Circadian control of tumor immunosuppression affects efficacy of immune checkpoint blockade.

The circadian clock is a critical regulator of immunity, and this circadian control of immune modulation has an essential function in host defense and tumor immunosurveillance. Here we use a single-cell RNA sequencing approach and a genetic model of colorectal cancer to identify clock-dependent changes to the immune landscape that control the abundance of immunosuppressive cells and consequent suppression of cytotoxic CD8+ T cells. Of these immunosuppressive cell types, PD-L1-expressing myeloid-derived suppressor cells (MDSCs) peak in abundance in a rhythmic manner. Disruption of the epithelial cell clock regulates the secretion of cytokines that promote heightened inflammation, recruitment of neutrophils and the subsequent development of MDSCs. We also show that time-of-day anti-PD-L1 delivery is most effective when synchronized with the abundance of immunosuppressive MDSCs. Collectively, these data indicate that circadian gating of tumor immunosuppression informs the timing and efficacy of immune checkpoint inhibitors.

Health-Related Quality of Life Following Simultaneous Resection for Synchronous Colorectal Cancer Liver Metastases.

INTRODUCTION: Up to 25% of colorectal cancer patients present with synchronous liver metastases that can be treated with two operations or a single 'simultaneous' operation. Morbidity and mortality appear similar between approaches, however changes in health-related quality-of-life following simultaneous resection are not well reported. METHODS: A prospective, feasibility trial for simultaneous resection of synchronous colorectal liver metastases was conducted. Patients completed the European Organization for Research and Treatment of Cancer QLQ-C30 and LMC21 at baseline (preoperatively), and 4 and 12 weeks postoperatively. Week 4 and 12 scores were compared with baseline using t-tests. Minimally important clinical differences were considered as a 10-point difference from baseline. RESULTS: C30 and QLQ-LMC21 were completed at baseline, 4 weeks, and 12 weeks by 39 (95%), 35 (85%) and 34 (83%) patients, and 39 (95%), 33 (80%) and 33 (80%) patients, respectively; 79% and 75% had at least one MICD according to QLQ-C30 at 4 and 12 weeks. At 4 weeks, physical functioning (mean difference (MD) - 11.9%, p = 0.002), role functioning (MD - 23.6, p = 0.007), and pain (MD + 19.7, p = 0.017) had significant worsening from baseline. At 12 weeks postoperatively, role functioning (MD - 19.7, p = 0.011) and fatigue (MD + 14.3, p = 0.03) were the only domains that remained significantly worse. By 12 weeks, pain and physical functioning had returned to baseline. There were no major demographic differences among those with and without an MICD at 12 weeks. CONCLUSIONS: Simultaneous resection of colorectal liver metastases led to clinically significant worsening fatigue and role functioning that persisted at 12 weeks post-surgery.

Molecular patterns of response and treatment failure after frontline venetoclax combinations in older patients with AML.

The BCL-2 inhibitor venetoclax combined with hypomethylating agents or low-dose cytarabine represents an important new therapy for older or unfit patients with acute myeloid leukemia (AML). We analyzed 81 patients receiving these venetoclax-based combinations to identify molecular correlates of durable remission, response followed by relapse (adaptive resistance), or refractory disease (primary resistance). High response rates and durable remissions were typically associated with NPM1 or IDH2 mutations, with prolonged molecular remissions prevalent for NPM1 mutations. Primary and adaptive resistance to venetoclax-based combinations was most commonly characterized by acquisition or enrichment of clones activating signaling pathways such as FLT3 or RAS or biallelically perturbing TP53. Single-cell studies highlighted the polyclonal nature of intratumoral resistance mechanisms in some cases. Among cases that were primary refractory, we identified heterogeneous and sometimes divergent interval changes in leukemic clones within a single cycle of therapy, highlighting the dynamic and rapid occurrence of therapeutic selection in AML. In functional studies, FLT3 internal tandem duplication gain or TP53 loss conferred cross-resistance to both venetoclax and cytotoxic-based therapies. Collectively, we highlight molecular determinants of outcome with clinical relevance to patients with AML receiving venetoclax-based combination therapies.

