Canadian Journal Of Physiology And Pharmacology[JOURNAL]
Sun
200 papers
Effects of prenatal dexamethasone exposure on adult C57BL/6J mouse metabolism and oxidative stress.
Nemec-Bakk AS, Bel J, Niccoli S … +4 more , Boreham DR, Tai TC, Lees SJ, Khaper N
Can J Physiol Pharmacol · 2024 Mar · PMID 38329060 · Publisher ↗
Prenatal glucocorticoid exposure has been shown to alter hypothalamic-pituitary-adrenal axis function resulting in altered fetal development that can persist through adulthood. Fetal exposure to excess dexamethasone, a s...
Prenatal glucocorticoid exposure has been shown to alter hypothalamic-pituitary-adrenal axis function resulting in altered fetal development that can persist through adulthood. Fetal exposure to excess dexamethasone, a synthetic glucocorticoid, has been shown to alter adult behaviour and metabolism. This study investigated the effects prenatal dexamethasone exposure had on adult offspring cardiac and liver metabolism and oxidative stress. Pregnant C57BL/6 mice received a dose of 0.4 mg/kg dexamethasone on gestational days 15-17. Once pups were approximately 7 months old, glucose uptake was determined using positron emission tomography and insulin resistance (IR) was determined by homeostatic model assessment (HOMA) IR calculation. Oxidative stress was assessed by measuring 4-hydroxynonenal protein adduct formation and total reactive oxygen species. Female dexamethasone group had significantly increased glucose uptake when insulin stimulated compared to vehicle-treated mice. HOMA IR revealed no evidence of IR in either male or female offspring. There was also no change in oxidative stress markers in either cardiac or liver tissues of male or female offspring. These data suggest that prenatal dexamethasone exposure in male mice does not alter oxidative stress or metabolism. However, prenatal dexamethasone exposure increased glucocorticoids, cardiac glucose uptake, and pAkt signaling in female heart tissues in adult mice, suggesting there are sex differences in prenatal dexamethasone exposure.
The influence of estrogen on myocardial post-translational modifications and cardiac function in women.
Shorthill SK, Jones TLM, Woulfe KC … +2 more , Cherrington BD, Bruns DR
Can J Physiol Pharmacol · 2024 Aug · PMID 38266237 · Publisher ↗
The lifetime risk of heart failure (HF) is comparable in men and women; nevertheless, disparities exist in our understanding of how HF differs between sexes. Several differences in cardiac physiology exist between men an...
The lifetime risk of heart failure (HF) is comparable in men and women; nevertheless, disparities exist in our understanding of how HF differs between sexes. Several differences in cardiac physiology exist between men and women including the propensity to develop specific HF phenotypes. Men are more likely to be diagnosed with HF failure with reduced ejection fraction, while women have a greater propensity to develop HF with preserved ejection fraction. The mechanisms responsible for these differences remain unclear. Post-translational modifications (PTMs) of myofilament proteins likely contribute to these sex-specific propensities. The role of PTMs in heart disease is an expanding field with immense potential therapeutic targets. However, numerous PTMs remain underexplored, particularly in the context of the female heart. Estrogen, a key gonadal hormone, cardioprotective in pre-menopausal women and its loss with menopause likely contributes to disease in aging women. However, how estrogen regulates PTMs to contribute to HF development is not fully clear. This review outlines key sex differences in HF along with characterizing the contributions of novel myocardial PTMs in cardiac physiology and their regulation by estrogen. Collectively, we highlight the necessity for further investigation into women's heart health and the distinctive mechanisms distinguishing women from men.
Butorphanol inhibits androgen biosynthesis and metabolism in rat immature Leydig cells in vitro.
Li C, Shi L, Su M … +4 more , Li X, Zhu Q, Ge RS, Li H
Can J Physiol Pharmacol · 2024 Apr · PMID 38258745 · Publisher ↗
Butorphanol is a synthetic opioid analgesic medication that is primarily used for the management of pain. Butorphanol may have an inhibitory effect on androgen biosynthesis and metabolism in rat immature Leydig cells. Th...
