A cytoprotective role for the heme oxygenase-1/CO pathway during neural differentiation of human mesenchymal stem cells

The inducible protein heme oxygenase-1 (HO-1) catalyzes the oxidation of heme to carbon monoxide (CO) and biliverdin, which play a concerted action in cytoprotection against oxidative stress and in the modulation of cell proliferation and differentiation. Here we report that both HO-1 expression and activity can be highly increased in undifferentiated human mesenchymal stem cells (MSCs) treated with hemin, a known HO-1 inducer. However, HO-1 mRNA and protein expression gradually decrease when MSCs undergo neural differentiation in vitro, making them extremely susceptible to glutamate-mediated cytotoxicity. A time course for HO-1 revealed that this protein is markedly down-regulated after 2 days and returns to control levels 6 days after differentiation. Treatment with glutamate (250 microM) after 2 days of neural differentiation resulted in a more pronounced lactate dehydrogenase release, a marker of cell injury, compared with undifferentiated cells. Notably, cells pretreated with hemin (50 microM) or compounds that release small amounts of CO (10 microM CORM-3 and CORM-A1) rendered cells more resistant to glutamate-induced toxicity; this effect was evident in both undifferentiated and differentiated MSCs. Our findings indicate that MSCs become more vulnerable to oxidative injury during the early stages of differentiation via mechanisms that involve a temporary inhibition of HO-1 expression. Thus, overexpression of HO-1 and CO-releasing molecules could provide a possible therapeutic strategy to improve cell viability during neural differentiation in applications that use stem cell technology.     

The DYMUS questionnaire for the assessment of dysphagia in multiple sclerosis

Swallowing problems can be relevant, even if underestimated, in Multiple Sclerosis (MS) patients. However, no specific questionnaire for the assessment of dysphagia in MS is available.

We built a questionnaire (DYsphagia in MUltiple Sclerosis, DYMUS) that was administered to 226 consecutive MS patients (168 F, 58 M, mean age 40.5 years, mean disease duration 10.1 years, mean EDSS 3.1) during control visits in four Italian MS Centres. DYMUS was abnormal in 80 cases (35%).

The patients who claimed to have swallowing problems had a significantly higher mean DYMUS score that the other patients (p < 0.0001). Mean DYMUS scores were significantly higher in the progressive forms (p = 0.003). DYMUS values were significantly correlated to EDSS (p = 0.0007).

DYMUS showed a very good internal consistency (Cronbach's alpha 0.877). Factor analysis allowed us to sub-divide DYMUS in two sub-scales, ‘dysphagia for solid’ and ‘dysphagia for liquid’, both of them had a very good internal consistency (Cronbach's alpha 0.852 and 0.870 respectively).

DYMUS demonstrated to be an easy and consistent tool to detect dysphagia and its main characteristics in MS. It can be used for preliminary selection of patients to submit to more specific instrumental analyses, and to direct toward programs for prevention of aspiration.     

Vasculature-targeted tumor necrosis factor-alpha increases the therapeutic index of doxorubicin against prostate cancer

BACKGROUND: Poor penetration and uneven distribution of doxorubicin in tumors limits the efficacy of this drug in patients with prostate cancer (PC). Aim of the study was to investigate whether pre-treatment with NGR-TNF, a tumor necrosis factor-alpha derivative able to target tumor vessels and alter vessel permeability, increases the penetration and the efficacy of doxorubicin in pre-clinical models of PC. METHODS: Wild type C57BL/6 mice bearing androgen-independent TRAMP-C1 PC and transgenic adenocarcinoma of the mouse prostate (TRAMP) mice, which spontaneously develop PC and metastasis, were treated with repeated cycles of doxorubicin, administered either alone or following NGR-TNF. Tumor growth and drug uptake by cancer cells was evaluated. RESULTS: Doxorubicin as a single agent blocked the growth of TRAMP-C1 cells in vitro but not in vivo. Pre-treatment of mice bearing subcutaneous TRAMP-C1 tumors with NGR-TNF favored doxorubicin penetration into the tumor mass, and in both TRAMP-C1 and TRAMP models significantly delayed tumor growth without increasing drug-related toxicity. CONCLUSIONS: Pre-treatment with NGR-TNF significantly expanded the therapeutic index of doxorubicin in mouse models of hormone-dependent and -independent PC.     

A molecular analysis of prokaryotic and viral DNA sequences in prostate tissue from patients with prostate cancer indicates the presence of multiple and diverse microorganisms

BACKGROUND: Inflammation, both acute and chronic, is a common feature of prostate histology. While inflammation has been proposed to play an important role in both benign and malignant growth of the prostate, the stimuli for this inflammation remain poorly characterized. Infectious pathogens are potential stimuli for prostatic inflammation. METHODS: Universal eubacterial PCR was used to test 170 prostate tissue core samples from 30 cancer patients for 16S rDNA gene sequences. Positive PCR products (n=64, 37%) were cloned and sequenced. For comparison, tissue samples from 30 patients were cultured using standard clinical microbiological techniques. DNA samples from 200 additional patients were tested by organism-specific PCR for the presence of Chlamydia trachomatis, Propionibacterium acnes, Trichomonas vaginalis, BK virus, Epstein-Barr virus, human cytomegalovirus, human papillomavirus, and xenotropic murine leukemia-related virus. RESULTS: 16S sequencing results indicated the presence of 83 distinct microorganisms. Microbiological culture isolated markedly fewer species. In general, organism-specific PCR failed to detect multiple organisms previously reported as common in the prostate. There was no significant association between the presence of particular species of bacteria and histologic evidence of acute or chronic inflammation. CONCLUSIONS: Most prostates from men undergoing prostatectomy (87%) contain bacterial DNA from one or more species. However, the majority of individual tissue core samples were negative, suggesting regional heterogeneity in the presence of bacteria and a lack of a generalized or ubiquitous prostatic flora. Culture results suggest either the "unculturable" nature of species present in the prostate or that 16S rDNA sequences were derived from non-viable bacteria.