MicroRNAs (miRNAs or miRs) are small, non-coding RNAs that modulate mRNA stability and post-transcriptional translation. A growing body of evidence indicates that specific miRNAs can affect the ...cellular function of cardiomyocytes. In the present study, miRNAs that are highly expressed in the heart were overexpressed in neonatal rat ventricular myocytes, and cellular ATP levels were assessed. As a result, miR-15b, -16, -195, and -424, which have the same seed sequence, the most critical determinant of miRNA targeting, decreased cellular ATP levels. These results suggest that these miRNAs could specifically down-regulate the same target genes and consequently decrease cellular ATP levels. Through a bioinformatics approach, ADP-ribosylation factor-like 2 (Arl2) was identified as a potential target of miR-15b. It has already been shown that Arl2 localizes to adenine nucleotide transporter 1, the exchanger of ADP/ATP in mitochondria. Overexpression of miR-15b, -16, -195, and -424 suppressed the activity of a luciferase reporter construct fused with the 3'-untranslated region of Arl2. In addition, miR-15b overexpression decreased Arl2 mRNA and protein expression levels. The effects of Arl2 siRNA on cellular ATP levels were the same as those of miR-15b, and the expression of Arl2 could restore ATP levels reduced by miR-15b. A loss-of-function study of miR-15b resulted in increased Arl2 protein and cellular ATP levels. Electron microscopic analysis revealed that mitochondria became degenerated in cardiomyocytes that had been transduced with miR-15b and Arl2 siRNA. The present results suggest that miR-15b may decrease mitochondrial integrity by targeting Arl2 in the heart.
Herbicides targeting photosystem II (PSII) block the electron transfer beyond QA by binding to the QB site. Upon binding, the redox potential of QA shifts differently depending on the types of ...herbicides. In this study, we have investigated the structures, interactions, and locations of phenolic herbicides in the QB site to clarify the molecular mechanism of the QA potential shifts by herbicides. Fourier transform infrared (FTIR) difference spectra upon photoreduction of the preoxidized non-heme iron (Fe2+/Fe3+ difference) were measured with PSII membranes in the presence of bromoxynil or ioxynil. The CN and CO stretching vibrations of these phenolic herbicides were identified at 2215−2200 and 1516−1505 cm−1, respectively, in the Fe2+/Fe3+ difference spectra. Comparison with the spectra of bromoxynil in ethanol solutions along with density functional theory analysis strongly suggests that the phenolic herbicides take a deprotonated form in the binding pocket. In addition, the CN stretching, NH bending, and NH stretching vibrations of a His side chain, which were found at 1109−1101, 1187−1185, and 3000−2500 cm−1, respectively, in the Fe2+/Fe3+ difference spectra, showed characteristic features in the presence of phenolic herbicides. These signals are probably attributed to D1-His215, one of the ligands to the non-heme iron. Docking calculations for herbicides to the QB pocket confirmed the binding of deprotonated bromoxynil to D1-His215 at the CO group, whereas the protonated form of bromoxynil and DCMU were found to bind to the opposite side of the pocket without an interaction with D1-His215. From these results, it is proposed that a strong hydrogen bond of the phenolate CO group with D1-His215 induces the change in the hydrogen bond strength of the QA CO group through the QA-His-Fe-His-phenolate bridge causing the downshift of the QA redox potential.
A better understanding on the transport phenomena, momentum (flow), heat, and mass transfer of acoustically levitated droplets is very important for several scientific and industrial fields. The flow ...generated by a nonlinear acoustic field is known as acoustic streaming. In acoustic levitation, multiscale acoustic streaming can be induced both inside and outside the droplet. In the internal flow field, the streaming configuration is affected by the physical properties of the droplet. The external flow field can be characterized by the applied sound pressure, physical properties of the droplet, and surrounding gas. These flow fields are instrumental in the heat and mass transfer of the levitated droplet. This review provides a recent advancement on the flow fields, heat, and mass transfer enhancement of the acoustically levitated droplet.
Smoking cessation plays a crucial role in reducing preventable morbidity and mortality. However, some smokers find smoking cessation difficult, despite receiving treatment. This includes heavy ...smokers with chronic obstructive pulmonary disease, smokers with a psychiatric disorder, and female and underage smokers. This review article describes smoking cessation approaches for patients who find it difficult to quit smoking.
