Receptor Gamma Research Articles

Contractile regulation of the glucocorticoid-sensitive transcriptome in young and aged skeletal muscle.

Elevated glucocorticoids alter the skeletal muscle transcriptome to induce a myopathy characterized by muscle atrophy, muscle weakness, and decreased metabolic function. These effects are more likely to occur and be more severe in aged muscles. Resistance exercise can blunt the development of glucocorticoid myopathy in young muscle, but the potential to oppose the signals initiating myopathy in aged muscle is unknown. To answer this, young (4-mo-old) and aged (24-to 25-mo-old) male C57BL/6 mice were randomized to receive either an intraperitoneal (IP) injection of dexamethasone (DEX; 2 mg/kg) or saline as a control. Two hours postinjections, the tibialis anterior (TA) muscles of mice were subjected to unilateral high-force contractions. Muscles were harvested 4 h later. The glucocorticoid- and contraction-sensitive genes were determined by RNA sequencing. The number of glucocorticoid-sensitive genes was similar between young and aged muscle. Contractions opposed changes to more glucocorticoid-sensitive genes in aged muscle, with this outcome primarily occurring when hormone levels were elevated. Glucocorticoid-sensitive gene programs opposed by contractions were primarily related to metabolism in young mice and muscle size regulation and inflammation in aged mice. In silico analysis implied peroxisome proliferator-activated receptor gamma-1 (PPARG) contributed to the contraction-induced opposition of glucocorticoid-sensitive genes in aged muscle. Increasing PPARG expression in the TA of aged mice using adeno-associated virus serotype 9 partially counteracted the glucocorticoid-induced reduction in runt-related transcription factor 1 (Runx1) mRNA content, recapitulating the effects observed by contractions. Overall, these data contribute to our understanding of the contractile regulation of the glucocorticoid transcriptome in aged skeletal muscle.NEW & NOTEWORTHY We establish the extent to which muscle contractions oppose changes to the glucocorticoid-sensitive transcriptome in both young and aged muscle. We also identify peroxisome proliferator-activated receptor gamma (PPARG) as a transcription factor likely contributing to contraction-induced opposition to the glucocorticoid transcriptome in aged muscle. Overall, these data contribute to our understanding of the contractile regulation of the glucocorticoid transcriptome.

Design, Synthesis and Computational Insight of Isolated and Thiophene fused 2H‐Pyran‐2‐ones as PPAR‐γ Agonist

AbstractPeroxisome proliferator‐activated receptor gamma (PPAR‐γ) is a well‐known member of the PPAR family and a potential target for the treatment of various disorders. Herein, we present the design and synthesis of various 6‐aryl‐4‐sec.amino‐2‐oxo‐2H‐pyran‐3‐carbonitrile derivatives and functionalized thieno[3,2‐c]pyran‐2‐ones, derived from ketene dithioacetal. Then all the synthesized compounds were docked for their activity as PPAR‐γ to predict the binding mechanism and affinities regarding rosiglitazone and muraglitazar. Our studies revealed that three compounds 10 e, 10 f, and 10 h showed significant binding affinities, with energy ranges comparable to standard drugs rosiglitazone and muraglitazar. The docking conformation studies revealed that the selected compounds nicely interact with PPAR‐γ in the ligand binding domain with positive predictive values. We also performed molecular dynamics of the most potent compounds to validate the result. Our results indicate that these novel compounds are potential PPAR‐γ ligands, offering new possibilities for therapeutic applications. This study underscores the potential of these synthesized compounds in the development of novel PPAR‐γ agonists.

Evidence for thyroid hormone regulation of amygdala-dependent fear-relevant memory and plasticity.

The amygdala is an established site for fear memory formation, and clinical studies suggest involvement of hormone signaling cascades in development of trauma-related disorders. While an association of thyroid hormone (TH) status and mood disorders is established, the related brain-based mechanisms and the role of TH in anxiety disorders are unknown. Here we examine the role that TH receptor (TR, a nuclear transcriptional repressor when unbound and a transcriptional activator when bound to TH) may have in mediating the initial formation of fear memories in the amygdala. We identified mRNA levels of TR and other TH pathway regulatory genes, including thyrotropin-releasing hormone (Trh), transthyretin (Ttr), thyrotropin-releasing hormone receptor (Trhr), type 2 iodothyronine deiodinase (Dio2), mediator complex subunit 12 (Med12/Trap230) and retinoid X receptor gamma (Rxrg) to be altered in the amygdala following Pavlovian fear conditioning. Using TH agonist and antagonist infusion into the amygdala, we demonstrated that this pathway is both necessary and sufficient for fear memory consolidation. Inhibition of TH signaling with the TR antagonist 1-850 decreased fear memory consolidation; while activation of TR with T3 (triiodothyronine) resulted in increased memory formation. Using a systemic hypothyroid mouse model, we found that intra-amygdala infusions of T3 were sufficient to rescue deficits in fear memory. Finally, we demonstrated that T3 was sufficient to activate TR-specific gene pathways in the amygdala. These findings on the role of activity-dependent TR modulation support a model in which local TH is a critical regulator of fear memory-related plasticity in the amygdala.

