Abstract Heart as one high ATP consuming organ accounts for 5% of the total oxygen demands. The central question of heart health is how mitochondria fit its needs. Impaired mitochondrial dynamics (fission and fusion) have been observed in failing heart, but whether and how phosphorylation events involved in mitochondrial quality control are still imperceptive. The phosphatase 2A catalytic subunit α (PP2A cα) cardiac-specific knockout mouse (KO), which exhibited a hypertrophic cardiomyopathy phenotype, was studied. We profiled the pattern of morphological and functional alteration of cardiac mitochondria that appeared during postnatal development. Increased heterogeneity of mitochondria and a decreased ATP yield was displayed. Notably, a fission procedure escalated. To illustrate the protagonist of the mitochondrial dynamics, we applied a high-throughput spectrometry-based phosphoproteomic screening following by GO and KEGG pathway annotations for 788 phosphosites, accounting for 90 proteins. Results suggested that the MAPK signaling may be a predominant factor associated with those mitochondrial alternations in KO hearts. Furthermore, we identified hyperphosphorylated ERK2 accumulated into the nucleus regarding PP2Acα depletion. Consequently, Fis1 expression was accelerated at the transcriptional level which facilitated recruitment of Drp1 onto the outer mitochondrial membrane. The mitochondrial fission towards shifting led to excessed mitophagy and is considered the culprit in early mortality. These findings are indicative of the fundamental role of PP2A in mitochondrial dynamics regulation and cardiomyopathy progression. During the progression of heart failure, the phospho-regulation of ERK2 could be a novel therapeutic approach to prevent or attenuate adverse hypertrophic cardiomyopathy.

Dysregulation of cholesterol metabolism can lead to obesity and increase the risk of developing many diseases, including type 2 diabetes and cardiovascular diseases. Our previous studies have identified postsynaptic density-95, disc large, and zonula occludens-1 (PDZ) adaptor proteins Na+/H+ exchange regulatory factor Nherf1 (encoded by Nherf1) and Nherf2 (encoded by Nherf2) to be potential regulators of cholesterol metabolism in vitro. In this study, we explored their physiological regulatory function in vivo by using Nherf1- and Nherf2-deficient (Nherf1-/- and Nherf2-/-), and wild-type (C57BL/6) mice. All mice were fed either a chow diet or a cholesterol-enriched Western diet (42% fat, 0.2% cholesterol) for 8 wk starting at 8-wk-old. Our results demonstrate that Nherf2-/-, but not Nherf1-/-, mice are resistant to diet-induced obesity. In Nherf2-/- mice, serum high-density lipoprotein and low-density lipoprotein/very low-density lipoprotein decreased substantially without affecting lipolysis or steroid hormone levels. In addition, distended gallbladders were observed in Nherf2-/- mice, with reduced bile acid output into the intestine and feces, which correlated with decreased cholesterol reabsorption. This led to attenuated Fxr/Shp signaling in the liver and derepressing Cyp7a1 transcription in the absence of Nherf2. These findings suggest a potential role of in regulating gallbladder emptying and lipid homeostasis, offering new insights into potential therapeutic targets for treating diet-induced obesity.NEW & NOTEWORTHY Nherf2-/- but not Nherf1-/- mice demonstrate a resistance to diet-induced obesity. Notably, male Nherf2-/- mice exhibit impaired glucose tolerance and insulin responsiveness, yet neither sex shows further worsening with diet challenge. In addition, elevated hepatic Cyp7a1 levels were observed in Nherf2-/- mice, but there was reduced cholesterol absorption in the ileum, along with enlarged gallbladders and diminished ileal bile acid content, highlighting significant metabolic alterations linked to Nherf2 deficiency.

Deletion of the SPPL3 sheddase improves allogeneic CAR T cell persistence.

OBJECTIVE:SNAP-25 is one of the key proteins involved in formation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes that are at the core of hormonal secretion and synaptic transmission. Altered expression or function of SNAP-25 can contribute to the development of neuropsychiatric and metabolic disease. A dominant negative (DN) I67T missense mutation in the b-isoform of SNAP-25 (DN-SNAP25mut) mice leads to abnormal interactions within the SNARE complex and impaired exocytotic vesicle recycling, yet the significance of this mutation to any association between the central nervous system and metabolic homeostasis is unknown. METHODS:Here we explored aspects of metabolism, steroid hormone production and neurobehavior of DN-SNAP25mut mice. RESULTS:DN-SNAP25mut mice displayed enhanced insulin function through increased Akt phosphorylation, alongside increased adrenal and gonadal hormone production. In addition, increased anxiety behavior and beigeing of white adipose tissue with increased energy expenditure were observed in mutants. CONCLUSIONS:Our results show that SNAP25 plays an important role in bridging central neurological systems with peripheral metabolic homeostasis, and provide potential insights between metabolic disease and neuropsychiatric disorders in humans.

