Expression Of Creatine Kinase Research Articles

Effect of creatine administration on locomotor activity and stress response in olive flounder (Paralichthys olivaceus)

The creatine kinase system is crucial for maintaining cellular energy homeostasis and plays a role in regulating locomotor behavior in organisms, but its significance in the regulating the motionless behavior in olive flounder is limited. In the first experiment of this study, elevated levels of creatine kinase (CK) activity in the spinal cord were detected in the juvenile group (JG) flounder compared to the adult group (AG) flounder. In the second experiment, to further confirm the involvement of CK in the locomotor behavior, the adult flounder was given an intraperitoneal injection of creatine (150 mg/kg), while the flounder in the control group received a saline solution. After one week post-injection, the behavioral analysis revealed that the flounder in the creatine-treated group displayed higher levels of locomotor activity and a greater number of escape attempts in response to external stimuli when compared to the control group. However, the acute stress response, induced by intraperitoneal injection and characterized by tail beating, was significantly alleviated in the flounder in the creatine-treated group. Additionally, there was an upregulation of the UII and AchR genes in the spinal cord, as well as increased levels of UII and AchR in the muscle tissues of the creatine-treated flounder. However, a reduction in UI mRNA levels was observed in the brain of the flounder. Collectively, our data provide the evidence that the elevated enzyme activity and gene expression of creatine kinase play important roles in off-bottom swimming behavior in the JG flounder. Furthermore, administration of creatine improved the locomotor activity and alleviated the stress response in flounder, which is associated with regulation of the locomotor- and stress-related gene in the brain, spinal cord, and muscle.

Phenotypic and gene expression characteristics of Japanese eel late-stage leptocephali and glass eels after growth on different diets with a focus on nutrient-accumulation status

To evaluate the quality of glass eels that were derived from late-stage Anguilla japonica leptocephali raised on an old-type of shark egg-based diet (SE) or a new-type of fish meal-based diet (FSY), specific gravity (SG), feeding tests, and body compositional and RNA-seq gene-expression analyses were conducted. The largest content difference between the two dietary groups was in lipids, with the body-compositional index (BCI) being 29.2% lower in FSY-leptocephali and 43.1% lower in FSY-glass eels at day 3 post-metamorphosis, but the difference between groups narrowed to 21.6% at post-metamorphosis first feeding. FSY-leptocephali had heavier SG, a larger number of differentially expressed genes (DEGs) related to muscle development and/or movement, and higher creatine kinase expression, suggesting that they settled easily, and were forced to swim more against fast bottom currents in the tanks while consuming more energy. It was found that the days until first feeding in FSY-glass eels was significantly shorter than in SE glass eels, with lower variability among eels. The number of DEGs was larger in FSY-glass eels, with the largest difference of 3.6 times occurring at day 10 post-metamorphosis, especially in the metabolism category, but at first feeding, they decreased drastically in both groups narrowing the difference. In the FSY-glass eels, the number of DEGs related to lipid, amino acid, and protein metabolisms were larger at days 3–20 after metamorphosis. Total enzyme expression levels for acylglycerol degradation, ketone body biosynthesis and citric acid cycle pathways also tended to be higher, suggesting that they obtained energy aerobically using lipids and other materials. Based on the patterns of up- and down-regulation of expression levels, growth hormone, ghrelin/obestatin prepropeptide and pro-melanin-concentrating hormone-like were detected as possible orexigenic hormones, and proopiomelanocortin and nucleobindin-2 as possible anorexigenic hormones. These results indicate that diet quality affects not only SG and other characteristics of leptocephali, but even body composition, metabolism and time to first feeding in the post-metamorphic glass eels for use as seedlings for aquaculture.

