Nutritional status and nutritional intervention of older inpatients in China

BACKGROUND

Malnutrition is a critical issue among older inpatients, yet limited large-scale research related to this issue has been conducted in China. This study aimed to examine the nutritional status and support of older inpatients in China, assess the associations between disease categories and malnutrition on admission, and explore effective nutritional intervention.

METHODS

A total of 24,139 older participants from the China Nutrition Fundamental Data 2020 Project were included. Malnutrition was measured by the Global Leadership Initiative on Malnutrition criteria. Adjusted odds ratios (aORs) were calculated using logistic analysis.

RESULTS

The overall frequency of malnutrition on admission was 18.9%. Participants with infections were more likely to have malnutrition (aOR = 1.929, 95% CI 1.486-2.504). Risks that were also noted for malnutrition included neoplasms (aOR = 1.822, 95% CI 1.697-1.957), hemic and lymphatic diseases (aOR = 1.671, 95% CI 1.361-2.051), nervous system diseases (aOR = 1.222, 95% CI 1.126-1.326), respiratory diseases (aOR = 1.613, 95% CI 1.490-1.746), and digestive system diseases (aOR = 1.462, 95% CI 1.357-1.577). Further, 32.26% inpatients with malnutrition during hospitalization didn't receive nutritional support. Oral nutrition supplements, enteral tube feeding, and parenteral nutrition were associated with stable or improved nutritional status.

CONCLUSIONS

Older inpatients were at a high risk for malnutrition but did not receive adequate nutritional intervention. More resources and attention need to be devoted to the nutritional status of older inpatients and targeted nutritional support.

Effects of intra-annual precipitation patterns on grassland productivity moderated by the dominant species phenology

Phenology and productivity are important functional indicators of grassland ecosystems. However, our understanding of how intra-annual precipitation patterns affect plant phenology and productivity in grasslands is still limited. Here, we conducted a two-year precipitation manipulation experiment to explore the responses of plant phenology and productivity to intra-annual precipitation patterns at the community and dominant species levels in a temperate grassland. We found that increased early growing season precipitation enhanced the above-ground biomass of the dominant rhizome grass, Leymus chinensis, by advancing its flowering date, while increased late growing season precipitation increased the above-ground biomass of the dominant bunchgrass, Stipa grandis, by delaying senescence. The complementary effects in phenology and biomass of the dominant species, L. chinensis and S. grandis, maintained stable dynamics of the community above-ground biomass under intra-annual precipitation pattern variations. Our results highlight the critical role that intra-annual precipitation and soil moisture patterns play in the phenology of temperate grasslands. By understanding the response of phenology to intra-annual precipitation patterns, we can more accurately predict the productivity of temperate grasslands under future climate change.

MIF is a common genetic determinant of COVID-19 symptomatic infection and severity

BACKGROUND

Genetic predisposition to coronavirus disease 2019 (COVID-19) may contribute to its morbidity and mortality. Because cytokines play an important role in multiple phases of infection, we examined whether commonly occurring, functional polymorphisms in macrophage migration inhibitory factor (MIF) are associated with COVID-19 infection or disease severity.

AIM

To determine associations of common functional polymorphisms in MIF with symptomatic COVID-19 or its severity.

METHODS

This retrospective case-control study utilized 1171 patients with COVID-19 from three tertiary medical centers in the USA, Hungary and Spain, together with a group of 637 pre-pandemic, healthy control subjects. Functional MIF promoter alleles (-794 CATT5-8,rs5844572), serum MIF and soluble MIF receptor levels, and available clinical characteristics were measured and correlated with COVID-19 diagnosis and hospitalization. Experimental mice genetically engineered to express human high- or low-expression MIF alleles were studied for response to coronavirus infection.

RESULTS

In patients with COVID-19, there was a lower frequency of the high-expression MIF CATT7 allele when compared to healthy controls [11% vs. 19%, odds ratio (OR) 0.54 [0.41-0.72], P < 0.0001]. Among inpatients with COVID-19 (n = 805), there was a higher frequency of the MIF CATT7 allele compared to outpatients (n = 187) (12% vs. 5%, OR 2.87 [1.42-5.78], P = 0.002). Inpatients presented with higher serum MIF levels when compared to outpatients or uninfected healthy controls (87 ng/ml vs. 35 ng/ml vs. 29 ng/ml, P < 0.001, respectively). Among inpatients, circulating MIF concentrations correlated with admission ferritin (r = 0.19, P = 0.01) and maximum CRP (r = 0.16, P = 0.03) levels. Mice with a human high-expression MIF allele showed more severe disease than those with a low-expression MIF allele.

CONCLUSIONS

In this multinational retrospective study of 1171 subjects with COVID-19, the commonly occurring -794 CATT7MIF allele is associated with reduced susceptibility to symptomatic SARS-CoV-2 infection but increased disease progression as assessed by hospitalization. These findings affirm the importance of the high-expression CATT7MIF allele, which occurs in 19% of the population, in different stages of COVID-19 infection.

Intra-annual growing season climate variability drives the community intra-annual stability of a temperate grassland by altering intra-annual species asynchrony and richness in Inner Mongolia, China

Understanding the factors that regulate the functioning of our ecosystems in response to environmental changes can help to maintain the stable provisioning of ecosystem services to mankind. This is especially relevant given the increased variability of environmental conditions due to human activities. In particular, maintaining a stable production and plant biomass during the growing season (intra‐annual stability) despite pervasive and directional changes in temperature and precipitation through time can help to secure food supply to wild animals, livestock, and humans. Here, we conducted a 29‐year field observational study in a temperate grassland to explore how the intra‐annual stability of primary productivity is influenced by biotic and abiotic variables through time. We found that intra‐annual precipitation variability in the growing season indirectly influenced the community intra‐annual biomass stability by its negative effect on intra‐annual species asynchrony. While the intra‐annual temperature variability in the growing season indirectly altered community intra‐annual biomass stability through affecting the intra‐annual species richness. At the same time, although the intra‐annual biomass stability of the dominant species and the dominant functional group were insensitive to climate variability, they also promoted the stable community biomass to a certain extent. Our results indicate that ongoing intra‐annual climate variability affects community intra‐annual biomass stability in the temperate grassland, which has important theoretical significance for us to take active measures to deal with climate change.

Distinct Roles of Type I and Type III Interferons during a Native Murine β Coronavirus Lung Infection

Coronaviruses are a major health care threat to humankind. Currently, the host factors that contribute to limit disease severity in healthy young patients are not well defined. Interferons are key antiviral molecules, especially type I and type III interferons. The role of these interferons during coronavirus disease is a subject of debate. Here, using mice that are deficient in type I (IFNAR1-/-), type III (IFNLR1-/-), or both (IFNAR1/LR1-/-) interferon signaling pathways and murine-adapted coronavirus (MHV-A59) administered through the intranasal route, we define the role of interferons in coronavirus infection. We show that type I interferons play a major role in host survival in this model, while a minimal role of type III interferons was manifested only in the absence of type I interferons or during a lethal dose of coronavirus. IFNAR1-/- and IFNAR1/LR1-/- mice had an uncontrolled viral burden in the airways and lung and increased viral dissemination to other organs. The absence of only type III interferon signaling had no measurable difference in the viral load. The increased viral load in IFNAR1-/- and IFNAR1/LR1-/- mice was associated with increased tissue injury, especially evident in the lung and liver. Type I but not type III interferon treatment was able to promote survival if treated during early disease. Further, we show that type I interferon signaling in macrophages contributes to the beneficial effects during coronavirus infection in mice. IMPORTANCE The antiviral and pathological potential of type I and type III interferons during coronavirus infection remains poorly defined, and opposite findings have been reported. We report that both type I and type III interferons have anticoronaviral activities, but their potency and organ specificity differ. Type I interferon deficiency rendered the mice susceptible to even a sublethal murine coronavirus infection, while the type III interferon deficiency impaired survival only during a lethal infection or during a sublethal infection in the absence of type I interferon signaling. While treatment with both type I and III interferons promoted viral clearance in the airways and lung, only type I interferons promoted the viral clearance in the liver and improved host survival upon early treatment (12 h postinfection). This study demonstrates distinct roles and potency of type I and type III interferons and their therapeutic potential during coronavirus lung infection.