Metabolic Remodeling Promotes Cardiac Hypertrophy by Directing Glucose to Aspartate Biosynthesis.

RATIONALE: Hypertrophied hearts switch from mainly using fatty acids (FAs) to an increased reliance on glucose for energy production. It has been shown that preserving FA oxidation (FAO) prevents the pathological shift of substrate preference, preserves cardiac function and energetics, and reduces cardiomyocyte hypertrophy during cardiac stresses. However, it remains elusive whether substrate metabolism regulates cardiomyocyte hypertrophy directly or via a secondary effect of improving cardiac energetics. OBJECTIVE: The goal of this study was to determine the mechanisms of how preservation of FAO prevents the hypertrophic growth of cardiomyocytes. METHODS AND RESULTS: We cultured adult rat cardiomyocytes in a medium containing glucose and mixed-chain FAs and induced pathological hypertrophy by phenylephrine. Phenylephrine-induced hypertrophy was associated with increased glucose consumption and higher intracellular aspartate levels, resulting in increased synthesis of nucleotides, RNA, and proteins. These changes could be prevented by increasing FAO via deletion of ACC2 (acetyl-CoA-carboxylase 2) in phenylephrine-stimulated cardiomyocytes and in pressure overload-induced cardiac hypertrophy in vivo. Furthermore, aspartate supplementation was sufficient to reverse the antihypertrophic effect of ACC2 deletion demonstrating a causal role of elevated aspartate level in cardiomyocyte hypertrophy. 15N and 13C stable isotope tracing revealed that glucose but not glutamine contributed to increased biosynthesis of aspartate, which supplied nitrogen for nucleotide synthesis during cardiomyocyte hypertrophy. CONCLUSIONS: Our data show that increased glucose consumption is required to support aspartate synthesis that drives the increase of biomass during cardiac hypertrophy. Preservation of FAO prevents the shift of metabolic flux into the anabolic pathway and maintains catabolic metabolism for energy production, thus preventing cardiac hypertrophy and improving myocardial energetics.

[Ruxolitinib combined with liposomal doxorubicin, etoposide, methylprednisolone+/-PEG-asparaginase in treatment of relapsed/refractory pediatric hemophagocytic lymphohistiocytosis].

Objective: To investigate the efficacy and safety of ruxolitinib, liposomal doxorubicin, etoposide, methylprednisolone+/-PEG-asparaginase (RU-DEP+/-L) in the treatment of relapsed/refractory (R/R) pediatric hemophagocytic lymphohistiocytosis (HLH). Methods: The clinical data of R/R pediatric HLH, who accepted the RU-DEP+/-L regimen at Beijing Children's Hospital from January 2018 to December 2019 was retrospectively analyzed. Results: A total of 16 patients were included in this study, including 13 males and 3 females, aged[M(Q1,Q3)] 1 (1, 2) years at diagnosis. Thirteen patients were diagnosed with Epstein-Barr virus (EBV)-HLH, 2 with EBV-induced primary HLH, and 1 with unclear etiology, among which 3 patients were co-infected with CMV. After the first-line treatment, 11 patients had no response, and 5 patients relapsed after complete response. Nine patients received the RU-L-DEP regimen, and 7 patients received the RU-DEP regimen. The overall response rate and complete response of RU-DEP+/-L treatment were 10/16 and 3/16, respectively. The negative conversion rate of plasma EBV-DNA was 7/15. The median follow-up time was 35.1 (2.4, 40.7) months, and 9/16 patients were survival. The 3-year overall survival rate after RU-DEP+/-L treatment in response and accepted hematopoietic stem cell transplantation (HSCT) was higher than that without response and did not receive HSCT (P=0.048). Among the 16 patients, 9 had varying degrees of myelosuppression, and 13 had an infection. Conclusions: RU-DEP+/-L can be used as a salvage treatment in R/R pediatric HLH, which can provide a bridge to HSCT and play an important role in the control of HLH. The main adverse reactions are myelosuppression and infection, which can be tolerated.

