Pyrrolidine Dithiocarbamate Activates p38 MAPK and Protects Brain Endothelial Cells From Apoptosis: A Mechanism for the Protective Effect in Stroke?

The antioxidant and inhibitor of nuclear factor κB pyrrolidine dithiocarbamate (PDTC) potently reduces infarct size in various experimental stroke models. In addition, it has been shown to have a favourable safety profile in humans. In this study, we further investigated the mechanistic actions of PDTC on cerebral microvascular endothelial cells as main components of the blood–brain barrier. We propose activation of p38 MAPK by PDTC as an additional protective mechanism. C57/BL6 mice were subjected to transient MCAO for 2 h and treated with PDTC (100 mg/kg) or vehicle i.p. before reperfusion. Infarct size was determined after 24 h. Apoptosis was induced in a cerebral microvascular endothelial cell line and the effect of pretreatment with PDTC and its dependency on p38 MAPK activity was assayed. PDTC administered 2 h after MCAO reduced infarct size by 61% (P < 0.05) and reduces the apoptotic death rate in vivo. In vitro, PDTC reduces the apoptotic death rate of bEnd.3 cells. p38 MAPK was activated by PDTC and its inhibition abrogated the protective effect of PDTC. PDTC reduces infarct size after stroke with a reasonable time window and decreases apoptotic cell death in vivo and in vitro. The attenuation of apoptotic cell death in brain microvascular endothelial cells is dependent on p38 MAPK activity.     

Predator–prey interactions and metabolic rates are altered in stable and unstable groups in a social fish

Understanding the determinants and consequences of predation effort, success and prey responses is important since these factors affect the fitness of predators and prey. When predators are also invasive species, the impacts on prey can be particularly far-reaching with ultimate ecosystem-level consequences. However, predators are typically viewed as behaviourally fixed within this interaction and it is unclear how variation in predator social dynamics affects predator–prey interactions. Using the invasive eastern mosquitofish Gambusia holbrooki and a native glass shrimp Paratya australiensis in Australia, we investigated how varying levels of social conflict within predator groups influences predator–prey interactions. By experimentally manipulating group stability of G. holbrooki, we show that rates of social conflict were lower in groups with large size differences, but that routine metabolic rates were higher in groups with large size differences. Predation effort and success did not vary depending on group stability, but in stable groups predation effort by aggressive dominants was greater than subordinates. The anti-predator responses of prey to the stability of predator groups were mixed. While more prey utilized shelters when exposed to stable compared to unstable groups of predators, a greater proportion were sedentary when predator groups were unstable. Overall, this study demonstrates predator group stability is modulated by differences in body size and can influence prey responses. Further, it reveals a hidden metabolic cost of living in stable groups despite reduced overt social conflict. For invasive species management, it is therefore important to consider the behavioural and physiological plasticity of the invasive predators, whose complex social interactions and metabolic demands can modulate patterns of predator–prey interactions.     

Maternal care of heterozygous dopamine receptor D4 knockout mice: Differential susceptibility to early‐life rearing conditions

The differential susceptibility hypothesis proposes that individuals who are more susceptible to the negative effects of adverse rearing conditions may also benefit more from enriched environments. Evidence derived from human experiments suggests the lower efficacy dopamine receptor D4 (DRD4) 7‐repeat as a main factor in exhibiting these for better and for worse characteristics. However, human studies lack the genetic and environmental control offered by animal experiments, complicating assessment of causal relations. To study differential susceptibility in an animal model, we exposed Drd4^+/? mice and control litter mates to a limited nesting/bedding (LN), standard nesting (SN) or communal nesting (CN) rearing environment from postnatal day (P) 2‐14. Puberty onset was examined from P24 to P36 and adult females were assessed on maternal care towards their own offspring. In both males and females, LN reared mice showed a delay in puberty onset that was partly mediated by a reduction in body weight at weaning, irrespective of Drd4 genotype. During adulthood, LN reared females exhibited characteristics of poor maternal care, whereas dams reared in CN environments showed lower rates of unpredictability towards their own offspring. Differential susceptibility was observed only for licking/grooming levels of female offspring towards their litter; LN reared Drd4^+/? mice exhibited the lowest and CN reared Drd4^+/? mice the highest levels of licking/grooming. These results indicate that both genetic and early‐environmental factors play an important role in shaping maternal care of the offspring for better and for worse.     