Estrogen‐Related Receptor Gamma (ERRγ) as Biomarker and Novel Target for Therapeutic Intervention on Cancer: A Review

AbstractEstrogen‐related receptors (ERRs), genes similar to estrogen receptors, are identified as hormone‐responsive systems associated with the ERR subfamily. These hormone‐responsive systems facilitate oncometabolic programs to nourish cancer cell growth, a central node at the interface of cellular energy metabolism and cancer. Several independent studies have implicated ERR isoforms like ERRα, ERRβ, and ERRγ in the pathways of cancer development and progression. The construction of tissue‐specific ERR transgenic or knockout mice and the application of synthetic ligands have precisely indicated the critical and diverse role of ERRγ than other isoforms. ERRγ, plays a critical and diverse role, enabling switching metabolism to oncometabolism in favor of cancer cells, making it a “hot target” in cancer therapy. ERRγ expression is correlated with the clinical status of diverse cancer types and various cancer tissue treatments. The dual feature of ERRγ raises interest in understanding its biogenesis and function in different tissues. This review aims to describe the structural organization of ERRs, their central occupancy at the interface of cancer and metabolism, and their biogenesis and expression profile across different cancers. It concludes that ERRγ has potential as a clinical marker in cancer prognosis and a novel non‐conventional therapeutic target.

Physiologically based pharmacokinetic modeling of CYP2C8 substrate rosiglitazone and its metabolite to predict metabolic drug-drug interaction

Rosiglitazone is an activator of nuclear peroxisome proliferator-activated (PPAR) receptor gamma used in the treatment of type 2 diabetes mellitus. The elimination of rosiglitazone occurs mainly via metabolism, with major contribution by enzyme cytochrome P450 (CYP) 2C8. Primary routes of rosiglitazone metabolism are N-demethylation and hydroxylation. Modulation of CYP2C8 activity by co-administered drugs lead to prominent changes in the exposure of rosiglitazone and its metabolites. Here, we attempt to develop mechanistic parent-metabolite physiologically based pharmacokinetic (PBPK) model for rosiglitazone. Our goal is to predict potential drug-drug interaction (DDI) and consequent changes in metabolite N-desmethyl rosiglitazone exposure. The PBPK modeling was performed in the PKSim® software using clinical pharmacokinetics data from literature. The contribution to N-desmethyl rosiglitazone formation by CYP2C8 was delineated using vitro metabolite formation rates from recombinant enzyme system. Developed model was verified for prediction of rosiglitazone DDI potential and its metabolite exposure based on observed clinical DDI studies. Developed model exhibited good predictive performance both for rosiglitazone and N-desmethyl rosiglitazone respectively, evaluated based on commonly acceptable criteria. In conclusion, developed model helps with prediction of CYP2C8 DDI using rosiglitazone as a substrate, as well as changes in metabolite exposure. In vitro data for metabolite formation can be successfully utilized to translate to in vivo conditions.

Gold(I) N‐heterocyclic carbene (NHC) complexes containing 6‐mercaptopurine derivatives and their in vitro anticancer and anti‐inflammatory effects