Increasing Fatty Acid Oxidation Prevents High-Fat Diet-Induced Cardiomyopathy Through Regulating Parkin-Mediated Mitophagy.

BACKGROUND: Increased fatty acid oxidation (FAO) has long been considered a culprit in the development of obesity/diabetes mellitus-induced cardiomyopathy. However, enhancing cardiac FAO by removing the inhibitory mechanism of long-chain fatty acid transport into mitochondria via deletion of acetyl coenzyme A carboxylase 2 (ACC2) does not cause cardiomyopathy in nonobese mice, suggesting that high FAO is distinct from cardiac lipotoxicity. We hypothesize that cardiac pathology-associated obesity is attributable to the imbalance of fatty acid supply and oxidation. Thus, we here seek to determine whether further increasing FAO by inducing ACC2 deletion prevents obesity-induced cardiomyopathy, and if so, to elucidate the underlying mechanisms. METHODS: We induced high FAO in adult mouse hearts by cardiac-specific deletion of ACC2 using a tamoxifen-inducible model (ACC2 iKO). Control and ACC2 iKO mice were subjected to high-fat diet (HFD) feeding for 24 weeks to induce obesity. Cardiac function, mitochondria function, and mitophagy activity were examined. RESULTS: Despite both control and ACC2 iKO mice exhibiting a similar obese phenotype, increasing FAO oxidation by deletion of ACC2 prevented HFD-induced cardiac dysfunction, pathological remodeling, and mitochondria dysfunction, as well. Similarly, increasing FAO by knockdown of ACC2 prevented palmitate-induced mitochondria dysfunction and cardiomyocyte death in vitro. Furthermore, HFD suppressed mitophagy activity and caused damaged mitochondria to accumulate in the heart, which was attenuated, in part, in the ACC2 iKO heart. Mechanistically, ACC2 iKO prevented HFD-induced downregulation of parkin. During stimulation for mitophagy, mitochondria-localized parkin was severely reduced in control HFD-fed mouse heart, which was restored, in part, in ACC2 iKO HFD-fed mice. CONCLUSIONS: These data show that increasing cardiac FAO alone does not cause cardiac dysfunction, but protects against cardiomyopathy in chronically obese mice. The beneficial effect of enhancing cardiac FAO in HFD-induced obesity is mediated, in part, by the maintenance of mitochondria function through regulating parkin-mediated mitophagy. Our findings also suggest that targeting the parkin-dependent mitophagy pathway could be an effective strategy against the development of obesity-induced cardiomyopathy.

Coupled approach for radiometric calibration and parameter retrieval to improve SPM estimations in turbid inland/coastal waters.

High-precision radiometric calibration (RC) coefficients are required to retrieve reliable water quality parameter products in turbid inland/coastal waters. However, unreliable RC coefficients when satellite sensors lack accurate and in-time RC may lead to pronounced uncertainties in the products through error propagation. To address this issue, a novel approach for estimating water quality parameters, taking suspended particulate matter (SPM) as a case, was proposed by coupling the procedures of RC and SPM model development. The coupled models were established using digital numbers (DNs) from target sensors and "in-situ" SPM measurements from concurrent well-calibrated reference sensors, with the RC coefficients introduced as unknown model parameters. The approach was tested and validated in varied Chinese inland/coastal regions, including the Hongze lake (HL), Taihu lake (TL), and Hangzhou bay (HB). The results show: (1) the DN-based SPM models can achieve a degree of accuracy comparable to reflectance-based SPM models with determination coefficients (R2) of 0.94, 0.92, and 0.72, and root-mean-square errors (RMSE) of 7.02 mg/L, 15.73 mg/L, and 619.2 mg/L for the HL, TL, and HB, respectively, and the biases less than 3% between the derived and official gain RC coefficients; (2) the uncertainty of SPM products increases exponentially as the RC uncertainty increases for exponential reflectance-based SPM models; (3) the DN-based SPM models are less sensitive to the uncertainties of atmospheric correction and RC coefficients, while the reflectance-based models suffer deeply. This study provides encouraging results to the improvement of SPM retrieval using the DN-based models by coupling RC and SPM retrieving processes, especially for sensors without precise RC coefficients.

