PD-L2 is expressed on activated human T cells and regulates their function

T-cell activation and proliferation are regulated by cosignaling adhesion molecules involved in positive or negative signals. Programmed death (PD)-1 is one of immune inhibitory molecules that is expressed in activated T cells and is a promising target for immunotherapy. Both PD-1 ligands, PD-L1 and PD-L2 are expressed on antigen presenting cells (APCs) involved in the dialogue between a T cell and an APC. Here, we analysed the expression of these ligands, especially for PD-L2, on T cells. PD-L2 appears to be expressed on activated CD4 and CD8T cell subsets. Moreover, as PD-1 molecule, PD-L2 engagement at the surface of T cells is able to down-modulate cytokine production and cell proliferation. These observations indicate that PD-L2 is expressed following activation and is involved in the regulation of T cell function, highlighting the level of complexity in the T cell cosignaling network.     

Stress by noise produces differential effects on the proliferation rate of radial astrocytes and survival of neuroblasts in the adult subgranular zone

The subgranular zone (SGZ) in the dentate gyrus contains radial astrocytes, known as Type-1 or Type-B cells, which generate neuroblasts (Type-2 cells or Type-D cells) that give rise to granular neurons. Stress increases glucocorticoid levels that target SGZ and modify the proliferation and apoptosis of hippocampal cells. Yet, it is not well-known whether stress differentially affects SGZ progenitors. We investigated the effects of noise-induced stress on the rate of proliferation and apoptosis of the Type-1 cells, Type-2 cells and newly generated granular neurons in the SGZ. We exposed Balb/C mice to noise using a standardized rodents' audiogram-fitted adaptation of a human noisy environment. We measured corticosterone serum levels at different time points. Animals received BrdU injections for 3 days and sequential sacrifices were done to carry out double-immunohistochemical analyses. We found that a 24-h noise exposure did not produce adaptative response in the curve of corticosterone as compared to a 12-h noise exposure. The percentage of BrdU+/GFAP+ cells was significantly reduced in the stress group as compared to controls. A high proportion of CASP-3+/GFAP+ radial astrocytes were found in the stress group. The percentage of BrdU+/doublecortin+ cells was higher in controls than in the stress group. Interestingly, the apoptosis rate of doublecortin-expressing cells in the stress group was slightly lesser than in controls. Remarkably, we did not find significant differences in the number of BrdU+/NeuN+ and CASP-3+/NeuN+ neurons. These data indicate that stress differentially affects the rate of proliferation and apoptosis in SGZ progenitors and suggest a possible compensatory mechanism to keep the net number of granular neurons.     

Perflurooctanoic acid induces developmental cardiotoxicity in chicken embryos and hatchlings

Perfluorooctanoic acid (PFOA) is a widespread environmental contaminant that is detectable in serum of the general U.S. population. PFOA is a known developmental toxicant that induces mortality in mammalian embryos and is thought to induce toxicity via interaction with the peroxisome proliferator activated receptor alpha (PPARα). As the cardiovascular system is crucial for embryonic survival, PFOA-induced effects on the heart may partially explain embryonic mortality. To assess impacts of PFOA exposure on the developing heart in an avian model, we used histopathology and immunohistochemical staining for myosin to assess morphological alterations in 19-day-old chicken embryo hearts after PFOA exposure. Additionally, echocardiography and cardiac myofibril ATPase activity assays were used to assess functional alterations in 1-day-old hatchling chickens following developmental PFOA exposure. Overall thinning and thinning of a dense layer of myosin in the right ventricular wall were observed in PFOA-exposed chicken embryo hearts. Alteration of multiple cardiac structural and functional parameters, including left ventricular wall thickness, left ventricular volume, heart rate, stroke volume, and ejection fraction were detected with echocardiography in the exposed hatchling chickens. Assessment of ATPase activity indicated that the ratio of cardiac myofibril calcium-independent ATPase activity to calcium-dependent ATPase activity was not affected, which suggests that developmental PFOA exposure may not affect cardiac energetics. In summary, structural and functional characteristics of the heart appear to be developmental targets of PFOA, possibly at the level of cardiomyocytes. Additional studies will investigate mechanisms of PFOA-induced developmental cardiotoxicity.     

