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Realistic simulation models for interventional radiology procedures are limited, including for placement of double-J stents (DJS). Utilizing a porcine kidney and empty saline bag (bladder), an ex-vivo model aiming to improve operator's knowledge and confidence in performing a DJS procedure was developed. Six faculty and fourteen trainees successfully operated on the model. Mean results for faculty vs. trainees are as follows: 2.2 ± 1.5 vs 2.4 ± 1.9 puncture attempts to access collecting system (p = 0.78), 14.5 ± 4.8 vs. 15.1 ± 6.0 minutes for insertion time (p = 0.84), 7.3 ± 2.8 vs. 10.3 ± 2.6 minutes for exchange time (p = 0.04), 8.48 ± 2.0 vs. 8.01 ± 2.6 minutes for fluoroscopy time (p = 0.70), and 5.7 ± 1.6 vs. 5.4 ± 2.0 mGy for absorbed air kerma (p = 0.77). Self-assessed knowledge and confidence with DJS placement increased for all participants following model use.
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Autophagy is an essential self-degradative and recycling mechanism that maintains cellular homeostasis. Estrogen receptor-related orphan receptors (ERRs) are fundamental in regulating cardiac metabolism and function. Previously, we showed that ERR agonists improve cardiac function in models of heart failure and induce autophagy in cardiomyocytes. Here, we characterized a mechanism by which ERRs induce the autophagy pathway in cardiomyocytes. Transcription factor EB (TFEB) is a master regulator of the autophagy-lysosome pathway and has been shown to be important in cardiac autophagy. We discovered that TFEB is a direct ERR target gene whose expression is induced by ERR agonists. Activation of ERR results in increased TFEB expression in both neonatal rat ventricular myocytes and C2C12 myoblast cells. ERR-dependent increases in TFEB expression result in increased expression of an array of TFEB target genes, which are critical for the stimulation of autophagy. Pharmacologically targeting ERR is a promising potential method for the treatment of many diseases where stimulation of autophagy may be therapeutic, including heart failure. Significance Statement Estrogen receptor-related receptor agonists function as exercise mimetics and also display efficacy in animal models of metabolic disease, obesity, and heart failure.
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The mitochondrial pyruvate carrier (MPC) plays a role in numerous diseases including neurodegeneration, metabolically dependent cancers, and the development of insulin resistance. Several previous studies in genetic mouse models or with existing inhibitors suggest that inhibition of the MPC could be used as a viable therapeutic strategy in these diseases. However, the MPC's structure is unknown, making it difficult to screen for and develop therapeutically viable inhibitors. Currently known MPC inhibitors would make for poor drugs due to their poor pharmacokinetic properties, or in the case of the thiazolidinediones (TZDs), off-target specificity for peroxisome-proliferator activated receptor gamma (PPARγ) leads to unwanted side effects. In this study, we develop several structural models for the MPC heterodimer complex and investigate the chemical interactions required for the binding of these known inhibitors to MPC and PPARγ. Based on these models, the MPC most likely takes on outward-facing (OF) and inward-facing (IF) conformations during pyruvate transport, and inhibitors likely plug the carrier to inhibit pyruvate transport. Although some chemical interactions are similar between MPC and PPARγ binding, there is likely enough difference to reduce PPARγ specificity for future development of novel, more specific MPC inhibitors.
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Bile leaks arise from various causes such as trauma, complications after hepatobiliary surgery, and intrahepatic malignancies or their associated liver-directed treatments. Bile leaks can result in significant morbidity and mortality. Delayed diagnosis is not uncommon due to nonspecific manifestations; therefore, a high clinical suspicion is needed. A multidisciplinary approach for treatment of biliary leaks with prompt referral to tertiary care centers with experienced hepatobiliary surgeons, advanced endoscopists, and interventional radiologists is needed to address these challenging complications. Management of biliary leaks can range from conservative management to open surgical repair. Minimally invasive procedures play a crucial role in biliary leak treatment, and the interventional radiologist can help guide appropriate management on the basis of a clear understanding of the pathophysiology of biliary leaks and a current knowledge of the armamentarium of treatment options. In most cases, a simple diversion of bile to decompress the biliary system may prove effective. However, persistent and high-output biliary leaks require delineation of the source with tailored treatment options to control the leak. This may be done by additional diversions, occluding the source, reestablishing connections, or using a combination of therapies to bridge to more definitive surgical interventions. The authors describe the different treatment options and emphasize the role of interventional radiology. ©RSNA, 2024.
