Corticotropin-releasing hormone affects cytokine production in human HaCaT keratinocytes

CRH cutaneous expression is significantly enhanced after exposure to various stimuli (Physiol Rev 2000, 80;979-1020). We evaluated the effect of CRH on cytokine production in HaCaT keratinocytes, a cell line shown to express CRH receptors coupled to cAMP activation and calcium-dependent transmission pathways. It is demonstrated for the first time that exogenously added CRH stimulates production of IL-6 and IL-11. It also inhibits production of IL-1beta and does not affect TNF-alpha production. Our results indicate that CRH function(s) during cutaneous stress may be mediated by differential effects on cytokine production.     

Stable Isotope Signatures of Middle Palaeozoic Ahermatypic Rugose Corals – Deciphering Secondary Alteration,Vital Fractionation Effects,and Palaeoecological Implications

This study investigates stable isotope signatures of five species of Silurian and Devonian deep-water, ahermatypic rugose corals, providing new insights into isotopic fractionation effects exhibited by Palaeozoic rugosans, and possible role of diagenetic processes in modifying their original isotopic signals. To minimize the influence of intraskeletal cements on the observed signatures, the analysed specimens included unusual species either devoid of large intraskeletal open spaces (''button corals'': Microcyclus, Palaeocyclus), or typified by particularly thick corallite walls (Calceola). The corals were collected at four localities in the Holy Cross Mountains (Poland), Mader Basin (Morocco) and on Gotland (Sweden), representing distinct diagenetic histories and different styles of diagenetic alteration. To evaluate the resistance of the corallites to diagenesis, we applied various microscopic and trace element preservation tests. Distinct differences between isotopic compositions of the least-altered and most-altered skeleton portions emphasise a critical role of material selection for geochemical studies of Palaeozoic corals. The least-altered parts of the specimens show marine or near-marine stable isotope signals and lack positive correlation between δ¹³C and δ¹⁸O. In terms of isotopic fractionation mechanisms, Palaeozoic rugosans must have differed considerably from modern deep-water scleractinians, typified by significant depletion in both ¹⁸O and ¹³C, and pronounced δ¹³C-δ¹⁸O co-variance. The fractionation effects exhibited by rugosans seem similar rather to the minor isotopic effects typical of modern non-scleractinian corals (octocorals and hydrocorals). The results of the present study add to growing evidence for significant differences between Scleractinia and Rugosa, and agree with recent studies indicating that calcification mechanisms developed independently in these two groups of cnidarians. Consequently, particular caution is needed in using scleractinians as analogues in isotopic studies of extinct coral lineages. Answering some of the pertinent palaeoecological questions, such as that of the possibility of photosymbiosis in Palaeozoic corals, may not be possible based on stable isotope data.     

Genetic variants in transforming growth factor-β gene (TGFB1) affect susceptibility to schizophrenia

Immense body of evidence indicates that dysfunction of immune system is implicated in the etiology of schizophrenia. The immune theory of schizophrenia is supported by alterations in cytokine profile in the brain and peripheral blood. Given the strong genetic background of schizophrenia, it might be assumed that aberrant production of cytokines might be the consequence of genetic factors. This study aimed at investigating the association between schizophrenia susceptibility and selected functional polymorphisms in genes encoding cytokines including: interleukin-2 (IL2 ?330T>G, rs2069756), interleukin-6 (IL-6 ?174G>C, rs1800795), interferon-γ (IFNG +874T>A, rs2430561) as well as for the first time transforming growth factor-β1 (TGFB1 +869T>C, rs1800470 and +916G>C, rs1800471). We recruited 151 subjects with schizophrenia and 279 controls. There was a significant difference in the genotype distribution and allelic frequency of the TGFB1 +869T>C between patients with schizophrenia and healthy controls (p < 0.05). The risk of schizophrenia was more than two-fold higher in carriers of T allele (CT+TT genotypes) than individuals with CC genotype. Given documented gender differences in incidence of schizophrenia, we conducted separate analyses of male and female participants. We have shown that the association was significant in females, while in males it reached a trend toward statistical significance. To the best of our knowledge, it is the first report showing the association between TGFB1 +869T>C polymorphism and schizophrenia.     

