Post-ischemic Intravenous Administration of Allogeneic Dental Pulp-Derived Neurosphere Cells Ameliorated Outcomes of Severe Forebrain Ischemia in Rats

Background

Transplantation of bone marrow or adipose-derived mesenchymal stem cells (MSCs) for various neurological disorders has yielded promising results in models of focal cerebral ischemia. Dental pulp stem cells (DPSCs) are a type of MSC. In serum-free culture, they can form neurospheres that contain nestin-positive neuronal progenitor cells. We hypothesized that transplantation of dental pulp-derived neurosphere cells would ameliorate outcomes of global cerebral ischemia, the pathophysiology of which is known to resist conventional treatments.We also hypothesized that transplantation of dental pulp-derived cells would provide some neuroprotection in this pathology due to the presence of DPSCs.

Methods

Using adult rats, ischemia was induced by two-vessel occlusion of both carotid arteries in combination with systemic hypotension. Allogeneic dental pulp cells from juvenile rats were cultured in advance in serum-free medium to obtain neurospheres. Dental pulp-derived neurosphere cells or dental pulp-derived cells were intravenously administered at 3 h after ischemic insult, with normal saline as a control. Animals were observed for 14 days after ischemia. Neurological outcome was assessed using the water-maze test and neuromotor test. Histological outcome was measured by counting the percentage of dead neurons in the hippocampal CA1 and CA3 regions.

Results

Transplantation of both dental pulp-derived neurosphere cells and dental pulp-derived cells significantly improved survival rate and water-maze test results. Neurosphere cell transplantation was related to significantly better neuromotor test and histological outcomes, as indicated by the reduced percentage of dead neurons in CA1.

Conclusions

Transplantation of dental pulp-derived neurosphere cells ameliorated outcomes of global cerebral ischemia. It was also demonstrated that dental pulp-derived cell administration provided some neuroprotection.

     

Visual afferents from an eye in the terrestrial slug Limax valentianus

Terrestrial gastropods have a lens-bearing eye on the tip of their tentacles. There are two morphologically distinct photoreceptors, called Type-I and Type-II photoreceptors, in the retina. Type-I photoreceptors are equipped with highly developed photoreceptive microvilli in their outer rhabdomeric segment, whereas Type-II photoreceptors have short and fewer microvilli. Although both types of photoreceptors send afferent projections directly to the brain, their destinations in the brain, called optic neuropiles, have not been sufficiently investigated. Our recent studies revealed that there are commissural fibers in the cerebral ganglia that transmit photic information acquired by bilateral eyes. Moreover, some of the retinal photoreceptors are connected by gap junctions to the photosensitive brain neurons, suggesting the functional interaction of the photic information between the eye and brain photoreceptors, as well as between bilateral eyes. However, it has not been clarified which type of retinal photoreceptors send commissural projections to the contralateral hemiganglion nor interact with the brain photoreceptors. In the present study, we demonstrated by molecular histological analyses and tracer injections that (1) Type-I and Type-II photoreceptors send glutamatergic afferent projections to the medial and lateral lobes of the ipsilateral optic neuropile, respectively, (2) direct synaptic interaction between bilateral optic nerves occurs in the medial lobe of the optic neuropile, and (3) brain photosensory neurons form gap junctions with the medial lobe of the contralateral optic neuropile. These results reveal an ordered pattern of afferent projections from the retina and provide insight into the different functional roles of retinal photoreceptors.     

25-hydroxyvitamin D-1α-hydroxylase (CYP27B1) induces ectopic calcification

Vascular calcification is an important pathogenesis related to cardiovascular disease and high mortality rate in chronic kidney disease (CKD) patients. It has been well-known that hyper­phosphatemia induces osteochondrogenic transition of vascular smooth muscle cells (VSMCs) resulting ectopic calcification in aortic media, cardiac valve, and kidney. However, the detailed mechanism of the ectopic calcification has been not clarified yet. Here, we found that the co-localization of CYP27B1 with the calcified lesions of aorta and arteries in kidney of klotho mutant (kl/kl) mice, and then investigated the role of CYP27B1 in the mineralization of the VSMCs. Under high phosphate condition, overexpression of CYP27B1 induced calcification and osteocalcin mRNA expression in the VSMCs. Inversely, siRNA-CYP27B1 inhibited high phosphate-induced calcification of the VSMCs. We also found that the accumulated CYP27B1 protein was glycosylated in the kidney of kl/kl mice. Therefore, overexpression of CYP27B1-N310A and CYP27B1-T439A, which are a mutation for N-linked glycosylation site (N310A) and a mutation for O-linked glycosylation site (T439A) in CYP27B1, decreased calcium deposition and expression of RUNX2 induced by high phosphate medium in VSMCs compared with wild-type CYP27B1. These results suggest that extra-renal expression of glycosylated CYP27B1 would be required for ectopic calcification of VSMCs under hyperphosphatemia.     