The effect of hibernation on the morphological structure and expression of creatine kinase in the intestine of Pelodiscus sinensis

The intestinal function of hibernating animals undergoes seasonal changes, during which they are in a fasting state, which also affects the morphology, structure, and function of intestine. The aim of this study was to analyse the histological differences in the intestinal structure, goblet cells, and mucosa of the initial (ISI), anterior (ASI), middle (MSI) and posterior (PSI) of small intestine of Pelodiscus sinensis during the whole hibernation process and to investigate the role of the key enzyme creatine kinase (CK) in regulating energy homeostasis during hibernation. The results of HE staining showed that the intestinal mucosa of the P. sinensis during hibernation presented detachment and atrophy of villus, and narrowing of gaps while the villous length of the ISI, ASI, MSI, and PSI were significantly decreased than those in normal stage. As hibernation progresses, the intestinal crypt of the ISI first increased and then decreased significantly. The AB-PAS staining results revealed that as hibernation progressed, the number of type Ⅰ goblet cells in the ISI significantly increased, while the number of type Ⅲ goblet cells significantly decreased. The immunohistochemical results revealed that CK-MB was highly expressed in the intestinal villus of P. sinensis. During hibernation, the expression of CK-MB in P. sinensis continued to increase in the ISI and decrease in the PSI. In summary, the results of this study suggested that hibernation process could alter the morphological structure of the ISI and ASI of P. sinensis, making them more vulnerable. Meanwhile, the ISI may protect the mucosal tissue during hibernation by increasing type Ⅲ goblet cells and decreasing type I goblet cells. During this process, the continuously increasing expression of CK in the ISI may participate in the adaptation of P. sinensis to intestinal hibernation by regulating energy metabolism.

Rat and mouse cardiomyocytes show subtle differences in creatine kinase expression and compartmentalization.

Creatine kinase (CK) and adenylate kinase (AK) are energy transfer systems. Different studies on permeabilized cardiomyocytes suggest that ADP-channelling from mitochondrial CK alone stimulates respiration to its maximum, VO2_max, in rat but not mouse cardiomyocytes. Results are ambiguous on ADP-channelling from AK to mitochondria. This study was undertaken to directly compare the CK and AK systems in rat and mouse hearts. In homogenates, we assessed CK- and AK-activities, and the CK isoform distribution. In permeabilized cardiomyocytes, we assessed mitochondrial respiration stimulated by ADP from CK and AK, VO2_CK and VO2_AK, respectively. The ADP-channelling from CK or AK to mitochondria was assessed by adding PEP and PK to competitively inhibit the respiration rate. We found that rat compared to mouse hearts had a lower aerobic capacity, higher VO2_CK/VO2_max, and different CK-isoform distribution. Although rat hearts had a larger fraction of mitochondrial CK, less ADP was channeled from CK to the mitochondria. This suggests different intracellular compartmentalization in rat and mouse cardiomyocytes. VO2_AK/VO2_max was similar in mouse and rat cardiomyocytes, and AK did not channel ADP to the mitochondria. In the absence of intracellular compartmentalization, the AK- and CK-activities in homogenate should have been similar to the ADP-phosphorylation rates estimated from VO2_AK and VO2_CK in permeabilized cardiomyocytes. Instead, we found that the ADP-phosphorylation rates estimated from permeabilized cardiomyocytes were 2 and 9 times lower than the activities recorded in homogenate for CK and AK, respectively. Our results highlight the importance of energetic compartmentalization in cardiac metabolic regulation and signalling.

Mimicking Ding's Roll Method on Notexin-Induced Muscle Injury in Rats.

Ding's roll method is one of the most commonly used manipulations in traditional Chinese massage (Tuina) clinics and one of the most influential contemporary Tuina manipulations in China. It is based on the traditional rolling method commonly used in the one finger Zen genre and named Ding's roll method. Due to its anti-inflammatory and blood circulation-promoting effects, Ding's rolling method has sound therapeutic effects on myopathy. Because of the large area of force applied to human skin, Ding's roll method is challenging to perform on experimental animals with small skin areas, such as rats and rabbits. Additionally, the strength of Tuina applied to the human body differs from that applied to experimental animals, so it may happen that the strength is too high or too low to achieve the therapeutic effect of Tuina during the experiment. This experiment aims to create a simple massager suitable for rats based on Ding's rolling manipulation parameters (strength, frequency, Tuina duration). The device can standardize manipulation in animal experiments and reduce the variation in Tuina force applied to different animals due to subjective factors. A rat model of notexin-induced skeletal muscle injury was established, and plasma injury markers creatine kinase (CK) and fatty acid binding protein 3 (FABP3) were used to assess the therapeutic effect of Tuina on skeletal muscle injury. The results showed that this Tuina massager could reduce the levels of CK and FABP3 expression and slow down the degree of skeletal muscle injury. Therefore, the Tuina massager described here, mimicking Ding's roll method, contributes to standardizing Tuina manipulation in experimental research and is of great help for subsequent research on the molecular mechanism of Tuina for myopathy.