Growth performance of Ganoderma lucidum using billet method in Garhwal Himalaya,India

Medicinal mushrooms have been used in various treatments from a very long time, among which, Ganoderma lucidum is one of the most important medicinal mushroom. It is cultivated worldwide to meet its ever-increasing demand in the market. It is generally cultivated by bed log (Sawdust) and wood log (billet) method. This study was an attempt to observe the growth performance of G. lucidum on poplar billets (Populus deltoides) in the Sherpur Village (Dehradun) and Manjgaun village (Tehri Garhwal) of Garhwal Himalaya, India. The farmers’ field with empty house/ rooms having proper growing conditions especially humidity and light were used for the cultivation of G. lucidum. The G. lucidum spawn was inoculated in poplar wood billets and these billets were installed in well prepared soil. The results demonstrated that cropping cycle of G. lucidum was shorter (132–136 days) in Sherpur Village (Dehradun) as compared to Manjgaun village (141–145 days) in Tehri Garhwal. Further the results also revealed that yield was decreased in the subsequent flushes. In Village Sherpur, the fruiting bodies of G. lucidum were harvested between 64-66 days, 100-101  days and 135-136  days during first, second and third flush after the installation of billets, respectively. However; in village Manjgaun, the fruiting bodies of G. lucidum were harvested between 69 and 71 days, 107-108  days and 144-145 days in first, second and third after the installation of billets respectively. Warmer temperature in Village Sherpur resulted in the early emergence and development of the fruiting bodies as compared to village Manjgaun where pinhead and fruiting body development was delayed due to the lower temperature during cropping cycle.     

Recreational physical activity and risk of papillary thyroid cancer among women in the California Teachers Study

Purpose: Little is known about the relationship between physical activity and thyroid cancer risk, and few cohort data on this association exist. Thus, the present study aimed to prospectively examine long-term activity and risk of papillary thyroid cancer among women. Methods: 116,939 women in the California Teachers Study, aged 22–79 years with no history of thyroid cancer at cohort entry, were followed from 1995–1996 through 2009; 275 were diagnosed with invasive papillary thyroid cancer. Cox proportional-hazards regression provided relative risk (RR) estimates and 95% confidence intervals (CI) for associations between thyroid cancer and combined strenuous and moderate recreational physical activity both in the long-term (high school through age 54 years or current age if younger than 54 years) and recently (during the three years prior to joining the cohort). Results: Overall, women whose long-term recreational physical activity averaged at least 5.5 MET-hours/week (i.e. were active) had a non-significant 23% lower risk of papillary thyroid cancer than inactive women (RR = 0.77, 95% CI: 0.57, 1.04). RR estimates were stronger among normal weight or underweight women (body mass index, BMI < 25.0 kg/m², trend p = 0.03) than among overweight or obese women (trend p = 0.35; homogeneity-of-trends p = 0.03). A similar pattern of risk was observed for recent activity (BMI < 25 kg/m², trend p = 0.11; BMI ≥ 25 kg/m², trend p = 0.16; homogeneity-of-trends p = 0.04). Associations for long-term activity did not appear to be driven by activity in any particular life period (e.g. youth, adulthood). Conclusions: Long-term physical activity may reduce papillary thyroid cancer risk among normal weight and underweight women.     

WISP1/CCN4: A Potential Target for Inhibiting Prostate Cancer Growth and Spread to Bone

Prostate cancer (PC) is a leading cause of death in men however the factors that regulate its progression and eventual metastasis to bone remain unclear. Here we show that WISP1/CCN4 expression in prostate cancer tissues was up-regulated in early stages of the disease and, further, that it correlated with increased circulating levels of WISP1 in the sera of patients at early stages of the disease. WISP1 was also elevated in the mouse prostate cancer model TRAMP in the hypoplastic diseased tissue that develops prior to advanced carcinoma formation. When the ability of anti-WISP1 antibodies to reduce the spread of PC3-Luc cells to distant sites was tested it showed that twice weekly injections of anti-WISP1 antibodies reduced the number and overall size of distant tumors developed after intracardiac (IC) injection of PC3-Luc cells in mice. The ability of antibodies against WISP1 to inhibit growth of PC3-Luc cancer cells in mice was also evaluated and showed that twice weekly injections of anti-WISP1 antibodies reduced local tumor growth when examined in xenografts. To better understand the mechanism of action, the migration of PC3-Luc cells through membranes with or without a Matrigel™ barrier showed the cells were attracted to WISP1, and that this attraction was inhibited by treatment with anti-WISP1 antibodies. We also show the expression of WISP1 at the bone-tumor interface and in the stroma of early grade cancers suggested WISP1 expression is well placed to play roles in both fostering growth of the cancer and its spread to bone. In summary, the up-regulation of WISP1 in the early stages of cancer development coupled with its ability to inhibit spread and growth of prostate cancer cells makes it both a potential target and an accessible diagnostic marker for prostate cancer.     