Preclinical discovery of duloxetine for the treatment of depression

INTRODUCTION: Affective disorders, including major depressive disorder (MDD), are among the most severely disabling mental disorders, and in many cases are associated with poor treatment outcomes. From the emergence of the monoamine hypothesis of depression, the first-line treatment for MDD had mainly acted by inhibiting monoamine reuptake, and thereby increasing these levels in the synaptic cleft. However, in recent years, several new antidepressant drugs have appeared, including duloxetine, a dual serotonin (5-HT) and noradrenaline (NA) reuptake inhibitor recommended for the treatment of MDD. AREAS COVERED: The article reviews and discusses the biochemical and functional profile of duloxetine splitting the review into acute and long-term treatment with this dual monoamine reuptake inhibitor. In addition, the authors summarize available preclinical behavioral research data, which have demonstrated among other effects, the antidepressant-like activity of duloxetine in several animal models. The authors focus on the most recent literature on synaptic neuroplasticity modulation of this antidepressant drug. Finally, the authors briefly mention other approved indications of duloxetine. EXPERT OPINION: Duloxetine inhibits 5-HT and NA reuptake, effectively desensitizes various autoreceptors and promotes neuroplasticity. Clinically, duloxetine is an effective antidepressant that is well tolerated and has significant efficacy in the treatment of MDD.     

The usefulness of p57 immunohistochemical staining and genotyping test in the diagnosis of the hydatidiform mole

Classification of molar gestations into complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM) and their differentiation from nonmolar hydropic abortions (HA) are traditionally accomplished by morphology alone. Sometimes, the process may be inaccurate or inconclusive especially in early diagnosed cases. With the availability of p57^KIP2 immunostaining (the product of a strongly paternally imprinted and maternally expressed gene), it may be possible to classify these lesions objectively. P57^KIP2 immunostaining is absent in CHM because it lacks a maternal genome, whereas PHM and HA show positive staining. The aims of this study were to evaluate the results of routine histopathological examination and p57^KIP2 immunoreactivity in a large series of molar and nonmolar HA in Tunisia, and to compare the accuracy of p57^KIP2 immunohistochemistry with that of nuclear DNA microsatellite polymorphism in identifying CHM. The immunohistochemical expression of p57^KIP2 protein was investigated in 220 specimens of first trimester hydropic abortuses, and it was compared with the original diagnosis based on morphology, including 132 CHM, 49 PHM, and 39 HA. Concordant results were obtained in 210 cases. In 9 of 10 cases with a discordant diagnosis (negative immunostaining in 8 cases morphologically diagnosed as PHM and one case diagnosed as HA), microsatellite DNA genotyping analysis agreed with the results of p57^KIP2 staining, confirming the diagnosis of CHM in these cases. Twenty cases of CHM with negative p57^KIP2 immunostaining were also analyzed by genotyping and indicated the absence of maternal contribution and the homozygosity for a single paternal allele in concordance with the androgenetic and monospermic origin of CHM in these cases. We confirm that for distinguishing CHM from its mimics, p57^KIP2 immunohistochemistry can be used as successfully as DNA microsatellite genotyping. However, molecular techniques are still required for the evaluation of some difficult cases with discordant positive p57^KIP2 staining.     

Drosophila orthologue of WWOX, the chromosomal fragile site FRA16D tumour suppressor gene, functions in aerobic metabolism and regulates reactive oxygen species

Common chromosomal fragile sites FRA3B and FRA16D are frequent sites of DNA instability in cancer, but their contribution to cancer cell biology is not yet understood. Genes that span these sites (FHIT and WWOX, respectively) are often perturbed (either increased or decreased) in cancer cells and both are able to suppress tumour growth. While WWOX has some tumour suppressor characteristics, its normal role and functional contribution to cancer has not been fully determined. We find that a significant proportion of Drosophila Wwox interactors identified by proteomics and microarray analyses have roles in aerobic metabolism. Functional relationships between Wwox and either CG6439/isocitrate dehydrogenase (Idh) or Cu-Zn superoxide dismutase (Sod) were confirmed by genetic interactions. In addition, altered levels of Wwox resulted in altered levels of endogenous reactive oxygen species. Wwox (like FHIT) contributes to pathways involving aerobic metabolism and oxidative stress, providing an explanation for the 'non-classical tumour suppressor' behaviour of WWOX. Fragile sites, and the genes that span them, are therefore part of a protective response mechanism to oxidative stress and likely contributors to the differences seen in aerobic glycolysis (Warburg effect) in cancer cells.     