Butorphanol is a synthetic opioid analgesic medication that is primarily used for the management of pain. Butorphanol may have an inhibitory effect on androgen biosynthesis and metabolism in rat immature Leydig cells. The objective of this study was to investigate the influence of butorphanol on androgen secretion by rat Leydig cells isolated from the 35-day-old male rats. Rat Leydig cells were cultured with 0.5-50 μM butorphanol for 3 h in vitro Butorphanol at 5 and 50 μM significantly inhibited androgen secretion in immature Leydig cells. At 50 μM, butorphanol also blocked the effects of luteinizing hormone (LH) and 8bromo-cAMP-stimulated androgen secretion and 22R-hydroxycholesterol- and pregnenolone-mediated androgen production. Further analysis of the results showed that butorphanol downregulated the expression of genes involved in androgen production, including (LH receptor), (cholesterol side-chain cleavage enzyme), (5α-reductase 1), and (3α-hydroxysteroid dehydrogenase). Additionally, butorphanol directly inhibited HSD3B1 (3β-hydroxysteroid dehydrogenase 1) and SRD5A1 activity. In conclusion, butorphanol may have side effects of inhibiting androgen biosynthesis and metabolism in Leydig cells.
Stem cell therapy for cardiac regeneration: past, present, and future.
Gill JK, Rehsia SK, Verma E … +2 more , Sareen N, Dhingra S
Can J Physiol Pharmacol · 2024 Mar · PMID 38226807 · Publisher ↗
Cardiac disorders remain the leading cause of mortality worldwide. Current clinical strategies, including drug therapy, surgical interventions, and organ transplantation offer limited benefits to patients without regener...
Cardiac disorders remain the leading cause of mortality worldwide. Current clinical strategies, including drug therapy, surgical interventions, and organ transplantation offer limited benefits to patients without regenerating the damaged myocardium. Over the past decade, stem cell therapy has generated a keen interest owing to its unique self-renewal and immune privileged characteristics. Furthermore, the ability of stem cells to differentiate into specialized cell types, has made them a popular therapeutic tool against various diseases. This comprehensive review provides an overview of therapeutic potential of different types of stem cells in reference to cardiovascular diseases. Furthermore, it sheds light on the advantages and limitations associated with each cell type. An in-depth analysis of the challenges associated with stem cell research and the hurdles for its clinical translation and their possible solutions have also been elaborated upon. It examines the controversies surrounding embryonic stem cells and the emergence of alternative approaches, such as the use of induced pluripotent stem cells for cardiac therapeutic applications. Overall, this review serves as a valuable resource for researchers, clinicians, and policymakers involved in the field of regenerative medicine, guiding the development of safe and effective stem cell-based therapies to revolutionize patient care.
Uncovering the link between diabetes and cardiovascular diseases: insights from adipose-derived stem cells.
Meechem MB, Jadli AS, Patel VB
Can J Physiol Pharmacol · 2024 Apr · PMID 38198660 · Publisher ↗
Cardiovascular diseases (CVDs) are the leading causes of morbidity and mortality worldwide. The escalating global occurrence of obesity and diabetes mellitus (DM) has led to a significant upsurge in individuals afflicted...
Cardiovascular diseases (CVDs) are the leading causes of morbidity and mortality worldwide. The escalating global occurrence of obesity and diabetes mellitus (DM) has led to a significant upsurge in individuals afflicted with CVDs. As the prevalence of CVDs continues to rise, it is becoming increasingly important to identify the underlying cellular and molecular mechanisms that contribute to their development and progression, which will help discover novel therapeutic avenues. Adipose tissue (AT) is a connective tissue that plays a crucial role in maintaining lipid and glucose homeostasis. However, when AT is exposed to diseased conditions, such as DM, this tissue will alter its phenotype to become dysfunctional. AT is now recognized as a critical contributor to CVDs, especially in patients with DM. AT is comprised of a heterogeneous cellular population, which includes adipose-derived stem cells (ADSCs). ADSCs resident in AT are believed to regulate physiological cardiac function and have potential cardioprotective roles. However, recent studies have also shown that ADSCs from various adipose tissue depots become pro-apoptotic, pro-inflammatory, less angiogenic, and lose their ability to differentiate into various cell lineages upon exposure to diabetic conditions. This review aims to summarize the current understanding of the physiological roles of ADSCs, the impact of DM on ADSC phenotypic changes, and how these alterations may contribute to the pathogenesis of CVDs.
Note of appreciation.
Can J Physiol Pharmacol · 2024 Jan · PMID 38164926 · Publisher ↗
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Azilsartan prevents muscle loss and fast- to slow-twitch muscle fiber shift in natural ageing sarcopenic rats.