Apart from its role in inflammation and immunity, chemerin is also involved in white adipocyte biology. To study the role of chemerin in adipocyte metabolism, we examined the function of chemerin in brown adipose tissue. Brown and white adipocyte precursors were differentiated into adipocytes in the presence of Chemerin siRNA. Chemerin-deficient (Chem-/- ) mice were compared to wild-type mice when fed a high-fat diet. Chemerin is expressed during brown adipocyte differentiation and knock down of chemerin mRNA results in decreased brown adipocyte differentiation with reduced fatty acid uptake in brown adipocytes. Chem-/- mice are leaner than wild-type mice but gain more weight when challenged with high-fat diet feeding, resulting in a larger increase in fat deposition. Chem-/- mice develop insulin resistance when on a high-fat diet or due to age. Brown adipose depots in Chem-/- mice weigh more than in wild-type mice, but with decreased mitochondrial content and function. Compared to wild-type mice, male Chem-/- mice have decreased oxygen consumption, CO2 production, energy expenditure, and a lower respiratory exchange ratio. Additionally, body temperature of Chem-/- mice is lower than that of wild-type mice. These results revealed that chemerin is expressed during brown adipocyte differentiation and has a pivotal role in energy metabolism through brown adipose tissue thermogenesis.

miRNAs are endogenous noncoding single-stranded small RNAs of ~22 nucleotides in length that post-transcriptionally repress the expression of their various target genes. They contribute to the regulation of a variety of physiologic processes including embryonic development, differentiation and proliferation, apoptosis, metabolism, hemostasis and inflammation. In addition, aberrant miRNA expression is implicated in the pathogenesis of numerous diseases including cancer, hepatitis, cardiovascular diseases and metabolic diseases. Steroid hormones regulate virtually every aspect of metabolism, and acute and chronic steroid hormone biosynthesis is primarily regulated by tissue-specific trophic hormones involving transcriptional and translational events. In addition, it is becoming increasingly clear that steroidogenic pathways are also subject to post-transcriptional and post-translational regulations including processes such as phosphorylation/dephosphorylation, protein‒protein interactions and regulation by specific miRNAs, although the latter is in its infancy state. Here, we summarize the recent advances in miRNA-mediated regulation of steroidogenesis with emphasis on adrenal and gonadal steroidogenesis.

Loss of DCAF1 and resulting ROS leads to T reg aging and inflammation.

In recent years, the prevalence of obesity, metabolic syndrome and type 2 diabetes is increasing dramatically. They share pathophysiological mechanisms and often lead to cardiovascular diseases. The ZDSD rat was suggested as a new animal model to study diabetes and the metabolic syndrome. In the current study, we have further characterized metabolic and hepatic gene expression changes in ZDSD rats. Immuno-histochemical staining of insulin and glucagon on pancreas sections of ZDSD and control SD rats revealed that ZDSD rats have severe damage to their islet structures as early as 15 weeks of age. Animals were followed till they were 26 weeks old, where they exhibited obesity, hypertension, hyperglycemia, dyslipidemia, insulin resistance and diabetes. We found that gene expressions involved in glucose metabolism, lipid metabolism and amino acid metabolism were changed significantly in ZDSD rats. Elevated levels of ER stress markers correlated with the dysregulation of hepatic lipid metabolism in ZDSD rats. Key proteins participating in unfolded protein response pathways were also upregulated and likely contribute to the pathogenesis of dyslipidemia and insulin resistance. Based on its intact leptin system, its insulin deficiency, as well as its timeline of disease development without diet manipulation, this insulin resistant, dyslipidemic, hypertensive, and diabetic rat represents an additional, unique polygenic animal model that could be very useful to study human diabetes.

Creosote bush (Larrea tridentata)-derived nordihydroguaiaretic acid (NDGA) was shown to have profound effects on the core components of metabolic syndrome. This study investigated the in vivo potential of NDGA for prevention or attenuation of the pathophysiologic abnormalities of NASH. A novel dietary NASH model with feeding C57BL/6J mice with a high trans-fat, high cholesterol and high fructose (HTF) diet, was used. The HTF diet fed mice exhibited obesity, insulin resistance, hepatic steatosis, fibrosis, inflammation, ER stress, oxidative stress, and liver injury. NDGA attenuated these metabolic abnormalities as well as hepatic steatosis and fibrosis together with attenuated expression of genes encoding fibrosis, progenitor and macrophage markers with no effect on the levels of mRNAs for lipogenic enzymes. NDGA increased expression of fatty acid oxidation genes. In conclusion, NDGA exerts anti-NASH/anti-fibrotic actions and raises the therapeutic potential of NDGA for treatment of NASH patients with fibrosis and other associated complications.

