The n-terminal 5-MER peptide analogue P165 of amyloid precursor protein exerts protective effects on SH-SY5Y cells and rat hippocampus neuronal synapses

The disturbance of the insulin-signaling pathway plays an important role in Alzheimer's disease. Resistance to insulin signaling renders neurons energy-deficient and vulnerable to oxidization or other metabolic insults and impairs synaptic plasticity. In search of neuroprotective drugs, we synthesized a peptide analogue, P165, an active domain of the soluble amyloid precursor protein, which is resistant to degradation and is suitable for oral administration in a clinical setting. Initially, we confirmed that P165 can protect cells from streptozotocin-caused damage and stimulate cell outgrowth using cultured SH-SY5Y cell lines treated with streptozotocin. P165 significantly reduced lactate dehydrogenase leakage from damaged cells, thereby rescuing cell energy production. Insulin signaling such as insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K) proteins were upregulated to stimulate cell survival and growth. We proceeded to investigate the effect of P165 on streptozotocin-treated Alzheimer's disease (AD) rats. The data showed that P165 protected synaptic loss and dysfunction by increasing synaptophysin and PSD-95 (post synaptic density-95), while simultaneously decreasing α-synuclein expression. Moreover, animal behavior testing clearly showed that P165 increased rats' learning and memory activity. Overall, these results constitute evidence that peptide analogue 165 may protect synapse and improve learning and memory ability in AD.

Morphological study on microvasculature of left ventricular wall in infant and adult yaks

Observations on the microvasculature in the left ventricular wall of infant and adult yaks under light and scanning electron microscope (SEM) were presented. Moreover, the diameter of different microvasculature and the density of the capillaries in three layers of the ventricular myocardium were measured using Image Pro-Plus 5.0. The results showed that the average luminal diameter of arterioles and precapillary arterioles in adult yak's hearts were, in most cases, larger than those in infant yaks. On the contrary, the diameters of the capillary in infant yak's hearts were larger than those in adult yaks. The density of capillary in the myocardium of adult yak's heart had significantly higher values (P<0.01) than those in infant yaks. Arterioles of yak's hearts were characterized by the bark-like structure and the impressions of endothelial cell nuclei, and it always gave rise to capillary after three to four grades of embranchment. The outer surface of capillaries cast in infant yak's hearts was smooth, and no constrictions were found. This was different from adult yak that always had some constrictions. The capillary anastomosis of "H" and "Y" usually existed in the myocardium of both adult and infant yaks; however, those in infant yaks were not typical as in adult yaks in their shape. The peculiar arrangement of the venules in infant yak was a "baggy" or "bulgy" arrangement, while in the adult yak, they had a root-like pattern. Our findings suggest that the patterns of microvasculature in yak's heart could be propitious to adapt better in their environment following their increase of age.

Activation of phosphatidylinositol 3-kinase/Akt-mammalian target of Rapamycin signaling pathway in the hippocampus is essential for the acquisition of morphine-induced place preference in rats

Hippocampus is a critical structure for the acquisition of morphine-induced conditioned place preference (CPP), which is a usual learning paradigm for assessing drug reward. However, the precise mechanisms remain largely unknown. Phosphatidylinositol 3-kinase (PI3K) and its downstream targets, including Akt, mammalian target of Rapamycin (mTOR) and 70-kDa ribosomal S6 kinase (p70S6K), are critical molecules implicated in learning and memory. Here, we tested the role of PI3K/Akt-mTOR-p70S6K signaling pathway in morphine-induced CPP in the hippocampus. Our results showed that the acquisition of morphine CPP increased phosphorylation of Akt in the hippocampal CA3, but not in the nucleus accumbens (NAc), the ventral tegmental area (VTA) or the CA1. Moreover, the phosphorylated Akt exclusively expressed in the CA3 neurons. Likewise, levels of phosphorylated mTOR and p70S6K were significantly enhanced in the CA3 following morphine CPP. The alterations of these phosphorylated proteins are positively correlated with the acquisition of morphine CPP. More importantly, microinjection of PI3K inhibitor (LY294002) or mTOR inhibitor (Rapamycin) into the CA3 prevented the acquisition of CPP and inhibited the activation of PI3K-Akt signaling pathway. In addition, pre-infusion of β-FNA (β-funaltrexamine hydrochloride), a selective irreversible μ opioid receptor antagonist, into CA3 significantly prevented the acquisition of CPP and impaired Akt phosphorylation. All these results strongly implied that the PI3K-Akt signaling pathway activated by μ opioid receptor in hippocampal CA3 plays an important role in acquisition of morphine-induced CPP.