Prajapati P, Kumar A, Mangrulkar S … +3 more , Chaple DR, Saraf SA, Kushwaha S
Can J Physiol Pharmacol · 2024 May · PMID 38118126 · Publisher ↗
Sarcopenia is a musculoskeletal disease that reduces muscle mass and strength in older individuals. The study investigates the effects of azilsartan (AZL) on skeletal muscle loss in natural sarcopenic rats. Male Sprague-...
Sarcopenia is a musculoskeletal disease that reduces muscle mass and strength in older individuals. The study investigates the effects of azilsartan (AZL) on skeletal muscle loss in natural sarcopenic rats. Male Sprague-Dawley rats aged 4-6 months and 18-21 months were selected as young-matched control and natural-aged (sarcopenic) rats, respectively. Rats were allocated into young and old control (YC and OC) and young and old AZL treatment (YT and OT) groups, which received vehicles and AZL (8 mg/kg, orally) for 6 weeks. Rats were then sacrificed after muscle function analysis. Serum and gastrocnemius (GN) muscles were isolated for further endpoints. AZL significantly improved muscle grip strength and antioxidant levels in sarcopenic rats. AZL also restored the levels of insulin, testosterone, and muscle biomarkers such as myostatin and creatinine kinase in sarcopenic rats. Furthermore, AZL treatment improved the cellular and ultrastructure of GN muscle and prevented the shift of type II (glycolytic) myofibers to type I (oxidative) myofibers. The results showed that AZL intervention restored protein synthesis in natural sarcopenic rats by increasing p-Akt-1 and decreasing muscle RING-finger protein-1 and tumor necrosis factor alpha immunoexpressions. In conclusion, the present findings showed that AZL could be an effective intervention in treating age-related muscle impairments.
Formation of a border ischemic zone depends on plasma potassium concentration.
Bernikova O, Durkina A, Gonotkov M … +3 more , Minnebaeva E, Arteyeva N, Azarov J
Can J Physiol Pharmacol · 2024 May · PMID 38118123 · Publisher ↗
Extracellular potassium concentration might modify electrophysiological properties in the border zone of ischemic myocardium. We evaluated the depolarization and repolarization characteristics across the ischemic-normal...
Extracellular potassium concentration might modify electrophysiological properties in the border zone of ischemic myocardium. We evaluated the depolarization and repolarization characteristics across the ischemic-normal border under [K] variation. Sixty-four-lead epicardial mapping was performed in 26 rats ([K] 2.3-6.4 mM) in a model of acute ischemia/reperfusion. The animals with [K] < 4.7 mM (low-normal potassium) had an ischemic zone with ST-segment elevation and activation delay, a border zone with ST-segment elevation and no activation delay, and a normal zone without electrophysiological abnormalities. The animals with [K] >4.7 mM (normal-high potassium) had only the ischemic and normal zones and no transitional area. Activation-repolarization intervals and local conduction velocities were inversely associated with [K] in linear regression analysis with adjustment for the zone of myocardium. The reperfusion extrasystolic burden (ESB) was greater in the low-normal as compared to normal-high potassium animals. Ventricular tachycardia/fibrillation incidence did not differ between the groups. In patch-clamp experiments, hypoxia shortened action potential duration at 5.4 mM but not at 1.3 mM of [K]. IK(ATP) current was lower at 1.3 mM than at 5.4 mM of [K]. We conclude that the border zone formation in low-normal [K] was associated with attenuation of IK(ATP) response to hypoxia and increased reperfusion ESB.
The role of melatonin in preventing amiodarone-induced rat liver damage.
Petrović D, Ilić MD, Simonović D … +6 more , Stojanović M, Stanković M, Stanišić S, Stojanović S, Arsić N, Sokolović DT
Can J Physiol Pharmacol · 2024 Jun · PMID 38079620 · Publisher ↗
Long-term exposure to amiodarone, an antiarrhythmic drug, can induce different organ damage, including liver. Cell damage included by amiodarone is a consequence of mitochondrial damage, reactive oxygen species productio...
Long-term exposure to amiodarone, an antiarrhythmic drug, can induce different organ damage, including liver. Cell damage included by amiodarone is a consequence of mitochondrial damage, reactive oxygen species production, and cell energy depletion leading to programmed cell death. In the present study, hepatoprotective potential of neurohormone melatonin (50 mg/kg/day) was evaluated in a chronic experimental model of liver damage induced by a 4-week application of amiodarone (70 mg/kg/day). The obtained results indicate that amiodarone induces an increase in xanthine oxidase activity, as well as the content of the lipid and protein oxidatively modified products and p53 levels. Microscopic analysis further corroborated the biochemical findings revealing hepatocyte degeneration, apoptosis, and occasional necrosis, with the activation of Kupffer cells. Coadministration of melatonin and amiodaron prevented an increase in certain damage associated parameters, due to its multiple targets. In conclusion, the application of melatonin together with amiodarone prevented an increase in tissue oxidative damage parameters and moderately prevented liver cell apoptosis, indicating that the damage of hepatocytes provoked by amiodarone supersedes the protective properties of melatonin in a given dose.