Colorectal polyps increase the glycolytic activity.

In colorectal cancer (CRC) energy metabolism research, the precancerous stage of polyp has remained rather unexplored. By now, it has been shown that CRC has not fully obtained the glycolytic phenotype proposed by O. Warburg and rather depends on mitochondrial respiration. However, the pattern of metabolic adaptations during tumorigenesis is still unknown. Understanding the interplay between genetic and metabolic changes that initiate tumor development could provide biomarkers for diagnosing cancer early and targets for new cancer therapeutics. We used human CRC and polyp tissue material and performed high-resolution respirometry and qRT-PCR to detect changes on molecular and functional level with the goal of generally describing metabolic reprogramming during CRC development. Colon polyps were found to have a more glycolytic bioenergetic phenotype than tumors and normal tissues. This was supported by a greater GLUT1, HK, LDHA, and MCT expression. Despite the increased glycolytic activity, cells in polyps were still able to maintain a highly functional OXPHOS system. The mechanisms of OXPHOS regulation and the preferred substrates are currently unclear and would require further investigation. During polyp formation, intracellular energy transfer pathways become rearranged mainly by increasing the expression of mitochondrial adenylate kinase (AK) and creatine kinase (CK) isoforms. Decreased glycolysis and maintenance of OXPHOS activity, together with the downregulation of the CK system and the most common AK isoforms (AK1 and AK2), seem to play a relevant role in CRC development.

CREATINE KINASE EXPRESSION IS PROTECTIVE IN A MOUSE COLITIS MODEL

We have previously identified a loss of expression of creatine pathway proteins in mucosal tissue samples from inflammatory bowel disease patients. This is important as creatine is vital to ATP buffering in energetically active cells. The goal of this study was to determine the impact of decreased creatine kinase (CK) expression on mucosal inflammation by utilizing a whole body CK Brain and CK Mitochondrial knockout mouse (CKB/MitKO) in the dextran sulfate sodium (DSS) model of acute colitis.

Metabolites, gene expression, and gut microbiota profiles suggest the putative mechanisms via which dietary creatine increases the serum taurine and g-ABA contents in Megalobrama amblycephala.

A 90-day experiment was conducted to explore the effects of creatine on growth performance, liver health status, metabolites, and gut microbiota in Megalobrama amblycephala. There were 6 treatments as follows: control (CD, 29.41% carbohydrates), high carbohydrate (HCD, 38.14% carbohydrates), betaine (BET, 1.2% betaine + 39.76% carbohydrates), creatine 1 (CRE1, 0.5% creatine + 1.2% betaine + 39.29% carbohydrates), creatine 2 (CRE2, 1% creatine + 1.2% betaine + 39.50% carbohydrates), and creatine 3 (CRE3, 2% creatine + 1.2% betaine + 39.44% carbohydrates). The results showed that supplementing creatine and betaine together reduced the feed conversion ratio significantly (P < 0.05, compared to CD and HCD) and improved liver health (compared to HCD). Compared with the BET group, dietary creatine significantly increased the abundances of Firmicutes, Bacteroidota, ZOR0006, and Bacteroides and decreased the abundances of Proteobacteria, Fusobacteriota, Vibrio, Crenobacter, and Shewanella in the CRE1 group. Dietary creatine increased the content of taurine, arginine, ornithine, γ-aminobutyric acid (g-ABA), and creatine (CRE1 vs. BET group) and the expression of creatine kinase (ck), sulfinoalanine decarboxylase (csad), guanidinoacetate N-methyltransferase (gamt), glycine amidinotransferase (gatm), agmatinase (agmat), diamine oxidase1 (aoc1), and glutamate decarboxylase (gad) in the CRE1 group. Overall, these results suggested that dietary supplementation of creatine (0.5-2%) did not affect the growth performance, but it altered the gut microbial composition at the phylum and genus levels, which might be beneficial to the gut health of M. amblycephala; dietary creatine also increased the serum content of taurine by enhancing the expressions of ck and csad and increased the serum content of g-ABA by enhancing the arginine content and the expressions of gatm, agmat, gad, and aoc1.

