Endothelial progenitor cells in peripheral blood of cardiac catheterization personnel

The aim of the present study was to evaluate the rejuvenation capacity among cardiac catheterization technicians occupationally exposed to ionizing radiation. The individual annual collective dose information was measured by thermoluminscent personal dosimeters [TLD] for those technicians and found to be ranging between 2.16 and 8.44 mSv/y. Venous blood samples were obtained from 30 cardiac catheterization technicians exposed to X-ray during fluoroscopy procedures at the National Heart Institute in Embaba. The control group involved 25 persons not exposed to ionizing radiation and not working in hospitals in addition to 20 persons not exposed to ionizing radiation and working in hospitals. Blood samples were assayed for total and differential blood counts, micronucleus formation [FMN] plasma stromal derived growth factor-1alpha [SDF-1 alpha] and cell phenotype of circulating endothelial progenitor cells [EPCs], whose surface markers were identified as the CD34, CD133 and kinase domain receptors [KDR]. SDF-1alpha [2650 +/- 270 vs. 2170 +/- 430 pg/ml] and FMN [19.9 +/- 5.5 vs. 2.8 +/- 1.4/1000 cells] were significantly higher among cardiac catheterization staff compared to those of the controls respectively. Similarly, EPCs: CD34 [53 +/- 3.9 vs. 48 +/- 8.5/10[5] mononuclear cells], CD133 [62.4 +/- 4.8 vs. 54.2 +/- 10.6 /10[5] mononuclear cells] KDR [52.7 +/- 10.6 vs.43.5 +/- 8.2 /10[5] mononuclear cells] were also significantly higher among cardiac catheterization staff compared to the values of controls respectively. Smoking seemed to have a positive effect on the FMN and SDF-1 but had a negative effect on EPCs. It was found that among cardiac catheterization staff, the numbers of circulating progenitor cells had increased and accordingly there was an increased capacity for tissue repair. In conclusion, the present work shows that occupational exposure to radiation, well within permissible levels, leaves a genetic mark on the somatic DNA of the cardiac catheterization technician. On the other hand, exposure of workers to ionizing radiation stimulates regenerative processes as indicated by the increase in EPCs numbers and SDF-1 levels. This regenerative process is decreased by smoking as evidenced by increased levels of SDF-1 and decreased numbers of EPCs. The technicians who work in cardiac catheterization laboratories should therefore carefully follow radiation protection procedures and should minimize radiation exposure to avoid possible genotoxic effects

Apoptosis, cytogenetic and endothelial progenitor cells in the peripheral blood of industrial radiographers

Radioactive sources and fixed or mobile X-ray equipment are used for both process and quality control in the metallurgical and fertilizer industries. Workers in the nuclear industry are a suitable sector of the populace for the direct estimation of radiation effects at low doses as they are typically monitored and restricted to effective doses of 100 mSv every 5 years. A dose-related increased mortality from circulatory diseases has been observed in some studies of nuclear industry workers, but it is unclear whether this reflects a real effect of radiation exposure or a spurious one. The aim of the present study was to detect the circulating endothelial progenitor cells [EPCs] in the peripheral blood and the frequency of micronuclei [FMN] among industrial radiographers occupationally exposed to ionizing radiation at the Steamer's Welding Company and EL Nasr Company for the manufacture of Fertilizers and Chemicals in Suez and Talkha, Egypt. Venous blood samples were obtained from 30 industrial radiographers exposed to x-rays during industrial procedures vs. 20 persons not exposed to ionizing radiation as control subjects. Blood samples were assayed for total and differential blood counts and cell phenotype of circulating EPCs, whose surface markers were identified as CD34, CD133 and kinase domain receptor [KDR], frequency of chromosomal aberrations [FCA], apoptosis percentage in circulating lymphocytes together with plasma stromal cell derived factor-1alpha [SDF-1alpha] and vascular endothelial growth factor [VEGF]. Results: The results of this study revealed a significant increase in FCA with respect to total number of dicentrics [0.09 +/- 0.03 vs. 0.0005 +/- 0.0001] and rings [0.01 +/- 0.0012 vs. 0] together with apoptosis percentage [7.3 +/- 2.8 % vs. 2.4 +/- 1.5 %] among industrial radiographers compared to control subjects respectively, indicating radiation exposure among such workers. Also a significant increase was observed in plasma SDF-1alpha [2750 +/- 370 vs. 2270 +/- 430 pg/ml], VEGF [157.9 +/- 16.9 vs. 137.5 +/- 12.6 pg/ml] among industrial radiographers compared to control subjects. Percentage of circulating mononuclear cells expressing CD34 [53 +/- 3.9 vs. 54.2 +/- 10.6/ 10[5] mononuclear cells], CD133 [82.4 +/- 4.8 vs. 54.2 +/- 10.6/ 10[5] mononuclear cells] and KDR [48.7 +/- 12.5 vs. 43.5 +/- 8.2/ 10[5] mononuclear cells] was significantly higher among industrial radiographers compared to control subjects. It is concluded that the industrial radiographers have increased numbers of circulating EPCs and increased levels of SDF-1 and VEGF, which denotes an increased capacity for tissue repair