Salvianolic acid B attenuates diabetic nephropathy through alleviating ADORA2B, NALP3 in flammasome, and NFκB activity.
Wang Y, Chang J, Qiao S … +4 more , Yang Y, Yun C, Li Y, Wang F
Can J Physiol Pharmacol · 2024 May · PMID 38070193 · Publisher ↗
Diabetic nephropathy is one of the microvascular complications of diabetes. This study is aimed at investigating the role and mechanisms of salvianolic acid B (Sal B) in diabetic nephropathy. High glucose (HG)-induced hu...
Diabetic nephropathy is one of the microvascular complications of diabetes. This study is aimed at investigating the role and mechanisms of salvianolic acid B (Sal B) in diabetic nephropathy. High glucose (HG)-induced human renal tubular epithelial HK-2 cells were treated with Sal B, BAY-60-6583 (agonist of adenosine 2B receptor), or PSB-603 (antagonist of adenosine 2B receptor) for 24 h. Adenosine A2b receptor (ADORA2B), NACHT, leucine-rich repeat (LRR), and pyrin (PYD) domains-containing protein 3 (NALP3), and nuclear factor Kappa B (NFκB) expressions, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) levels were examined. Following 6 weeks of Sal B treatment, db/db mice blood and kidney tissue were harvested for biochemical detection with hematoxylin-eosin (H&E), Masson's, periodic acid schiff (PAS), and Sirius red staining and detection of ADORA2B, NALP3, NFκB, interleukin 1β (IL-1β), and toll-like receptor 4 (TLR4) activity. NFκB, NALP3, and ADORA2B were found to be downregulated in Sal B treated HK-2 cells exposed to high glucose (HG), accompanied by elevated levels of MMPs and reduced intracellular ROS production. Sal B-treated diabetic mice had the improvement in body weight, water intake, hyperglycemia, hyperlipidemia, and liver and kidney function. Altogether, Sal B attenuates HG-induced kidney tubule cell injury and diabetic nephropathy in diabetic mice, providing clues to other novel mechanisms by which Sal B is beneficial in diabetic nephropathy.
Preventing broken hearts in women with breast cancer: a concise review on chemotherapy-mediated cardiotoxicity.
Bews HJ, Mackic L, Jassal DS
Can J Physiol Pharmacol · 2024 Sep · PMID 38039515 · Publisher ↗
Cancer and cardiovascular disease are the leading causes of death for Canadian women. One in eight Canadian women will receive the life-changing diagnosis of breast cancer (BC) in their lifetime, with 1 in 34 dying from...
Cancer and cardiovascular disease are the leading causes of death for Canadian women. One in eight Canadian women will receive the life-changing diagnosis of breast cancer (BC) in their lifetime, with 1 in 34 dying from the disease. Although doxorubicin (DOX) and trastuzumab (TRZ) have significantly improved survival in women diagnosed with human epidermal growth factor receptor 2 (HER2)-positive BC, approximately one in four women who receive this treatment are at risk of developing chemotherapy-induced cardiotoxicity. Cardiotoxicity is defined as a decline in left ventricular ejection fraction (LVEF) of >10% to an absolute value of <53%. Current guidelines recommend the serial monitoring of LVEF in this patient population using non-invasive cardiac imaging modalities including transthoracic echocardiography or multi-gated acquisition scan; however, this will only allow for the detection of established cardiotoxicity. Recent studies have demonstrated that a reduction in global longitudinal strain by speckle tracking echocardiography can identify pre-clinical systolic dysfunction prior to a decline in overall LVEF. Implementation of early detection techniques would allow for the prompt initiation of cardioprotective strategies. In addition to the early detection of chemotherapy-mediated cardiotoxicity, the prophylactic use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, statins, exercise, and nutraceutical therapies have been studied in the setting of cardio-oncology.
Existence and importance of NaK-ATPase in the plasma membrane of boar spermatozoa.