Provision of counseling on diabetes self-management: Are there any age disparities?

Objective

To determine whether there are any age-related disparities in the frequency of provision of counseling and education for diabetes care in a large HMO in Central Texas.

Methods

EMR search from 13 primary care clinics on patients aged ≥18 years (n = 1300) who had been diagnosed with type 2 diabetes.

Results

There were no significant age differences in the frequency of provision of counseling about HBGM, diet, smoking or diabetes education. However, there were significant age differences in the provision of exercise counseling. Patients aged ≥75 were significantly less likely to have been provided exercise counseling than those aged <65 (adjusted OR = 0.60; 95% CI = 0.37–0.98). The mean HbA1c for patients aged ≥75 and 65–74 were significantly lower than that of patients aged <65 (8.9 vs. 9.0 vs. 9.7; P < 0.001).

Conclusion

While age-related variations in self-management protocols were not found, the provision of formal diabetes education was low (29.4%). The persistence of key risk factors in later life (e.g., obesity) underscores the need for better self-management protocols for older adults.

Practice Implications

Additional efforts on strategies to increase counseling about lifestyle habits and diabetes self-management care by appropriate health care providers is needed. Diabetes counseling should be individually tailored in older population.     

Oxidative stress in soleus and extensor digitorum longus (EDL) muscles of spontaneously hypertensive rats

Systemic diseases affect skeletal muscle, and inflammation and oxidative stress are some of the involved mechanisms. There is scarce information about the effects of essential hypertension on skeletal muscle. The soleus and extensor digitorum longus (EDL) muscles of spontaneously hypertensive rats (SHR) were studied compared to control Wistar Kyoto (WKY) rats. The levels of nitrite and nitrate in micromol/mg-protein; endothelial (eNOS), neuronal (nNOS), and inducible (iNOS) nitric oxide synthases, nitrotyrosine and tumour necrosis factor alpha (TNF-alpha) in ng/mg-protein were determined. Compared with controls, the SHR showed increased levels of nitrotyrosine (soleus 24.4 +/- 5.0 vs. 3.3 +/- 0.3, p<0.001; EDL 20.2 +/- 4.3 vs. 4.5 +/- 0.4, p<0.0037), iNOS (soleus 26.6 +/- 3.7 vs. 8.3 +/- 0.9; EDL 21.3 +/- 3.7 vs. 11.0 +/- 0.8, both p<0.0001) and TNF-alpha (soleus 2.2 +/- 0.5 vs. 0.6 +/- 0.1, p<0.05; EDL 1.9 +/- 0.2 vs. 0.6 +/- 0.1, p<0.02). A decrease of eNOS was found in soleus muscle (20.6 +/- 1.4 vs. 30.3 +/- 1.2, p<0.00001); of nNOS (soleus 16.8 +/- 1.4 vs. 20.7 +/- 1.8, p< 0.05; EDL 13.6 +/- 1.3 vs. 21.9 +/- 1.8, p<.005) and nitrite in EDL (5.8 +/- 0.3 vs. 7.1 +/- 0.5, p<0.026).There was a positive correlation between TNF-alpha vs. nitrotyrosine in soleus (r=0.798; p<0.031) and a tendency in EDL (r=0.739; p=0.059); iNOS vs. nitrotyrosine (soleus: r=0.908; p<0.0001; EDL: r=0.707; p<0.01), a tendency between TNF-alpha and iNOS (EDL: r=0.736; p<0.059); and a negative correlation between eNOS vs. nitrotyrosine in soleus muscle (r=-0.816; p<0.0012). In conclusion, in skeletal muscles of SHR an inflammatory process was found evidenced by the increase in TNF-alpha, nitrotyrosine and iNOS. The decreased levels of constitutive synthases, together with the higher level of iNOS, are indicative of endothelial dysfunction.