A series of eight N‐heterocyclic carbenes (NHC) gold(I) complexes, involving 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (iPr) ligand in combination with 6‐mercaptopurine derivatives (HL1–8), has been prepared and thoroughly characterized, including elemental analysis, mass spectrometry, infrared and multinuclear NMR spectroscopy, and single crystal X‐ray analysis. The complexes, showing general composition of [Au (iPr)(Ln)] 1–8, were evaluated for their in vitro cytotoxicity against four human cancer cell lines including A2780 (ovarian) and A2780R (ovarian Cisplatin resistant), PC3 (prostate) and MCF‐7 (breast), and normal human MRC‐5 cells (lung fibroblasts). The complexes revealed significant cytotoxicity, with the best IC50 values ≈ 3.4–6.4 μM against A2780 and reasonable selectivity. Cellular effects of the selected complexes on the A2780 cells were evaluated using various flow cytometry assays. Complexes 1, 3, and 4 showed a strong pro‐apoptotic effect and a strong effect on the loss of mitochondrial membrane potential. These findings indicate that their major mechanism of action is based on the collapse of the mitochondrial metabolism and activation of the intrinsic signaling pathway of apoptosis, consequently resulting in cell death. The complexes 1–8 revealed only negligible effect on the production of inflammatory‐related cytokine (TNF‐α), as well as the activation of nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) or peroxisome proliferator‐activated receptor gamma (PPARγ). Moreover, the shotgun proteomic analysis was performed, and the obtained results suggest that the mechanism of action of complexes 1, 3, and 4 differs somewhat from that of Auranofin.

Temporal and differential proteomic profile of molecular mediators associated with chronic and acute wound healing.

The underlying pathophysiology of nonhealing chronic wounds is poorly understood due to the changes occurring at the gene level and the complexity arising in their proteomic profile. Here, we elucidated the temporal and differential profile of the normal and diabetic wound-healing mediators along with their interactions and associated pathways. Skin tissues corresponding to normal and diabetic wounds were isolated at Days 0, 3, 6, and 9 representing different healing phases. Temporal gene expression was analyzed by quantitative real-timePCR. Concurrently, differential protein patterns in the wound tissues were identified by Nano LC-ESI-TOF mass spectrometry and later confirmed by Western blot analysis. Gene ontology annotation, protein-protein interaction, and protein pathway analysis were performed using DAVID, PANTHER, and STRING bioinformatics resources. Uniquely identified proteins (complement C3, amyloid beta precursor protein, and cytoplasmic linker associated protein 2) in the diabetic wound tissue implied that these proteins are involved in the pathogenesis of diabetic wound. They exhibit enhanced catalytic activity, trigger pathways linked with inflammation, and negatively regulate wound healing. However, in the normal wound tissue, axin 1, chondroitin sulfate proteoglycan 4, and sphingosine-1-phosphate receptor were identified, which are involved in proliferation, angiogenesis, and remodeling. Our findings demonstrate the correlation between elevated gene expression of tumor necrosis factor-α, interleukin(IL)-1β, and identified mediators: aryl hydrocarbon receptor nuclear translocator, 5'-aminolevulinate synthase 2, and CXC-family, that inflicted an inflammatory response by activating downstream MAPK, JAK-STAT, and NF-κB pathways. Similarly, in normal wound tissue, the upregulated IL-4 and hepatocyte growth factor levels in conjunction with the identified proteins, serine/threonine-protein kinase mTOR and peroxisome proliferator-activated receptor gamma, played a significant role in the cellular response to platelet-derived growth factor stimulus, dermal epithelialization, and cell proliferation, processes associated with the repair mechanism. Furthermore, Western blot analysis indicated elevated levels of inflammatory markers and reduced levels of proliferative and angiogenic factors in the diabetic wound.

Combined orchiectomy and limb immobilization recapitulate early age‐related changes to skeletal muscle in mice

AbstractBackgroundMuscle mass and function decline in middle age, ultimately resulting in sarcopenia in the elderly and poor health outcomes, reducing quality of life. There is a lack of cost‐ and time‐effective murine models that recapitulate the physiological changes associated with muscle mass decline to study possible interventions to delay sarcopenia. We aimed to evaluate the effectiveness of combining orchiectomy (ORC) surgery to simulate age‐related androgen decline and hindlimb immobilization (IM) in inducing age‐related skeletal muscle changes.MethodsFour‐month‐old male C57BL/6J mice (n = 10) were subjected to ORC, followed by IM (right hindlimb casting) for 14 days. Upon completion of the casting period, ex vivo muscle contractile function, histology, and various mitochondrial markers were assessed, and results were compared with age‐matched controls (CON; n = 8) and middle‐aged (MA; 12 ± 1 months, n = 9) animals.ResultsIM combined with ORC induced a 30%–40% decrease in muscle mass across multiple hindlimb muscles (P < 0.0001), with the magnitude of muscle loss comparable with the MA group when corrected for body weight (P < 0.0001). In the IM limb of ORC mice, soleus muscle force significantly decreased when compared with the contralateral limb (P < 0.05) and aged‐matched CON group (P < 0.05). The decrements in muscle force and mass present in the IM limb of ORC mice were accompanied by a 70% reduction in the expression of the muscle structural protein dystrophin and various mitochondrial markers, including cytochrome C (−55%), peroxisome proliferator‐activated receptor gamma co‐activator 1‐beta (PGC1‐β) (−49%), and cytochrome oxidase IV (COX‐IV) (−73%) when compared with CON animals (P < 0.001). Lastly, our model also demonstrated specific fibre‐type shifts in fast‐ and slow‐twitch muscles, which mimicked changes in the MA group.ConclusionsApplying treatments during IM could target acute muscle atrophy in MA adults, while applying them following cast removal in a low‐testosterone environment could represent a window for rehabilitation therapeutics.

