Lifetime extension of humpback whale skin fibroblasts and their response to lipopolysaccharide (LPS) and a mixture of polychlorinated biphenyls (Aroclor).

Marine mammals, such as whales, have a high proportion of body fat and so are susceptible to the accumulation, and associated detrimental health effects, of lipophilic environmental contaminants. Recently, we developed a wild-type cell line from humpback whale fibroblasts (HuWa). Extensive molecular assessments with mammalian wild-type cells are typically constrained by a finite life span, with cells eventually becoming senescent. Thus, the present work explored the possibility of preventing senescence in the HuWa cell line by transfection with plasmids encoding the simian virus large T antigen (SV40T) or telomerase reverse transcriptase (TERT). No stable expression was achieved upon SV40 transfection. Transfection with TERT, on the other hand, activated the expression of telomerase in HuWa cells. At the time of manuscript preparation, the transfected HuWa cells (HuWaTERT) have been stable for at least 59 passages post-transfection. HuWaTERT proliferate rapidly and maintain initial cell characteristics, such as morphology and chromosomal stability. The response of HuWaTERT cells to an immune stimulant (lipopolysaccharide (LPS)) and an immunotoxicant (Aroclor1254) was assessed by measurement of intracellular levels of the pro-inflammatory cytokines interleukin (IL)-6, IL-1ß and tumour necrosis factor (TNF)-α. HuWaTERT cells constitutively express IL-6, IL-1ß and TNFα. Exposure to neither LPS nor Aroclor1254 had an effect on the levels of these cytokines. Overall, this work supports the diverse applicability of HuWa cell lines in that they display reliable long-term preservation, susceptibility to exogenous gene transfer and enable the study of humpback whale-specific cellular response mechanisms.

Leukocyte telomere length in mastocytosis: correlations with depression and perceived stress.

BACKGROUND: Mastocytosisis a rare disease associated with chronic symptoms related to mast cell mediator release. Patients with mastocytosis display high level of negative emotionality such as depression and stress sensibility. Brain mast cells are mainly localized in the diencephalon, which is linked to emotion regulatory systems. Negative emotionality has been shown to be associated with telomere shortening. Taken together these observations led us to hypothesize that mast cells activity could be involved in both negative emotionality and telomere shortening in mastocytosis. OBJECTIVE: To demonstrate a possible relationship between negative emotionality in mastocytosis and leukocytes telomere length. METHODS: Leukocyte telomere length and telomerase activity were measured among mastocytosis patients and were correlated with perceived stress and depression assessed by the Beck Depression Inventory revised and the Perceived Stress Scale. RESULTS: Mild-severe depression scores were frequent (78.9%) as well as high perceived stress (42.11%). Telomere length was correlated to perceived stress (r=0.77; p=0.0001) but not to depression in our population. Patients displaying Wild-type KIT significantly presented higher perceived stress levels. Patients with the D816VC KIT mutation who had high perceived stress scores displayed significantly shorter telomere but not if they had high depression scores. CONCLUSION: These findings suggest that high perceived stress in mastocytosis could accelerate the rate of leukocytes telomere shortening. Since mastocytosis is, by definition, a mast cell mediated disease; these cells could be involved in this phenomenon. Mechanistic causal relationships between these parameters need to be investigated.

The effect of Htr- antisense oligodeoxynucleotide in combination with DDP on human gastric carcinoma transplanted subcutaneously in nude mice in vivo / 肿瘤研究与临床

Objective To study whether hTR antisense PS ODN has anticancer effect and the effect of increasing the susceptibility of tumor to DDP, we explore the effect of hTR antisense oligodeoxynucleotide in combination with DDP on human gastric carcinoma transplanted subcutaneously in nude mice in vivo. Methods The model of human gastric carcinoma transplanted subcutaneously was established in thirty nude mice, then divided randomly into 5 groups (Control group, ASODN group, RODN group, DDP group and ASODN+DDP group). The weight of nude mice was measured, and the tumor growth inhibitory rate was calculated. The relative telomerase activity was quantitatively measured by TRAP PCR ELISA methods. Results The maximum tumor inhibitory rate in ASODN+DDP group, ASODN group, DDP group and RODN group was 94.2 %, 84.3 %, 92.8 % and 26.9 % respectively. There was significant difference in the relative telomerase activity among four treatment groups. Conclusions The results suggested that hTR antisense PS ODN may act as a specific tumor growth inhibitor and telomerase activity inhibitor may be in sequence specific manner, and have the effect of increasing the susceptibility of transplanted tumor to DDP.