Species richness and asynchrony maintain the stability of primary productivity against seasonal climatic variability

The stability of grassland communities informs us about the ability of grasslands to provide reliable services despite environmental fluctuations. There is large evidence that higher plant diversity and asynchrony among species stabilizes grassland primary productivity against interannual climate variability. Whether biodiversity and asynchrony among species and functional groups stabilize grassland productivity against seasonal climate variability remains unknown. Here, using 29-year monitoring of a temperate grassland, we found lower community temporal stability with higher seasonal climate variability (temperature and precipitation). This was due to a combination of processes including related species richness, species asynchrony, functional group asynchrony and dominant species stability. Among those processes, functional group asynchrony had the strongest contribution to community compensatory dynamics and community stability. Based on a long-term study spanning 29 years, our results indicate that biodiversity and compensatory dynamics a key for the stable provision of grassland function against increasing seasonal climate variability.

Perirenal Fat Thickness Is Significantly Associated With the Risk for Development of Chronic Kidney Disease in Patients With Diabetes

Perirenal fat is adjacent to kidneys and active in metabolism and adipokine secretion. We aimed to investigate whether perirenal fat is an independent predictor for chronic kidney disease (CKD) and compared it with total, subcutaneous, or visceral fat in patients with diabetes. Perirenal fat thickness (PRFT) was measured by computed tomography, and total body fat (TBF), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) were assessed by DEXA. In cross-sectional analysis, patients with higher PRFT had a lower estimated glomerular filtration rate (eGFR). Multiple linear regression analysis showed a negative correlation between PRFT and eGFR after confounders adjustment. No association between eGFR and TBF, SAT, or VAT was observed. Longitudinally, 190 patients with type 2 diabetes mellitus (T2DM) without CKD at baseline were followed for 2 years. A total of 29 participants developed CKD. After VAT-based multivariate adjustment, each SD (per-SD) increment in baseline PRFT was associated with a higher incidence of CKD (hazard ratio 1.67, 95% CI 1.04-2.68), while TBF, SAT, and VAT were not. Furthermore, PRFT predicted CKD, with a C-statistic (95% CI) of 0.668 (0.562, 0.774), which was higher than that of TPF [0.535 (0.433, 0.637)], SAT [0.526 (0.434, 0.618)], and VAT [0.602 (0.506, 0.698)]. In conclusion, with perirenal fat there was a higher predictive value for CKD than with total, subcutaneous, or visceral fat in T2DM.

Liver injury in COVID-19 and IL-6 trans-signaling-induced endotheliopathy

BACKGROUND AND AIMS

COVID-19 is associated with liver injury and elevated interleukin-6 (IL-6). We hypothesized that IL-6 trans-signaling in liver sinusoidal endothelial cells (LSECs) leads to endotheliopathy (a proinflammatory and procoagulant state) and liver injury in COVID-19.

METHODS

Coagulopathy, endotheliopathy, and alanine aminotransferase (ALT) were retrospectively analyzed in a subset (n = 68), followed by a larger cohort (n = 3,780) of patients with COVID-19. Liver histology from 43 patients with COVID-19 was analyzed for endotheliopathy and its relationship to liver injury. Primary human LSECs were used to establish the IL-6 trans-signaling mechanism.

RESULTS

Factor VIII, fibrinogen, D-dimer, von Willebrand factor (vWF) activity/antigen (biomarkers of coagulopathy/endotheliopathy) were significantly elevated in patients with COVID-19 and liver injury (elevated ALT). IL-6 positively correlated with vWF antigen (p = 0.02), factor VIII activity (p = 0.02), and D-dimer (p <0.0001). On liver histology, patients with COVID-19 and elevated ALT had significantly increased vWF and platelet staining, supporting a link between liver injury, coagulopathy, and endotheliopathy. Intralobular neutrophils positively correlated with platelet (p <0.0001) and vWF (p <0.01) staining, and IL-6 levels positively correlated with vWF staining (p <0.01). IL-6 trans-signaling leads to increased expression of procoagulant (factor VIII, vWF) and proinflammatory factors, increased cell surface vWF (p <0.01), and increased platelet attachment in LSECs. These effects were blocked by soluble glycoprotein 130 (IL-6 trans-signaling inhibitor), the JAK inhibitor ruxolitinib, and STAT1/3 small-interfering RNA knockdown. Hepatocyte fibrinogen expression was increased by the supernatant of LSECs subjected to IL-6 trans-signaling.

CONCLUSION

IL-6 trans-signaling drives the coagulopathy and hepatic endotheliopathy associated with COVID-19 and could be a possible mechanism behind liver injury in these patients.

LAY SUMMARY

Patients with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection often have liver injury, but why this occurs remains unknown. High levels of interleukin-6 (IL-6) and its circulating receptor, which form a complex to induce inflammatory signals, have been observed in patients with COVID-19. This paper demonstrates that the IL-6 signaling complex causes harmful changes to liver sinusoidal endothelial cells and may promote blood clotting and contribute to liver injury.

Evolution trace of SARS-CoV-2 from January 19 to March 12, 2020, in the United States

As a kind of human betacoronavirus, SARS‐CoV‐2 has endangered globally public health. As of January 2021, the virus had resulted in 2,209,195 deaths. By studying the evolution trend and characteristics of 265 SARS‐CoV‐2 strains in the United States from January to March, it is found that the strains can be divided into six clades, USA clade‐1, USA clade‐2, USA clade‐3, USA clade‐4, USA clade‐5, and USA clade‐6, in which US clade‐1 may be the most ancestral clade, USA clade‐2 is an interim clade of USA clade‐1 and USA clade‐3, the other three clades have similar codon usage pattern, while USA clade‐6 is the newest and most adaptable clade. Mismatch analysis and protein alignment showed that the evolution of the clades arises from some special mutations in viral proteins, which may help the strain to invade, replicate, transcribe and so on. Compared with previous research and classifications, we suggest that clade O in GISAID should not be an independent clade and Wuhan‐Hu‐1 (EPI_ISL_402125) should not be an ancestral reference sequence. Our study decoded the evolutionary dynamic of SARS‐CoV‐2 in the early stage from the United States, which give some clues to infer the current evolution trend of SARS‐CoV‐2 and study the function of viral mutational protein.

Basing on decoding the characteristics and evolution process of SARS‐CoV‐2 in the early stage of the USA, it is suggested that the clade O in GISAID should not be as an independent evolutionary clade by phylogenetic analysis or protein alignment. Secondly, Wuhan‐Hu‐1 (EPI_ISL_402125) should not be as an ancestral reference sequence and its candidate should be EPI_ISL_529213. Thirdly, many unique mutation sites in viral proteins were found to lay foundation to study the function of the mutational protein and to reveal the evolution trend of SARS‐CoV‐2 in coming days.