Vitamin D supplementation reduces systemic modulation of oxidative stress and collagen degradation in keratoconus patients

Aims/Purpose: To assess whether vitamin D (Vit D) supplementation modulates systemic biomarkers involved in collagen degradation and oxidative stress in adolescent patients affected with keratoconus (KC).Methods: This study included forty adolescent patients (age range: 16–19 years) with KC and Vit D insufficiency (<30 ng/mL). The patients were supplemented with vitamin D for 6 months and followed up for additional 6 months (total study duration: 12 months). Blood samples were collected at 1, 6, and 12 months. The levels of Vit D or its receptor (VDR), collagen catabolism (type I collagen degradation product; ICTP), and oxidative stress (Peroxisome proliferator‐activated receptor gamma; PPAR‐γ) were quantified by ELISA or RT‐PCR.Results: We found that Vit D levels significantly increased at 6 months after supplementation. Moreover, at month 6 the expression of VDR was upregulated (p < 0.01), while collagen degradation (ICTP; p < 0.01) and oxidative stress (PPAR‐γ; p < 0.05) were significantly reduced.Conclusions: Our findings show that Vit D supplementation reduces oxidative stress and collagen catabolism, which have a key role in KC pathophysiology. These findings provide a potential mechanism by which Vit D could impact KC progression and provide preliminary evidence that KC may be a systemic disease.

Brain Short-Chain Fatty Acids Induce ACSS2 to Ameliorate Depressive-Like Behavior via PPARγ–TPH2 Axis

Short-chain fatty acids (SCFAs) have been increasingly evidenced to be important bioactive metabolites of the gut microbiota and transducers in controlling diverse psychiatric or neurological disorders via the microbiota–gut–brain axis. However, the precise mechanism by which brain SCFAs extert multiple beneficial effects is not completely understood. Our previous research has demonstrated that the acetyl-coenzyme A synthetase short-chain family member 2 (ACSS2) is a novel target of the rapid and long-lasting antidepressant responses. Here, we show that micromolar SCFAs significantly augment both total cellular and nuclear ACSS2 to trigger tryptophan hydroxylase 2 (TPH2) promoter histone acetylation and its transcription in SH-SY5Y cells. In chronic-restraint-stress-induced depression mice, neuronal ACSS2 knockdown by stereotaxic injection of adeno-associated virus in the hippocampus abolished SCFA-mediated improvements in depressive-like behaviors of mice, supporting that ACSS2 is required for SCFA-mediated antidepressant responses. Mechanistically, the peroxisome-proliferator-activated receptor gamma (PPARγ) is identified as a novel partner of ACSS2 to activate TPH2 transcription. Importantly, PPARγ is also responsible for SCFA-mediated antidepressant-like effects via ACSS2–TPH2 axis. To further support brain SCFAs as a therapeutic target for antidepressant effects, d -mannose, which is a naturally present hexose, can significantly reverse the dysbiosis of gut microbiota in the chronic-restraint-stress-exposure mice and augment brain SCFAs to protect against the depressive-like behaviors via ACSS2–PPARγ–TPH2 axis. In summary, brain SCFAs can activate ACSS2–PPARγ–TPH2 axis to play the antidepressive-like effects, and d -mannose is suggested to be an inducer of brain SCFAs in resisting depression.

