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Frontiers in Endocrinology 2024During thermogenesis, adipose tissue (AT) becomes more active and enhances oxidative metabolism. The promotion of this process in white AT (WAT) is called "browning"...
INTRODUCTION
During thermogenesis, adipose tissue (AT) becomes more active and enhances oxidative metabolism. The promotion of this process in white AT (WAT) is called "browning" and, together with the brown AT (BAT) activation, is considered as a promising approach to counteract obesity and metabolic diseases. Transient receptor potential cation channel, subfamily M, member 2 (TRPM2), is an ion channel that allows extracellular Ca influx into the cytosol, and is gated by adenosine diphosphate ribose (ADPR), produced from NAD degradation. The aim of this study was to investigate the relevance of TRPM2 in the regulation of energy metabolism in BAT, WAT, and liver during thermogenesis.
METHODS
Wild type (WT) and mice were exposed to 6°C and BAT, WAT and liver were collected to evaluate mRNA, protein levels and ADPR content. Furthermore, O consumption, CO production and energy expenditure were measured in these mice upon thermogenic stimulation. Finally, the effect of the pharmacological inhibition of TRPM2 was assessed in primary adipocytes, evaluating the response upon stimulation with the β-adrenergic receptor agonist CL316,243.
RESULTS
mice displayed lower expression of browning markers in AT and lower energy expenditure in response to thermogenic stimulus, compared to WT animals. gene overexpression was observed in WAT, BAT and liver upon cold exposure. In addition, ADPR levels and mono/poly-ADPR hydrolases expression were higher in mice exposed to cold, compared to control mice, likely mediating ADPR generation.
DISCUSSION
Our data indicate TRPM2 as a fundamental player in BAT activation and WAT browning. TRPM2 agonists may represent new pharmacological strategies to fight obesity.
Topics: Mice; Animals; TRPM Cation Channels; Adipose Tissue, Brown; Adipose Tissue, White; Obesity; Thermogenesis
PubMed: 38390373
DOI: 10.3389/fendo.2023.1251351 -
Research and Practice in Thrombosis and... Jan 2024Active and passive biomechanical properties of platelets contribute substantially to thrombus formation. Actomyosin contractility drives clot contraction required for...
BACKGROUND
Active and passive biomechanical properties of platelets contribute substantially to thrombus formation. Actomyosin contractility drives clot contraction required for stabilizing the hemostatic plug. Impaired contractility results in bleeding but is difficult to detect using platelet function tests.
OBJECTIVES
To determine how diminished myosin activity affects platelet functions, including and beyond clot contraction.
METHODS
Using the myosin IIA-specific pharmacologic inhibitor blebbistatin, we modulated myosin activity in platelets from healthy donors and systematically characterized platelet responses at various levels of inhibition by interrogating distinct platelet functions at each stage of thrombus formation using a range of complementary assays.
RESULTS
Partial myosin IIA inhibition neither affected platelet von Willebrand factor interactions under arterial shear nor platelet spreading and cytoskeletal rearrangements on fibrinogen. However, it impacted stress fiber formation and the nanoarchitecture of cell-matrix adhesions, drastically reducing and limiting traction forces. Higher blebbistatin concentrations impaired platelet adhesion under flow, altered mechanosensing at lamellipodia edges, and eliminated traction forces without affecting platelet spreading, α-granule secretion, or procoagulant platelet formation. Unexpectedly, myosin IIA inhibition reduced calcium influx, dense granule secretion, and platelet aggregation downstream of glycoprotein (GP)VI and limited the redistribution of GPVI on the cell membrane, whereas aggregation induced by adenosine diphosphate or arachidonic acid was unaffected.
CONCLUSION
Our findings highlight the importance of both active contractile and passive crosslinking roles of myosin IIA in the platelet cytoskeleton. They support the hypothesis that highly contractile platelets are needed for hemostasis and further suggest a supportive role for myosin IIA in GPVI signaling.
PubMed: 38379711
DOI: 10.1016/j.rpth.2024.102322 -
Journal of Cancer 2024Olaparib and niraparib (poly adenosine diphosphate [ADP]-ribose polymerase [PARP] inhibitors) have significant antitumor action in patients with ovarian cancer....