Ketogenic diet restrains aging-induced exacerbation of coronavirus infection in mice

Increasing age is the strongest predictor of risk of COVID-19 severity and mortality. Immunometabolic switch from glycolysis to ketolysis protects against inflammatory damage and influenza infection in adults. To investigate how age compromises defense against coronavirus infection, and whether a pro-longevity ketogenic diet (KD) impacts immune surveillance, we developed an aging model of natural murine beta coronavirus (mCoV) infection with mouse hepatitis virus strain-A59 (MHV-A59). When inoculated intranasally, mCoV is pneumotropic and recapitulates several clinical hallmarks of COVID-19 infection. Aged mCoV-A59-infected mice have increased mortality and higher systemic inflammation in the heart, adipose tissue, and hypothalamus, including neutrophilia and loss of γδ T cells in lungs. Activation of ketogenesis in aged mice expands tissue protective γδ T cells, deactivates the NLRP3 inflammasome, and decreases pathogenic monocytes in lungs of infected aged mice. These data establish harnessing of the ketogenic immunometabolic checkpoint as a potential treatment against coronavirus infection in the aged.

Leptin mediates postprandial increases in body temperature through hypothalamus-adrenal medulla-adipose tissue crosstalk

Meal ingestion increases body temperature in multiple species, an effect that is blunted by obesity. However, the mechanisms responsible for these phenomena remain incompletely understood. Here we show that refeeding increases plasma leptin concentrations approximately 8-fold in 48-hour-fasted lean rats, and this normalization of plasma leptin concentrations stimulates adrenomedullary catecholamine secretion. Increased adrenal medulla-derived plasma catecholamines were necessary and sufficient to increase body temperature postprandially, a process that required both fatty acids generated from adipose tissue lipolysis and β-adrenergic activation of brown adipose tissue (BAT). Diet-induced obese rats, which remained relatively hyperleptinemic while fasting, did not exhibit fasting-induced reductions in temperature. To examine the impact of feeding-induced increases in body temperature on energy balance, we compared rats fed chronically by either 2 carbohydrate-rich boluses daily or a continuous isocaloric intragastric infusion. Bolus feeding increased body temperature and reduced weight gain compared with continuous feeding, an effect abrogated by treatment with atenolol. In summary, these data demonstrate that leptin stimulates a hypothalamus-adrenal medulla-BAT axis, which is necessary and sufficient to induce lipolysis and, as a result, increase body temperature after refeeding.

Ketogenesis restrains aging-induced exacerbation of COVID in a mouse model

Increasing age is the strongest predictor of risk of COVID-19 severity. Unregulated cytokine storm together with impaired immunometabolic response leads to highest mortality in elderly infected with SARS-CoV-2. To investigate how aging compromises defense against COVID-19, we developed a model of natural murine beta coronavirus (mCoV) infection with mouse hepatitis virus strain MHV-A59 (mCoV-A59) that recapitulated majority of clinical hallmarks of COVID-19. Aged mCoV-A59-infected mice have increased mortality and higher systemic inflammation in the heart, adipose tissue and hypothalamus, including neutrophilia and loss of γδ T cells in lungs. Ketogenic diet increases beta-hydroxybutyrate, expands tissue protective γδ T cells, deactivates the inflammasome and decreases pathogenic monocytes in lungs of infected aged mice. These data underscore the value of mCoV-A59 model to test mechanism and establishes harnessing of the ketogenic immunometabolic checkpoint as a potential treatment against COVID-19 in the elderly.

Highlights

- Natural MHV-A59 mouse coronavirus infection mimics COVID-19 in elderly.- Aged infected mice have systemic inflammation and inflammasome activation.- Murine beta coronavirus (mCoV) infection results in loss of pulmonary γδ T cells.- Ketones protect aged mice from infection by reducing inflammation.

eTOC Blurb

Elderly have the greatest risk of death from COVID-19. Here, Ryu et al report an aging mouse model of coronavirus infection that recapitulates clinical hallmarks of COVID-19 seen in elderly. The increased severity of infection in aged animals involved increased inflammasome activation and loss of γδ T cells that was corrected by ketogenic diet.

miR-196b-5p-enriched extracellular vesicles from tubular epithelial cells mediated aldosterone-induced renal fibrosis in mice with diabetes

INTRODUCTION

Aldosterone is a mediator of progressive renal disease, but the mechanisms for aldosterone-mediated renal impairment in mice with diabetes are not fully defined.

METHODS

Aldosterone and/or mineralocorticoid receptor antagonist eplerenone were used to treat the db/db mice with diabetes. Proximal tubule epithelial cells (PTECs) and fibroblasts were cultured. Blood and kidney samples from patients with diabetes with or without diabetic kidney disease (DKD) were used to verify the findings from animals and cultured cells.

RESULTS

We found that aldosterone promoted proteinuria and tubulointerstitial extracellular matrix (ECM) accumulation in db/db mice with diabetes while eplerenone mitigated the adverse effect of aldosterone. However, coculture of PTECs and fibroblasts found that when PTECs-derived extracellular vesicles (EVs) were taken up by fibroblasts, ECM production increased remarkably. Moreover, C57BL/6 mice injected with EVs from renal cortex of aldosterone-treated db/db mice showed increased ECM accumulation. Function of the ingredients of PTECs-derived EVs were analyzed, and RNAs were identified to be responsible for the EVs-induced fibroblast dysfunction. Furthermore, microRNA (miRNA) array analysis revealed that miR-196b-5p was the most remarkably increased miRNA in PTECs-derived EVs with aldosterone stimulation. Overexpression of miR-196b-5p in fibroblasts increased ECM production, accompanied by inhibition of the SOCS2 expression and enhanced STAT3 phosphorylation. In addition, plasma levels of miR-196b-5p was higher in patients with DKD as compared with patients without DKD and miR-196b-5p levels positively correlated with the albuminuria concentration. In kidney specimens from patients with diabetes, expression of miR-196b-5p, located mainly in PTECs, increased in patients with DKD as compared with the non-DKD.

CONCLUSION

This study demonstrates the involvement of miR-196b-5p-EVs pathway as a novel mechanism in aldosterone-induced renal fibrosis in diabetes. EVs rich in miR-196b-5p mediate the crosstalk between PTECs and fibroblast during the development of renal fibrosis, which might be associated with STAT3/SOCO2 signaling pathway.

Origin and Function of Stress-Induced IL-6 in Murine Models

Acute psychological stress has long been known to decrease host fitness to inflammation in a wide variety of diseases, but how this occurs is incompletely understood. Using mouse models, we show that interleukin-6 (IL-6) is the dominant cytokine inducible upon acute stress alone. Stress-inducible IL-6 is produced from brown adipocytes in a beta-3-adrenergic-receptor-dependent fashion. During stress, endocrine IL-6 is the required instructive signal for mediating hyperglycemia through hepatic gluconeogenesis, which is necessary for anticipating and fueling "fight or flight" responses. This adaptation comes at the cost of enhancing mortality to a subsequent inflammatory challenge. These findings provide a mechanistic understanding of the ontogeny and adaptive purpose of IL-6 as a bona fide stress hormone coordinating systemic immunometabolic reprogramming. This brain-brown fat-liver axis might provide new insights into brown adipose tissue as a stress-responsive endocrine organ and mechanistic insight into targeting this axis in the treatment of inflammatory and neuropsychiatric diseases.