Effect of melatonin‐induced exosomes on proregenerative and antifibrotic pathways involved in corneal scarring

Aims/Purpose: Melatonin is a time‐and‐concentration dependent pro and antiinflammatory agent that also regulates cell proliferation, migration, angiogenesis, fibrosis, and extracellular matrix synthesis. This study aims to assess the effect of exosomes obtained from melatonin‐treated human limbal mesenchymal stem cells (hLMSCs) on naive hLMSCs and ascertain their influence on antifibrotic and proregenerative pathways involved in corneal scarring.Methods: hLMSCs were harvested from the eye bank of Eskişehir Osmangazi University Hospital and were subsequently isolated and characterized. We then treated hLMSCs (Mel‐treated hLMSCs) with varying concentrations of melatonin followed by isolation and characterization of the procured exosomes. These exosomes were added to enrich cell culture media of naïve hLMSCs (Mel‐exo‐treated hLMSCs) to examine their antifibrotic and proregenerative effects. The expression of miR155, miR29 Transforming Growth Factor Beta 1 (TGFβ1), TGFβ3, Peroxisome Proliferator‐Activated Receptor Gamma (PPARγ), and Alpha‐Smooth Muscle Actin (α‐SMA) miRNA and genes were compared between Mel‐treated hLMSCs and Mel‐exo‐treated hLMSCs by using Real‐Time PCR.Results: TGFβ3 expression increased dramatically in response to Mel‐exo, while the increase in TGFβ1 expression was only minimal in correlation with levels of miR155 expression. Likewise, PPARγ expression was increased while an inhibition was observed in α‐SMA expression and miR29 expression in Mel‐exo‐treated hLMSCs compared to Mel‐treated hLMSCs.Conclusions: Melatonin treatment of hLMSCs resulted in expression of exosomes that could drive naïve hLMSCs in favour of antifibrotic and proregenerative effects as evidenced by higher TGFβ3 and PPARγ expressions and inhibition of α‐SMA. This approach could prove beneficial in cornea and ocular surface tissue engineering applications.The authors acknowledge the support from Eskisehir Osmangazi University, Scientific Research Projects (Grant ID: TOA‐2022‐2458).

Betanin from Beetroot (Beta vulgaris L.) Regulates Lipid Metabolism and Promotes Fat Browning in 3T3-L1 Adipocytes.

Fat browning, which converts white adipose tissue to brown, has attracted attention as a promising strategy for the treatment of obesity. Betanin (BT) has been reported to have potential anti-obesity activity. 3T3-L1 cells were differentiated for 7 days during BT treatment. The BT concentration range for the study was determined using an MTT assay, and lipid accumulation was evaluated by Oil-Red-O staining. The expression of protein level was analyzed by Western blot. Immunofluorescence images were performed with confocal microscopy to visually show the amount and location of thermogenesis factor uncoupling protein1 (UCP1) and mitochondria. qRT-PCR was performed to evaluate mRNA expression. BT inhibited lipid accumulation and increased the expression of UCP1, peroxisome-proliferator-activated receptor gamma (PPARγ), and PPARγ coactivator-1 alpha (PGC-1α). In addition, the increases in beige adipocyte-specific markers were observed, supporting BT-mediated browning of the fat tissue. The UCP1 was localized in the inner membrane of the mitochondria, and its expression was associated with mitochondrial activation. Consistent with this, the mRNA expression of mitochondrial biogenesis markers increased in 3T3-L1 cells after BT treatment. Immunofluorescence staining also indicated an increased number of mitochondria and UCP1, respectively. Moreover, BT inhibited lipogenesis and enhanced lipolysis and fatty acid oxidation. This mechanism has been suggested to be mediated by an adenosine monophosphate-activated protein kinase (AMPK) pathway. BT induces fat browning and regulates lipid metabolism via the AMPK-mediated pathway in 3T3-L1 cells, suggesting that BT can be a promising candidate for controlling obesity.

Blockade of Common Gamma Chain Cytokine Signaling with REGN7257, an Interleukin 2 Receptor Gamma (IL2RG) Monoclonal Antibody, in Combination with Costimulatory Blockers Delayed Skin Graft Rejection in Mice