Does the presence of an intact primary increase the risk of nonelective colorectal surgery in patients treated with bevacizumab?

AIM: In patients with incurable metastatic colorectal cancer (mCRC), resection of the primary tumour is debated; however, patients with intact primaries may be at a higher risk of complications requiring surgery when receiving treatment with bevacizumab. Our aim was to estimate the risk of nonelective colorectal surgery in patients undergoing bevacizumab therapy for mCRC and evaluate the association between intact primary tumours and risk of nonelective surgery. METHOD: We designed a population-based, retrospective cohort study using administrative and cancer registry data in Ontario, Canada. We included patients with mCRC who received bevacizumab from 1 January 2008 to 31 December 2014. The primary outcome was nonelective colorectal surgery after initiation of bevacizumab. We determined the cumulative incidence of nonelective colorectal surgery among patients with previously resected and unresected primaries, accounting for the competing risk of death. We explored the relationship between previous resection of the primary and need for nonelective surgery using a cause-specific hazards model, controlling for patient, tumour and treatment factors. RESULTS: We identified 1840 (32.7%) patients with intact primaries and 3784 (67.3%) patients with prior resection. The cumulative incidence of nonelective surgery 1 year after initiating bevacizumab for all patients was 3.9% (95% CI 3.4-4.5%). One-year cumulative incidence was higher in those with intact primaries than in those with resected primaries (6.1% vs 2.9%, P < 0.0001). After adjustment, an intact primary remained strongly associated with nonelective colorectal surgery (hazard ratio = 2.89, 95% CI 2.32-3.61; P < 0.0001). CONCLUSION: Bevacizumab is associated with a low but meaningful risk for serious gastrointestinal complications, necessitating vigilance, particularly among patients with an intact primary tumour.

SRSF9 selectively represses ADAR2-mediated editing of brain-specific sites in primates.

Adenosine-to-inosine (A-to-I) RNA editing displays diverse spatial patterns across different tissues. However, the human genome encodes only two catalytically active editing enzymes (ADAR1 and ADAR2), suggesting that other regulatory factors help shape the editing landscape. Here, we show that the splicing factor SRSF9 selectively controls the editing of many brain-specific sites in primates. SRSF9 is more lowly expressed in the brain than in non-brain tissues. Gene perturbation experiments and minigene analysis of candidate sites demonstrated that SRSF9 could robustly repress A-to-I editing by ADAR2. We found that SRSF9 biochemically interacted with ADAR2 in the nucleus via its RRM2 domain. This interaction required the presence of the RNA substrate and disrupted the formation of ADAR2 dimers. Transcriptome-wide location analysis and RNA sequencing revealed 1328 editing sites that are controlled directly by SRSF9. This regulon is significantly enriched for brain-specific sites. We further uncovered a novel motif in the ADAR2-dependent SRSF9 binding sites and provided evidence that the splicing factor prevents loss of cell viability by inhibiting ADAR2-mediated editing of genes involved in proteostasis, energy metabolism, the cell cycle and DNA repair. Collectively, our results highlight the importance of SRSF9 as an editing regulator and suggest potential roles for other splicing factors.

Boosted visual performance after eye blinks.

We blink more often than required for maintaining the corneal tear film. Whether there are perceptual or cognitive consequences of blinks that may justify their high frequency is unclear. Previous findings showed that blinks may indicate switches between large-scale cortical networks, such as dorsal attention and default-mode networks. Thus, blinks may trigger a refresh of visual attention. Yet, this has so far not been confirmed behaviorally. Here, we tested the effect of blinks on visual performance in a series of rapid serial visual presentation tasks. In Experiment 1, participants had to identify a target digit embedded in a random stream of letter distractors, presented foveally for 60 ms each. Participants blinked once during the presentation stream. In a separate condition, blinks were simulated by shutter glasses. Detection performance was enhanced (up to 13% point increase in accuracy) for targets appearing up to 300 ms after eye blinks. Performance boosts were stronger for voluntary blinks than artificial blinks. This performance boost was also replicated with more naturalistic stimuli (Experiment 2). We conclude that eye blinks lead to attentional benefits for object recognition in the period after reopening of the eyelids and may be used strategically for temporarily boosting visual performance.