Cloning and expression analysis of PRL and PRLR genes in black Muscovy duck

1. Prolactin hormone (governed by the PRL gene) is secreted by the anterior pituitary of animals, which combines with its receptor (prolactin receptor, PRLR) to act on target cells. Both PRL and PRLR are mainly associated with reproductive performance. The genetic mechanism of nesting in poultry is not yet clear, and so the aim of the current study was to determine expression patterns of PRL and PRLR at different times across the breeding stages of black Muscovy ducks.2. In this study, the CDS regions of PRL and PRLR were determined by RACE sequencing. The expression levels of PRL and PRLR in the pituitary, ovary and uterus from the black Muscovy duck were compared and analysed during the pre-laying, laying and nesting periods.3. The results showed that PRL and PRLR are highly homologous in a variety of poultry species. The expression of the PRL gene in the pituitary was the highest, which was significantly higher than seen in the ovary and uterus. This trend ran through the entire prenatal period, i.e. the laying period and the nesting period. The expression level of the PRLR gene in the pituitary and ovary was generally low, and expression in the uterus was the highest. There was no significant difference in expression of the PRLR gene between pituitary and ovary during different periods, but the expression level of the PRLR gene in the uterus reached its highest level during the nesting stage, which was significantly higher than seen in the early laying period.

The psychoactive cathinone derivative pyrovalerone alters locomotor activity and decreases dopamine receptor expression in zebrafish (Danio rerio)

INTRODUCTION

Pyrovalerone (4-methyl-β-keto-prolintane) is a synthetic cathinone (beta-keto-amphetamine) derivative. Cathinones are a concern as drugs of abuse, as related street drugs such as methylenedioxypyrovalerone have garnered significant attention. The primary mechanism of action of cathinones is to inhibit reuptake transporters (dopamine and norepinephrine) in reward centers of the central nervous system.

METHODS

We measured bioenergetic, behavioral, and molecular responses to pyrovalerone (nM-µM) in zebrafish to evaluate its potential for neurotoxicity and neurological impairment.

RESULTS

Pyrovalerone did not induce any mortality in zebrafish larvae over a 3- and 24-hr period; however, seizures were prevalent at the highest dose tested (100 µM). Oxidative phosphorylation was not affected in the embryos, and there was no change in superoxide dismutase 1 expression. Following a 3-hr treatment to pyrovalerone (1-100 µM), larval zebrafish (6d) showed a dose-dependent decrease (70%-90%) in total distance moved in a visual motor response (VMR) test. We interrogated potential mechanisms related to the hypoactivity, focusing on the expression of dopamine-related transcripts as cathinones can modulate the dopamine system. Pyrovalerone decreased the expression levels of dopamine receptor D1 (~60%) in larval zebrafish but did not affect the expression of tyrosine hydroxylase, dopamine active transporter, or any other dopamine receptor subunit examined, suggesting that pyrovalerone may regulate the expression of dopamine receptors in a specific manner.

DISCUSSION

Further studies using zebrafish are expected to reveal new insight into molecular mechanisms and behavioral responses to cathinone derivates, and zebrafish may be a useful model for understanding the relationship between the dopamine system and bath salts.

Divergent water sources of three dominant plant species following precipitation events in enclosed and mowing grassland steppes

Understanding of the dynamic patterns of plant water use in a changing environment is one of foci in plant ecology, and can provide basis for the development of best practice in restoration and protection of ecosystem. We studied the water use sources of three coexisting dominant plant species Leymus chinensis, Stipa grandis and Cleistogenes squarrosa growing in both enclosed and mowing grassland in a typical steppe. The oxygen stable isotope ratios (δ¹⁸O) of soil water and stem water of these three species were determined, along with soil moisture, before and after precipitation events. The results showed that (1) mowing had no significant effect on the soil moisture and its δ¹⁸O, whereas precipitation significantly changed the soil moisture though no significant effect detected on its δ¹⁸O. (2) C. squarrosa took up water majorly from top soil layer due to its shaollow root system; L. chinensis took up relative more water from deep soil layer, and S. grandis took up water from the middle to deep soil layers. (3) L. chinensis and S. grandis in mowing grassland tended to take up more water from the upper soil layers following precipitation events, but showed no sensitive change in water source from soil profile following the precipitation in the enclosed grassland, indicating a more sensitive change of soil water sources for the two species in mowing than enclosed grassland. The differences in root morphology and precipitation distribution may partly explain the differences in their water uptake from different soil layers. Our results have important theoretical values for understanding the water competition among plants in fluctuating environment and under different land use in the typical steppe.

Role of neutrophil extracellular traps in chronic kidney injury induced by bisphenol-A

Bisphenol-A (BPA) is a common environmental pollutant, and exposure to it is associated with proteinuria and may predict the progression of chronic kidney disease，however, the mechanism is not clear. Neutrophil extracellular traps (NETs) is a DNA skeleton coated with various proteases, and it is associated with various autoimmune nephritis. In this study, we examine whether NETs is involved in BPA-induced chronic kidney injury. In vivo, BPA exposure resulted in impaired renal function and altered renal morphology, including glomerular mesangial matrix expansion and increased renal interstitial fibroblast markers. Meanwhile, more dsDNA can be detected in the serum, and the NETs-associated proteins, MPO and citH3 were deposited in the renal system. In vitro, BPA and NETs treatment caused podocyte injury, a loss of marker proteins, and disorder in the actin skeleton. After NETs inhibition via DNase administration, BPA-induced injuries were significantly relieved. In conclusion, the increase of NETosis in circulation and the renal system during BPA exposure suggests that NETs may be involved in BPA-induced chronic kidney injury.

Effects of Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers on All-Cause Mortality and Renal Outcomes in Patients with Diabetes and Albuminuria: a Systematic Review and Meta-Analysis

BACKGROUND/AIMS

Whether angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARB) could benefit patients with diabetes and albuminuria remains controversial. A systematic review and meta-analysis were conducted to answer this question by comparing ACE inhibitors or ARB with placebo among these patients.

METHODS

In this meta-analysis, electronic data sources (Medline, the Cochrane Collaboration, and EMBASE) were searched. Randomized controlled trials (RCTs) comparing ACE inhibitors or ARB with placebo in subjects with diabetes and albuminuria (defined as urinary albumin-to-creatinine ratio, UACR≥30mg/g Cr) were included. Outcomes parameters were all-cause mortality, end stage renal disease (ESRD), doubling of serum creatinine levels, and cardiovascular events (CV).

RESULTS

Twenty-six RCTs (including 20 for ACE inhibitors and 6 for ARB) were included, comprising 10378 participants with diabetes and albuminuria. Compared to placebo, treatment with ACE inhibitors or ARBs did not reduce all-cause mortality or CV. For renal outcomes, ARBs significantly reduced the risk of ESRD by 23% (odds ratio 0.77, 95%CI 0.65-0.92), while ACE inhibitors were not associated with a decreased risk of ESRD (0.69, 0.43-1.10). Both ACE inhibitors and ARBs reduced the risk of doubling of the serum creatinine level (0.60, 0.39-0.91 for ACE inhibitors; 0.75, 0.64-0.88 for ARBs), and subgroup analyses for patients with macroalbuminuria or microalbuminuria showed similar results.

CONCLUSION

In patients with diabetes and albuminuria, ARBs reduced risks of ESRD and doubling of the serum creatinine level. ACE inhibitors and ARBs failed to reduce all-cause mortality and CV. Based on the renoprotective effects, ARBs may be preferred for diabetic patients with albuminuria.