Olaparib and niraparib (poly adenosine diphosphate [ADP]-ribose polymerase [PARP] inhibitors) have significant antitumor action in patients with ovarian cancer. However, the incidence of nausea and vomiting among patients on these drugs in clinical trials is rather high. There are no guidelines on antiemetic treatment for nausea caused by oral anticancer agents. This study aimed to investigate the incidence of nausea and vomiting caused by PARP inhibitors and the actual situation of antiemetic therapy in patients with gynecologic cancer. Patients with gynecologic cancer who were scheduled to receive PARP inhibitors were enrolled. Data on PARP inhibitor-induced nausea and vomiting were collected from patient diaries for 21 days. The primary endpoint was the incidence of vomiting during the 21 days after starting olaparib and niraparib. Overall, between January 2020 and March 2023, 134 patients were enrolled. Of the 129 patients who were evaluated, 28 (21.7%) received prophylactic antiemetics for 21 days, and 101 (78.3%) did not. The overall incidence of PARP inhibitor-induced vomiting was 16.3%. The incidence of vomiting in the group that did not receive antiemetic prophylaxis was 13.9%. On dividing the group that did not receive antiemetic prophylaxis into the olaparib and niraparib subgroups, the incidence of vomiting was found to be 18.6% for the olaparib group and 10.3% for the niraparib group. The incidence of emesis without antiemetic prophylaxis among patients on olaparib and niraparib ranged from 10% to 30%. Therefore, olaparib and niraparib can be classified in the low emetogenic risk and prophylactic antiemetic therapy at the time of treatment initiation may be unnecessary.
PubMed: 38370375
DOI: 10.7150/jca.91675 -
Heart, Lung & Circulation May 2024Increased cancer survivorship represents a remarkable achievement for modern medicine. Unfortunately, cancer treatments have inadvertently contributed to cardiovascular...
BACKGROUND
Increased cancer survivorship represents a remarkable achievement for modern medicine. Unfortunately, cancer treatments have inadvertently contributed to cardiovascular (CV) damage, significantly threatening the health and quality of life of patients living with, through and beyond cancer. Without understanding the mechanisms, including whether the cardiotoxicity is due to the direct or indirect effects on cardiomyocytes, prevention and management of cardiotoxicity can pose challenges in many patients. To date, the cardiotoxicity profiles of most of the chemotherapy drugs are still poorly understood.
AIM
To conduct a pilot study to investigate the direct effects of a range of cancer therapies on cardiomyocyte viability.
METHODS
Primary human cardiomyocytes (HCM) were cultured and seeded into 96-well culture plates. A total of 35 different Food and Drug Administration-approved anti-cancer drugs were added to the HCM cells with a concentration of 1uM for 72 hours. The viability of HCMs was determined using CellTitre-Glo. The experiments were repeated at least three times for each drug with HCMs of different passages.
RESULTS
We identified 15 anti-cancer agents that significantly reduced HCM viability. These drugs were: (1) anthracyclines (daunorubicin [HCM viability, mean %±standard error, 13.7±3.2%], epirubicin [47.6±5.3%]), (2) antimetabolite (azacitidine [67.1±2.4%]), (3) taxanes (paclitaxel [60.2±3.0%]), (4) protein kinase inhibitors (lapatinib [49.8±7.0%], ponatinib [42.4±9.0%], pemigatinib [68.1±2.3%], sorafenib [52.9±10.6%], nilotinib [64.4±4.5%], dasatinib [38.5±3.6%]), (5) proteasome inhibitors (ixazomib citrate [65.4±7.2%]), (6) non-selective histone-deacetylase inhibitor (panobinostat [19.1±4.1%]), poly adenosine diphosphate-ribose polymerase inhibitor (olaparib [68.2±1.7%]) and (7) vinca alkaloids (vincristine [44.6±7.4%], vinblastine [31.2±3.9%]).
CONCLUSIONS
In total, 15 of the 35 commercially available anti-cancer drugs have direct cardiotoxic effects on HCM. Some of those, have not been associated with clinical cardiotoxicity, while others, known to be cardiotoxic do not appear to mediate it via direct effects on cardiomyocytes. More detailed investigations of the effects of cancer therapies on various cardiovascular cells should be performed to comprehensively determine the mechanisms of cardiotoxicity.