Degradation of the human mitotic checkpoint kinase Mps1 is cell cycle-regulated by APC-cCdc20 and APC-cCdh1 ubiquitin ligases

Mps1 is a dual specificity protein kinase with key roles in regulating the spindle assembly checkpoint and chromosome-microtubule attachments. Consistent with these mitotic functions, Mps1 protein levels fluctuate during the cell cycle, peaking at early mitosis and abruptly declining during mitotic exit and progression into the G(1) phase. Although evidence in budding yeast indicates that Mps1 is targeted for degradation at anaphase by the anaphase-promoting complex (APC)-c(Cdc20) complex, little is known about the regulatory mechanisms that govern Mps1 protein levels in human cells. Here, we provide evidence for the ubiquitin ligase/proteosome pathway in regulating human Mps1 levels during late mitosis through G(1) phase. First, we showed that treatment of HEK 293T cells with the proteosome inhibitor MG132 resulted in an increase in both the polyubiquitination and the accumulation of Mps1 protein levels. Next, Mps1 was shown to co-precipitate with APC and its activators Cdc20 and Cdh1 in a cell cycle-dependent manner. Consistent with this, overexpression of Cdc20 or Cdh1 led to a marked reduction of endogenous Mps1 levels during anaphase or G(1) phase, respectively. In contrast, depletion of Cdc20 or Cdh1 by RNAi treatment both led to the stabilization of Mps1 protein during mitosis or G(1) phase, respectively. Finally, we identified a single D-box motif in human Mps1 that is required for its ubiquitination and degradation. Failure to appropriately degrade Mps1 is sufficient to trigger centrosome amplification and mitotic abnormalities in human cells. Thus, our results suggest that the sequential actions of the APC-c(Cdc20) and APC-c(Cdh1) ubiquitin ligases regulate the clearance of Mps1 levels and are critical for Mps1 functions during the cell cycle in human cells.

Glycemic index, glycemic load, and the risk of pancreatic cancer among postmenopausal women in the women's health initiative observational study and clinical trial

BACKGROUND

Several reports have suggested that conditions associated with hyperinsulinemia and insulin resistance, such as diets high in carbohydrates, may influence the risk of pancreatic cancer, although results from prior studies have been mixed.

METHODS

We utilized data from the population-based women's health initiative (WHI) cohort to determine whether dietary factors that are associated with increased postprandial blood glucose levels are also associated with an increased risk of pancreatic cancer. The WHI included 161,809 postmenopausal women of ages 50-79, in which 332 cases of pancreatic cancer were identified over a median of 8 years of follow-up; 287 of these cases met the criteria for analysis. A validated 122-item food frequency questionnaire was used to estimate dietary glycemic load (GL), glycemic index (GI), total and available carbohydrates, fructose and sucrose. Baseline questionnaires and physical exams provided information on demographic, medical, lifestyle, and anthropometric characteristics. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between the exposures of interest and pancreatic cancer risk, with adjustment for potential confounders.

RESULTS

Dietary GL, GI, carbohydrates, fructose, and sucrose were not associated with increased risk of pancreatic cancer. The multivariable adjusted HR for the highest vs. the lowest quartile of GL was 0.80 (95% CI = 0.55-1.15, trend p = 0.31) and 1.13 (95% CI = 0.78-1.63, trend p = 0.94) for GI. The results remained negative when individuals with a history of diabetes were excluded.

CONCLUSIONS

Our results do not support the hypothesis that dietary intake of carbohydrates is associated with increased risk of pancreatic cancer.

Upregulation of caspase-3 expression in esophageal cancer correlates with favorable prognosis: an immunohistochemical study from a high incidence area in northern China

Caspase-3 plays an important role as the key effector during apoptosis, but there are very few studies of caspase-3 in esophageal squamous cell carcinoma (ESCC). The purpose of this study was to investigate the expression and prognostic significance of caspase-3 in ESCC from Linzhou City, a high incidence area in northern China. All 64 patients underwent esophagectomy for ESCC between January 2002 and December were enrolled in this study. Caspase-3 expression was assessed by immunohistochemistry (IHC) in primary ESCC and paired normal esophageal epithelium. The positive rate of caspase-3 expression was higher in ESCC than in normal esophageal epithelium (79.7% vs. 50.0%, Chi-square = 12.372, P= 0.001). Caspase-3 expression was correlated with tumor cell differentiation (Phi = 0.717, P < 0.001), tumor infiltration depth (Phi =-0.334, P= 0.008), and pathologic TNM (pTNM) staging (rs =-0.268, P= 0.032). Patients in caspase-3 positive group had a significantly better 5-year overall survival than those in the negative group (77.4% vs. 35.9%, chi(2)= 7.344, P= 0.007). Our results showed that caspase-3 expression was upregulated in ESCC compared with normal esophageal epithelium in population of Chinese high incidence area, and patients with caspase-3 positive expression had better prognosis. Therefore, caspase-3 immunostaining could be a simple and useful tool for predicting survival in ESCC patients.

