bluuebunny/crossref_metadata_2025_split huggingface dataset:
A SUMO‐Acetyl Switch in PXR Biology
Authors: Cui Wenqi , Sun Mengxi , Shen Xunan , Staudinger Jeff 
Published: November 2023

Pregnane x Receptor (PXR, NR1I2) was initially described as a master‐regulator of drug‐inducible xenobiotic detoxification pathways in the enterohepatic system. However, there is increasing recognition that PXR activation has a multiplicity of ‘non‐canonical’ roles including anti‐inflammatory effects, alterations in glucose and lipid homeostasis, development of cancer therapy resistance, and in driving tumor progression. There is a clear recognition that alterations in post‐translational modifications (PTMs) of PXR play a pivotal role in regulating its biological function. Precisely how these PTMs influence each other is a current area of interest in our laboratory. We have investigated the interaction of two distinct PTMs at the level of PXR, namely, SUMOylation and acetylation. We detect acetylation of PXR in mouse hepatocytes using an immunoprecipitation approach. The enzyme that modulates PXR de‐acetylation is likely HDAC3 in a complex with a well‐known co‐repressor protein‐SMRT. PXR and HDAC3 co‐localize in mouse hepatocytes, and the acetylation alters the sub‐cellular localization of PXR. Treatment of hepatocytes with the class I histone deacetylase (HDAC) inhibitor trichostatin A (TSA) produces synergistic transactivation of a PXR‐reporter gene when combined with rifampicin, a prototypical PXR agonist. Enzymatic de‐acetylation with HDAC3/SMRT inhibits SUMO‐modification of PXR, while pharmacological promotion of acetylation with TSA promotes high levels of SUMO‐modification of PXR. Treatment with TSA produces increased acetylation of PXR in hepatocytes. The acetylation and SUMOylation of PXR also differentially modulated its ability to associate with the canonical co‐repressor proteins HDAC3/SMRT. We show that SUMOylated PXR has an intrinsic repressive function that is mediated by a currently unknown mechanism. Taken together, our data support a model in which a SUMO‐acetyl ‘switch’ occurs at the level of PXR, such that acetylation is prerequisite for SUMO‐modification of PXR to promote active repression of target gene expression.Support or Funding InformationNational Institute of Digestive Diabetic and Kidney Diseases (R01DK090558) National Institute of Health National Center for Research Resources COBRE (P20 GM103549) University of Kansas J.R. & Inez Jay Fund
STAT3 as a Multi‐organ Target for Tissue Fibrosis
Authors: Haak Andrew , Choi Kyoung , Oh Raymond , Smith Karry M. J. , Tschumperlin Daniel 
Published: November 2023

Despite recent therapeutic developments, pulmonary fibrosis remains a debilitating disease with poor prognosis. In order to create effective treatments, promising molecular targets need to be identified and validated. Across multiple organs, mesenchymal derived myofibroblasts play an essential role in matrix deposition and tissue contraction. We previously carried out a high‐content, RNAi screen to characterize myofibroblast cytoskeletal phenotypes (α‐SMA and organized F‐actin) in cultured fibroblasts. Hits from this screen, including STAT3 (Signal transducer and activator of transcription 3), were validated in primary lung fibroblasts from patients with IPF (idiopathic pulmonary fibrosis) on compliant hydrogels. To further evaluate STAT3 as a therapeutic target, we have focused on LLL12, a small molecule inhibitor of STAT3. LLL12 dose‐dependently (0.3, 1.0μM) reduced RNA expression of profibrotic genes (ACTA2, CTGF, COL1A1, and FN1) as well as protein deposition of collagen III and fibronectin, in TGFβ stimulated cultured fibroblasts. LLL12 also reduced contractile force, as measured by traction force microscopy, to levels comparable to that seen with inhibition of Rho kinase (Y27632, 20μM). In an effort to support the role of STAT3 as a multi‐organ regulator of tissue fibrosis we confirmed similar effects of LLL12 in primary human hepatic stellate cells and cardiac fibroblasts. Using the bleomycin model of pulmonary fibrosis we assessed the in vivo efficacy of STAT3 inhibition. The lungs of the mice treated therapeutically (day 14–28) with LLL12 (5 mg/kg i.p. daily) showed reduced collagen and fibrotic matrix content measured by hydroxyproline and trichrome histology. RNA expression of COL1A1, FN1, CTGF, and ACTA2 also decreased (~50%) in the mice treated with LLL12. Importantly, in the mice which did not receive bleomycin, LLL12 had no effect on RNA expression of these genes. These data not only validate the RNAi screening approach, but also point towards STAT3 as an important molecular target for regulation of myofibroblast activation in pulmonary fibrosis and other fibrotic diseases.Support or Funding InformationSupported by NIH RO1 HL092961 and HL113796, and Boehringer Ingelheim.