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Complicações Pós-Operatórias , Humanos , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/terapia , Doenças Biliares/diagnóstico por imagem , Doenças Biliares/terapia , Fístula Anastomótica/diagnóstico por imagem , Fístula Anastomótica/terapia , Equipe de Assistência ao PacienteRESUMO
Mechanobiology is a rapidly advancing field, with growing evidence that mechanical signaling plays key roles in health and disease. To accelerate mechanobiology-based drug discovery, novel in vitro systems are needed that enable mechanical perturbation of cells in a format amenable to high throughput screening. Here, both a mechanical stretch device and 192-well silicone flexible linear stretch plate were designed and fabricated to meet high throughput technology needs for cell stretch-based applications. To demonstrate the utility of the stretch plate in automation and screening, cell dispensing, liquid handling, high content imaging, and high throughput sequencing platforms were employed. Using this system, an assay was developed as a biological validation and proof-of-concept readout for screening. A mechano-transcriptional stretch response was characterized using focused gene expression profiling measured by RNA-mediated oligonucleotide Annealing, Selection, and Ligation with Next-Gen sequencing. Using articular chondrocytes, a gene expression signature containing stretch responsive genes relevant to cartilage homeostasis and disease was identified. The possibility for integration of other stretch sensitive cell types (e.g., cardiovascular, airway, bladder, gut, and musculoskeletal), in combination with alternative phenotypic readouts (e.g., protein expression, proliferation, or spatial alignment), broadens the scope of high throughput stretch and allows for wider adoption by the research community. This high throughput mechanical stress device fills an unmet need in phenotypic screening technology to support drug discovery in mechanobiology-based disease areas.
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PURPOSE: To utilize a novel ex vivo perfused human renal model and quantify microwave ablation (MWA) size differences in renal tissue when combining MWA with transarterial embolization (TAE). MATERIALS AND METHODS: Human kidneys (n = 5) declined for transplantation were obtained and connected to a fluoroscopy-compatible ex vivo perfusion system. Two ablations-1 standard MWA and 1 TAE-MWA-were performed in each kidney for 2 minutes at 100 W using a MWA system (Solero Angiodynamics). MWA alone was performed in the upper pole. In the lower pole, MWA was performed after TAE with 40-90 µm radiopaque microspheres to achieve angiographic stasis. Ablation zones of coagulative necrosis were sectioned along the long axis and segmented for maximal short-axis diameter (SAD) and long-axis diameter (LAD) measurements. RESULTS: A total of 10 ablations (5 MWAs and 5 TAE-MWAs) were performed in 5 human kidneys. TAE-MWA resulted in significantly increased SAD, LAD, volume, and sphericity compared with standard MWA ± SD, with mean measurements as follows (5 standard MWAs ± SD vs 5 TAE-MWAs ± SD, 2-tailed t-test): (a) SAD, 1.8 cm (SD ± 0.1) versus 2.5 cm (SD ± 0.1) (P < .001); (b) LAD, 2.9 cm (SD ± 0.3) versus 3.2 cm (SD ± 0.1) (P = .039); (c) volume, 5.0 mL (SD ± 0.5) versus 11.0 mL (SD ± 0.7) (P < .001); and (d) sphericity, 0.4 (SD ± 0.2) versus 0.6 (SD ± 0.1) (P = .049). Histology demonstrated no differences in TAE-MWA other than concentrated microspheres. CONCLUSIONS: This ex vivo human kidney perfusion model confirmed that combined MWA-TAE significantly increased ablation size and spherical shape compared with MWA alone.