ACSL4 is a member of the ACSL family that catalyzes the conversion of long-chain fatty acids to acyl-coenzyme As, which are essential for fatty-acid incorporation and utilization in diverse metabolic pathways, including cholesteryl ester synthesis. Steroidogenic tissues such as the adrenal gland are particularly enriched in cholesteryl esters of long-chain polyunsaturated fatty acids, which constitute an important pool supplying cholesterol for steroid synthesis. The current studies addressed whether ACSL4 is required for normal steroidogenesis. CYP11A1 promoter‒mediated Cre was used to generate steroid tissue‒specific ACSL4 knockout (KO) mice. Results demonstrated that ACSL4 plays an important role in adrenal cholesteryl ester formation, as well as in determining the fatty acyl composition of adrenal cholesteryl esters, with ACSL4 deficiency leading to reductions in cholesteryl ester storage and alterations in cholesteryl ester composition. Statistically significant reductions in corticosterone and testosterone production, but not progesterone production, were observed in vivo, and these deficits were accentuated in ex vivo and in vitro studies of isolated steroid tissues and cells from ACSL4-deficient mice. However, these effects on steroid production appear to be due to reductions in cholesteryl ester stores rather than disturbances in signaling pathways. We conclude that ACSL4 is dispensable for normal steroidogenesis.

Cholesterol is an important component of plasma membranes (PMs) and the precursor of all steroid hormones. In steroidogenic tissues, upon hormone stimulation, there is a rapid transfer of cholesterol to the mitochondria, which is the site of the initial step in steroidogenesis. In the current study, we examined PM cholesterol trafficking for steroidogenesis. In a mitochondrial reconstitution assay, adrenal PMs supported steroidogenesis in the absence of additional transport proteins. Depletion of cholesterol in PMs by 50% eliminated the membranes' ability to support steroidogenesis in vitro and reduced steroid production in intact Y1 adrenocortical cells. Syntaxin (STX)-5 and α-soluble N-ethylmaleimide-sensitive factor attachment protein (α-SNAP) are enriched in adrenal PMs, and adrenocorticotropic hormone treatment of rats recruited STX5 and α-SNAP to adrenal PMs and mitochondria. Immunodepletion of STX5 and α-SNAP from PMs decreased steroidogenesis supported by PMs in vitro. Protease digestion of PMs decreased, whereas recombinant STX5 or α-SNAP restored, the PMs' ability to support steroidogenesis. Knockdown of either STX5 or α-SNAP in Y1 cells decreased stimulated steroidogenesis. These results indicate that STX5 and α-SNAP facilitate cholesterol trafficking from PMs to mitochondria for adrenal steroid synthesis and underscore the importance of vesicular trafficking of PM cholesterol for steroidogenesis.-Deng, B., Shen, W.-J., Dong, D., Azhar, S., Kraemer, F. B. Plasma membrane cholesterol trafficking in steroidogenesis.

Our understanding of how metabolic switches occur in the failing heart is still limited. Here, we report the emblematic pattern of metabolic alternations in two different mouse models. PP2Acα deficient hearts exhibited a dramatic decrease in the levels of mRNA encoding for transporters and enzymes involved in glucose utilization, which compensated by higher expression levels of genes controlling fatty acid utilization. These features were partly reproduced in cultured PP2Acα KD cardiomyocytes. Equivalently, a decrease in the expression of most of the transporters and enzymes controlling both glucose and fatty acid metabolism were observed in TAC model.

It has been reported that ophiopogonin D (OP-D), a steroidal glycoside and an active component extracted from Ophiopogon japonicas, promotes antioxidative protection of the cardiovascular system. However, it is unknown whether OP-D exerts protective effects against doxorubicin (DOX)-induced autophagic cardiomyocyte injury. Here, we demonstrate that DOX induced excessive autophagy through the generation of reactive oxygen species (ROS) in H9c2 cells and in mouse hearts, which was indicated by a significant increase in the number of autophagic vacuoles, LC3-II/LC3-I ratio, and upregulation of the expression of GFP-LC3. Pretreatment with OP-D partially attenuated the above phenomena, similar to the effects of treatment with 3-methyladenine. In addition, OP-D treatment significantly relieved the disruption of the mitochondrial membrane potential by antioxidative effects through downregulating the expression of both phosphorylated c-Jun N-terminal kinase and extracellular signal-regulated kinase. The ability of OP-D to reduce the generation of ROS due to mitochondrial damage and, consequently, to inhibit autophagic activity partially accounts for its protective effects in the hearts against DOX-induced toxicity.