Polar gigantism and the oxygen-temperature hypothesis: a test of upper thermal limits to body size in Antarctic pycnogonids.

The extreme and constant cold of the Southern Ocean has led to many unusual features of the Antarctic fauna. One of these, polar gigantism, is thought to have arisen from a combination of cold-driven low metabolic rates and high oxygen availability in the polar oceans (the 'oxygen-temperature hypothesis'). If the oxygen-temperature hypothesis indeed underlies polar gigantism, then polar giants may be particularly susceptible to warming temperatures. We tested the effects of temperature on performance using two genera of giant Antarctic sea spiders (Pycnogonida), Colossendeis and Ammothea, across a range of body sizes. We tested performance at four temperatures spanning ambient (-1.8°C) to 9°C. Individuals from both genera were highly sensitive to elevated temperature, but we found no evidence that large-bodied pycnogonids were more affected by elevated temperatures than small individuals; thus, these results do not support the predictions of the oxygen-temperature hypothesis. When we compared two species, Colossendeis megalonyx and Ammothea glacialis, C. megalonyx maintained performance at considerably higher temperatures. Analysis of the cuticle showed that as body size increases, porosity increases as well, especially in C. megalonyx, which may compensate for the increasing metabolic demand and longer diffusion distances of larger animals by facilitating diffusive oxygen supply.

Predictors of Post-operative Pain and Opioid Consumption in Patients Undergoing Liver Surgery.

BACKGROUND: Post-operative pain management is a critical component of perioperative care. Patients at risk of poorly controlled post-operative pain may benefit from early measures to optimize pain management. We sought to identify risk factors for post-operative pain and opioid consumption in patients undergoing liver resection. METHODS: This is a multi-institutional prospective nested cohort study of patients undergoing open liver resection. Opioid consumption and pain scores were collected following surgery. To estimate the effects of patient factors on opioid consumption (oral morphine equivalents-OME) and on pain scores (NRS-11), we used generalized linear models and multivariable linear regression model, respectively. RESULTS: One hundred and fifty-three patients who underwent open liver resection between 2013 and 2016 were included in the study. The mean patient age was 62.2 years, and 43.3% were female. Younger patients were significantly more likely to use more opioids in the early post-operative period (16.7 OME/10 years, p < 0.001). Patient factors that were significantly associated with increased NRS-11 pain scores also included younger patient age (difference in pain score of 0.3/10 years with cough and 0.2/10 years at rest, p < 0.01 for both) as well as a history of analgesic use (difference in pain score of 0.9 with cough and 0.6 at rest, p < 0.01 and p = 0.07, respectively). CONCLUSION: Younger patients and those with a history of analgesic use are more likely to report higher post-operative pain and require higher doses of opioids. Early identification of these patients, and measures to better manage their pain, may contribute to optimal perioperative care.

Microvesicles containing miRNAs promote muscle cell death in cancer cachexia via TLR7.

MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression and, in cancers, are often packaged within secreted microvesicles. The cachexia syndrome is a debilitating state of cancer that predominantly results from the loss of skeletal muscle mass, which is in part associated with apoptosis. How tumors promote apoptosis in distally located skeletal muscles has not been explored. Using both tumor cell lines and patient samples, we show that tumor-derived microvesicles induce apoptosis of skeletal muscle cells. This proapoptotic activity is mediated by a microRNA cargo, miR-21, which signals through the Toll-like 7 receptor (TLR7) on murine myoblasts to promote cell death. Furthermore, tumor microvesicles and miR-21 require c-Jun N-terminal kinase activity to regulate this apoptotic response. Together, these results describe a unique pathway by which tumor cells promote muscle loss, which might provide a great insight into elucidating the causes and treatment options of cancer cachexia.

Lack of glucuronidation products of trans-resveratrol in plasma and urine of cats.

