OGR1/GPR68 Modulates the Severity of Experimental Autoimmune Encephalomyelitis and Regulates Nitric Oxide Production by Macrophages

Ovarian cancer G protein-coupled receptor 1 (OGR1) is a proton-sensing molecule that can detect decreases in extracellular pH that occur during inflammation. Although OGR1 has been shown to have pro-inflammatory functions in various diseases, its role in autoimmunity has not been examined. We therefore sought to determine whether OGR1 has a role in the development of T cell autoimmunity by contrasting the development of experimental autoimmune encephalomyelitis between wild type and OGR1-knockout mice. OGR1-knockout mice showed a drastically attenuated clinical course of disease that was associated with a profound reduction in the expansion of myelin oligodendrocyte glycoprotein 35-55-reactive T helper 1 (Th1) and Th17 cells in the periphery and a reduced accumulation of Th1 and Th17 effectors in the central nervous system. We determined that these impaired T cell responses in OGR1-knockout mice associated with a reduced frequency and number of dendritic cells in draining lymph nodes during EAE and a higher production of nitric oxide by macrophages. Our studies suggest that OGR1 plays a key role in regulating T cell responses during autoimmunity.     

Extracellular vesicles in bone and tooth: A state-of-art paradigm in skeletal regeneration

Bone and tooth, fundamental parts of the craniofacial skeleton, are anatomically and developmentally interconnected structures. Notably, pathological processes in these tissues underwent together and progressed in multilevels. Extracellular vesicles (EVs) are cell-released small organelles and transfer proteins and genetic information into cells and tissues. Although EVs have been identified in bone and tooth, particularly EVs have been identified in the bone formation and resorption, the concrete roles of EVs in bone and tooth development and diseases remain elusive. As such, we review the recent progress of EVs in bone and tooth to highlight the novel findings of EVs in cellular communication, tissue homeostasis, and interventions. This will enhance our comprehension on the skeletal biology and shed new light on the modulation of skeletal disorders and the potential of genetic treatment.     

Selection for High Oridonin Yield in the Chinese Medicinal Plant Isodon (Lamiaceae) Using a Combined Phylogenetics and Population Genetics Approach

Oridonin is a diterpenoid with anti-cancer activity that occurs in the Chinese medicinal plant Isodon rubescens and some related species. While the bioactivity of oridonin has been well studied, the extent of natural variation in the production of this compound is poorly known. This study characterizes natural variation in oridonin production in order to guide selection of populations of Isodon with highest oridonin yield. Different populations of I. rubescens and related species were collected in China, and their offspring were grown in a greenhouse. Samples were examined for oridonin content, genotyped using 11 microsatellites, and representatives were sequenced for three phylogenetic markers (ITS, rps16, trnL-trnF). Oridonin production was mapped on a molecular phylogeny of the genus Isodon using samples from each population as well as previously published Genbank sequences. Oridonin has been reported in 12 out of 74 species of Isodon examined for diterpenoids, and the phylogeny indicates that oridonin production has arisen at least three times in the genus. Oridonin production was surprisingly consistent between wild-collected parents and greenhouse-grown offspring, despite evidence of gene flow between oridonin-producing and non-producing populations of Isodon. Additionally, microsatellite genetic distance between individuals was significantly correlated with chemical distance in both parents and offspring. Neither heritability nor correlation with genetic distance were significant when the comparison was restricted to only populations of I. rubescens, but this result should be corroborated using additional samples. Based on these results, future screening of Isodon populations for oridonin yield should initially prioritize a broad survey of all species known to produce oridonin, rather than focusing on multiple populations of one species, such as I. rubescens. Of the samples examined here, I. rubescens or I. japonicus from Henan province would provide the best source of oridonin.     

Use of acyclovir in the prevention of herpes infections after allogenic bone marrow grafts

In a double-bind controlled study, oral Acyclovir has been compared to a placebo in a series of 39 consecutive patients undergoing bone marrow transplantation. A dose of 200 mg was given every 6 h from day 8 to day 35 after transplantation. Pharmacokinetic studies have shown the good absorption of the drug despite intestinal damage related to chemoradiotherapy or gut graft-versus-host disease (GVHD), there was no sign of toxicity. The protection against herpes simplex virus (HSV) infection was complete in the treated group when compared to the control group even in patients with high anti-HSV antibody titres. The same protection was observed against cytomegalovirus (CMV) infection. The incidence of HSV and CMV was the same in both groups after treatment ended. This study confirms the efficacy of Acyclovir against HSV infection and possibly against CMV infection when it is given prophylactically after bone marrow transplantation.     

Bcl-2 phosphorylation is required for inhibition of oxidative stress-induced lysosomal leak and ensuing apoptosis.

B-cell leukemia/lymphoma 2 (Bcl-2) blocks oxidant-induced apoptosis at least partly by stabilizing lysosomes. Here we report that phosphorylation of Bcl-2 may be required for these protective effects. J774 cells overexpressing wild-type Bcl-2 resist oxidant-induced lysosomal leak as well as apoptosis, and this protection is amplified by pretreatment with phorbol 12-myristate 13-acetate (which promotes protein kinase C (PKC)-dependent phosphorylation of Bcl-2). In contrast, cells overexpressing the Bcl-2 mutant S70A (which cannot be phosphorylated) are not protected in either circumstance. Transfection with Bcl-2(S70E), a constitutively active Bcl-2 mutant which does not require phosphorylation, is protective independent of PKC activation. In contrast, C(2)-ceramide, a putative protein phosphatase 2A activator, abolishes the protective effects of wild-type Bcl-2 overexpression but does not diminish protection afforded by Bcl-2(S70E). Additional results suggest that, perhaps as a consequence of lysosomal stabilization, Bcl-2 may prevent activation of phospholipase A2, an event potentially important in the ultimate initiation of apoptosis.