There is a current medical need to identify innovative maintenance therapies to prevent allograft rejection in solid organ transplantation. During transplant rejection, recipient immune cells identify a grafted organ as foreign and attack it: CD4 + T cells orchestrate transplant rejection by recruiting a range of effector cells responsible for the damage of rejection including CD8 + T cells, NK cells, B cells and macrophages. These pathogenic immune cell responses can be driven by cytokines of the common gamma chain (γ c) cytokine family (IL2, IL4, IL7, IL9, IL15, and IL21). γ c cytokines signal through their corresponding receptors, expressed primarily on immune cells, that share a common coreceptor, interleukin 2 receptor subunit gamma (IL2RG) that is required for signaling. To understand the role of γ c cytokines in driving transplant rejection, we generated REGN7257, a fully human IL2RG monoclonal antibody that inhibits γ c cytokine-induced signaling, and we tested its ability to suppress allogeneic immune cell responses in a mouse model of skin graft rejection when delivered as a monotherapy and in combination with mycophenolate mofetil (MMF) or T cell costimulatory pathway blockers. In this model, recipient B6/129 (mixed background) Il2rg hu/hu mice were transplanted with tail skin from BALB/cJ donor mice. Graft survival was analyzed using a log rank Mantel-Cox test to detect statistically significant differences across groups (*=p<0.033; **= p<0.002; ***=p<0.0002; ****=p<0.0001). In a mouse model of skin graft rejection, γ c cytokine signaling blockade with REGN7257 given as maintenance immunosuppression effectively improved overall graft survival (Median Survival Time [MST] IL2RG=13) compared to mice that received a control antibody (MST CTRL=9 [****vs IL2RG Ab]), and with similar efficacy to that observed with the calcineurin inhibitor tacrolimus (MST TAC=12.5 [**vs control, n.s. vs IL2RG Ab]). In treatment combination experiments, while monotherapy treatment with the antiproliferative agent MMF was not as efficient as REGN7257 at delaying skin graft rejection (MST MMF=10 [*vs control] and MST IL2RG=12 [*vs MMF]), simultaneous blockade of cell proliferation and γ c cytokine signaling conferred an advantage over monotherapies (MST MMF+IL2RG=15.5 [****vs control, **vs IL2RG Ab]). Similarly, induction therapy consisting of γ c cytokine signaling blockade followed by maintenance immunosuppression using the CTLA4-Ig fusion protein abatacept, significantly improved overall skin graft survival (MST IL2RG+CTLA4=19.5 [****vs control]) compared to REGN7257 induction only (MST IL2RG=11 [****vs control and combo]) or abatacept maintenance only (MST CTLA4=10 [*vs control, ****vs combo]). Finally, maintenance immunosuppression combining blocking of γc cytokine signaling together with blocking of both CD28 and CD40L costimulatory signals prolonged skin graft survival better than any combination therapies of only 2 pathway blockers (MST TRIPLE=26 [**vs control] and MST DOUBLE=16-21 [n.s.-** vs triple]). Overall, our study showed that γ c cytokine blockade could potentially be an alternative to calcineurin inhibitor-based regimens to prevent rejection by specifically targeting immune cells. Our data also highlighted the inherent complexity of effector mechanisms and pathways involved in allograft rejection and showed that prolonged allograft survival requires simultaneous blockade of multiple T cell activating signals, including inhibition of cytokine signaling and costimulatory signals. These data provide evidence of γ c cytokines as key drivers of allogeneic immune cell responses during acute transplant rejection, offering a potentially novel strategy for the management of transplant patients.

Oridonin attenuates atherosclerosis by inhibiting foam macrophage formation and inflammation through FABP4/PPARγ signalling.

Both lipid accumulation and inflammatory response in lesion macrophages fuel the progression of atherosclerosis, leading to high mortality of cardiovascular disease. A therapeutic strategy concurrently targeting these two risk factors is promising, but still scarce. Oridonin, the bioactive medicinal compound, is known to protect against inflammatory response and lipid dysfunction. However, its effect on atherosclerosis and the underlying molecular mechanism remain elusive. Here, we showed that oridonin attenuated atherosclerosis in hyperlipidemic ApoE knockout mice. Meanwhile, we confirmed the protective effect of oridonin on the oxidized low-density lipoprotein (oxLDL)-induced foam macrophage formation, resulting from increased cholesterol efflux, as well as reduced inflammatory response. Mechanistically, the network pharmacology prediction and further experiments revealed that oridonin dramatically facilitated the expression of peroxisome proliferator-activated receptor gamma (PPARγ), thereby regulating liver X receptor-alpha (LXRα)-induced ATP-binding cassette transporter A1 (ABCA1) expression and nuclear factor NF-kappa-B (NF-κB) translocation. Antagonist of PPARγ reversed the cholesterol accumulation and inflammatory response mediated by oridonin. Besides, RNA sequencing analysis revealed that fatty acid binding protein 4 (FABP4) was altered responding to lipid modulation effect of oridonin. Overexpression of FABP4 inhibited PPARγ activation and blunted the benefit effect of oridonin on foam macrophages. Taken together, oridonin might have potential to protect against atherosclerosis by modulating the formation and inflammatory response in foam macrophages through FABP4/PPARγ signalling.

Association between GABRG2 Gene Single Nucleotide Polymorphisms and Susceptibility to Ischemic Stroke in a Chinese Population.

