quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, Cell Counting Kit-8 (CCK-8) assay and transwell assay were conducted to analyze the expression and function of the PPAR genes in STAD cell lines (AGS and SGC7901 cells).
RESULTS
PPARA, PPARD and PPARG were more abnormally expressed in STAD samples and cell lines when compared to most of 32 type cancers in TCGA. In STAD, the expression of PPARD was higher in Grade 3+4 and male patients, while that of PPARG was higher in patient with Grade 3+4 and age > 60. Patients in high-PPARA expression group tended to have longer survival time. Co-expression analysis revealed 6 genes significantly correlated with the three PPAR genes in STAD. Single-sample GSEA (ssGSEA) showed that the three PPAR genes were enriched in 23 pathways, including MITOTIC_SPINDLE, MYC_TARGETS_V1, E2F_TARGETS and were closely correlated with immune cells, including NK_cells_resting, T_cells_CD4_memory_resting, and macrophages_M0. Immune checkpoint genes (CD274, SIGLEC15) were abnormally expressed between high-PPAR expression and low-PPAR expression groups. TTN, MUC16, FAT2 and ANK3 genes had a high mutation frequency in both high-PPARA/PPARG and low-PPARA/PPARG expression group. Fourteen and two PPARA/PPARD drugs were identified to be able to effectively treat patients in high-PPARA/PPARG and low-PPARA/PPARG expression groups, respectively. We also found that the chemotherapy drug Vinorelbine was positively correlated with the three PPAR genes, showing the potential of Vinorelbine to serve as a treatment drug for STAD. Furthermore, cell experiments demonstrated that PPARG had higher expression in AGS and SGC7901 cells, and that inhibiting PPARG suppressed the viability, migration and invasion of AGS and SGC7901 cells.
CONCLUSIONS
The current results confirmed that the three PPAR genes (PPARA, PPARD and PPARG) affected STAD development through mediating immune microenvironment and genome mutation.
Topics: Humans; Male; PPAR gamma; Vinorelbine; PPAR alpha; PPAR delta; Adenocarcinoma; Drug Resistance; Stomach; Tumor Microenvironment
PubMed: 38529307
DOI: 10.7717/peerj.17082