Cerebral Creatine Deficiency Affects the Timing of Oligodendrocyte Myelination.

Cerebral creatine deficiency syndrome (CCDS) is an inborn error of metabolism characterized by intellectual delays, seizures, and autistic-like behavior. However, the role of endogenously synthesized creatine on CNS development and function remains poorly understood. Here, magnetic resonance spectroscopy of adult mouse brains from both sexes revealed creatine synthesis is dependent on the expression of the enzyme, guanidinoacetate methyltransferase (GAMT). To identify Gamt-expressed cells, and how Gamt affects postnatal CNS development, we generated a mouse line by knocking-in a GFP, which is expressed on excision of Gamt We found that Gamt is expressed in mature oligodendrocytes during active myelination in the developing postnatal CNS. Homozygous deletion of Gamt resulted in significantly reduced mature oligodendrocytes and delayed myelination in the corpus callosum. Moreover, the absence of endogenous creatine resulted in altered AMPK signaling in the brain, reduced brain creatine kinase expression in cortical neurons, and signs of axonal damage. Experimental demyelination in mice after tamoxifen-induced conditional deletion of Gamt in oligodendrocyte lineage cells resulted in delayed maturation of oligodendrocytes and myelin coverage in lesions. Moreover, creatine and cyclocreatine supplementation can enhance remyelination after demyelination. Our results suggest endogenously synthesized creatine controls the bioenergetic demand required for the timely maturation of oligodendrocytes during postnatal CNS development, and that delayed myelination and altered CNS energetics through the disruption of creatine synthesis might contribute to conditions, such as CCDS.SIGNIFICANCE STATEMENT Cerebral creatine deficiency syndrome is a rare disease of inborn errors in metabolism, which is characterized by intellectual delays, seizures, and autism-like behavior. We found that oligodendrocytes are the main source of endogenously synthesized creatine in the adult CNS, and the loss of endogenous creatine synthesis led to delayed myelination. Our study suggests impaired cerebral creatine synthesis affects the timing of myelination and may impact brain bioenergetics.

CREATINE KINASE EXPRESSION IS PROTECTIVE IN A MOUSE COLITIS MODEL

Abstract BACKGROUND We have previously identified a loss of expression of creatine pathway proteins in mucosal tissue samples from inflammatory bowel disease patients. This is important as creatine is vital to ATP buffering in energetically active cells. The goal of this study was to determine the impact of decreased creatine kinase (CK) expression on mucosal inflammation by utilizing a whole body CK Brain and CK Mitochondrial knockout mouse (CKB/MitKO) in the dextran sulfate sodium (DSS) model of acute colitis. METHODS CKB/MitKO and matched controls were administered 1.5% DSS in drinking water for 5 days and assessed by body weight loss, disease activity index, mucosal permeability, histology and inflammatory cytokine production by Mesoscale analysis. In subsequent experiments, interferon-γ (IFN-γ) was given by intraperitoneal injection during the DSS experiment. We also analyzed transcriptional differences between CKB/MitKO and controls using a transcription factor array and western blot. Finally, we evaluated the impact of CK on the regulation of IFN-γ and transcriptional regulation of IFN-γ production in immune cells by flow cytometry. RESULTS Loss of CKB/Mit did not result in detectable baseline inflammation or barrier dysfunction in CKB/MitKO mice as compared to controls. However, in the setting of the chemical irritant DSS, CKB/MitKO mice had significantly increased weight loss, disease activity, intestinal permeability, histologic inflammation and decreased colon length. While control mice treated with DSS had significant increases in mucosal IFN-γ, the CKB/MitKO mice had strikingly absent mucosal protein concentrations of IFN-γ. Although IFN-γ is commonly considered a pro-inflammatory cytokine, it has also been shown to help promote inflammatory resolution. Therefore, we proceeded to add back IFN-γ in DSS experiments and we identified significant protection from weight loss and histologic damage with the addition of IFN-γ. We went on to identify transcription factor differences between CKB/MitKO and control splenocytes that revealed a &amp;gt;40-fold increase in the hypoxia responsive factor, HIF-1a, in CKB/MitKO splenocytes. We confirmed a causative relationship between HIF-1 expression and IFN-γ by treating mouse splenocytes with a HIF stabilizer and identified that HIF stabilization results in a reduction of IFN-γ production by CD4+ and CD8+ T cells. CONCLUSIONS CK is an essential energetic regulator. Using CK knockout mice we have identified an important role for CK in regulating IFN-γ production, mediated at least in part by HIF stabilization. These findings support a novel role for CK in tissue protection by immune regulation during acute colitis. Better understanding the role of energetics and the creatine pathway in particular may provide novel therapeutic options in inflammatory bowel disease.