Awda BJ, Mahoney IV, Pettitt M … +3 more , Imran M, Katselis GS, Buhr MM
Can J Physiol Pharmacol · 2024 Apr · PMID 38029410 · Publisher ↗
Sodium-potassium-ATPase (NaK-ATPase), a target to treat congestive heart failure, is the only known receptor for cardiac glycosides implicated in intracellular signaling and additionally functions enzymatically in ion tr...
Sodium-potassium-ATPase (NaK-ATPase), a target to treat congestive heart failure, is the only known receptor for cardiac glycosides implicated in intracellular signaling and additionally functions enzymatically in ion transport. Spermatozoa need transmembrane ion transport and signaling to fertilize, and NaK-ATPase is identified here for the first time in boar spermatozoa. Head plasma membrane (HPM) isolated from boar spermatozoa was confirmed pure by marker enzymes acid and alkaline phosphatase (218 ± 23% and 245 ± 38% enrichment, respectively, versus whole spermatozoa). Western immunoblotting detected α and β subunits (isoforms α1, α3, β1, β2, and β3) in different concentrations in whole spermatozoa and HPM. Immunofluorescence of intact sperm only detected α3 on the post-equatorial exterior membrane; methanol-permeabilized sperm also had α3 post-equatorially and other isoforms on the acrosomal ridge and cap. Mass spectrometry confirmed the presence of all isoforms in HPM. Incubating boar sperm in capacitating media to induce the physiological changes preceding fertilization significantly increased the percentage of capacitated sperm compared to 0 h control (33.0 ± 2.6% vs. 19.2 ± 2.6% capacitated sperm, respectively; = 0.014) and altered the β2 immunofluorescence pattern. These results demonstrate the presence of NaK-ATPase in boar sperm HPM and that it changes during capacitation.
Efficacy and safety of fenofibrate in combination with phototherapy for the treatment of neonatal hyperbilirubinemia: a systematic review and meta-analyses.
Abdellatif M, Abozaid AAF, Shah PS … +11 more , Dhouibi N, Nguyen-Khac T, Khleif R, Luu MN, Quyen DK, Mohareb A, Vaghela G, Khan ZA, Pham HN, Makram AM, Huy NT
Can J Physiol Pharmacol · 2024 Apr · PMID 38011686 · Publisher ↗
Phototherapy is the standard treatment for neonatal jaundice. We aimed to review the efficacy and safety of fenofibrate as an adjunct therapy. Twelve databases were searched and a systematic review and meta-analysis were...
Phototherapy is the standard treatment for neonatal jaundice. We aimed to review the efficacy and safety of fenofibrate as an adjunct therapy. Twelve databases were searched and a systematic review and meta-analysis were conducted. Mean change (MC), mean difference (MD), and risk ratios (RR) with a 95% confidence interval (CI) were calculated using a random effects model. The GRADE approach was used to evaluate the evidence's certainty. Nine randomized trials were included. The MC of total serum bilirubin (mg/dL) was significant at 12, 24, 36, 48, and 72 h with respective MC (95% CI) values of -0.46 (-0.61, -0.310), -1.10 (-1.68, -0.52), -2.06 (-2.20, -1.91), -2.15 (-2.74, -1.56), and -1.13 (-1.71, -0.55). The FEN + PT group had a shorter duration of phototherapy (MD: -14.36 h; 95% CI: -23.67, -5.06) and a shorter hospital stay (MD: -1.40 days; 95% CI: -2.14, -0.66). There was no significant difference in the risk of complications (RR: 0.89; 95% CI: 0.54, 1.46) or the need for exchange transfusion (RR: 0.58; 95% CI: 0.12, 2.81). The certainty of the evidence was very low for all outcomes. In conclusion, fenofibrate might be a safe adjunct to neonatal phototherapy. Larger randomized controlled trials are needed for the confirmation of these results.
Deciphering MMP9's dual role in regulating SOD3 through protein-protein interactions.
Gawargi FI, Mishra PK
Can J Physiol Pharmacol · 2024 Mar · PMID 37992301 · Full text
Although the collagenase enzyme activity of matrix metalloproteinase-9 (MMP9) is well-documented, its non-enzymatic functions remain less understood. The interaction between intracellular superoxide dismutase-1 (SOD1) an...