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Multidrug-resistant Acinetobacter baumannii is a serious threat pathogen rapidly spreading in clinics and causing a range of complicated human infections. The major contributor to A. baumannii antibiotic resistance is the overproduction of AdeIJK and AdeABC multidrug efflux pumps of the resistance-nodulation-division (RND) superfamily of proteins. The dominant role of efflux in antibiotic resistance and the relatively high permeability of the A. baumannii outer membrane to amphiphilic compounds make this pathogen a promising target for the discovery of clinically relevant efflux pump inhibitors. In this study, we identified 4,6-diaminoquoniline analogs with inhibitory activities against A. baumannii AdeIJK efflux pump and followed up on these compounds with a focused synthetic program to improve the target specificity and to reduce cytotoxicity. We identified several candidates that potentiate antibacterial activities of antibiotics erythromycin, tetracycline, and novobiocin not only in the laboratory antibiotic susceptible strain A. baumannii ATCC17978 but also in multidrug-resistant clinical isolates AB5075 and AYE. The best analogs potentiated the activities of antibiotics in low micromolar concentrations, did not have antibacterial activities on their own, inhibited AdeIJK-mediated efflux of its fluorescent substrate ethidium ion, and had low cytotoxicity in A549 human lung epithelial cells.
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Infecções por Acinetobacter , Acinetobacter baumannii , Antibacterianos , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Acinetobacter baumannii/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Infecções por Acinetobacter/microbiologia , Infecções por Acinetobacter/tratamento farmacológico , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Células A549 , Sinergismo FarmacológicoRESUMO
Immune checkpoint inhibitors (ICIs), have emerged to the forefront of management for various advanced cancers, such as melanoma, lung cancer and renal cell carcinoma. Immune checkpoints such as CTLA-4 and PD-1 serve to inhibit T cell activation and signaling; therefore through blockade of these pathways, ICIs promote anti-tumour immune activation. However, as a result of T cell disinhibition, ICIs have been reported to cause immune related adverse events (irAEs) affecting numerous organ systems. One of the most serious and potentially life-threatening irAE is inflammatory myositis. Myositis, which generally presents with progressive proximal muscle weakness and elevated serum creatine kinase (CK), has been reported in <1% of patients who have received ICI therapy. A rare cause of elevated CK is adrenal insufficiency, which has been reported in up to 6% of ICI users. Here we report a case of ICI-related hypophysitis related myopathy that was initially misdiagnosed as ICI-associated inflammatory myositis. This case illustrates the importance of considering a wide differential when assessing hyperCKemia in the setting of ICI use.
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PURPOSE: Acquired resistance to immune checkpoint blockers (ICBs) is a major barrier in cancer treatment, emphasizing the need for innovative strategies. Dectin-1 (gene Clec7a) is a C-type lectin receptor best known for its ability to recognize ß-glucan-rich structures in fungal cell walls. While Dectin-1 is expressed in myeloid cells and tumor cells, its significance in cancer remains the subject of controversy. METHODS: Using Celc7a-/- mice and curdlan administration to stimulate Dectin-1 signaling, we explored its impact. VISTA KO mice were employed to assess VISTA's role, and bulk RNAseq analyzed curdlan effects on neutrophils. RESULTS: Our findings reveal myeloid cells as primary Dectin-1 expressing cells in the tumor microenvironment (TME), displaying an activated phenotype. Strong Dectin-1 co-expression/co-localization with VISTA and PD-L1 in TME myeloid cells was observed. While Dectin-1 deletion lacked protective effects, curdlan stimulation significantly curtailed B16-F10 tumor progression. RNAseq and pathway analyses supported curdlan's role in triggering a cascade of events leading to increased production of pro-inflammatory mediators, potentially resulting in the recruitment and activation of immune cells. Moreover, we identified a heterogeneous subset of Dectin-1+ effector T cells in the TME. Similar to mice, human myeloid cells are the prominent cells expressing Dectin-1 in cancer patients. CONCLUSION: Our study proposes Dectin-1 as a potential adjunctive target with ICBs, orchestrating a comprehensive engagement of innate and adaptive immune responses in melanoma. This innovative approach holds promise for overcoming acquired resistance to ICBs in cancer treatment, offering avenues for further exploration and development.