Mealworm Ethanol Extract Enhances Myogenic Differentiation and Alleviates Dexamethasone-Induced Muscle Atrophy in C2C12 Cells.

Aging, and other disease-related muscle disorders are serious health problems. Dexamethasone (DEX), a synthetic glucocorticoid, can trigger skeletal muscle atrophy. This study examined the effects of mealworm (Tenebrio molitor larva) ethanol extract (TME) on C2C12 myoblast differentiation and DEX-induced myotube atrophy. TME induced myotube formation compared to the differentiation medium (DM) group. TME also significantly increased the mRNA expression of muscle creatine kinase (CKm) and myogenic regulatory factors (MRFs), such as myogenin (MyoG), myogenic factor (Myf)5, and MRF4 (Myf6). TME dramatically increased the muscle-specific protein, MyoG, compared to the control, whereas the expression of myogenic differentiation 1 (MyoD) remained unchanged. It also activated the mammalian target of rapamycin (mTOR) signaling pathway. In the DEX-induced muscle atrophy C2C12 model, TME reduced the gene expression of atrogin-1, muscle RING finger protein-1 (MuRF-1), and myostatin, which are involved in protein degradation in skeletal muscles. Furthermore, TME elevated the phosphorylation of forkhead box O3 (FoxO3α) and protein kinase B (Akt). These findings suggest that TME can enhance myotube hypertrophy by regulating the mTOR signaling pathway, and can rescue DEX-induced muscle atrophy by alleviating atrophic muscle markers mediated by Akt activation. Thus, TME can be a potential therapeutic agent for treating muscle weakness and atrophy.

Desmin Knock-Out Cardiomyopathy: A Heart on the Verge of Metabolic Crisis.

Desmin mutations cause familial and sporadic cardiomyopathies. In addition to perturbing the contractile apparatus, both desmin deficiency and mutated desmin negatively impact mitochondria. Impaired myocardial metabolism secondary to mitochondrial defects could conceivably exacerbate cardiac contractile dysfunction. We performed metabolic myocardial phenotyping in left ventricular cardiac muscle tissue in desmin knock-out mice. Our analyses revealed decreased mitochondrial number, ultrastructural mitochondrial defects, and impaired mitochondria-related metabolic pathways including fatty acid transport, activation, and catabolism. Glucose transporter 1 and hexokinase-1 expression and hexokinase activity were increased. While mitochondrial creatine kinase expression was reduced, fetal creatine kinase expression was increased. Proteomic analysis revealed reduced expression of proteins involved in electron transport mainly of complexes I and II, oxidative phosphorylation, citrate cycle, beta-oxidation including auxiliary pathways, amino acid catabolism, and redox reactions and oxidative stress. Thus, desmin deficiency elicits a secondary cardiac mitochondriopathy with severely impaired oxidative phosphorylation and fatty and amino acid metabolism. Increased glucose utilization and fetal creatine kinase upregulation likely portray attempts to maintain myocardial energy supply. It may be prudent to avoid medications worsening mitochondrial function and other metabolic stressors. Therapeutic interventions for mitochondriopathies might also improve the metabolic condition in desmin deficient hearts.

Creatine Kinase Is Decreased in Childhood Asthma.