Topics: Humans; Myocytes, Cardiac; Antineoplastic Agents; Cell Survival; Cardiotoxicity; Neoplasms; Cells, Cultured; Pilot Projects; Female
PubMed: 38365500
DOI: 10.1016/j.hlc.2024.01.013 -
Nucleic Acids Research Apr 2024Double-strand DNA breaks are the severest type of genomic damage, requiring rapid response to ensure survival. RecBCD helicase in prokaryotes initiates processive and...
Double-strand DNA breaks are the severest type of genomic damage, requiring rapid response to ensure survival. RecBCD helicase in prokaryotes initiates processive and rapid DNA unzipping, essential for break repair. The energetics of RecBCD during translocation along the DNA track are quantitatively not defined. Specifically, it's essential to understand the mechanism by which RecBCD switches between its binding states to enable its translocation. Here, we determine, by systematic affinity measurements, the degree of coupling between DNA and nucleotide binding to RecBCD. In the presence of ADP, RecBCD binds weakly to DNA that harbors a double overhang mimicking an unwinding intermediate. Consistently, RecBCD binds weakly to ADP in the presence of the same DNA. We did not observe coupling between DNA and nucleotide binding for DNA molecules having only a single overhang, suggesting that RecBCD subunits must both bind DNA to 'sense' the nucleotide state. On the contrary, AMPpNp shows weak coupling as RecBCD remains strongly bound to DNA in its presence. Detailed thermodynamic analysis of the RecBCD reaction mechanism suggests an 'energetic compensation' between RecB and RecD, which may be essential for rapid unwinding. Our findings provide the basis for a plausible stepping mechanism' during the processive translocation of RecBCD.
Topics: Exodeoxyribonuclease V; Binding Sites; DNA; Protein Binding; Adenosine Diphosphate; Nucleotides; Escherichia coli Proteins; Escherichia coli; DNA Repair
PubMed: 38364872
DOI: 10.1093/nar/gkae108 -
Gynecologic Oncology Reports Feb 2024Poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi) are metabolized either via carboxylesterase (niraparib) or cytochrome P450 (CYP) enzymes (olaparib...
Cytochrome P450 inhibitor/inducer treatment patterns among patients in the United States with advanced ovarian cancer who were prescribed or were eligible for poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors in the first-line maintenance setting.
Poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi) are metabolized either via carboxylesterase (niraparib) or cytochrome P450 (CYP) enzymes (olaparib and rucaparib). Patients with advanced epithelial ovarian cancer (aOC) who receive concomitant medication metabolized by the CYP system may be at risk of drug-drug interactions impacting PARPi efficacy and tolerability. This study investigated CYP inhibitor/inducer treatment patterns in the first-line maintenance (1Lm) setting for patients with aOC. This retrospective cohort study used de-identified databases of US patients with aOC. Eligible patients were aged ≥18 years, diagnosed with aOC between January 2015-March 2021, and received CYP inhibitors/inducers during 1Lm PARPi initiation or the eligibility window (90 days before to 120 days after first-line platinum-based therapy ended [index]). Patients were either prescribed 1Lm PARPi monotherapy (PARPi cohort) or were not prescribed any 1Lm therapy within 120 days post-index (PARPi-eligible cohort). Strong/moderate CYP inhibitors/inducers were defined as area under the plasma concentration-time curve ratio (AUCR) ≥2 or clearance ratio (CL) ≤0.5 (inhibitors), and AUCR ≤0.5 or CL ratio ≥2 (inducers). Of 1411 patients (median age 63), 158 were prescribed PARPis and 1253 were PARPi-eligible. Among the PARPi cohort, 46.2%, 48.7%, and 5.1% were prescribed niraparib, olaparib, and rucaparib, respectively. For patients prescribed olaparib or rucaparib, 42.4% also received strong and/or moderate CYP inhibitors/inducers. This real-world study indicated a considerable proportion of patients received strong and/or moderate CYP inhibitors/inducers and were prescribed PARPis metabolized by the CYP system. Understanding potential impacts of concomitant CYP inhibitors/inducers on PARPi efficacy and safety is warranted.