Lepidium meyenii inhibits MAGL and increases the expression of LRP1 in neuroblastoma SH‐SY5Y cells
Authors: Rondon‐Ortiz Alejandro , Su Pei Ying , Khan Rimmal , Böhlke Mark , Maher Timothy , Pino‐Figueroa Alejandro 
Published: November 2023

Lepidium meyenii (Maca) is a Peruvian plant that has previously been implicated to have effects on the endocannabinoid system. N‐Benzylamides, also known as macamides, are compounds present in the Maca pentane extract (MPE) with a demonstrated inhibitory effect on fatty acid amide hydrolase (FAAH), one of the enzymes that terminates endocannabinoid signaling. The purpose of this project was to evaluate the effect of MPE on monoacyl glycerol lipase (MAGL), another enzyme involved in the endocannabinoid system, and additionally to demonstrate the effect of MPE on the expression of the low density lipoprotein receptor‐related protein 1 (LRP1) in neuroblastoma SH‐SY5Y cells. LRP1 is a receptor involved in the transcellular transport of peptides and proteins, including β‐amyloid.Macamides were quantified by LC‐MS/MS, demonstrating that N‐benzylpalmitamide, N‐benzyloctadeca‐9Z, 12Z‐dienamide and N‐benzyloctadeca‐9Z, 12Z, 15Z‐trienamide were the most predominant compounds in the MPE with concentrations of 27.0, 8.4 and 5.5 mg/g, respectively. The FAAH and MAGL inhibitory activity of MPE was demonstrated with IC50 values of 9.15 and 7.12 μg/mL, respectively, supporting an action via the endocannabinoid system.SH‐SY5Y neuroblastoma cells were treated with MPE at three different concentrations between 0.1 and 10 μg/mL. Cells were lysed and LRP1 levels were analyzed by immunoblotting, demonstrating that Lepidium meyenii was able to significantly increase LRP1 expression.While MPE was previously demonstrated to have neuroprotective effects associated with the inhibition of FAAH, this investigation reports that MPE additionally inhibits MAGL. This dual inhibitory activity on FAAH and MAGL could be responsible for the upregulation of LRP1. It is well known that LRP1 reduction is associated with neurological disorders such as Alzheimer's disease. The increase of LRP1 levels by MPE supports a novel mechanism which might be responsible for some of the biological activity of this plant. Further studies are necessary to better elucidate the activation of transcription factors by Maca constituents.