Resveratrol has generated interest in cats due to reported health benefits. Cats have low activity of ß-glucuronidase, and we hypothesized they could not form two common resveratrol metabolites, resveratrol-3-O-glucuronide and resveratrol-4'-O-glucuronide. Resveratrol, 3 mg/cat/day, was given orally to intact male (n = 5) and female cats (n = 5) for 4 weeks. A control group (8 intact males) was used for comparison. Plasma and urine were collected weekly and analysed using high-pressure liquid chromatography coupled with tandem mass spectrometry. Resveratrol and resveratrol-3-O-sulphate, but no glucuronide metabolites, were detected in plasma and urine. Median (range 10-90th percentile) plasma resveratrol for control and treatment groups was 0.46 ng/ml (0.02-1.74 ng/ml) and 0.96 ng/ml (0.65-3.21 ng/ml). Median (range) plasma resveratrol-3-O-sulphate for control and treatment groups was 6.32 ng/ml (2.55-10.29 ng/ml) and 11.45 ng/ml (1.47-53.29 ng/ml). Plasma resveratrol differed from control in week 4, while plasma resveratrol-3-O-sulphate was different in all weeks (p < 0.05). Median (range) urine resveratrol for control and treatment groups was 0.28 ng/ml (0.05-1.59 ng/ml) and 19.98 ng/ml (8.44-87.54 ng/ml). Median (range) urine resveratrol-3-O-sulphate for control and treatment groups was 26.71 ng/ml (10.50-75.58 ng/ml) and 108.69 ng/ml (11.83-231.05 ng/ml). All time points for urine resveratrol and resveratrol-3-O-sulphate were significantly different from control (p < 0.05), except for weeks 1, 3 and 4 for resveratrol. The results support our hypothesis that cats are unlikely able to glucuronidate resveratrol, most likely due to a reduction in the activity of ß-glucuronidase.

Role of the dorsal medial habenula in the regulation of voluntary activity, motor function, hedonic state, and primary reinforcement.

The habenular complex in the epithalamus consists of distinct regions with diverse neuronal populations. Past studies have suggested a role for the habenula in voluntary exercise motivation and reinforcement of intracranial self-stimulation but have not assigned these effects to specific habenula subnuclei. Here, we have developed a genetic model in which neurons of the dorsal medial habenula (dMHb) are developmentally eliminated, via tissue-specific deletion of the transcription factor Pou4f1 (Brn3a). Mice with dMHb lesions perform poorly in motivation-based locomotor behaviors, such as voluntary wheel running and the accelerating rotarod, but show only minor abnormalities in gait and balance and exhibit normal levels of basal locomotion. These mice also show deficits in sucrose preference, but not in the forced swim test, two measures of depression-related phenotypes in rodents. We have also used Cre recombinase-mediated expression of channelrhodopsin-2 and halorhodopsin to activate dMHb neurons or silence their output in freely moving mice, respectively. Optical activation of the dMHb in vivo supports intracranial self-stimulation, showing that dMHb activity is intrinsically reinforcing, whereas optical silencing of dMHb outputs is aversive. Together, our findings demonstrate that the dMHb is involved in exercise motivation and the regulation of hedonic state, and is part of an intrinsic reinforcement circuit.

The involvement of insulin-like growth factor 2 binding protein 3 (IMP3) in pancreatic cancer cell migration, invasion, and adhesion.

BACKGROUND: Over-expression of insulin-like growth factor 2 mRNA binding protein 3 (IMP3) is correlated with poor prognosis in pancreatic ductal adenocarcinoma (PDAC). Previous studies examining other cancer types have implicated IMP3 in the regulation of several cellular functions that are characteristic of tumour cells. However, the role of this oncofetal protein in PDAC progression remained unclear. METHODS: Using siRNA, we examined the effect of IMP3 inhibition on the motility, invasive ability, and matrix adhesion of PDAC cells. In addition, we also evaluated the expression of cytoskeleton-associated genes following IMP depletion. RESULTS: Knockdown of IMP3 significantly decreased the motility, invasion, and extracellular matrix adhesion of select PDAC cells in vitro. In addition, IMP3-depleted cells exhibited lower levels of CD44 protein and KIF11 mRNA. Moreover, we also observed a reduction in downstream RhoA signaling following IMP3 knockdown, indicating that IMP3 modulates the levels of proteins involved in cytoskeletal organization. CONCLUSIONS: These results suggest that IMP3 facilitates PDAC progression by enhancing the pro-metastatic behaviour of tumour cells.