Retrovirus insertion-mediated random mutagenesis was applied in 3T3-L1 preadipocyte cells to better understand the molecular basis of obesity (the expansion of individual adipocytes). We found that ...tryptophan hydroxylase-1, a rate-limiting enzyme for the synthesis of serotonin (5-HT), is expressed in adipocytes and is required for their differentiation. A 5-HT type 2A receptor (5-HT(2A)R) antagonist, ketanserin, and a 5-HT(2c)R antagonist, SB-242084, inhibited adipocyte differentiation. Because 5-HT(2c)R mRNA levels are up-regulated during adipocyte differentiation and micro-RNA (miR)-448 is located in the fourth intron of Htr2c, we also studied the role of miR-448 in 3T3-L1 cells. Through a bioinformatics approach, Krüppel-like factor 5 (KLF5) was identified as a potential target of miR-448. Using a luciferase reporter assay, we confirmed that miR-448 targets the Klf5 3'-intranslated region. Overexpression of miR-448 reduced the expression of Klf5 and adipocyte differentiation, which was confirmed by the reduced expression of adipogenic genes and triglyceride accumulation. To examine the loss of miR-448 function, we constructed a decoy gene that had tandem complementary sequences for miR-448 in the 3'-untranslated region of a luciferase gene under the control of a cytomegalovirus promoter. When the miR-448 decoy gene was introduced into 3T3-L1 preadipocytes, KLF5 was up-regulated and triglyceride concentration was increased. In this study, we identified the regulation of adipocyte differentiation by 5-HT, 5-HT(2A)R, and 5-HT(2C)R. miR-448-mediated repression of KLF5 was identified as a negative regulator for adipocyte differentiation.
The zinc finger protein GATA4 is a transcription factor involved in cardiomyocyte hypertrophy. It forms a functional complex with the intrinsic histone acetyltransferase (HAT) p300. The HAT activity ...of p300 is required for the acetylation and transcriptional activity of GATA4, as well as for cardiomyocyte hypertrophy and the development of heart failure. In the present study, we have identified Receptor for Activated Protein Kinase C1 (RACK1) as a novel GATA4-binding protein using tandem affinity purification and mass spectrometry analyses. We found that exogenous RACK1 repressed phenylephrine (PE)-induced hypertrophic responses, such as myofibrillar organization, increased cell size, and hypertrophy-associated gene transcription, in cultured cardiomyocytes. RACK1 physically interacted with GATA4 and the overexpression of RACK1 reduced PE-induced formation of the p300/GATA4 complex and the acetylation and DNA binding activity of GATA4. In response to hypertrophic stimulation in cultured cardiomyocytes and in the hearts of hypertensive heart disease model rats, the tyrosine phosphorylation of RACK1 was increased, and the binding between GATA4 and RACK1 was reduced. In addition, the tyrosine phosphorylation of RACK1 was required for the disruption of the RACK1/GATA4 complex and for the formation of the p300/GATA4 complex. These findings demonstrate that RACK1 is involved in p300/GATA4-dependent hypertrophic responses in cardiomyocytes and is a promising therapeutic target for heart failure.
•RACK1 inhibits cardiomyocyte hypertrophy by inhibiting the interaction between p300 and GATA4.•The tyrosine residue of RACK1 is phosphorylated by hypertrophic stimulation.•The phosphorylation of RACK1 triggers the dissociation of RACK1 from GATA4.•Inhibition of RACK1 phosphorylation represses cardiomyocyte hypertrophy.
Introduction Even after the peak of the COVID-19 pandemic, the number of mild cases remains high, requiring continuous control. Curcumin, owing to its anti-inflammatory properties, can suppress vital ...proliferation and cytokine secretion in animal models. We developed a highly absorbable curcumin, curcuRouge.sup.R (cR), which is approximately 100 times more orally bioavailable than conventional curcumin. We evaluated the effect of cR on the inhibition of disease progression in asymptomatic or mildly symptomatic COVID-19 patients. Methods This study evaluated the effect of 7-day oral intake of cR (360 mg twice daily). Patients within 5 days of COVID-19 diagnosis were randomly assigned to a placebo or cR group in a double-blind manner. Results Primary endpoint events body temperature (BT) greater than or equal to 37.5 degreesC and saturation of percutaneous oxygen (SpO2) < 96% were fewer than expected, and the rate of these events was 2.8% in the cR group (2/71) and 6.0% in the placebo group (4/67); hazard ratio (HR) = 0.532, 95% confidence interval (CI) 0.097-2.902. Patients receiving cR tended to take fewer antipyretic medications than those receiving placebo (HR = 0.716, 95% CI 0.374-1.372). Among patients with a normal range of BT at baseline, the BT change rate was significantly (p = 0.014) lower in the cR group (- 0.34%) versus placebo (- 0.01%). Conclusion The relative suppression of event rates and antipyretic medications taken, and significant decrease of subclinical BT support the anti-inflammatory effects of cR in asymptomatic or mildly symptomatic patients with COVID-19. Trial registration: Japan Registry of Clinical Trials (CRB5200002). Keywords: COVID-19, Curcumin, curcuRouge.sup.R, Clinical trial, Saturation of percutaneous oxygen, Body temperature