Current evidence suggests that Gamma-aminobutyric acid (GABA) receptors are associated with the occurrence and progression of cerebrovascular diseases. The present study investigated the association between single nucleotide polymorphisms (SNPs) in the Gamma-aminobutyric acid type A receptor gamma2 subunit (GABRG2) gene and ischemic stroke (IS). A total of 120 healthy volunteers and 187 patients with IS were recruited. Patients underwent complete neurological assessment and classification with the National Institute of Health Stroke Scale (NIHSS) and the Trial of ORG 10172 in Acute Stroke Treatment (TOAST). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to analyze SNP sites in 4 different regions (rs211037, rs418210, rs211035, and rs424740) of the GABRG2 gene. SHEsis online platform was used to assess SNP allele and genotype frequencies. Multivariate logistic regression analysis was performed to identify the risk factors for IS. Univariate analysis showed that the T allele and TT genotype distribution for rs211037 were significantly more frequent in the IS group compared to controls (pallele = 0.01, odds ratio (OR) = 1.673, 95% confidence intervals (CI), 1.119-2.500, pgenotype = 0.03). Furthermore, multivariate logistic regression analysis revealed the TT genotype for rs211037 was an independent risk factor for IS (p = 0.017, OR = 1.925, 95% CI, 1.122-3.303). Age was also found to be an independent risk factor, and the older the age, the higher the risk of IS (p = 0.001, OR = 1.047, 95% CI, 1.020-1.073). Finally, subgroup analysis revealed that patients with the rs211037 TT genotype were associated with a higher NIHSS score (p = 0.03), and that large-artery atherosclerosis (LAA) subtype was predominant in patients with the rs211037 TT genotype (p = 0.042). These findings suggest the rs211037 polymorphism in the GABRG2 gene is an independent risk factor for IS in the Chinese population. GABRG2 could thus be a potential biomarker to assess the risk of IS.

Reduction in Obesity-Related Hepatic Fibrosis by SR1664.

Peroxisome-proliferator-activated receptor gamma (PPARγ) is a transcription factor with adipogenic, insulin-sensitizing, and antifibrotic properties. Strong PPARγ activators, such as the thiazolidinediones, can induce unwanted effects such as edema, weight gain, and bone loss, and therefore selective modulators of PPARγ are in development. We previously reported that one selective PPARγ modulator, SR1664, reduced toxin-induced hepatic fibrosis and the activation of hepatic stellate cells (HSCs), the main collagen-producing liver cell in fibrosis. In this study, we used a high fat and high carbohydrate (HFHC) model of hepatic steatosis and fibrosis to determine the effect of SR1664. Mice were placed on a standard chow or HFHC diet for 16 weeks, with SR1664 or control treatment for the final 4 weeks. SR1664 did not alter weight gain or fasting insulin or glucose levels. The size of lipid droplets in the HFHC group was reduced by SR1664, but there was no effect on total liver triglyceride levels. The degree of fibrosis was significantly reduced by SR1664 in mice on the HFHC diet, and this was accompanied by a decrease in activated HSC. In summary, SR1664 improved insulin sensitivity and reduced fibrosis in the HFHC diet, suggesting selective PPARγ modulation is effective in obesity-related liver fibrosis.

Zinc methionine improves the lipid metabolism that is associated with the alteration of intestine mucosal proteomes and microbiota of newborn Holstein dairy calves

AbstractSupplementation of diets with a modest amount of zinc methionine (ZM) has been documented to improve the growth performance and antioxidant function of dairy calves, but the underlying mechanisms remain elusive. In the present study, 16 dairy calves were allocated to a control (CON) group (calves consumed a basal diet) and a ZM group (calves ingested the basal diet and had an additional 455 mg ZM/day, corresponding to 80 mg zinc/day). The calves were fed these diets for 2 weeks, after which their serum antioxidant parameters, lipids, and jejunal mucosal proteome and microbiota were analyzed. The ZM group had lower levels of total cholesterol, triglycerides, and malondialdehyde but higher high‐density lipoprotein cholesterol and glutathione peroxidase activity in the serum. A total of 142 differentially expressed proteins in the intestinal mucosa between the CON and ZM groups had been identified (ZM upregulated 117 proteins and downregulated 25 proteins). In addition, the protein expression of acyl‐coenzyme A oxidase 1, fatty acid binding protein 2, and peroxisome proliferator‐activated receptor gamma was higher in the ZM group. 16S rRNA gene sequencing indicated beneficial microbes, such as Veillonellaceae, Akkermansia_muciniphila, and Bifidobacterium adolescentis, which were more abundant, whereas Acinetobacter lwoffii was less abundant in calf jejunal mucosa in the ZM group. Finally, the propionate, butyrate, and iso‐valerate concentrations in the jejunal digesta were greater in the ZM group than those in the CON group. Collectively, the present study shows that ZM supplementation improves the serum and intestine mucosal lipid metabolism associated with the alterations in mucosal fatty acids β‐oxidation and microbiota.