Myocardin restores erectile function in diabetic rats: phenotypic modulation of corpus cavernosum smooth muscle cells.

This study aimed to investigate whether gene transfer of myocardin to the penis of diabetic rats can modulate corpus cavernosum smooth muscle (CCSM) cells phenotype and restore erectile function. Five normal control rats, and 22 diabetic rats were randomly divided into four groups: rats transfected with adCMV-myocardin (N = 6), treated with empty vector (N = 6), injected with medium (N = 5), and sham-operated rats (N = 5). The erectile response was measured 7 days after transfection. The percent of smooth muscle and the expressions of SMα-actin, smooth muscle myosin heavy chain (SMMHC), calponin were evaluated. The increases in intracorporal pressure(ICP)/mean arterial pressure and total ICP in response to nerve stimulation in the adCMV-myocardin treated rats were significantly greater than those in the empty vector (P < 0.001 and P < 0.001), medium only (P < 0.001 and P < 0.001), and sham-operated rats (P < 0.001 and P < 0.001). The suppressed expressions of SMα-actin, SMMHC and calponin were completely restored, and the amount of smooth muscle in diabetic rats were not restored after treatment. It is concluded that myocardin ameliorated erectile responses in diabetic rats mainly via promoting phenotypic modulation of CCSM cells from a proliferative to a contractile state.

Effect of chronic hypoxia on penile erectile function in rats.

We examined the relationship between chronic hypoxia and erectile dysfunction in rat and its possible pathogenic mechanism. Forty-eight white male adult Sprague-Dawley rats were randomly divided into a test group and a control group. In accordance with the experimental time (2, 6, and 10 weeks), each group was divided into 3 subgroups, with 8 rats in each subgroup. Rats in the test group were fed in an airtight hypoxia cabin, while rats in the control group were maintained in a normal environment, with other conditions kept the same. At 2, 6, and 10 weeks, the rats in each group were observed for erectile function. Affinity purification was used to detect neural nitric oxide synthase (nNOS)-positive nerve fibers and endothelial nitric oxide synthase (eNOS) expression. After hypoxia, erectile frequency decreased significantly compared to before hypoxia (P < 0.001). Comparison of the test group and control group revealed a significant difference in the quantity of nNOS-positive nerve fiber and eNOS protein expression (P < 0.01). Hypoxia may influence erectile function and nNOS and eNOS expression in rats. The decrease in the quantity of nNOS nerve fibers and expression of eNOS may contribute to erectile dysfunction under hypoxic conditions in rats.

Influence of dietary protein level on body composition and energy expenditure in calorically restricted overweight cats.

High-protein (HP) diets help prevent loss of lean mass in calorie-restricted (CR) cats. However, it is not entirely known whether these diets also induce changes of energy expenditure during periods of CR. To investigate this issue, sixteen overweight cats were fed either a high-protein [(HP), 54.2% of metabolizable energy (ME)] or a moderate-protein [(MP), 31.5% of ME] diet at 70% of their maintenance energy intakes for 8 weeks, and energy expenditure, energy intake, body weight and composition, and serum metabolites and hormones were measured. While both groups of cats lost weight at a similar rate, only cats eating the HP diet maintained lean mass during weight loss. Indirect respiration calorimetry measurements revealed that both total and resting energy expenditure (kcal/d) significantly decreased during weight loss for both treatment groups. However, only cats eating the MP diet exhibited significant decreases of total and resting energy expenditures after energy expenditure was normalized for body weight or lean mass. Results from this study suggest that in addition to sparing the loss of lean mass, feeding HP diets to overweight cats in restricted amounts may be beneficial for preventing or minimizing decreases of mass-adjusted energy expenditure during weight loss.