Age-Related Cutoffs of Plasma Aldosterone/Renin Concentration for Primary Aldosteronism Screening

AIM

This retrospective study is aimed at investigating whether aldosterone-renin ratio (ARR) cutoffs calculated by the plasma aldosterone concentration (PAC)/plasma renin concentration (PRC) should be set differently in patients of different ages.

METHODS

521 hypertensive patients were screened for primary aldosteronism (PA) by the PAC/PRC. 174 patients diagnosed with PA and 311 patients with essential hypertension (EH) were included in the final analysis. Subjects were subdivided into four age groups: <40, 40-49, 50-59, and ≥60 years old.

RESULTS

The accuracy of the ARR varied greatly among the different age groups. An ARR of 3.7 (ng/dl)/(μIU/ml) had a sensitivity of 100% and a specificity of 80% in patients ≥ 60 years old. With this cutoff, the sensitivities in patients < 40, 40-49, and 50-59 years old were 74%, 82%, and 87%, respectively, and the specificities were 94%, 95%, and 94%, respectively. To achieve a sensitivity higher than 90%, the ARR cutoff needed to be lowered to 2.0 (ng/dl)/(μIU/ml) for patients 40-49 and 50-59 years old, resulting in sensitivities of 90% and 95%, respectively, and specificities of 80% and 84%, respectively. To achieve a sensitivity higher than 90%, the ARR cutoff needed to be lowered to 1.0 (ng/dl)/(μIU/ml) for patients < 40 years old, resulting in a sensitivity of 90% and a specificity of 82%.

CONCLUSIONS

An ARR of 3.7 (ng/dl)/(μIU/ml) is optimal for patients ≥ 60 years; for patients 40-59 years, the optimal ARR cutoff is 2.0; for those younger than 40 years, an ARR of 1.0 may be more reasonable.

[Prosthodontic specialty training in the United States: what can we learn]

Prosthodontics is one of the nine recognized specialties by American Dental Association. The postgraduate prosthodontic program used to train prosthodontic specialists in U S A started about 70 years ago. Compared to China which just launched the dental residency programs, the programs in U S A have more developed and relatively more mature education system. It is worthwhile for China to study and learn the U S A prosthodontic residency education program. Prosthodontics is a specialty to diagnose and treat complex dental problems, and is often considered as the 'orchestrator' directing and coordinating all the other dental specialists to manage complex situations. This specialty plays an important role in a nation's oral health system. The present article is aimed to introduce the history of US prosthodontic residency program, initial accreditation, curriculum, education standards and mechanisms of the residency program, and how the program is monitored and managed post initial accreditation, with the hope that this system can serve as a reference for China's developing its own residency program.

Confirmatory Tests for the Diagnosis of Primary Aldosteronism: A Prospective Diagnostic Accuracy Study

The diagnosis of primary aldosteronism typically requires at least one confirmatory test. The fludrocortisone suppression test is generally accepted as a reliable confirmatory test, but it is cumbersome. Evidence from accuracy studies of the saline infusion test (SIT) and the captopril challenge test (CCT) has provided conflicting results. This prospective study aimed to evaluate the diagnostic accuracy of the SIT and CCT using fludrocortisone suppression test as the reference standard. One hundred thirty-five patients diagnosed with primary aldosteronism and 101 patients diagnosed with essential hypertension who completed the 3 confirmatory tests were included for the diagnostic accuracy analysis. The areas under the receiver-operator characteristics curves of the CCT and SIT were 0.96 (95% confidence interval [CI], 0.92-0.98) and 0.96 (95% CI, 0.92-0.98), respectively, using post-test plasma aldosterone concentration (PAC) for diagnosis. However, the areas under the receiver-operator characteristics curves of the CCT decreased to 0.71 (95% CI, 0.65-0.77) when the PAC suppression percentage was used to diagnose primary aldosteronism. The optimal cutoff of PAC post-CCT was set at 11 ng/dL, resulting in a sensitivity of 0.90 (95% CI, 0.84-0.95) and a specificity of 0.90 (95% CI, 0.83-0.95), which were not significantly different from those of SIT (with PAC post-SIT set at 8 ng/dL, sensitivity: 0.85 [95% CI, 0.78-0.91], P=0.192; specificity: 0.92 [95% CI, 0.85-0.97], P=0.551). In conclusion, both CCT and SIT are accurate alternatives to the more complex fludrocortisone suppression test. Because CCT is safe and much easier to perform, it may serve as a more feasible alternative. When interpreting the results of CCT, PAC post-CCT is highly recommended.

Deletion of the NR4A nuclear receptor NOR1 in hematopoietic stem cells reduces inflammation but not abdominal aortic aneurysm formation

Background

The NR4A3 orphan nuclear hormone receptor, NOR1, functions as a constitutively active transcription factor to regulate inflammation, proliferation, and cell survival during pathological vascular remodeling. Inflammatory processes represent key mechanisms leading to abdominal aortic aneurysm (AAA) formation. However, a role of NOR1 in AAA formation has not been investigated previously.

Methods

Inflammatory gene expression was analyzed in bone marrow-derived macrophages isolated from NOR1-deficient mice. Low-density lipoprotein receptor-deficient (LDLr^−/−) mice were irradiated and reconstituted with hematopoietic stem cells obtained from NOR1−/− or wild-type littermate mice. Animals were infused with angiotensin II and fed a diet enriched in saturated fat to induce AAA formation. Quantification of AAA formation was performed by ultrasound and ex vivo measurements.

Results

Among 184 inflammatory genes that were analyzed, 36 genes were differentially regulated in LPS-treated NOR1-deficient macrophages. Albeit this difference in gene regulation, NOR1-deficiency in hematopoietic stem cells did not affect development of AAA formation in bone marrow-derived stem cell transplanted LDLr-deficient mice.

Conclusion

NOR1 deletion induced differential inflammatory gene transcription in macrophages but did not influence AAA formation in mice.

Electronic supplementary material

The online version of this article (10.1186/s12872-017-0701-4) contains supplementary material, which is available to authorized users.

Analysis of the genetic diversity of Lonicera japonica Thumb. using inter-simple sequence repeat markers

Inter-simple sequence repeats (ISSRs) were used to analyze the genetic diversity of 21 accessions obtained from four provinces in China, Shandong, Henan, Hebei, and Sichuan. A total of 272 scored bands were generated using the eight primers previously screened across 21 accessions, of which 267 were polymorphic (98.16%). Genetic similarity coefficients varied from 0.4816 to 0.9118, with an average of 0.6337. The UPGMA dendrogram grouped 21 accessions into two main clusters. Cluster A comprised four Lonicera macranthoides Hand. Mazz. accessions, of which J10 was found to be from Sichuan, and J17, J18, and J19 were found to be from Shandong. Cluster B comprised 17 Lonicera japonica Thumb. accessions, divided into the wild accession J16 and the other 16 cultivars. The results of the principal component analysis were comparable to the cluster analysis. Therefore, the ISSR markers could be effectively used to distinguish interspecific and intraspecific variations, which may facilitate identification of Lonicera japonica cultivars for planting, medicinal use, and germplasm conservation.

Telomerase Reverse Transcriptase Deficiency Prevents Neointima Formation Through Chromatin Silencing of E2F1 Target Genes

OBJECTIVE

Aberrant proliferation of smooth muscle cells (SMC) in response to injury induces pathological vascular remodeling during atherosclerosis and neointima formation. Telomerase is rate limiting for tissue renewal and cell replication; however, the physiological role of telomerase in vascular diseases remains to be determined. The goal of the present study was to determine whether telomerase reverse transcriptase (TERT) affects proliferative vascular remodeling and to define the molecular mechanism by which TERT supports SMC proliferation.