Cytotoxic and chemo‐sensitizing effects of ferulic acid, fromTamarix aucheriana, on colorectal cancer cells: insights into mechanisms of therapeutic efficacy
Authors: Abaza Mohamed Salah I. , Afzal Mohammmad , Al‐Attiyah Rajaa , Guleri Radhika 
Published: November 2023

Natural products are valuable source for anticancer agents. The present study focuses on the isolation and identification of potential chemo‐therapeutic/preventive constituents from Tamarix aucheriana using bioactivity guided fractionation. Ferulic acid (FA) was identified as an active agent. The potential of FA to control the growth of human colorectal cancer cells, enhance their sensitivity to conventional chemotherapeutic drugs and the potential biological targets and molecular mechanisms of FA action were investigated. FA showed time‐ and dose‐dependent anti‐mitogenic effect on colorectal cancer cells with little cytotoxicity for normal human fibroblasts. FA inhibited the colony formation, induced morphological changes, induced apoptosis, and inhibited DNA‐binding activity of NFkB, the various proteolytic activities of proteasome and invasion in colorectal cancer cells. FA up‐regulated p15, p18, p19, p21, p27, p53, and p57, pro‐apoptotic gene expression and down‐regulated Cdk1, Cdk2, Cdk4, and Cdk6, anti‐apoptotic gene expression. FA showed differential potential to enhance the sensitivity of colorectal cancer cells to conventional chemotherapeutic drugs. These results indicate the chemo‐therapeutic potential of FA.Support or Funding InformationKuwait University, Research Project No. SL05‐04
Investigation of the Lipoxygenase Pathway in Cisplatine Induced Nephrotoxicity
Authors: Al‐khamees Osama A 
Published: November 2023

Nephrotoxicity is a major side effect for the widely used antineoplastic agent, cisplatin. Several studies have investigated the possible mechanisms for such toxicity. HETEs and leukotrienes were found in several studies to mediate many physiological functions in the kidney including regulation of glomerular filtration or renal vasoconstriction. This study was designed, therefore, mainly to investigate the possible involvement of lipoxygenase (LOX) pathway in cisplatin induced‐nephrotoxicity in Wistar rats. Nephrotoxicity was induced by IP injection of cisplatin (6 mg/kg/day). Genes and protein expression of the major lipoxygenases pathway biomarkers including 5‐LOX, 12‐LOX and 15‐LOX in animals’ kidneys were quantified using real time PCR and western plot, respectively. Cisplatin challenge to the animals markedly altered renal LOX pathway genes expression. There was a marked up regulation in 5‐LOX, 12‐LOX and 15‐LOX genes in the kidneys of cisplatin treated animals. Moreover, protein expressions of 5‐LOX, 12‐LOX, 15‐LOX were also significantly increased in the kidneys of cisplatin treated animals. To the best of our knowledge, the linkage between LOX pathway and cisplatine nephrotoxicity has not been investigated. Combination of several agents with the anticancer drug is frequently used to alleviate the associated side effect. Therefore, the current project is a preclinical study that might provide a therapeutic benefit LOX inhibitors combination with cispaltin.Support or Funding InformationThis research was supported by the National Science, Technology and Innovation Plan (MAARIFAH) under grant (12‐MED2780‐08).
Fibroblast growth factor 21 is critically involved in alcohol‐induced hepatic lipid metabolism and adipose tissue lipolysis in mice
Authors: Zhao Cuiqing , Liu Liming , Yang Ying , McClain Craig , Feng Wenke 
Published: November 2023

PurposeFibroblast growth factor 21 (FGF21) is a novel metabolic regulator produced primarily in the liver that regulates hepatic fat metabolism in various models of metabolic syndromes. Alcoholic liver disease (ALD) is characterized by hepatic lipid accumulation. Here, we sought to determine the role of FGF21 in mice exposed to alcohol and to discern underlying mechanisms.MethodsMale FGF21 knockout (KO) and control (WT) mice were fed either the Lieber DeCarli diet containing 5% alcohol (AF) or an isocaloric diet (PF). For the chronic alcohol exposure, mice were fed for 4 weeks. For the chronic‐binge alcohol exposure, mice were fed for 12 days, followed by a single dose of alcohol (5g/kg) or isocaloric maltose dextrin treatment by gavage. Mice were sacrificed 6 hours later. One group of AF mice were administered with recombinant human FGF21 (rhFGF21) for the last 5 days. Liver steatosis and inflammation and epididymal white adipose tissue (eWAT) lipolysis were investigated.ResultsAlcohol