A Gene Signature to Determine Metastatic Behavior in Thymomas

Purpose

Thymoma represents one of the rarest of all malignancies. Stage and completeness of resection have been used to ascertain postoperative therapeutic strategies albeit with limited prognostic accuracy. A molecular classifier would be useful to improve the assessment of metastatic behaviour and optimize patient management.

Methods

qRT-PCR assay for 23 genes (19 test and four reference genes) was performed on multi-institutional archival primary thymomas (n = 36). Gene expression levels were used to compute a signature, classifying tumors into classes 1 and 2, corresponding to low or high likelihood for metastases. The signature was validated in an independent multi-institutional cohort of patients (n = 75).

Results

A nine-gene signature that can predict metastatic behavior of thymomas was developed and validated. Using radial basis machine modeling in the training set, 5-year and 10-year metastasis-free survival rates were 77% and 26% for predicted low (class 1) and high (class 2) risk of metastasis (P = 0.0047, log-rank), respectively. For the validation set, 5-year metastasis-free survival rates were 97% and 30% for predicted low- and high-risk patients (P = 0.0004, log-rank), respectively. The 5-year metastasis-free survival rates for the validation set were 49% and 41% for Masaoka stages I/II and III/IV (P = 0.0537, log-rank), respectively. In univariate and multivariate Cox models evaluating common prognostic factors for thymoma metastasis, the nine-gene signature was the only independent indicator of metastases (P = 0.036).

Conclusion

A nine-gene signature was established and validated which predicts the likelihood of metastasis more accurately than traditional staging. This further underscores the biologic determinants of the clinical course of thymoma and may improve patient management.     

Gene expression profiling of early intervertebral disc degeneration reveals a down-regulation of canonical Wnt signaling and caveolin-1 expression: implications for development of regenerative strategies

Introduction

Early degeneration of the intervertebral disc (IVD) involves a change in cellular differentiation from notochordal cells (NCs) in the nucleus pulposus (NP) to chondrocyte-like cells (CLCs). The purpose of this study was to investigate the gene expression profiles involved in this process using NP tissue from non-chondrodystrophic and chondrodystrophic dogs, a species with naturally occurring IVD degeneration.

Methods

Dual channel DNA microarrays were used to compare 1) healthy NP tissue containing only NCs (NC-rich), 2) NP tissue with a mixed population of NCs and CLCs (Mixed), and 3) NP tissue containing solely CLCs (CLC-rich) in both non-chondrodystrophic and chondrodystrophic dogs. Based on previous reports and the findings of the microarray analyses, canonical Wnt signaling was further evaluated using qPCR of relevant Wnt target genes. We hypothesized that caveolin-1, a regulator of Wnt signaling that showed significant changes in gene expression in the microarray analyses, played a significant role in early IVD degeneration. Caveolin-1 expression was investigated in IVD tissue sections and in cultured NCs. To investigate the significance of Caveolin-1 in IVD health and degeneration, the NP of 3-month-old Caveolin-1 knock-out mice was histopathologically evaluated and compared with the NP of wild-type mice of the same age.

Results

Early IVD degeneration involved significant changes in numerous pathways, including Wnt/β-catenin signaling. With regard to Wnt/β-catenin signaling, axin2 gene expression was significantly higher in chondrodystrophic dogs compared with non-chondrodystrophic dogs. IVD degeneration involved significant down-regulation of axin2 gene expression. IVD degeneration involved significant down-regulation in Caveolin-1 gene and protein expression. NCs showed abundant caveolin-1 expression in vivo and in vitro, whereas CLCs did not. The NP of wild-type mice was rich in viable NCs, whereas the NP of Caveolin-1 knock-out mice contained chondroid-like matrix with mainly apoptotic, small, rounded cells.

Conclusions

Early IVD degeneration involves down-regulation of canonical Wnt signaling and Caveolin-1 expression, which appears to be essential to the physiology and preservation of NCs. Therefore, Caveolin-1 may be regarded an exciting target for developing strategies for IVD regeneration.