Although the collagenase enzyme activity of matrix metalloproteinase-9 (MMP9) is well-documented, its non-enzymatic functions remain less understood. The interaction between intracellular superoxide dismutase-1 (SOD1) and MMP9 is known, with SOD1 suppressing MMP9. However, the mechanism by which MMP9, a secretory protein, influences the extracellular antioxidant superoxide dismutase-3 (SOD3) is not yet clear. To explore MMP9's regulatory impact on SOD3, we employed human embryonic kidney-293 cells, transfecting them with MMP9 overexpresssion and catalytic-site mutant plasmids. Additionally, MMP9 overexpressing cells were treated with an MMP9 activator and inhibitor. Analyses of both cell lysates and culture medium provided insights into MMP9's intracellular and extracellular regulatory roles. In-silico analysis and experimental approaches like proximal ligation assay and co-immunoprecipitation were utilized to delineate the protein-protein interactions between MMP9 and SOD3. Our findings indicate that activated MMP9 enhances SOD3 levels, a regulation not hindered by MMP9 inhibitors. Intriguingly, catalytically inactive MMP9 appeared to reduce SOD3 levels, likely due to MMP9's binding with SOD3, leading to their proteolytic degradation. This MMP9 influence on SOD3 was consistent in both intracellular and extracellular environments, suggesting a parallel in MMP9-SOD3 interactions across these domains. Ultimately, this study unveils a novel interaction between MMP9 and SOD3, highlighting the unique regulatory role of catalytically inactive MMP9 in diminishing SOD3 levels, contrasting its usual upregulation by active MMP9.
Role of circadian clock system in the mitochondrial trans-sulfuration pathway and tissue remodeling.
Tyagi SC, Pushpakumar S, Sen U … +5 more , Akinterinwa OE, Zheng Y, Mokshagundam SPL, Kalra DK, Singh M
Can J Physiol Pharmacol · 2024 Feb · PMID 37979203 · Publisher ↗
Previous studies from our laboratory revealed that the gaseous molecule hydrogen sulfide (HS), a metabolic product of epigenetics, involves trans-sulfuration pathway for ensuring metabolism and clearance of homocysteine...
Previous studies from our laboratory revealed that the gaseous molecule hydrogen sulfide (HS), a metabolic product of epigenetics, involves trans-sulfuration pathway for ensuring metabolism and clearance of homocysteine (Hcy) from body, thereby mitigating the skeletal muscle's pathological remodeling. Although the master circadian clock regulator that is known as brain and muscle aryl hydrocarbon receptor nuclear translocator like protein 1 (i.e., BMAL 1) is associated with -adenosylhomocysteine hydrolase (SAHH) and Hcy metabolism but how trans-sulfuration pathway is influenced by the circadian clock remains unexplored. We hypothesize that alterations in the functioning of circadian clock during sleep and wake cycle affect skeletal muscle's biology. To test this hypothesis, we measured serum matrix metalloproteinase (MMP) activities using gelatin gels for analyzing the MMP-2 and MMP-9. Further, employing casein gels, we also studied MMP-13 that is known to be influenced by the growth arrest and DNA damage-45 (GADD45) protein during sleep and wake cycle. The wild type and cystathionine β synthase-deficient (CBS) mice strains were treated with HS and subjected to measurement of trans-sulfuration factors from skeletal muscle tissues. The results suggested highly robust activation of MMPs in the wake mice versus sleep mice, which appears somewhat akin to the "1-carbon metabolic dysregulation", which takes place during remodeling of extracellular matrix during muscular dystrophy. Interestingly, the levels of trans-sulfuration factors such as CBS, cystathionine γ lyase (CSE), methyl tetrahydrofolate reductase (MTHFR), phosphatidylethanolamine -methyltransferase (PEMT), and Hcy-protein bound paraoxonase 1 (PON1) were attenuated in CBS mice. However, treatment with HS mitigated the attenuation of the trans-sulfuration pathway. In addition, levels of mitochondrial peroxisome proliferator-activated receptor-gamma coactivator 1-α (PGC 1-α) and mitofusin-2 (MFN-2) were significantly improved by HS intervention. Our findings suggest participation of the circadian clock in trans-sulfuration pathway that affects skeletal muscle remodeling and mitochondrial regeneration.
Nitric oxide and potassium channels but not opioid and cannabinoid receptors mediate tramadol-induced peripheral antinociception in rat model of paw pressure withdrawal.
Soares-Santos RR, Machado DP, Romero TL … +1 more , Duarte IDG
Can J Physiol Pharmacol · 2024 Mar · PMID 37976474 · Publisher ↗
Tramadol, an analgesic classified as an "atypical opioid", exhibits both opioid and non-opioid mechanisms of action. This study aimed to explore these mechanisms, specifically the opioid-, cannabinoid-, nitric oxide-, an...