exposure induced plasma FGF21 elevation. FGF21 knockout exacerbated chronic alcohol‐induced hepatic steatosis and liver injury, which was associated with increased activation of genes involved in lipogenesis mediated by SREBP1c and decreased expression of genes involved in fatty acid (FA) β‐oxidation mediated by PGC1α. Chronic alcohol exposure induced a moderate adipose tissue lipolysis in eWAT. rhFGF21 administration reduced alcohol‐induced hepatic steatosis and inflammation in WT mice. Surprisingly, in the chronic‐binge model, alcohol consumption‐induced fatty liver is blunted in the KO mice. Chronic‐binge alcohol exposure‐induced in situ hepatic lipogenesis and FA β‐oxidation were comparable to that in chronic alcohol‐exposed mice. However, FGF21 deficiency markedly reduced chronic‐binge alcohol exposure‐induced eWAT lipolysis, which may contribute to hepatic FA uptake. Further analysis showed that in the KO mice alcohol induced significant elevation in systemic catecholamine, which is known to promote adipose lipolysis. rhFGF21 administration increased alcohol‐ induced fat loss in parallel with an increase of circulating norepinephrine concentration in KO mice.ConclusionOur results demonstrated that the role of FGF21 in ALD is alcohol exposure model dependent. Lack of FGF21 exacerbates chronic alcohol exposure‐induced fatty liver, and this exaggeration is overridden in chronic‐binge alcohol exposed mice through a reduction of adipose lipolysis mediated by systemic catecholamine release involving sympathetic nervous system activation. Pharmacologic strategies targeting hepatic FGF21 elevation and reduction in adipose tissue lipolysis are warranted.Support or Funding InformationSupported by the NIH and Veterans Administration
Sulfation of Environmental Estrogens by Human Cytosolic Sulfotransferase (SULT) 1C4
Authors: Guidry Amber L , Runge‐Morris Melissa , Falany Charles N 
Published: November 2023

Sulfation plays an important role in the metabolism of drugs and hormones, the bioactivation of carcinogens, and the detoxification of xenobiotics. Human cytosolic sulfotransferase (SULT) 1C4, a Phase II conjugating enzyme, catalyzes the transfer of the sulfonate group from 3′‐phosphoadensosine 5′‐phosphosulfate (PAPS) to the hydroxyl or amine group of the substrate. SULT1C4 expression has been reported to be highest in fetal lung and fetal kidney, with lower expression in the fetal heart and adult kidney, ovary, and spinal cord. SULT1C4's expression suggests a role in detoxication defenses across the maternal‐fetal barrier and integration of hormonal and metabolic signals that are generated during organ development. Unlike many of the other cytosolic SULTs, the role of SULT1C4 in endogenous metabolism and physiology remains poorly understood; however, previous studies have shown that SULT1C4 can sulfate environmental estrogen‐like compounds, such as bisphenol A (BPA). Numerous studies have shown that exposure to environmental estrogens can have harmful effects on fetal development. The objective of this study is to characterize the sulfation of environmental estrogens by SULT1C4 using molecular modeling and kinetic analysis. Native SULT1C4 was bacterially expressed with the pKK233‐2 bacterial expression vector and purified using affinity chromatography (Ni‐NTA) and DEAE‐ion exchange chromatography. To identify environmental estrogens sulfated by SULT1C4, we performed a combination approach, including modeling, pharmacophore analysis, and kinetics. Pharmacophore analysis helps to initially screen potential substrates by fitting possible substrates into a defined catalytic pocket; lead compounds were tested for sulfation by SULT1C4 using a [35S]PAPS thin layer chromatography assay. Daidzein and BPA appear to be better substrates for SULT1C4 than genistein. In silico substrate docking into the SULT1C4 active site did not identify daidzein as a substrate suggesting that the current model for SULT1C4 (PDB 2GWH) may not be predictive of substrate binding, or daidzein binds only to the unliganded (open) enzyme. Inhibition assays using [14C]‐1‐naphthol identified apigenin as an inhibitor of SULT1C4. Our data suggests that SULT1C4 sulfates selected environmental estrogen‐like compounds, including phytoestrogens and industrial chemicals, although some of these compounds may be non‐catalytic competitive inhibitors. Further characterization of SULT1C4's substrate reactivity is needed to gain a better understanding of its role in physiology and metabolism.Support or Funding InformationThis work was supported by NIH ES022606 and GM038953.