TNIP1, SLC15A4, ETS1, RasGRP3 and IKZF1 are associated with clinical features of systemic lupus erythematosus in a Chinese Han population

Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous clinical manifestations influenced by genetic and environmental factors. Five novel susceptibility genes (TNIP1, SLC15A4, ETS1, RasGRP3 and IKZF1) for SLE have been identified in a recent genome-wide association study of a Chinese Han population. This study investigated their relationships with disease subphenotypes, including renal nephritis, photosensitivity, antinuclear antibody (ANA), age at diagnosis, malar rash, discoid rash, immunological disorder, oral ulcer, hematological disorder, neurological disorder, serositis, arthritis and vasculitis. Significant associations were found for the single nucleotide polymorphism rs10036748 of TNIP1 with photosensitivity (odds ratio (OR) = 0.87, p = 0.01) and vasculitis (OR = 1.18, p = 0.04); rs10847697 of SLC15A4 with discoid rash (OR = 1.18, p = 0.02); rs6590330 of ETS1 with SLE of age at diagnosis <20 years (OR = 1.24, p = 8.91 x 10(-5)); rs13385731 of RasGRP3 with malar rash (OR = 1.20, p = 0.01), discoid rash (OR = 0.78, p = 0.02) and ANA (OR = 0.72, p = 0.004); rs4917014 of IKZF1 with renal nephritis (OR = 1.13, p = 0.02) and malar rash (OR = 0.83, p = 0.00038), respectively. The study suggested that these susceptibility genes might not only play important roles in the development of SLE, but also contribute to the complex phenotypes of SLE.

Curcumin for the prevention of progression in monoclonal gammopathy of undetermined significance: A word of caution

A recent pilot study found that curcumin, in certain patients with monoclonal gammopathy of undetermined significance (MGUS), decreases the paraprotein load and the urinary N-telopeptide of type 1 collagen bone turnover marker. While this result is encouraging, the easy availability of the food component turmeric, containing curcumin, may lead to intake by MGUS patients without medical supervision. Curcumin is generally considered safe. Nevertheless, it is known that curcumin inhibits interleukin-12 production in dendritic cells, thereby dampening the Th1 response. It is also well established that Th1 cells are protective against invading pathogens and tumors. The present study describes a case in which bronchitis developed upon turmeric intake for gastrointestinal complaints. While one case does not provide proof of curcumin toxicity, a thorough literature overview suggests that turmeric may have an immunosuppressive effect, notably in patients with a compromised immune system. A warning against the use of turmeric or curcumin without medical supervision in immunocompromised patients seems therefore very opportune. Patients with MGUS, in whom the levels of non-affected immunoglobulins are reduced, should be carefully monitored for toxicity when curcumin is administered.

Altered global gene expressions of human placentae subjected to assisted reproductive technology treatments

BACKGROUND

Researchers are more and more concerning the safety of fetus or offspring derived from assisted reproductive technology (ART) treatment. As the placenta is a critical organ that sustains and protects the fetus, we hypothesize that altered global gene expression of the placenta subjected to ART manipulation may reflect changes associated with ART procedures and subsequently causal related to offspring health.

METHODS

Three term placenta samples were obtained from patients undergone in vitro fertilization and embryo transfer due to oviductal factors only. Other three control placentae were from those underwent normal pregnancy. A GeneChip Affymetrix HG-U133 Plus 2.0 Array was utilized to analyze the genes. Using qRT-PCR we certified microarray data from 10 dysregulated genes. Five genes were localized precisely in the placenta as per immunohistochemistry.

RESULTS

Twenty-six differentially expressed genes were identified in the ART-treated placentae: 17 up-regulated; 9 down-regulated. Eighteen of these were classified into six groups according to critical placental function: immune response; transmembrane transport; metabolism; oxidative stress; cell differentiation; and other functions. Genes involved in immune response, such as ERAP2 and STAT4, and those regulating cell differentiations, such as MUC1, were discerned to be differentially expressed. These gene products were expressed in the placental villus tissues, either in the cytoplasm or in the membrane of syncytiotrophoblastic cells.

CONCLUSION

To our knowledge, this is the first study in comparing differentially expressed genes in placentae from patients undergone ART treatment vs. those underwent normal pregnancy. Abnormal profiles of critical placental functioning genes, such as ERAP2, STAT4 and MUC1, may be valuable biomarkers to understand how the placenta affects fetal development and ART-derived offspring's health problems.