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Heat shock protein 90 (Hsp90) is a molecular chaperone important for maintaining protein homeostasis (proteostasis) in the cell. Hsp90 inhibitors are being explored as cancer therapeutics because of their ability to disrupt proteostasis. Inhibiting Hsp90 increases surface density of the immunological receptor Major Histocompatibility Complex 1 (MHC1). Here we show that this increase occurs across multiple cancer cell lines and with both cytosol-specific and pan-Hsp90 inhibitors. We demonstrate that Hsp90 inhibition also alters surface expression of both IFNGR and PD-L1, two additional immunological receptors that play a significant role in anti-tumour or anti-immune activity in the tumour microenvironment. Hsp90 also negatively regulates IFN-γ activity in cancer cells, suggesting it has a unique role in mediating the immune system's response to cancer. Our data suggests a strong link between Hsp90 activity and the pathways that govern anti-tumour immunity. This highlights the potential for the use of an Hsp90 inhibitor in combination with another currently available cancer treatment, immune checkpoint blockade therapy, which works to prevent immune evasion of cancer cells. Combination checkpoint inhibitor therapy and the use of an Hsp90 inhibitor may potentiate the therapeutic benefits of both treatments and improve prognosis for cancer patients.
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The ability Gram-negative pathogens have at adapting and protecting themselves against antibiotics has increasingly become a public health threat. Data-driven models identifying molecular properties that correlate with outer membrane (OM) permeation and growth inhibition while avoiding efflux could guide the discovery of novel classes of antibiotics. Here we evaluate 174 molecular descriptors in 1260 antimicrobial compounds and study their correlations with antibacterial activity in Gram-negative Pseudomonas aeruginosa. The descriptors are derived from traditional approaches quantifying the compounds' intrinsic physicochemical properties, together with, bacterium-specific from ensemble docking of compounds targeting specific MexB binding pockets, and all-atom molecular dynamics simulations in different subregions of the OM model. Using these descriptors and the measured inhibitory concentrations, we design a statistical protocol to identify predictors of OM permeation/inhibition. We find consistent rules across most of our data highlighting the role of the interaction between the compounds and the OM. An implementation of the rules uncovered in our study is shown, and it demonstrates the accuracy of our approach in a set of previously unseen compounds. Our analysis sheds new light on the key properties drug candidates need to effectively permeate/inhibit P. aeruginosa, and opens the gate to similar data-driven studies in other Gram-negative pathogens.
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Giant colonic diverticulum (GCD) is a well-recognized but infrequently encountered disease in clinical practice. GCD is its own unique entity and differs from commonly seen diverticular disease in both size and management. Initial clinical presentation is typically associated with diverticulitis and symptoms such as abdominal pain, fever, nausea, vomiting, rectal bleeding, or even a palpable abdominal mass. Surgery is the recommended treatment option largely due to the risk of associated complications including colonic perforation. We describe the case of a 56-year-old female diagnosed with a sigmoid GCD that was successfully stabilized medically and definitively treated surgically.