APPROACH AND RESULTS

We first demonstrate high levels of TERT expression in replicating SMC of atherosclerotic and neointimal lesions. Using a model of guidewire-induced arterial injury, we demonstrate decreased neointima formation in TERT-deficient mice. Studies in SMC isolated from TERT-deficient and TERT overexpressing mice with normal telomere length established that TERT is necessary and sufficient for cell proliferation. TERT deficiency did not induce a senescent phenotype but resulted in G1 arrest albeit hyperphosphorylation of the retinoblastoma protein. This proliferative arrest was associated with stable silencing of the E2F1-dependent S-phase gene expression program and not reversed by ectopic overexpression of E2F1. Finally, chromatin immunoprecipitation and accessibility assays revealed that TERT is recruited to E2F1 target sites and promotes chromatin accessibility for E2F1 by facilitating the acquisition of permissive histone modifications.

CONCLUSIONS

These data indicate a previously unrecognized role for TERT in neointima formation through epigenetic regulation of proliferative gene expression in SMC.

Telomerase Inhibition by Everolimus Suppresses Smooth Muscle Cell Proliferation and Neointima Formation Through Epigenetic Gene Silencing

Proliferation of smooth muscle cells (SMCs) during neointima formation is prevented by drug-eluting stents. The replicative capacity of mammalian cells is enhanced by telomerase expression; however, the contribution of telomerase to the proliferative response underlying neointima formation and its potential role as a pharmacological target are unknown. The present study investigated the mechanisms underlying the mitogenic function of telomerase, and tested the hypothesis that everolimus, which is commonly used on drug-eluting stents, suppresses SMC proliferation by targeting telomerase. Inhibition of neointima formation by everolimus was lost in mice overexpressing telomerase reverse transcriptase (TERT), indicating that repression of telomerase confers the anti-proliferative efficacy of everolimus. Everolimus reduced TERT expression in SMC through an Ets-1-dependent inhibition of promoter activation. The inhibition of TERT-dependent SMC proliferation by everolimus occurred in the absence of telomere shortening but rather as a result of a G1→S-phase arrest. Although everolimus failed to inhibit phosphorylation of the retinoblastoma protein as the gatekeeper of S-phase entry, it potently repressed downstream target genes. Chromatin immunoprecipitation assays demonstrated that TERT induced E2F binding to S-phase gene promoters and supported histone acetylation. These effects were sensitive to inhibition by everolimus. These results characterize telomerase as a previously unrecognized target for the antiproliferative activity of everolimus, and further identify a novel mitogenic pathway in SMC that depends on the epigenetic activation of S-phase gene promoters by TERT.

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The proliferative capacity of smooth muscle cells (SMC) during neointima formation is prevented by everolimus-coated drug-eluting stents.

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Everolimus failed to inhibit neointima formation by in mice overexpressing telomerase reverse transcriptase (TERT).

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Everolimus reduced TERT-dependent SMC proliferation through inhibition of Ets-1–dependent promoter activation.

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The inhibition of TERT-dependent SMC proliferation by everolimus occurred as a result of a G1→S-phase arrest, rather than telomerase shortening.

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Chromatin immunoprecipitation assays demonstrated that TERT induced E2F binding to S-phase gene promoters and supported histone acetylation.

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These studies identify a novel mitogenic pathway in SMC that depends on the epigenetic activation of S-phase gene promoters by TERT.

Deficiency of the NR4A orphan nuclear receptor NOR1 in hematopoietic stem cells accelerates atherosclerosis

The NR4A orphan nuclear receptor NOR1 functions as a constitutively active transcription factor regulating cellular inflammation and proliferation. In this study, we used bone marrow transplantation to determine the selective contribution of NOR1 expression in hematopoietic stem cells to the development of atherosclerosis. Reconstitution of lethally irradiated apoE(-/-) mice with NOR1-deficient hematopoietic stem cells accelerated atherosclerosis formation and macrophage recruitment following feeding a diet enriched in saturated fat. NOR1 deficiency in hematopoietic stem cells induced splenomegaly and monocytosis, specifically the abundance of inflammatory Ly6C(+) monocytes. Bone marrow transplantation studies further confirmed that NOR1 suppresses the proliferation of macrophage and dendritic progenitor (MDP) cells. Expression analysis identified RUNX1, a critical regulator of hematopoietic stem cell expansion, as a target gene suppressed by NOR1 in MDP cells. Finally, in addition to inducing Ly6C(+) monocytosis, NOR1 deletion increased the replicative rate of lesional macrophages and induced local foam cell formation within the atherosclerotic plaque. Collectively, our studies demonstrate that NOR1 deletion in hematopoietic stem cells accelerates atherosclerosis formation by promoting myelopoiesis in the stem cell compartment and by inducing local proatherogenic activities in the macrophage, including lesional macrophage proliferation and foam cell formation.

Differential Regulation of Telomerase Reverse Transcriptase Promoter Activation and Protein Degradation by Histone Deacetylase Inhibition

Telomerase reverse transcriptase (TERT) maintains telomeres and is rate limiting for replicative life span. While most somatic tissues silence TERT transcription resulting in telomere shortening, cells derived from cancer or cardiovascular diseases express TERT and activate telomerase. In the present study, we demonstrate that histone deacetylase (HDAC) inhibition induces TERT transcription and promoter activation. At the protein level in contrast, HDAC inhibition decreases TERT protein abundance through enhanced degradation, which decreases telomerase activity and induces senescence. Finally, we demonstrate that HDAC inhibition decreases TERT expression during vascular remodeling in vivo. These data illustrate a differential regulation of TERT transcription and protein stability by HDAC inhibition and suggest that TERT may constitute an important target for the anti-proliferative efficacy of HDAC inhibitors.

Efficacy of metformin-based oral antidiabetic drugs is not inferior to insulin glargine in newly diagnosed type 2 diabetic patients with severe hyperglycemia after short-term intensive insulin therapy

BACKGROUND

Insulin therapy should be strongly considered in newly diagnosed type 2 diabetic (T2D) patients with severe hyperglycemia. However, whether insulin be continued or patients switched to an oral antidiabetic drug (OAD) after short-term intensive insulin therapy (ITT) is not clear.

METHODS

After ITT for 10-14 days, 47 patients were randomized into either a glargine (n = 21) or metformin-based OAD (n = 26) group for a 6-month intervention. After these 6 months, patients in the glargine group were switched to metformin-based OAD therapy, whereas treatment in the OAD group was unchanged. Patients were followed-up for another 6 months.

RESULTS

At the end of the 6-month intervention, HbA1c was similarly reduced in both the glargine (from 11.81 ± 1.70% to 6.48 ± 0.79%; P < 0.001) and OAD (from 11.71 ± 1.89% to 6.16 ± 0.52%; P < 0.001) groups. At the end of 12 months, HbA1c was at comparable and near optimal levels in both groups. Similar increases were seen in homeostatic model assessment of β-cell function in the two groups after 6 months. There were no significant differences between the two groups in insulin sensitivity improvement, hypoglycemic episodes, weight change, treatment satisfaction and quality of life after the 6-month intervention.

CONCLUSIONS

The effects of metformin-based OAD therapy on glycemic control and improvements in β-cell function are not inferior to glargine in newly diagnosed T2D patients with severe hyperglycemia after short-term ITT. Considering the superiority of metformin in terms of safety, cost, and convenience, metformin-based OAD therapy is strongly recommended for these patients.