Rationale: The identification of novel molecules associated with asthma may provide insights into the mechanisms of disease and their potential clinical implications. Objectives: To conduct a screening of circulating proteins in childhood asthma and to study proteins that emerged from human studies in a mouse model of asthma. Methods: We included 2,264 children from eight birth cohorts from the Mechanisms of the Development of ALLergy project and the Tucson Children's Respiratory Study. In cross-sectional analyses, we tested 46 circulating proteins for association with asthma in the selection stage and carried significant signals forward to a validation and replication stage. As CK (creatine kinase) was the only protein consistently associated with asthma, we also compared whole blood CK gene expression between subjects with and without asthma (n = 249) and used a house dust mite (HDM)-challenged mouse model to gain insights into CK lung expression and its role in the resolution of asthma phenotypes. Measurements and Main Results: As compared with the lowest CK tertile, children in the highest tertile had significantly lower odds for asthma in selection (adjusted odds ratio, 95% confidence interval: 0.31; 0.15-0.65; P = 0.002), validation (0.63; 0.42-0.95; P = 0.03), and replication (0.40; 0.16-0.97; P = 0.04) stages. Both cytosolic CK forms (CKM and CKB) were underexpressed in blood from asthmatics compared with control subjects (P = 0.01 and 0.006, respectively). In the lungs of HDM-challenged mice, Ckb expression was reduced, and after the HDM challenge, a CKB inhibitor blocked the resolution of airway hyperresponsiveness and reduction of airway mucin. Conclusions: Circulating concentrations and gene expression of CK are inversely associated with childhood asthma. Mouse models support a possible direct involvement of CK in asthma protection via inhibition of airway hyperresponsiveness and reduction of airway mucin.

Molecular Investigations of the Effect of Thermal Manipulation During Embryogenesis on the Enzymatic Activity of Creatine Kinase and Lactate Dehydrogenase in Broiler Muscle

Incubating temperature and timing or duration is critical to determine the optimum protocol of thermal manipulation (TM), which underlines muscle growth improvement. Therefore, the aim of the present study is to determine the optimum period of embryonic TM that may result in the improvement of pectoral and thigh muscle myogenesis. This is done by investigating the level of mRNA expression of creatine kinase (CK) and lactate dehydrogenase (LDH). An additional goal is measuring the blood levels of CK and LDH as a biomarker of muscle injury due to the experimental thermal challenge on post-hatch day 35. The study was conducted on 1,440 fertile eggs (Ross broilers) that were divided randomly and equally into a control group and four treatment groups (TM1, TM2, TM3, and TM4). The treatment groups were daily subjected to TM at 39 ºC for 18h with 65% relative humidity (RH) during embryonic days (EDs) 7-11, 11-15, 15-18, and 7-18, respectively. Among the thermally manipulated groups that were investigated, TM1 (ED 7-11) resulted in significant improvement of mRNA expression and enzymatic concentration of CK and LDH in muscle during embryogenesis, as compared to the control. Six hours of TC showed the highest significant CK and LDH expression and concentration levels in the control as compared to TM groups. Thus, the results of this study indicate that TM during ED 7-11 improves pectoral and thigh muscles’ response to heat stress without adversely affecting their performance. This finding could be used by commercial breeders to enhance local broiler production.

MicroRNA-124a Protects the Myocardium Against Ischemia Reperfusion Injury Through Regulation of the Notch Signaling Pathway.

IntroductionThis study’s objective is to investigate the effect of downregulation of micro ribonucleic acid (miR)-124a on myocardial injury after ischemia reperfusion (I/R) in rats.MethodsSprague Dawley (SD) rats (n=20) were divided into four groups - sham, I/R, I/R+miR-124a antagomir (I/R+ant-miR-124a), and I/R+ant-normal control (NC). The pathomorphological and infarct size variance of injured myocardial tissues with IR were conducted with hematoxylin (HE) and triphenyltetrazolium chloride (TTC) staining. The expression levels of miR-124a, BAX, nuclear factor kappa B (NF-KB), Notch1, and Hes1 were examined by quantitative real-time polymerase chain reaction or Western blot in myocardium. The inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α) were detected by the enzyme-linked immunosorbent assay, as well as the activity of lactate dehydrogenase (LDH) and creatine kinase (CK) in serum by colorimetry.ResultsThe expression of miR-124a was increased in the I/R group. Compared with I/R and I/R+ant-NC groups, after downregulating miR-124a, the expression of IL-6, IL-1β, TNF-α, BAX, NF-KB, LDH, and CK were decreased, but the expression of Notch1 and Hes1 were increased. In HE staining, myocardial tissue edema, red blood cell exudation, and myocardial fiber arrangement disorder were accompanied by inflammatory cell infiltration and local necrosis in the I/R group. However, the pathological injury of myocardial tissue was alleviated after downregulating miR-124a. Additionally, TTC results showed that the myocardial infarction area was decreased in the I/R+ant-miR-124a group.ConclusionDownregulation of miR-124a expression through Notch pathway can significantly reduce myocardial damage after 24 hours of I/R in SD rats. Therefore, miR-124a may become a potential therapeutic target for I/R injury.