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BACKGROUND & AIMS: Existing skeletal muscle index (SMI) thresholds for sarcopenia are inconsistent, and do not reflect severity of depletion. In this study we aimed to define criterion values for moderate and severe skeletal muscle depletion based on the risk of mortality in a population of patients with head and neck cancer (HNC). Additionally, we aimed to identify clinical and demographic predictors of skeletal muscle depletion, evaluate the survival impact of skeletal muscle depletion in patients with minimal nutritional risk or good performance status, and finally, benchmarking SMI values of patients with HNC against healthy young adults. METHODS: Population cohort of 1231 consecutive patients and external validation cohorts with HNC had lumbar SMI measured by cross-sectional imaging. Optimal stratification determined sex-specific thresholds for 2-levels of SMI depletion (Class I and II) based on overall survival (OS). Adjusted multivariable regression analyses (tumor site, stage, performance status, age, sex, dietary intake, weight loss) determined relationships between 2-levels of SMI depletion and OS. RESULTS: Mean SMI (cm2/m2) was 51.7 ± 9.9 (males) and 39.8 ± 7.1 (females). The overall and sex-specific population demonstrated an increased risk of mortality associated with decreasing SMI. Sex-specific SMI (cm2/m2) depletion thresholds for 2-levels of muscle depletion determined by optimal stratification for males and females, respectively (male: 45.2-37.5, and <37.5; female: 40.9-34.2, and <34.2). In the overall population, Normal SMI, Class I and II SMI depletion occurred in 65.0%, 24.0%, and 11.0%, respectively. Median OS was: Normal SMI (114 months, 95% CI, 97.1-130.8); Class I SMI Depletion (42 months, 95% CI, 28.5-55.4), and Class II SMI Depletion (15 months, 95% CI, 9.8-20.1). Adjusted multivariable analysis compared with Normal SMI (reference), Class I SMI Depletion (HR, 1.49; 95% CI, 1.18-1.88; P < .001), Class II SMI Depletion (HR, 1.91; 95% CI, 1.42-2.58; P < .001). CONCLUSIONS: Moderate and severe SMI depletion demonstrate discrimination in OS in patients with HNC. Moderate and severe SMI depletion is prevalent in patients with minimal nutrition risk and good performance status. Benchmarking SMI values against healthy young adults exemplifies the magnitude of SMI depletion in patients with HNC and may be a useful method in standardizing SMI assessment.
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Neoplasias de Cabeça e Pescoço , Sarcopenia , Adulto Jovem , Humanos , Masculino , Feminino , Sarcopenia/etiologia , Tomografia Computadorizada por Raios X/métodos , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/patologia , Neoplasias de Cabeça e Pescoço/complicações , Neoplasias de Cabeça e Pescoço/patologia , Estudos Retrospectivos , PrognósticoRESUMO
Locally advanced cutaneous squamous cell carcinoma can erode into blood vessels, leading to vascular blowout, requiring emergent surgical intervention. We describe a first case of this disease complication which was effectively managed with endovascular stenting as a bridge to effective systemic and regional therapy. We discuss the efficacy of this staged approach which is novel and timely in a clinical environment of increasingly effective systemic therapies.
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Carcinoma de Células Escamosas , Neoplasias Cutâneas , Stents , Humanos , Carcinoma de Células Escamosas/terapia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgia , Neoplasias Cutâneas/terapia , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/instrumentação , Masculino , Pessoa de Meia-Idade , IdosoRESUMO
CSB (Cockayne syndrome group B) and SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent, regulator of chromatin, subfamily A-like 1) are DNA translocases that belong to the SNF2 helicase family. They both are enriched at stalled replication forks. While SMARCAL1 is recruited by RPA32 to stalled forks, little is known about whether RPA32 also regulates CSB's association with stalled forks. Here, we report that CSB directly interacts with RPA, at least in part via a RPA32C-interacting motif within the N-terminal region of CSB. Modeling of the CSB-RPA32C interaction suggests that CSB binds the RPA32C surface previously shown to be important for binding of UNG2 and SMARCAL1. We show that this interaction is necessary for promoting fork slowing and fork degradation in BRCA2-deficient cells but dispensable for mediating restart of stalled forks. CSB competes with SMARCAL1 for RPA32 at stalled forks and acts non-redundantly with SMARCAL1 to restrain fork progression in response to mild replication stress. In contrast to CSB stimulated restart of stalled forks, SMARCAL1 inhibits restart of stalled forks in BRCA2-deficient cells, likely by suppressing BIR-mediated repair of collapsed forks. Loss of CSB leads to re-sensitization of SMARCAL1-depleted BRCA2-deficient cells to chemodrugs, underscoring a role of CSB in targeted cancer therapy.