Epigenetic regulation of the NR4A orphan nuclear receptor NOR1 by histone acetylation

The nuclear receptor NOR1 is an immediate-early response gene implicated in the transcriptional control of proliferation. Since the expression level of NOR1 is rapidly induced through cAMP response element binding (CREB) protein-dependent promoter activation, we investigated the contribution of histone acetylation to this transient induction. We demonstrate that NOR1 transcription is induced by histone deacetylase (HDAC) inhibition and by depletion of HDAC1 and HDAC3. HDAC inhibition activated the NOR1 promoter, increased histone acetylation and augmented the recruitment of phosphorylated CREB to the promoter. Furthermore, HDAC inhibition increased Ser133 phosphorylation of CREB and augmented NOR1 protein stability. These data outline previously unrecognized mechanisms of NOR1 regulation and illustrate a key role for histone acetylation in the rapid induction of NOR1.

Abstract 162: Everolimus Prevents Vascular Smooth Muscle Cell Proliferation by Repressing Cell Cycle-Dependent Telomerase Activation

INTRODUCTION: Everolimus is a potent antiproliferative agent that prevents growth factor-stimulated proliferation of vascular smooth muscle cells and is frequently used as platform for drug-eluting coronary stents to prevent restenosis after coronary artery angioplasty. We have previously demonstrated that telomerase plays a crucial role in vascular smooth muscle cell proliferation. However, whether telomerase is involved in the anti-proliferative activity of everolimus and the putative molecular mechanisms underlying this activity remain elusive. In this study, we assessed the hypothesis that telomerase is a key downstream target for the anti-proliferative activity of everolimus.

METHODS AND RESULTS: We demonstrate that everolimus treatment resulted in a dose-dependent inhibition of mitogen-induced telomerase activity in human coronary artery VSMCs (hcVSMCs). Moreover mitogen-induced telomerase reverse transcriptase (TERT) promoter activity and protein expression were dose-dependently repressed by everolimus treatment. Everolimus inhibited mitogen-induced cell proliferation as a result of a G1 →S phase arrest of the cell cycle. In addition, everolimus repressed protein expression of cell cycle-regulated genes (MCM 7, PCNA and Cyclin A) without altering phosphorylation of the retinoblastoma (Rb) protein, being the key gatekeeper of cell cycle transition. In addition, the effects of everolimus were not related to telomere shorting and cellular senescence, supporting the concept of a noncanonical telomere length-independent mechanism. Finally, we demonstrated in transient transfection studies that TERT overexpression abolished the anti-proliferative effect of everolimus in hcVSMC, pointing to a key role of telomerase as a target for the anti-proliferative effects of everolimus.

CONCLUSIONS: These results indicate that telomerase constitutes a key target for the anti-proliferative activity of everolimus and identify a novel mechanism for the inhibition of hcVSMC proliferation.

Transcriptome analysis of glioma cells for the dynamic response to γ-irradiation and dual regulation of apoptosis genes: a new insight into radiotherapy for glioblastomas

Ionizing radiation (IR) is of clinical importance for glioblastoma therapy; however, the recurrence of glioma characterized by radiation resistance remains a therapeutic challenge. Research on irradiation-induced transcription in glioblastomas can contribute to the understanding of radioresistance mechanisms. In this study, by using the total mRNA sequencing (RNA-seq) analysis, we assayed the global gene expression in a human glioma cell line U251 MG at various time points after exposure to a growth arrest dose of γ-rays. We identified 1656 genes with obvious changes at the transcriptional level in response to irradiation, and these genes were dynamically enriched in various biological processes or pathways, including cell cycle arrest, DNA replication, DNA repair and apoptosis. Interestingly, the results showed that cell death was not induced even many proapoptotic molecules, including death receptor 5 (DR5) and caspases were activated after radiation. The RNA-seq data analysis further revealed that both proapoptosis and antiapoptosis genes were affected by irradiation. Namely, most proapoptosis genes were early continually responsive, whereas antiapoptosis genes were responsive at later stages. Moreover, HMGB1, HMGB2 and TOP2A involved in the positive regulation of DNA fragmentation during apoptosis showed early continual downregulation due to irradiation. Furthermore, targeting of the TRAIL/DR5 pathway after irradiation led to significant apoptotic cell death, accompanied by the recovered gene expression of HMGB1, HMGB2 and TOP2A. Taken together, these results revealed that inactivation of proapoptotic signaling molecules in the nucleus and late activation of antiapoptotic genes may contribute to the radioresistance of gliomas. Overall, this study provided novel insights into not only the underlying mechanisms of radioresistance in glioblastomas but also the screening of multiple targets for radiotherapy.

Abstract 157: Bone Marrow Deficiency of the NR4A Orphan Nuclear Receptor NOR1 Accelerates Atherosclerosis by Increasing Myeloid Progenitor Cell Proliferation

The NR4A orphan nuclear receptor NOR1 functions as a constitutively active transcription factor regulating cellular inflammation and proliferation during atherosclerosis formation. In the present study, we characterize NOR1 as a suppressor of hematopoietic stem cell proliferation. NOR1 deficiency in mice induces the expansion of myeloid progenitor cells in the bone marrow resulting in monocytosis and splenomegaly in mice. In addition to increasing the proliferation of macrophage dendritic cell progenitors (MDP), NOR1 depletion induces a proinflammatory phenotype with increased numbers of Ly6+ monocytes. Bone marrow transplantation experiments confirmed monocytosis and increased Ly6+ monocytes in mice reconstituted with NOR1-deficient bone marrow, indicative of a defect intrinsic to the transplanted hematopoietic cells. Using a thioglycollate-induced peritonitis model, deletion of the NOR1 locus was associated with increased recruitment of macrophages into the exudate following peritoneal lavage. Finally, we demonstrate that bone marrow transplantation of lethally irradiated apoE-deficient mice with NOR1-deficient hematopoietic stem cells increases atherosclerosis formation following Western diet feeding. Collectively, these experiments point to a previously unrecognized role of NOR1 in the suppression of myeloid progenitor cell proliferation, inflammatory responses, and atherosclerosis.

Glutathione depletion prevents diet-induced obesity and enhances insulin sensitivity

Excessive accumulation of reactive oxygen species (ROS) in adipose tissue has been implicated in the development of insulin resistance and type 2 diabetes. However, emerging evidence suggests a physiologic role of ROS in cellular signaling and insulin sensitivity. In this study, we demonstrate that pharmacologic depletion of the antioxidant glutathione in mice prevents diet-induced obesity, increases energy expenditure and locomotor activity, and enhances insulin sensitivity. These observations support a beneficial role of ROS in glucose homeostasis and warrant further research to define the regulation of metabolism and energy balance by ROS.