PubMed: 38362364
DOI: 10.1016/j.gore.2024.101332 -
Research (Washington, D.C.) 2024The ALPK1 (alpha-kinase 1)-TIFA (TRAF-interacting protein with fork head-associated domain)-TRAF6 signaling pathway plays a pivotal role in regulating inflammatory...
The ALPK1 (alpha-kinase 1)-TIFA (TRAF-interacting protein with fork head-associated domain)-TRAF6 signaling pathway plays a pivotal role in regulating inflammatory processes, with TIFA and TRAF6 serving as key molecules in this cascade. Despite its significance, the functional mechanism of TIFA-TRAF6 remains incompletely understood. In this study, we unveil that TIFA undergoes liquid-liquid phase separation (LLPS) induced by ALPK1 in response to adenosine diphosphate (ADP)-β-D-manno-heptose (ADP-Hep) recognition. The phase separation of TIFA is primarily driven by ALPK1, the pT9-FHA domain, and the intrinsically disordered region segment. Simultaneously, TRAF6 exhibits phase separation during ADP-Hep-induced inflammation, a phenomenon observed consistently across various inflammatory signal pathways. Moreover, TRAF6 is recruited within the TIFA condensates, facilitating lysine (K) 63-linked polyubiquitin chain synthesis. The subsequent recruitment, enrichment, and activation of downstream effectors within these condensates contribute to robust inflammatory signal transduction. Utilizing a novel chemical probe (compound ), our analysis demonstrates that the activation of the ALPK1-TIFA-TRAF6 signaling pathway in response to small molecules necessitates the phase separation of TIFA. In summary, our findings reveal TIFA as a sensor for upstream signals, initiating the LLPS of itself and downstream proteins. This process results in the formation of membraneless condensates within the ALPK1-TIFA-TRAF6 pathway, suggesting potential applications in therapeutic biotechnology development.
PubMed: 38357697
DOI: 10.34133/research.0315 -
Animals : An Open Access Journal From... Jan 2024Training has a significant effect on the physiology of blood coagulation in humans and in horses. Several hemostatic changes have been reported after exercise in the...
Training has a significant effect on the physiology of blood coagulation in humans and in horses. Several hemostatic changes have been reported after exercise in the horse but data available are inconclusive. The aim of this study was to investigate platelet activation and primary platelet-related hemostasis modifications in young never-trained Thoroughbreds in the first incremental training period in order to improve knowledge on this topic. Twenty-nine clinically healthy, untrained, 2-year-old Thoroughbred racehorses were followed during their incremental 4-month sprint exercise training. Blood collection was performed once a month, five times in total (T-30, T0, T30, T60, and T90). Platelet aggregation was measured by light transmission aggregometry in response to various agonists: adenosine diphosphate (ADP), collagen, and calcium ionophore A23187. Platelet function was evaluated using a platelet function analyzer (PFA-100) using collagen/ADP and collagen/adrenaline cartridges. Nitrite-nitrate (NOx) plasma concentrations were measured via a colorimetric assay to assess in vivo nitric oxide bioavailability. Platelet activation was also investigated through gene expression analyses (selectin P-, ectonucleotidase CD39-, prostaglandin I2 synthase-, endothelial nitric oxide synthase 3-). Differences among the time points were analyzed and mean ± SEM were calculated. Significant modifications were identified compared with T-30, with an increase in platelet aggregation (collagen:32.6 ± 4.8 vs. 21.6 ± 4.9%; ADP: 35.5 ± 2.0 vs. 24.5 ± 3.1%; A23187: 30 ± 4.7 vs. 23.8 ± 4%) and a shorter closure time of C-ADP cartridges (75.6 ± 4.4 vs. 87.7 ± 3.4 s) that tended to return to the baseline value at T90. NOx concentrations in plasma significantly increased after 30 days of the training program compared with the baseline. The first long-term training period seems to induce platelet hyperactivity after 30 days in never-trained Thoroughbreds. Regular physical training reduces the negative effects of acute efforts on platelet activation.