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Proteína BRCA2 , DNA Helicases , Enzimas Reparadoras do DNA , Replicação do DNA , Proteínas de Ligação a Poli-ADP-Ribose , Proteína de Replicação A , DNA Helicases/metabolismo , DNA Helicases/genética , Humanos , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteína BRCA2/metabolismo , Proteína BRCA2/genética , Enzimas Reparadoras do DNA/metabolismo , Enzimas Reparadoras do DNA/genética , Proteína de Replicação A/metabolismo , Proteína de Replicação A/genética , Ligação Proteica , Linhagem Celular Tumoral , Reparo do DNARESUMO
BACKGROUND: Myeloproliferative neoplasms (MPNs) are a group of disorders of clonal haemopoiesis associated with an inherent risk of arterial and venous thrombotic complications. The prevalence of thrombotic complications and the impact of cardiovascular risk factors (CVRFs) in contemporary patient cohorts within the current era of MPN treatments have not been completely defined. OBJECTIVES: We aim to characterise the cardiovascular risk of patients with MPN by identifying the prevalence of CVRFs and describing the pattern of thrombotic events. We also aim to utilise the QRISK3 algorithm, which is a validated model used to estimate an individual's risk of developing cardiovascular disease, to further phenotype this cohort of patients. METHODS: We perform a retrospective analysis on a single-centre cohort of 438 patients with MPN. RESULTS: MPN patients continue to carry a high burden of vascular morbidity with a prevalence of arterial thrombotic events in 15.8 % (69/438) and venous thrombotic events in 13.2 % (58/438) of the cohort. The novel use of the QRISK3 algorithm, which showed a mean score of 13.7 % across the MPN population, provides further evidence to suggest an increased cardiovascular risk in MPN patients. CONCLUSION: With an increased risk of cardiovascular disease in patients with MPN, we propose an integrated approach between primary and specialised healthcare services using risk stratification tools such as QRISK3, which will allow aggressive optimisation of CVRFs to prevent thrombosis and reduce the overall morbidity and mortality in patients with MPN.
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Doenças Cardiovasculares , Transtornos Mieloproliferativos , Neoplasias , Trombose , Humanos , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/complicações , Estudos Retrospectivos , Fatores de Risco , Transtornos Mieloproliferativos/complicações , Transtornos Mieloproliferativos/epidemiologia , Transtornos Mieloproliferativos/genética , Trombose/etiologia , Trombose/genética , Fatores de Risco de Doenças Cardíacas , Neoplasias/complicaçõesRESUMO
BACKGROUND: Junipers (Juniperus spp.) are woody native, invasive plants that have caused encroachment problems in the U.S. western rangelands, decreasing forage productivity and biodiversity. A potential solution to this issue is using goats in targeted grazing programs. However, junipers, which grow in dry and harsh environmental conditions, use chemical defense mechanisms to deter herbivores. Therefore, genetically selecting goats for increased juniper consumption is of great interest for regenerative rangeland management. In this context, the primary objectives of this study were to: 1) estimate variance components and genetic parameters for predicted juniper consumption in divergently selected Angora (ANG) and composite Boer x Spanish (BS) goat populations grazing on Western U.S. rangelands; and 2) to identify genomic regions, candidate genes, and biological pathways associated with juniper consumption in these goat populations. RESULTS: The average juniper consumption was 22.4% (± 18.7%) and 7.01% (± 12.1%) in the BS and ANG populations, respectively. The heritability estimates (realized heritability within parenthesis) for juniper consumption were 0.43 ± 0.02 (0.34 ± 0.06) and 0.19 ± 0.03 (0.13 ± 0.03) in BS and ANG, respectively, indicating that juniper consumption can be increased through genetic selection. The repeatability values of predicted juniper consumption were 0.45 for BS and 0.28 for ANG. A total of 571 significant SNP located within or close to 231 genes in BS, and 116 SNP related to 183 genes in ANG were identified based on the genome-wide association analyses. These genes are primarily associated with biological pathways and gene ontology terms related to olfactory receptors, intestinal absorption, and immunity response. CONCLUSIONS: These findings suggest that juniper consumption is a heritable trait of polygenic inheritance influenced by multiple genes of small effects. The genetic parameters calculated indicate that juniper consumption can be genetically improved in both goat populations.