Transcriptional regulation of S phase kinase-associated protein 2 by NR4A orphan nuclear receptor NOR1 in vascular smooth muscle cells

Members of the NR4A subgroup of the nuclear hormone receptor superfamily have emerged as key transcriptional regulators of proliferation and inflammation. NOR1 constitutes a ligand-independent transcription factor of this subgroup and induces cell proliferation; however, the transcriptional mechanisms underlying this mitogenic role remain to be defined. Here, we demonstrate that the F-box protein SKP2 (S phase kinase-associated protein 2), the substrate-specific receptor of the ubiquitin ligase responsible for the degradation of p27(KIP1) through the proteasome pathway, constitutes a direct transcriptional target for NOR1. Mitogen-induced Skp2 expression is silenced in vascular smooth muscle cells (VSMC) isolated from Nor1-deficient mice or transfected with Nor1 siRNA. Conversely, adenovirus-mediated overexpression of NOR1 induces Skp2 expression in VSMC and decreases protein abundance of its target p27. Transient transfection experiments establish that NOR1 transactivates the Skp2 promoter through a nerve growth factor-induced clone B response element (NBRE). Electrophoretic mobility shift and chromatin immunoprecipitation assays further revealed that NOR1 is recruited to this NBRE site in the Skp2 promoter in response to mitogenic stimulation. In vivo Skp2 expression is increased during the proliferative response underlying neointima formation, and this transcriptional induction depends on the expression of NOR1. Finally, we demonstrate that overexpression of Skp2 rescues the proliferative arrest of Nor1-deficient VSMC. Collectively, these results characterize Skp2 as a novel NOR1-regulated target gene and detail a previously unrecognized transcriptional cascade regulating mitogen-induced VSMC proliferation.

Oxidative stress accumulates in adipose tissue during aging and inhibits adipogenesis

Aging constitutes a major independent risk factor for the development of type 2 diabetes and is accompanied by insulin resistance and adipose tissue dysfunction. One of the most important factors implicitly linked to aging and age-related chronic diseases is the accumulation of oxidative stress. However, the effect of increased oxidative stress on adipose tissue biology remains elusive. In this study, we demonstrate that aging in mice results in a loss of fat mass and the accumulation of oxidative stress in adipose tissue. In vitro, increased oxidative stress through glutathione depletion inhibits preadipocyte differentiation. This inhibition of adipogenesis is at least in part the result of reduced cell proliferation and an inhibition of G₁→S-phase transition during the initial mitotic clonal expansion of the adipocyte differentiation process. While phosphorylation of the retinoblastoma protein (Rb) by cyclin/cdk complexes remains unaffected, oxidative stress decreases the expression of S-phase genes downstream of Rb. This silencing of S phase gene expression by increased oxidative stress is mediated through a transcriptional mechanism involving the inhibition of E2F recruitment and transactivation of its target promoters. Collectively, these data demonstrate a previously unrecognized role of oxidative stress in the regulation of adipogenesis which may contribute to age-associated adipose tissue dysfunction.

Serum pigment epithelium-derived factor is elevated in women with polycystic ovary syndrome and correlates with insulin resistance

CONTEXT

Serum pigment epithelium-derived factor (PEDF) is highly expressed in adipose tissue and plays an important role in insulin resistance (IR). However, there are no data on serum PEDF levels and their relationship with IR in polycystic ovary syndrome (PCOS) women.

OBJECTIVE

To quantitate serum PEDF levels and examine their relationship with IR in women with PCOS.

PARTICIPANTS AND DESIGN

Ninety-six PCOS women and 63 healthy age-matched controls were recruited. Ninety-six PCOS women and 20 controls underwent hyperinsulinemic-euglycemic clamp to assess their insulin sensitivity, which was expressed as M value. IR was also estimated by homeostasis model assessment 2 (HOMA2-IR).

SETTING

The study was performed at a clinical research center.

RESULTS

PCOS women had lower M value and higher HOMA2-IR as compared with controls. Serum PEDF levels were much higher in PCOS women than in controls (5.45 ± 1.85 vs. 3.97 ± 0.98 μg/ml, P < 0.01). Spearman correlation analysis showed that in PCOS women, PEDF positively correlated with body mass index, waist circumference, HOMA2-IR, triglycerides, total cholesterol, low-density lipoprotein cholesterol, and systolic blood pressure and negatively correlated with M value and high-density lipoprotein cholesterol. Multiple linear regression analysis revealed that in PCOS women, after adjustment for body mass index, systolic blood pressure, and serum lipids (triglycerides, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol), PEDF was still associated with M value or HOMA2-IR.

CONCLUSIONS

The serum PEDF level is elevated in women with PCOS and is associated with IR. PEDF may play a role in the pathogenesis of IR in PCOS.

Serum complement C3 has a stronger association with insulin resistance than high-sensitivity C-reactive protein in women with polycystic ovary syndrome

OBJECTIVE

To compare the association of complement C3 (C3) versus high-sensitivity C-reactive protein (hs-CRP) with insulin resistance (IR) in women with polycystic ovary syndrome (PCOS).

DESIGN

Cross-sectional analysis.

SETTING

Clinical research center in China.

PATIENT(S)

One hundred thirty-three women with PCOS and 116 healthy, age-matched controls were recruited.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

One hundred one women with PCOS and 20 controls underwent hyperinsulinemic-euglycemic clamp to assess their insulin sensitivity, which was expressed as an M value.

RESULT(S)

Compared with controls, women with PCOS had a lower M value and higher C3 (1.37 ± 0. 34 vs. 1.10 ± 0.22 g/L) and hs-CRP levels (1.46 ± 2.29 vs. 0.49 ± 0.88 mg/L). In women with PCOS, C3 and hs-CRP negatively correlated with M value (r = -0.61 and r = -0.47, respectively). By regression analysis, C3 was found to have a greater impact on the M value (standardized coefficient β = -0.24) than did hs-CRP (standardized coefficient β = -0.13). After adjusting for body mass index (BMI), women with PCOS in the upper quartile were 4.30 times more likely to exhibit IR compared with those in the lower quartiles, whereas hs-CRP was not a statistically significant predictor of IR in women with PCOS.

CONCLUSION(S)

Compared with hs-CRP, serum C3 might be a stronger inflammatory marker of IR in women with PCOS.

Epigenetic regulation of vascular smooth muscle cell proliferation and neointima formation by histone deacetylase inhibition

OBJECTIVE

Proliferation of smooth muscle cells (SMC) in response to vascular injury is central to neointimal vascular remodeling. There is accumulating evidence that histone acetylation constitutes a major epigenetic modification for the transcriptional control of proliferative gene expression; however, the physiological role of histone acetylation for proliferative vascular disease remains elusive.

METHODS AND RESULTS

In the present study, we investigated the role of histone deacetylase (HDAC) inhibition in SMC proliferation and neointimal remodeling. We demonstrate that mitogens induce transcription of HDAC 1, 2, and 3 in SMC. Short interfering RNA-mediated knockdown of either HDAC 1, 2, or 3 and pharmacological inhibition of HDAC prevented mitogen-induced SMC proliferation. The mechanisms underlying this reduction of SMC proliferation by HDAC inhibition involve a growth arrest in the G(1) phase of the cell cycle that is due to an inhibition of retinoblastoma protein phosphorylation. HDAC inhibition resulted in a transcriptional and posttranscriptional regulation of the cyclin-dependent kinase inhibitors p21(Cip1) and p27(Kip). Furthermore, HDAC inhibition repressed mitogen-induced cyclin D1 mRNA expression and cyclin D1 promoter activity. As a result of this differential cell cycle-regulatory gene expression by HDAC inhibition, the retinoblastoma protein retains a transcriptional repression of its downstream target genes required for S phase entry. Finally, we provide evidence that these observations are applicable in vivo by demonstrating that HDAC inhibition decreased neointima formation and expression of cyclin D1 in a murine model of vascular injury.

CONCLUSIONS

These findings identify HDAC as a critical component of a transcriptional cascade regulating SMC proliferation and suggest that HDAC might play a pivotal role in the development of proliferative vascular diseases, including atherosclerosis and in-stent restenosis.