Clinical studies have indicated that 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, also known as statins, can potentially inhibit chronic heart failure. In the Stat-LVDF ...study, a difference was noted in terms of the effect of lipophilic pitavastatin (PTV) and hydrophilic rosuvastatin (RSV) on plasma BNP, suggesting that statin lipophilicity and pharmacokinetics change the pleiotropic effect on heart failure in humans. Therefore, we assessed the beneficial effects of PTV on hypertrophy in cardiac myocytes compared with RSV at clinically used doses. Cultured cardiomyocytes were stimulated with 30 μM phenylephrine (PE) in the presence of PTV (250 nM) or RSV (50 nM). These doses were calculated based on the maximum blood concentration of statins used in clinical situations in Japan. The results showed that PTV, but not RSV, significantly inhibits the PE-induced increase in cell size and leucine incorporation without causing cell toxicity. In addition, PTV significantly suppressed PE-induced mRNA expression of hypertrophic response genes. PE-induced ERK phosphorylation was inhibited by PTV, but not by RSV. Furthermore, PTV significantly suppressed the angiotensin-II-induced proline incorporation in primary cultured cardiac fibroblasts. In conclusion, a clinical dose of PTV was noted to directly inhibit cardiomyocyte hypertrophy and cardiac fibrosis, suggesting that lipophilic PTV can be a potential drug candidate against chronic heart failure.
•Myostatin is a myokine which negatively regulates skeletal muscle growth.•Serum myostatin level was positively correlated with muscle mass in obese patients.•Serum myostatin was positively ...correlated with serum immunoreactive insulin level.•Correlation of myostatin with immunoreactive insulin did not depend on muscle mass.•Myostatin may be a mediator of potential hyperinsulinemia–muscle atrophy axis.
The protein myostatin is a member of the transforming growth factor β superfamily. This is mainly expressed in skeletal muscle and negatively regulates skeletal muscle growth. The present study aimed to elucidate the associations among circulating myostatin level, skeletal muscle mass, and metabolic profiles in Japanese obese patients.
Japanese obese outpatients (n = 74) were enrolled. We measured clinical parameters, quantified serum myostatin levels, and examined their associations in a cross-sectional manner.
Both total skeletal muscle mass and serum myostatin level were higher in males than in females. Among 74 patients, serum myostatin level was positively correlated with skeletal muscle mass and serum immunoreactive insulin (IRI) level correlation coefficient (r) = 0.294, P = 0.011; r = 0.262, P = 0.024, respectively. Furthermore, multivariate linear regression analysis revealed that serum myostatin level was positively correlated with IRI after adjusting for gender and skeletal muscle mass (β-coefficient = 0.230, P = 0.029, R2 = 0.236).
In obese patients, serum myostatin level was elevated in conjunction with an increase in IRI level independent of skeletal muscle mass. This may imply possible novel pathological implications of serum myostatin in muscle mass and metabolism in obese patients with hyperinsulinemia.
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•curcuRougeTM is a micro amorphous curcumin formulation with light red color.•The bioavailability of curcuRougeTM was 3.7-fold higher than that of Theracurmin® in rats.•The ...bioavailability of curcuRougeTM was 3.4-fold higher than that of Theracurmin® in twelve healthy volunteers.•curcuRougeTM achieved Cmax in a shorter time than Theracurmin® in rats and humans.
Curcumin derived from Curcuma longa has beneficial pharmacological effects. However, its bioavailability is very low. To improve its bioavailability, we developed a novel amorphous formulation of curcumin, called curcuRougeTM. We investigated the bioavailability of curcuRougeTM and compared its efficiency with that of Theracurmin®. Male Sprague–Dawley rats were orally administered curcuRougeTM or Theracurmin® (10 mg/kg of curcumin). Based on the area under the plasma concentration-time curve, the bioavailability of curcuRougeTM was 3.7-fold higher than that of Theracurmin® in rats. We performed a single-dose, double-blind, two-way crossover study to compare the bioavailability of curcuRougeTM and Theracurmin® (90 mg of curcumin) in 12 volunteers (8 males, 4 females). The bioavailability of curcuRougeTM was 3.4-fold higher than that of Theracurmin®. curcuRougeTM achieved Cmax in a shorter time than Theracurmin® in both experiments. These findings indicate that curcuRougeTM, an amorphous formulation of curcumin, shows superior bioavailability to that of Theracurmin®.
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