Tramadol, an analgesic classified as an "atypical opioid", exhibits both opioid and non-opioid mechanisms of action. This study aimed to explore these mechanisms, specifically the opioid-, cannabinoid-, nitric oxide-, and potassium channel-based mechanisms, which contribute to the peripheral antinociception effect of tramadol, in an experimental rat model. The nociceptive threshold was determined using paw pressure withdrawal. To examine the mechanisms of action, several substances were administered intraplantarly: naloxone, a non-selective opioid antagonist (50 µg/paw); AM251 (80 µg/paw) and AM630 (100 µg/paw) as the selective antagonists for types 1 and 2 cannabinoid receptors, respectively; nitric oxide synthase inhibitors L-NOArg, L-NIO, L-NPA, and L-NIL (24 µg/paw); and the enzyme inhibitors of guanylatocyclase and phosphodiesterase of cGMP, ODQ, and zaprinast. Additionally, potassium channel blockers glibenclamide, tetraethylammonium, dequalinium, and paxillin were used. The results showed that opioid and cannabinoid receptor antagonists did not reverse tramadol's effects. L-NOarg, L-NIO, and L-NPA partially reversed antinociception, while ODQ completely reversed, and zaprinast enhanced tramadol's antinociception effect. Notably, glibenclamide blocked tramadol's antinociception in a dose-dependent manner. These findings suggest that tramadol's peripheral antinociception effect is likely mediated by the nitrergic pathway and sensitive ATP potassium channels, rather than the opioid and cannabinoid pathways.
Effects of sclerostin injection on soleus and extensor digitorum longus muscle tissue in male mice.
Stoikos J, Kurgan N, Kottaras S … +3 more , Fajardo VA, Gittings W, Klentrou P
Can J Physiol Pharmacol · 2024 Apr · PMID 37976473 · Publisher ↗
Sclerostin, a potent inhibitor of the Wnt signaling pathway, plays a critical role in bone homeostasis. Evidence suggests that sclerostin may also be involved in crosstalk between other tissues, including muscle. This pi...
Sclerostin, a potent inhibitor of the Wnt signaling pathway, plays a critical role in bone homeostasis. Evidence suggests that sclerostin may also be involved in crosstalk between other tissues, including muscle. This pilot study attempted to examine the effects of sclerostin on soleus and extensor digitorum longus (EDL) muscle tissue from male mice that were given continuous recombinant sclerostin injections for 4 weeks. A total of 48 10-week-old male C57BL/6J mice were assigned to be sedentary or perform 1 h treadmill running per day for 4 weeks and administered subcutaneous injections of either saline or recombinant sclerostin 5 days/week. Sclerostin injection led to a reduction in the soleus myosin heavy chain (MHC) I, MHC I/IIA, MHC IIA/X, and MHC IIB cross-sectional area ( < 0.05) with no exercise effects on these reductions. In contrast, there were no effects of sclerostin injections or exercise on the fast-twitch EDL muscle in terms of size, MHC protein, or markers of Wnt signaling. These findings provide preliminary evidence of sclerostin's endocrine role in muscle via decreases in myofiber cross-sectional area, which seems to be independent of fiber type but muscle type-specific. More studies, however, are needed to confirm these preliminary results.
Picroside Ⅱ attenuates neuropathic pain by regulating inflammation and spinal excitatory synaptic transmission.
Duan D, Wang L, Feng Y … +2 more , Hu D, Cui D
Can J Physiol Pharmacol · 2024 Apr · PMID 37976472 · Publisher ↗
Nerve injury induced microglia activation, which released inflammatory mediators and developed neuropathic pain. Picroside Ⅱ (PⅡ) attenuated neuropathic pain by inhibiting the neuroinflammation of the spinal dorsal horn;...
Nerve injury induced microglia activation, which released inflammatory mediators and developed neuropathic pain. Picroside Ⅱ (PⅡ) attenuated neuropathic pain by inhibiting the neuroinflammation of the spinal dorsal horn; however, how it engaged in the cross talk between microglia and neurons remained ambiguous. This study aimed to investigate PⅡ in the modulation of spinal synaptic transmission mechanisms on pain hypersensitivity in neuropathic rats. We investigated the analgesia of PⅡ in mechanical and thermal hyperalgesia using the spinal nerve ligation (SNL)-induced neuropathic pain model and formalin-induced tonic pain model, respectively. RNA sequencing and network pharmacology were employed to screen core targets and signaling pathways. Immunofluorescence staining and qPCR were performed to explore the expression level of microglia and inflammatory mediator mRNA. The whole-cell patch-clamp recordings were utilized to record miniature excitatory postsynaptic currents in excitatory synaptic transmission. Our results demonstrated that the analgesic of PⅡ was significant in both pain models, and the underlying mechanism may involve inflammatory signaling pathways. PⅡ reversed the SNL-induced overexpression of microglia and inflammatory factors. Moreover, PⅡ dose dependently inhibited excessive glutamate transmission. Thus, this study suggested that PⅡ attenuated neuropathic pain by inhibiting excitatory glutamate transmission of spinal synapses, induced by an inflammatory response on microglia.