Serological evidence for Borna disease virus infection in humans, wild rodents and other vertebrates in Finland.

BACKGROUND: Borna disease virus (BDV) can infect many vertebrate species, including humans. BDV infection may lead to meningoencephalomyelitis in animals. An association with human neuropsychiatric diseases has been reported, but the causal relationship between BDV and human disease remains unclear. OBJECTIVES AND STUDY DESIGN: To find out whether BDV is present in Finland and to look for a potential reservoir, we examined a large panel of blood samples from different vertebrate species with immunofluorescence assay. Samples from horses, cats, dogs, sheep, cattle, large predators, grouse, wild rodents and humans were included. Most positive results were confirmed by other specific methods and in other laboratories. RESULTS AND CONCLUSIONS: BDV-specific antibodies were detected in 10 horses, 2 cats, as well as 2 horses and 1 dog from farms housing a previously detected seropositive horse. Interestingly, BDV-specific antibodies were further detected in three wild rodents. In humans, BDV-specific antibodies were detected in a veterinarian and in two patients suspected to have a Puumala hantavirus infection. Our serological analysis suggests that BDV infects various vertebrates in Finland, including humans. Furthermore, our data indicate for the first time that BDV infects also wild rodents.     

The 'European Alliance Against Depression (EAAD)': a multifaceted, community-based action programme against depression and suicidality.

Action programmes fostering partnerships and bringing together regional and national authorities to promote the care of depressed patients are urgently needed. In 2001 the 'Nuremberg Alliance Against Depression' was initiated as a community-based model project within the large-scale 'German Research Network on Depression and Suicidality' (Kompetenznetz 'Depression, Suizidalit?t'). The 'Nuremberg Alliance Against Depression' was an action programme, conducted in the city of Nuremberg (500,000 inhabitants) in 2001/2002, addressing four intervention levels (Hegerl et al. Psychol Med 2006;36:1225). Based on the positive results of the Nuremberg project (a significant reduction of suicidal behaviour by more than 20%) 18 international partners representing 16 different European countries established the 'European Alliance Against Depression' (EAAD) in 2004. Based on the four-level approach of the Nuremberg project, all regional partners initiated respective regional intervention programmes addressing depression and suicidality. Evaluation of the activities takes place on regional and international levels. This paper gives a brief overview of the background for and experiences with the EAAD. It describes the components of the programme, provides the rationale for the intervention and outlines the current status of the project. The aim of the paper is to disseminate information about the programme's potential to reduce suicidal behaviour and to provide examples of how European community-based 'best practice' models for improving the care of depressed patients and suicidal persons can be implemented using a bottom-up approach. EAAD is mentioned by the European commission as a best practice example within the Green Paper 'Improving the mental health of the population: Towards a strategy on mental health for the European Union' (European Commission 2005).     

Substrate-dependent bidirectional modulation of P-glycoprotein-mediated drug resistance by erlotinib