Oral Supplementation With Butyrate Improves Myocardial Ischemia/Reperfusion Injury via a Gut-Brain Neural Circuit.

Objective: Butyrate, a short-chain fatty acid (SCFA) produced by the intestinal microbiota, plays a protective role in cardiovascular diseases (CVDs), but the mechanisms involved in this process remain unelucidated. We aimed to explore the effect of butyrate on myocardial ischemia/reperfusion (I/R) injury through the gut-brain neural circuit.Methods: Rats were randomly divided into four groups: sham group (sham), I/R group (I/R), I/R+ butyrate group (butyrate), and I/R+ butyrate+ vagotomy group (vagotomy). The rats were treated with sodium butyrate for 4 weeks, and the gut-brain neural circuit was investigated by subdiaphragmatic vagotomy.Results: Butyrate treatment significantly reduced the infarct size and decreased the expression of creatine kinase (CK), creatine kinase myocardial isoenzyme (CK-MB), and lactate dehydrogenase (LDH) compared with the values found for the I/R group. In addition, the I/R-induced increases in inflammation, oxidative stress, and apoptosis were attenuated by butyrate. However, the above-mentioned protective effects were diminished by subdiaphragmatic vagotomy. The RNA sequencing results also revealed that the butyrate-induced protective changes at the cardiac transcription level were reversed by vagotomy. An analysis of the heart rate variability (HRV) and the detection of norepinephrine (NE) showed that butyrate significantly inhibited the I/R-induced autonomic imbalance, but this inhibition was not observed in the vagotomy group. Butyrate treatment also suppressed the neural activity of the paraventricular nucleus (PVN) and superior cervical ganglion (SCG), and both of these effects were lost after vagotomy.Conclusions: Butyrate treatment significantly improves myocardial I/R injury via a gut-brain neural circuit, and this cardioprotective effect is likely mediated by suppression of the sympathetic nervous system.

Electroacupuncture Pretreatment at Neiguan (PC6) attenuates autophagy in rats with myocardial ischemia reperfusion through the phosphatidylinositol 3-kinase-Akt-mammalian target of rapamycin pathway.

To investigate the protective efficacy of electroacupuncture (EA) pretreatment at Neiguan (PC6) on myocardial ischemia-reperfusion (I/R) in rats. Fifty rats were randomly divided into five groups (n = 10): sham operation group, model group (underwent in vivo myocardial I/R), EA pretreatment group [EA at Neiguan (PC 6) 1 week before I/R], wortmannin group (1 week before I/R, the PI3K inhibitor, wortmannin, was injected), EA pretreatment + wortmannin group (both pretreatments were performed simultaneously). After establishing the I/R model, 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to analyze the weight and area of the myocardial infarction tissue. The biosignal and pressure test system was used to determine the left ventricular systolic mean pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), fractional shortening (FS), and ejection fraction (EF). Ultraviolet spectrophotometry was used to determine the expression of creatine kinase (CK)-MB, inducible nitric oxide synthase (iNOS), and total antioxidant capacity (T-AOC) in the serum. The expression of autophagy-related protein 13 (ATG13), mammalian target of rapamycin (mTOR), and phosphatidylinositol 3-kinase (PI3K) in cardiac muscle cells was determined by immunofluorescence. Hematoxylin and eosin staining was used to observe autophagy-related pathological changes in rat cardiomyocytes, and ultrastructural changes of cardiomyocytes were examined by transmission electron microscopy. In this study, the infarction size and tissue weight of the EA pretreatment group were decreased compared with the model group (P < 0.0001). Furthermore, compared with the model group, the LVEDP values of the EA pretreatment group were significantly reduced (P = 0.0091), and the LVSP, FS, and EF values were slightly increased (P = 0.0007, 0.0020, 0.0031). EA pretreatment also significantly decreased the expression of CK-MB and iNOS, while it increased the expression of T-AOC in the serum of rats with I/R injury (P < 0.0001). Furthermore, EA pretreatment slightly widened the myocardial fiber space, reduced necrosis and myocardial cell swelling and maintained the nucleus and mitochondria structure intact. EA pretreatment promoted autophagy flux and alleviated myocardial I/R injury through the PI3K-Akt-mTOR pathway.