Cadmium-induced ceramide formation triggers calpain-dependent apoptosis in cultured kidney proximal tubule cells

A major target of cadmium (Cd²⁺) toxicity is the kidney proximal tubule (PT) cell. Cd²⁺-induced apoptosis of PT cells is mediated by sequential activation of calpains at 3–6 h and caspases-9 and -3 after 24-h exposure. Calpains also partly contribute to caspase activation, which emphasizes the importance of calpains for PT apoptosis by Cd²⁺. Upstream processes underlying Cd²⁺-induced calpain activation remain unclear. We describe for the first time that 10–50 µM Cd²⁺ causes a significant increase in ceramide formation by 22% (3 h) and 72% (24 h), as measured by diacylglycerol kinase assay. Inhibition of ceramide synthase with fumonisin B₁ (3 µM) prevents ceramide formation at 3 h and abolishes calpain activation at 6 h, which is associated with significant attenuation of apoptosis at 3–6 h with Hoechst 33342 nuclear staining and/or 3(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) death assays. This indicates that Cd²⁺ enhances de novo ceramide synthesis and that calpains are a downstream target of ceramides in apoptosis execution. Moreover, addition of C₆-ceramide to PT cells increases cytosolic Ca²⁺ and activates calpains. Apoptosis mediated by C₆-ceramide at 24 h is significantly reduced by caspase-3 inhibition, which supports cross talk between calpain- and caspase-dependent apoptotic pathways. We conclude that Cd²⁺-induced apoptosis of PT cells entails endogenous ceramide elevation and subsequent Ca²⁺-dependent calpain activation, which propagates kidney damage by Cd²⁺. nephrotoxicity; cell signaling; cell biology and structure     

hTERT promoter methylation status in peripheral blood leukocytes as a molecular marker of head and neck cancer progression

Cancer cells, including head and neck cancer cell carcinoma (HNSCC), are characterized by an increased telomerase activity. This enzymatic complex is active in approximately 80–90% of all malignancies, and is regulated by various factors, including methylation status of hTERT gene promoter. hTERT methylation pattern has been thoroughly studied so far. It was proved that hTERT is aberrantly methylated in tumor tissue versus healthy counterparts. However, such effect has not yet been investigated in PBLs (peripheral blood leukocytes) of cancer patients. The aim of this study was to analyze the hTERT gene promoter methylation status in blood leukocytes. DNA was extracted from PBL of 92 patients with histologically diagnosed HNSCC and 53 healthy controls. Methylation status of whole hTERT promoter fragment with independent analysis of each 19 CpG sites was performed using bisulfide conversion technique followed by sequencing of PCR products. Not significant (p?=?0.0532) differences in the general frequency of hTERT CpG sites methylation were detected between patients and healthy controls. However, it was discovered that some of analyzed positions (CpG islands: 1 [p?=?0.0235], 5 [p?=?0.0462], 8 [p?=?0.0343]) are significantly more often methylated in HNSCC patients than in controls. The opposite finding was observed in case of CpG position 2 (p?=?0.0210). Furthermore, closer analysis of single CpG positions revealed differences in methylation status dependent on anatomical site and TNM classification. To conclude, hTERT promoter methylation status (general or single CpG sites) would be considered as a molecular markers of HNSCC diagnostics.     

Identification, Characterization, and Physical Mapping of 14 Polymorphic Simple Sequence Repeat Markers on Human Chromosome 21

Fourteen new dinucleotide repeat polymorphisms specific for human chromosome 21 have been identified, mapped, and characterized. The average heterozygosity of all markers was 0.66. The average PIC value was 0.61. The markers were mapped by STS content mapping of YACs previously assigned to chromosome 21. The correlation of polymorphic genetic markers with substantially complete physical maps should facilitate the identification of loci of interest on chromosome 21.     

The spatial-temporal redistribution of pulmonary blood flow with postnatal growth.

The pulmonary vascular tree undergoes remarkable postnatal development and remodeling. While a number of studies have characterized longitudinal changes in vascular function with growth, none have explored regional patterns of vascular remodeling. We therefore studied six neonatal pigs to see how regional blood flow changes with growth. We selected pigs because of their rapid growth and their similarities to human development with respect to the pulmonary vascular tree. Fluorescent microspheres of varying colors were injected into the pulmonary circulation to mark regional blood on days 3, 12, 27, 43, and 71 after birth. The animals were awake and in the prone posture for all injections. The lungs were subsequently removed, air dried, and sectioned into approximately 2-cm(3) pieces. Flow on each injection day was determined for each piece. Despite the increase in the hydrostatic gradient in the lung with growth, there was a strong correlation between blood flow to the same lung piece when compared on days 3 and 71 (0.73 +/- 0.12). Although a dorsal-ventral gradient of perfusion did not exist on day 3, blood flow increased more in the dorsal region by day 12 and then gradually became more uniform by day 71. Although most of the lung pieces did not show any discernable pattern of blood flow redistribution, there were spatial patterns of blood flow redistribution that were similar across animals. Our findings suggest that local mechanisms, shared across animals, guide regional changes in vascular resistance or vasoregulation during postnatal development. In the pig, these mechanisms act to produce more uniform flow in the normal posture for an ambulating quadruped. The stimuli for these changes have not yet been identified.