PubMed: 38338057
DOI: 10.3390/ani14030414 -
Biochemical Pharmacology Mar 2024Cancer is a disease with a high mortality rate characterized by uncontrolled proliferation of abnormal cells. The hallmarks of cancer evidence the acquired cells... (Review)
Review
Cancer is a disease with a high mortality rate characterized by uncontrolled proliferation of abnormal cells. The hallmarks of cancer evidence the acquired cells characteristics that promote the growth of malignant tumours, including genomic instability and mutations, the ability to evade cellular death and the capacity of sustaining proliferative signalization. Poly(ADP-ribose) polymerase-1 (PARP1) is a protein that plays key roles in cellular regulation, namely in DNA damage repair and cell survival. The inhibition of PARP1 promotes cellular death in cells with homologous recombination deficiency, and therefore, the interest in PARP protein has been rising as a target for anticancer therapies. There are already some PARP1 inhibitors approved by Food and Drug Administration (FDA), such as Olaparib and Niraparib. The last compound presents in its structure an indazole core. In fact, pyrazoles and indazoles have been raising interest due to their various medicinal properties, namely, anticancer activity. Derivatives of these compounds have been studied as inhibitors of PARP1 and presented promising results. Therefore, this review aims to address the importance of PARP1 in cell regulation and its role in cancer. Moreover, it intends to report a comprehensive literature review of PARP1 inhibitors, containing the pyrazole and indazole scaffolds, published in the last fifteen years, focusing on structure-activity relationship aspects, thus providing important insights for the design of novel and more effective PARP1 inhibitors.
Topics: Adenosine Diphosphate Ribose; Cell Cycle; Indazoles; Neoplasms; Pyrazoles; United States; Humans; Animals; Poly (ADP-Ribose) Polymerase-1
PubMed: 38336156
DOI: 10.1016/j.bcp.2024.116045 -
PloS One 2024Poly-(ADP-ribose) polymerases (PARPs) are a protein family that make ADP-ribose modifications on target genes and proteins. PARP family members contribute to the...
Poly-(ADP-ribose) polymerases (PARPs) are a protein family that make ADP-ribose modifications on target genes and proteins. PARP family members contribute to the pathogenesis of chronic inflammatory diseases, including atherosclerosis, in which monocytes/macrophages play important roles. PARP inhibition is protective against atherosclerosis. However, the mechanisms by which PARP inhibition exerts this beneficial effect are not well understood. Here we show that in THP-1 monocytes, inhibition of PARP by olaparib attenuated oxidized low-density lipoprotein (oxLDL)-induced protein expressions of nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing-3 (NLRP3) inflammasome components: NLRP3, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), and caspase-1. Consistent with this effect, olaparib decreased oxLDL-enhanced interleukin (IL)-1β and IL-18 protein expression. Olaparib also decreased the oxLDL-mediated increase in mitochondrial reactive oxygen species. Similar to the effects of the NLRP3 inhibitor, MCC950, olaparib attenuated oxLDL-induced adhesion of monocytes to cultured human umbilical vein endothelial cells and reduced foam cell formation. Furthermore, olaparib attenuated the oxLDL-mediated activation of nuclear factor (NF)-κB through the oxLDL-mediated increase in IκBα phosphorylation and assembly of NF-κB subunits, demonstrated by co-immunoprecipitation of IκBα with RelA/p50 and RelB/p52 subunits. Moreover, PARP inhibition decreased oxLDL-mediated protein expression of a NF-κB target gene, VCAM1, encoding vascular cell adhesion molecule-1. This finding indicates an important role for NF-κB activity in PARP-mediated activation of the NLRP3 inflammasome. Thus, PARP inhibition by olaparib attenuates NF-κB and NLRP3 inflammasome activities, lessening monocyte cell adhesion and macrophage foam cell formation. These inhibitory effects of olaparib on NLRP3 activity potentially protect against atherosclerosis.
Topics: Humans; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Monocytes; NF-kappa B; NF-KappaB Inhibitor alpha; Poly(ADP-ribose) Polymerases; Poly(ADP-ribose) Polymerase Inhibitors; Endothelial Cells; Adenosine Diphosphate Ribose; Atherosclerosis; Interleukin-1beta; Phthalazines; Piperazines
PubMed: 38335214
DOI: 10.1371/journal.pone.0295837