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs) inhibit the function of certain adenosine triphosphate (ATP)‐binding cassette transporters, including P‐glycoprotein/ABCB1 and breast cancer resistance protein (BCRP)/ABCG2. We previously reported an antagonistic activity of gefitinib towards BCRP. We have now analyzed the effects of erlotinib, another EGFR‐TKI, on P‐glycoprotein and BCRP. As with gefitinib, erlotinib effectively reversed BCRP‐mediated resistance to SN‐38 (7‐ethyl‐10‐hydroxycamptothecin) and mitoxantrone. In contrast, we found that erlotinib effectively suppressed P‐glycoprotein‐mediated resistance to vincristine and paclitaxel, but did not suppress resistance to mitoxantrone and doxorubicin. Conversely, erlotinib appeared to enhance P‐glycoprotein‐mediated resistance to mitoxantrone in K562/MDR cells. This bidirectional activity of erlotinib was not observed with verapamil, a typical P‐glycoprotein inhibitor. Flow cytometric analysis showed that erlotinib co‐treatment restored intracellular accumulation of mitoxantrone in K562 cells expressing BCRP, but not in cells expressing P‐glycoprotein. Consistently, erlotinib did not inhibit mitoxantrone efflux in K562/MDR cells although it did vincristine efflux in K562/MDR cells and mitoxantrone efflux in K562/BCRP cells. Intravesicular transport assay showed that erlotinib inhibited both P‐glycoprotein‐mediated vincristine transport and BCRP‐mediated estrone 3‐sulfate transport. Intriguingly, Lineweaver‐Burk plot suggested that the inhibitory mode of erlotinib was a mixed type for P‐glycoprotein‐mediated vincristine transport whereas it was a competitive type for BCRP‐mediated estrone 3‐sulfate transport. Collectively, these observations indicate that the pharmacological activity of erlotinib on P‐glycoprotein‐mediated drug resistance is dependent upon the transporter substrate. These findings will be useful in understanding the pharmacological interactions of erlotinib used in combinational chemotherapy. (Cancer Sci 2009; 100: 1701–1707)     

A Mechanical Analysis of Chemically Stimulated Linear Shape Memory Polymer Actuation

In the present work, we study the role of programming strain (50% and 100%), end loads (0, 0.5, 1.0, and 1.5 MPa), and chemical environments (acetone, ethanol, and water) on the exploitable stroke of linear shape memory polymer (SMP) actuators made from ESTANE ETE 75DT3 (SMP-E). Dynamic mechanical thermal analysis (DMTA) shows how the uptake of solvents results in a decrease in the glass temperature of the molecular switch component of SMP-E. A novel in situ technique allows studying chemically triggered shape recovery as a function of time. It is found that the velocity of actuation decreases in the order acetone > ethanol > water, while the exploitable strokes show the inverse tendency and increases in the order water > ethanol > acetone. The results are interpreted on the basis of the underlying chemical (how solvents affect thermophysical properties) and micromechanical processes (the phenomenological spring dashpot model of Lethersich type rationalizes the behavior). The study provides initial data which can be used for micromechanical modeling of chemically triggered actuation of SMPs. The results are discussed in the light of underlying chemical and mechanical elementary processes, and areas in need of further work are highlighted.     

Association of symptoms with gastrointestinal microbiota in irritable bowel syndrome

AIM:To investigate the correlations between selfreported symptoms of irritable bowel syndrome(IBS) and the gastrointestinal(GI) microbiota composition.METHODS:Fecal samples were collected from a total of 44 subjects diagnosed with IBS.Their symptoms were monitored with a validated inflammatory bowel disease questionnaire adjusted for IBS patients.Thirteen quantitative real-time polymerase chain reaction assays were applied to evaluate the GI microbiota composition.Eubacteria and GI bacterial genera(Bifidobacterium,Lactobacillus and Veillonella),groups(Clostridium coccoides/Eubacterium rectale,Desulfovibrio desulfuricans) and distinct bacterial phylotypes [closest 16S rDNA sequence resemblance to species Bifidobacterium catenulatum,Clostridium cocleatum,Collinsella aerofaciens(C.aerofaciens),Coprococcus eutactus(C.eutactus),Ruminococcus torques and Streptococcus bovis ] with a suspected association with IBS were quantified.Correlations between quantities or presence/absence data of selected bacterial groups or phylotypes and various IBSrelated symptoms were investigated.RESULTS:Associations were observed between subjects’ self-reported symptoms and the presence or quantities of certain GI bacteria.A Ruminococcus torques(R.torques)-like(94% similarity in 16S rRNA gene sequence) phylotype was associated with severity of bowel symptoms.Furthermore,among IBS subjects with R.torques 94% detected,the amounts of C.cocleatum 88%,C.aerofaciens-like and C.eutactus 97% phylotypes were significantly reduced.Interesting observations were also made concerning the effect of a subject’s weight on GI microbiota with regard to C.aerofaciens like phylotype,Bifidobacterium spp.and Lactobacillus spp.CONCLUSION:Bacteria seemingly affecting the symptom scores are unlikely to be the underlying cause or cure of IBS,but they may serve as biomarkers of the condition.