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Juniperus , Animais , Juniperus/genética , Cabras/genética , Estudo de Associação Genômica Ampla , Espectroscopia de Luz Próxima ao Infravermelho , Patrimônio GenéticoRESUMO
The hydrolytic activity of the ATP synthase in bovine mitochondria is inhibited by a protein called IF1, but bovine IF1 has no effect on the synthetic activity of the bovine enzyme in mitochondrial vesicles in the presence of a proton motive force. In contrast, it has been suggested based on indirect observations that human IFI inhibits both the hydrolytic and synthetic activities of the human ATP synthase and that the activity of human IF1 is regulated by the phosphorylation of Ser-14 of mature IF1. Here, we have made both human and bovine IF1 which are 81 and 84 amino acids long, respectively, and identical in 71.4% of their amino acids and have investigated their inhibitory effects on the hydrolytic and synthetic activities of ATP synthase in bovine submitochondrial particles. Over a wide range of conditions, including physiological conditions, both human and bovine IF1 are potent inhibitors of ATP hydrolysis, with no effect on ATP synthesis. Also, substitution of Ser-14 with phosphomimetic aspartic and glutamic acids had no effect on inhibitory properties, and Ser-14 is not conserved throughout mammals. Therefore, it is unlikely that the inhibitory activity of mammalian IF1 is regulated by phosphorylation of this residue.
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Trifosfato de Adenosina , Mitocôndrias , Proteínas Mitocondriais , ATPases Mitocondriais Próton-Translocadoras , Animais , Bovinos , Humanos , Trifosfato de Adenosina/biossíntese , Trifosfato de Adenosina/metabolismo , Aminoácidos/metabolismo , Hidrólise , Mitocôndrias/enzimologia , ATPases Mitocondriais Próton-Translocadoras/genética , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Serina/metabolismo , FosforilaçãoRESUMO
Physical exercise induces physiologic adaptations and is effective at reducing the risk of premature death from all causes. Pharmacological exercise mimetics may be effective in the treatment of a range of diseases including obesity and metabolic syndrome. Previously, we described the development of SLU-PP-332, an agonist for the estrogen-related receptor (ERR)α, ß, and γ nuclear receptors that activates an acute aerobic exercise program. Here we examine the effects of this exercise mimetic in mouse models of obesity and metabolic syndrome. Diet-induced obese or ob/ob mice were administered SLU-PP-332, and the effects on a range of metabolic parameters were assessed. SLU-PP-332 administration mimics exercise-induced benefits on whole-body metabolism in mice including increased energy expenditure and fatty acid oxidation. These effects were accompanied by decreased fat mass accumulation. Additionally, the ERR agonist effectively reduced obesity and improved insulin sensitivity in models of metabolic syndrome. Pharmacological activation of ERR may be an effective method to treat metabolic syndrome and obesity. SIGNIFICANCE STATEMENT: An estrogen receptor-related orphan receptor agonist, SLU-PP-332, with exercise mimetic activity, holds promise as a therapeutic to treat metabolic diseases by decreasing fat mass in mouse models of obesity.