TLR/mTOR inflammatory signaling pathway: novel insight for the treatment of schizophrenia.
Lashgari NA, Roudsari NM, Shamsnia HS … +3 more , Shayan M, Momtaz S, Abdolghaffari AH
Can J Physiol Pharmacol · 2024 Mar · PMID 37955633 · Publisher ↗
The Toll-like receptor (TLR)/mammalian target of rapamycin (mTOR) signaling pathway is involved in the intracellular regulation of protein synthesis, specifically the ones that mediate neuronal morphology and facilitate...
The Toll-like receptor (TLR)/mammalian target of rapamycin (mTOR) signaling pathway is involved in the intracellular regulation of protein synthesis, specifically the ones that mediate neuronal morphology and facilitate synaptic plasticity. The activity of TLR/mTOR signaling has been disrupted, leading to neurodevelopment and deficient synaptic plasticity, which are the main symptoms of schizophrenia. The TLR receptor activates the mTOR signaling pathway and increases the elevation of inflammatory cytokines. Interleukin (IL)-6 is the most commonly altered cytokine, while IL-1, tumor necrosis factor, and interferon (IFN) also lead to SCZ. Anti-inflammatory and anti-oxidative agents such as celecoxib, aspirin, minocycline, and omega-3 fatty acids have shown efficiency against SCZ. As a result, inhibition of the inflammatory process could be suggested for the treatment of SCZ. So mTOR/TLR blockers represent the treatment of SCZ due to their inflammatory consequences. The objective of the present work was to find a novel anti-inflammatory agent that may block the mTOR/TLR inflammatory signaling pathways and might pave the way for the treatment of neuroinflammatory SCZ. Data were collected from experimental and clinical studies published in English between 1998 and October 2022 from Google Scholar, PubMed, Scopus, and the Cochrane library.
SCH772984 ameliorates lipopolysaccharide-induced hypoglycemia in mice through reversing MEK/ERK/Foxo1-mediated gluconeogenesis suppression.
Wang Y, Qing S, Yang J … +1 more , Qian D
Can J Physiol Pharmacol · 2024 Jan · PMID 37944129 · Publisher ↗
Lipopolysaccharide (LPS) results in a lethal hypoglycemic response. However, the main molecular mechanism involved in LPS-induced glucose metabolism disorder is poorly understood. This study intends to investigate the si...
Lipopolysaccharide (LPS) results in a lethal hypoglycemic response. However, the main molecular mechanism involved in LPS-induced glucose metabolism disorder is poorly understood. This study intends to investigate the signaling pathways involved in LPS-induced hypoglycemia and potential efficacy of extracellular signal-regulated kinase (ERK) inhibitor SCH772984. The effects of LPS and SCH772984 on gluconeogenesis, glucose absorption, and glycogenolysis were evaluated by pyruvate tolerance test, oral glucose tolerance test, and glucagon test, respectively. After a single intraperitoneal injection of 0.5 mg/kg LPS, the mice's blood glucose levels and gluconeogenesis ability were significantly lower than that of control group. Besides, mRNA and protein expression of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) decreased significantly after LPS treatment. LPS induced the phosphorylation of ERK1/2, MEK1/2 (mitogen-activated protein kinase), and Foxo1 while inhibited Foxo1 expression in the nucleus, indicating an important role of the MEK/ERK/Foxo1 signaling in the inhibition of gluconeogenesis by LPS. Furthermore, SCH772984 elevated blood glucose, increased the G6Pase and PEPCK expression, and inhibited pERK1/2 and pFoxo1 expression in LPS-induced mice. In summary, LPS inhibited gluconeogenesis and induced hypoglycemia through the MEK/ERK/Foxo1 signal pathway, and ERK inhibitor could effectively reverse decreased blood glucose in mice with LPS treatment. These findings provide a novel therapeutic target for LPS-induced hypoglycemia.
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