Seasonal expression of cytoplasmic creatine kinase in the epididymal epithelium of Pelodiscus sinensis

ABSTRACT During hibernation of Pelodiscus sinensis, sperm mature and are stored in the epididymis. We investigated seasonal changes in the morphology of epithelial cells of the epididymis of P. sinensis and changes in expression of cytoplasmic creatine kinase (CK). We found that the epididymal epithelium proliferates rapidly to form multiple layers from June to September, while the epididymal epithelial cells are arranged in a single layer from October to May. From the March before the mating period to the end of the mating period in September, a large amount of neutral glycoprotein is secreted in the epididymal epithelium and in the sperm aggregation area; after October, the glycoprotein in the epididymis decreases. At sperm maturation, cytoplasmic CK is expressed abundantly in the villous epithelium, which is formed by proliferation of epididymal epithelial cells. During hibernation and reproduction, the epididymal epithelium of P. sinensis exhibits different proliferation and secretion patterns as the animal adapts to two types of sperm storage. Cytoplasmic CK may participate in regulating the energy metabolism of the epididymal epithelium; it is an important enzyme for regulating sperm maturation.

Creatine metabolism in the uterus: potential implications for reproductive biology

Creatine is an amino acid derivative synthesized from arginine, glycine and methionine. It serves as the substrate for the creatine kinase system, which is vital for maintaining ATP levels in tissues with high and fluctuating energy demand. There exists evidence that the creatine kinase system operates in both the endometrial and myometrial layers of the uterus. While use and regulation of this system in the uterus are not well understood, it is likely to be important given uterine tissues undergo phases of increased energy demand during certain stages of the female reproductive cycle, pregnancy, and parturition. This review discusses known adaptations of creatine metabolism in the uterus during the reproductive cycle (both estrous and menstrual), pregnancy and parturition, highlighting possible links to fertility and the existing knowledge gaps. Specifically, we discuss the adaptations and regulation of uterine creatine metabolite levels, cell creatine transport, de novo creatine synthesis, and creatine kinase expression in the various layers and cell types of the uterus. Finally, we discuss the effects of dietary creatine on uterine metabolism. In summary, there is growing evidence that creatine metabolism is up-regulated in uterine tissues during phases where energy demand is increased. While it remains unclear how important these adaptations are in the maintenance of healthy uterine function, furthering our understanding of uterine creatine metabolism may uncover strategies to combat poor embryo implantation and failure to conceive, as well as enhancing uterine contractile performance during labor.

Resistance Training during Chemotherapy with Doxorubicin.

Investigate the effects of RT before and during a 4-wk course of incremental DOX treatment on skeletal muscle function. Male, Sprague-Dawley rats (N = 36) were randomly assigned to the following groups: sedentary+saline (SED + SAL), sedentary+DOX (SED + DOX), RT + SAL, or RT + DOX. The RT protocol utilized a raised cage model, which provided progressive hindlimb loading throughout the 14-wk study, whereas SED animals were kept in normal housing. Starting at week 10, DOX-treated animals received 3 mg·kg DOX weekly for 4 wk (12 mg·kg cumulative); whereas SAL-treated groups received 0.9% NaCl as a placebo. Grip strength was recorded at 0, 10, 12, and 14 wk. Ex vivo muscle function was performed on excised soleus (SOL) and extensor digitorum longus (EDL) from the right hind limb 5 d after the last injection and were analyzed for expression of creatine kinase (CK) and creatine transporters. SED + DOX-treated animals had significantly lower EDL mass compared with SED + SAL- and RT + DOX-treated animals. Grip strength, EDL maximal force, and EDL force development were significantly lower in SED + DOX-treated animals compared with RT + SAL and SED + SAL. No significant differences in EDL function were found between RT + DOX and RT + SAL animals. DOX treatment reduced expression of CK in the SOL, which abated with RT. Low-intensity RT may attenuate the decline in skeletal muscle function during incremental DOX treatment.