Caveolin‐3 Regulation of Cardiac Contractile Function is Facilitated by Enhanced Mitochondrial Efficiency
Authors: Busija Anna R. , Schilling Jan M. , Roth David M. , Insel Paul A. , Patel Hemal H. 
Published: November 2023

Caveolins (Cavs) are scaffolding proteins integral to caveolae, membrane lipid raft domains that compartmentalize numerous proteins and signaling molecules, including β‐adrenergic receptors (β‐ARs). Mice with cardiac myocyte (CM)‐specific overexpression of Cav‐3 (Cav‐3 OE) have more caveolae in CMs and are protected from ischemia‐reperfusion injury. Here, we tested the hypothesis that increases in Cav‐3 expression in CMs may alter β‐AR response, especially since data from our laboratory have shown mitochondria from Cav‐3 OE hearts are resistant to calcium loading and generate fewer reactive oxygen species. We reasoned that Cav‐3 OE, by compartmentation of interdependent signaling components of the β‐AR response in close approximation to mitochondria, may change responses to β‐AR activation. Cav‐3 OE hearts treated with the β‐AR agonist isoproterenol (Iso) have augmented inotropy (+dP/dt) and lusitropy (−dP/dt) compared to transgene negative hearts. CMs isolated from Cav‐3 OE mice have a 2‐fold increase in maximal Iso‐promoted cAMP production. However, isolated Cav‐3 OE CMs incubated with Iso show only a small increase in mitochondrial respiration. Thus, increased expression of Cav‐3 enhances Iso‐mediated positive inotropy without a proportional increase in mitochondrial respiration. We conclude that increased expression of Cav‐3 enhances cardiac function by enhancing responsivity of the heart and increasing mitochondrial oxygen efficiency in response to βAR stimuli, thus identifying an increase in Cav‐3 as a novel means to increase cardiac function in a manner that may not require increased oxygen consumption.Support or Funding InformationNIH HL107200, AHA 14PRE20460372.
Role Of The NLRP3/Inflammasome On Aldosterone‐Induced Vascular Damage
Authors: do Nascimento Thiago Bruder , Ferreira Nathanne , Zanotto Camila , Campos Eduardo , Ramalho Fernanda , Orlandin Isabela P. , Olivon Vânia Claudia , Neves Karla Bianca , Lopes Rhéure A.M. , Silva Carlos Alberto , Carlos Daniela , Mestriner Fabiola , Alves‐Filho José Carlos , de Cássia Tostes Rita 
Published: November 2023

Aldosterone (Aldo), a steroid with mineralocorticoid activity, is closely associated with vascular inflammation, remodeling and dysfunction. NLRP3/inflammasome, a member of cytoplasmic NOD‐like receptors, plays important role on inflammatory processes. We postulated that NLRP3/inflammasome mediates aldosterone‐induced vascular damage. To test this hypothesis we analyzed vascular structure and function and inflammatory profile of wild‐type (WT), NLRP3 knockout (NLRP3−/−) and Caspase‐1 knockout (Casp‐1−/−) mice treated with vehicle or Aldo (600 ug/kg/day for 14 days, via osmotic mini‐pump) while receiving 1% saline to drink. Aldo infusion did not change the final mean arterial pressure (WT: 101,9 ± 4,8 vs Aldo: 107,4 ± 5,1), but increased plasma levels of IL‐1β (WT: 588,0 ± 103 vs Aldo: 2333,9 ± 658,8* pg/mL, *P<0.05), as well as cleaved caspase‐1 and mature IL‐1β in the mesentery arteries, determined by ELISA and western blot, respectively, in WT mice. Apocynin (antioxidant agent) treatment prevented Aldo‐induced effects. NLRP3−/−and Casp‐1−/− mice were protected against Aldo‐induced vascular changes, i.e. they did not exhibit hypercontractility to phenylephrine [maximal effects (Emax) (WT: 75,2 ± 9,6 vs Aldo: 155,1 ± 22,1* % of KCl‐induced contractility, *P<0.05)] or reduced ACh‐induced relaxation upon Aldo treatment maximal effects [(Emax) (WT: 87,7 ± 2,1 vs Aldo: 34,2 ± 3,3*, % of relaxation, *P<0.05)]. Aldo infusion increased media:lumen ratio and media cross‐sectional area of resistance arteries, augmented RNA expression for inflammatory markers [(ICAM‐1 and VCAM‐1) 3 and 5‐folds, respectively] and the number of adhered macrophages in aortic segments. These Aldo‐induced changes were blunted in NLRP3−/−and Casp‐1−/− mice. To elucidate the role of NLRP3 in the vasculature, we performed bone marrow transplantation (BMT) from WT to NLRP3−/− mice (WTàNLRP3−/−), BMT chimeric mice were protected from Aldo‐induced vascular dysfunction and remodeling. All together these data suggest that NLRP3/inflammasome activation in the vasculature is oxidative stress‐dependent, and plays a crucial role on Aldo‐induced vascular dysfunction and remodeling.Support or Funding InformationFinancial Support: Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) e Coordenação de Aperfeiçoamento de Ensino Superior 88887.092495/2015‐00 (CAPES), Brazil.
The role of cytochrome P450 1B1 and its associated mid‐chain hydroxyeicosatetraenoic acids metabolites in the development of cellular hypertrophy induced by isoproterenol
Authors: El‐Kadi Ayman O.S. , Maayah Zaid H. 
Published: November 2023

Heart failure is the leading cause of death, with a prevalence of over 23 million worldwide. The lifetime risk of developing heart failure is one in five. Numerous experimental studies have demonstrated the role cytochrome P450 1B1 (CYP1B1) and its associated mid‐chain hydroxyeicosatetraenoic acids (mid‐chain HETEs) metabolites in the pathogenesis of heart failure and cardiac hypertrophy. However, the ability of isoproterenol (ISO) to induce cardiac hypertrophy through mid‐chain HETEs has not been investigated yet. Therefore, we hypothesized that ISO induced cardiac hypertrophy through the induction of CYP1B1 and its associated mid‐chain HETEs metabolites. To test our hypothesis, the human ventricular cardiomyocytes, RL‐14 cells, were treated with ISO in the presence and absence of tetramethoxystilbene (TMS), a selective CYP1B1 inhibitor. Thereafter, the cellular hypertrophy markers, cell volume and mid‐chain HETEs metabolites were determined using real‐time polymerase chain reaction, phase contrast imaging and liquid chromatography‐electron spray ionization‐mass spectrometry, respectively. Our results showed that ISO induced cellular hypertrophy in RL‐14 cells as evidenced by the significant induction of β‐myocin heavy chain/α‐myocin heavy chain (β‐MHC/α‐MHC) and cell volume. Interestingly, ISO‐induced cellular hypertrophy was associated with a proportional increase in the protein expression of CYP1B1 and the formation of mid‐chain HETEs metabolites. The direct evidence for the involvement of CYP1B1 in the ISO‐induced cellular hypertrophy was supported by the ability of TMS and CYP1B1 siRNA to significantly inhibit the ISO‐mediated the induction of β‐MHC/α‐MHC and the increase cell volume. Mechanistically, the protective effect of TMS against ISO‐induced cellular hypertrophy was mediated through the inhibition of NF‐κB signaling pathway. In conclusion, our study provides the first evidence that the inhibition of CYP1B1 and hence mid‐chain HETEs attenuate ISO‐induced cellular hypertrophy.Support or Funding InformationThis work was supported by a grant from the CIHR to A.O.S.E.