Determination was made on DBH, height and weight of fell 5- and 7-year Phyllostachys heterocycla cv. pubescens. Multivariate linear equations were established as Y1= 8.336X1+2.882X2-70.954 (regression coefficient = 0.933), Y2 = 8.613X1+2.670X2-69.310 (regression coefficient=0.9820), in which X1=DBH,X2=height,Y1=weight of 5-year culm, and Y2=weight of 7-year culm.

To generate PP2A Cα knockout model in neonatal mouse ventricular myocytes.Male PP2A Cαfl/fl,Cre/-were selectively mated with female PP2A Cαfl/fl,Cre/-mice to obtain abundant offsprings with the same genotype.The neonatal mouse ventricular myocytes were digested by trypsinization and subsequently infected with Cre-adenovirus.The effects of adenovirus infection were observed by fluorescence microscope and identified by western blot analysis.The offsprings in aboundance were obtained by seting up a mating between male and female of PP2A Cαfl/fl,Cre/-mice,as a result,an abundance of neonatal mouse ventricular myocytes with the genotype of PP2A Cαfl/fl,Cre/-were available for Ad-Cre infection.Green fluorescence was observed after GFP labeled Cre-adenovirus(Cre-Ad) infection for 48 h.The expression level of PP2A Cα protein in Cre-Ad infected myocytes was 60%~80% lower than control.The PP2A Cα knockout model in neonatal mouse ventricular myocytes was successfully generated.

Dendrocalamopsis oldhami(Gramineae,Bambusoideae) is a species of sympodial bamboo.It is widely cultured in beach and mountain areas owing to its good properties,high shoot productivity,rapid growth and high salt tolerance.In April 2007,the D.oldhami were planted respectively in the intertidal lower reaches(the salt stress) and in the common cultivated soil in upper reaches(the control) of Feiyunjiang River.In November 2009,their chlorophyll fluorescence parameters of Photosystem Ⅱ(PSⅡ) were detected.The results indicated that the maximum photochemical efficiency(Fv/Fm) and RC/CSo under both treatments continued to increase with the age,whereas the tendency of the chlorophyll content and DIo/RC were opposite.For the leaves of one-year-old D.oldhami,the values of RC/CSo of those under salt stress were 35.86% higher than that of the control,while the chlorophyll content and Fv/Fm were respectively 18.03% and 7.56% less than that of the control.With the increase of age,there showed a gradually small difference in Fv/Fm,RC/CSo,chlorophyll content of D.oldhami leaves between two treatments.The tendency of DIo/RC content was contrary,although there was no difference in DIo/RC content of one-year-old D.oldhami under two treatments.These suggested that D.oldhami had stronger adaptation to salt stress owing to improving the reversible inactivation of PSⅡ reaction centers and dissipating excessive heat in the process of protecting the PSⅡ from being damaged.

To evaluate the relationship among reflectance spectra characteristics,pigment contents and fertilizer supplies,we tested the pigment contents and reflectance spectra index in the leaves of Phyllostachys pubescens under different fertilizer supplies,and analysed the correlation between red-edge parameters and pigment content.Results showed that the pigment contents in leaves of P.pubescens increased significantly under fertilizer supplies（urea）,the chlorophyll a,chlorophyll b,and carotenoids content increased by 19.9%,31.7%,and 14.0% than control under 250 kg/hm2 fertilizer supplies.The spectral reflectance decreased significantly in the visible region from 525 to 605 nm,while red-edge position shifted to longer wave lengths.There were significant relationships between red-edge parameters and chlorophyll a,chlorophyll b and carotenoids content.It is suggested that reflectance spectral index,especially red-edge parameters could be used for monitoring pigment content of P.pubescens as well as choosing the optimum fertilizer supplies more quickly than traditional methods.

To determine how Phyllostachys pubescens(moso bamboo),a highly efficient photosynthetic plant,efficiently used solar energy and what changes occurred with different light environments,the spectral reflectance of Ph.pubescens leaves was measured in different directions,heights,and ages.There were 36 treatments were set,and 108samples in total.Then,raw data was processed with Origin 8.0 software using a 4th order derivative.Derivative processing was utilized to decompose overlapped peaks so the derived spectra could improve the signal-to-noise ratio(SNR) of the crude data leading to better qualitative and quantitative analysis.Results showed that in shade conditions,the proportion of chlorophyll changed,chlorophyll a/b declined,and carotenoids and xanthophylls accumulated.Also,potential photosynthesis decreased as Ph.pubescens grew.These results suggested that sun leaves and upper leaves have higher utilization of photosynthesis.