Protective Effect of Water-Soluble Acacetin Prodrug on APAP-Induced Acute Liver Injury Is Associated with Upregulation of PPARγ and Alleviation of ER Stress.

A water-soluble acacetin prodrug has been synthesized and reported by our group previously. Acetaminophen (APAP) overdose is a leading cause of acute liver injury. We found that subcutaneous injection of acacetin prodrug (5, 10, 20 mg/kg) decreased serum ALT, AST, and ALP, corrected the abnormal MDA and GSH in liver, and improved intrahepatic hemorrhage and destruction of liver structures in APAP (300 mg/kg)-treated mice. Molecular mechanism analysis revealed that the expressions of endoplasmic reticulum (ER) stress markers ATF6, CHOP, and p-PERK, apoptosis-related protein BAX, and cleaved caspase 3 were decreased by acacetin in a dose-dependent manner in vivo and in vitro. Moreover, via the acacetin-upregulated peroxisome-proliferator-activated receptor gamma (PPARγ) of HepG2 cells and liver, the suppressive effect of acacetin on ER stress and apoptosis was abolished by PPARγ inhibitor (GW9662) or PPARγ-siRNA. Molecular docking revealed that acacetin can bind to three active pockets of PPARγ, mainly by hydrogen bond. Our results provide novel evidence that acacetin prodrug exhibits significant protective effect against APAP-induced liver injury by targeting PPARγ, thereby suppressing ER stress and hepatocyte apoptosis. Acacetin prodrug is likely a promising new drug candidate for treating patients with acute liver injury induced by APAP.

Synthesis, Anti‐adipogenic, and Insulin‐sensitizing Potential of Benzosuberene‐alkyl Sulfone (BSAS) Analogues

AbstractObesity and diabetes are the leading cause of mortality worldwide. Promising modulators exhibiting insulin sensitivity and anti‐adipogenic actions are highly desirable. Organic sulfone analogues are prominent structural units present in diverse bioactive molecules. However, sulfones‐derived anti‐adipogenic agents are currently unavailable. Therefore, different benzosuberene‐alkyl sulfone (BSAS) analogues were synthesized inspired by the molecular diversity of the essential oil of Cedrus deodara. Among the series, five BSAS analogues were assessed in‐silico for their binding towards native Peroxisome Proliferator‐Activated Receptor Gamma (PPARγ) and further validated in‐vitro for their anti‐adipogenic potential in differentiated 3T3‐L1 pre‐adipocytes. Their ability to improve insulin sensitivity was also examined in L6 myotubes to ascertain their role in insulin resistance. Our results demonstrated that BSAS‐1 was the partial PPARγ agonist. It has reduced adipogenesis efficiently by downregulating adipogenic genes, resulting in lower triglyceride levels. BSAS‐1 lowered oxidative stress, protected myotubes from insulin resistance, and improved glucose uptake by promoting GLUT4 translocation. Overall, BSAS‐1 has the potential to treat obesity and obesity‐induced insulin resistance.

Signaling mechanisms involved in the regulation of remyelination in multiple sclerosis: a mini review.

Multiple sclerosis is an autoimmune neurodegenerative disease of the CNS that causes progressive disabilities, owing to CNS axon degeneration as a late result of demyelination. In the search for the prevention of axonal loss, mitigating inflammatory attacks in the CNS and myelin restoration are two possible approaches. As a result, therapies that target diverse signaling pathways involved in neuroprotection and remyelination have the potential to overcome the challenges in the development of multiple sclerosis treatments. LINGO1 (Leucine rich repeat and Immunoglobulin domain containing, Nogo receptor- interaction protein), AKT/PIP3/mTOR, Notch, Wnt, RXR (Retinoid X receptor gamma), and Nrf2 (nuclear factor erythroid 2-related factor 2) signaling pathways are highlighted in this section. This article reviews the present knowledge regarding numerous signaling pathways and their functions in regulating remyelination in multiple sclerosis pathogenesis. These pathways are potential biomarkers and therapeutic targets in MS.