Markers of neural degeneration and regeneration in Down syndrome patients

On the trisomy Down syndrome Critical Region [DSCR1] is located the APP gene, which accelerates amyloid peptide protein [APP] expression leading to cerebral accumulation of APP-derived amyloid-beta peptides [Abeta] and age-dependent cognitive sequelae. Also DSCR1 attenuates endothelial cell proliferation and angiogenesis required for tissue repair. The aim of the present work is to determine markers of neural degeneration and regeneration in the blood of young and adolescent Down syndrome [DS] patients as well as controls. Markers of regeneration were measured in terms of circulating mononuclear cells expressing Nestin and CD34, while markers of degeneration were measured in terms of plasma Abeta[42] and advanced glycation end products receptors [RAGES]. Results showed a significant increase in plasma Ap[42] [20 +/- 5.1 vs. 11.9 +/- 3.4] and RAGES leucocytes mRNA relative expression [1.9 +/- 0.2 vs. 1.1 +/- 0.6] in adolescent DS patients compared to young DS. Both parameters were also significantly increased in DS compared to controls: Abeta[42] [15.4 +/- 5.9 vs. 12. 3 +/- 4.5]; RAGES [1.4 +/- 0.5 vs. 0.7 +/- 0.2]. Nestin [5.2 +/- 1.4 vs. 6.3 +/- 0.6] and CD34 [52 +/- 2.5 vs. 53 +/- 4.7] were non-significantly lower in adolescent DS patients compared to young DS, but significantly lower in DS patients compared to controls: Nestin [6.3 +/- 1.5 vs. 9 +/- 4.4]; CD34 [54 +/- 3.4 vs. 60 +/- 4.8]. The significant decrease in the number of mononuclear cells bearing Nestin and CD34 markers accompanied by a significant increase in Abeta[42] and RAGES indicate that degeneration in DS is an ongoing process, which is not counterbalanced by the regenerative mechanism

Telomerase activity and apoptosis genes as parameters of lymphocyte aging in down syndrome patients

It is hypothesized that Down syndrome [DS] patients are associated with abnormalities of the immune system. Accordingly, this study was conducted to measure replicative aging and apoptosis in lymphocytes, which play an important role in the immune system, before and after being biostimulated with He:Ne laser. Replicative aging was measured in terms of telomerase activity, and ETS-2 gene relative expression. Apoptosis was measured in terms of DNA fragmentation and apoptosis genes [Fas, FasL and Bax] and antiapoptotic Bcl-2 protein. Results showed that Telomerase activity, ETS-2 mRNA expression, plasma DNA fragmentation, Fas and FasL were significantly higher among DS patients compared to controls: Telomerase activity [1.5 +/- 0.5 vs. 0.9 +/- 0.4, p < 0.001]; ETS2 mRNA expression [0.6 +/- 0.1 vs. 0.43 +/- 0.04,p < 0.0001]; plasma DNA fragmentation [0.45% +/- 0.12 vs. 0.2% +/- 0.1, p < 0.0001]; Fas protein [5.3 +/- 1.2 vs. 2.3 +/- 0.2, p < 0.0001]; FasL mRNA relative expression [0.37 +/- 0.05 vs. 0.24 +/- 0.01, p < 0.001]; Bax mRNA relative expression [0.9 +/- 0.1 vs. 0.5 +/- 0.1, p < 0.00001]. Bcl-2 protein was significantly low in DS patients compared to controls [8.6 +/- 1.3 vs. 10 +/- 2.1, p < 0.01]. He:Ne laser biostimulation applied to evaluate lymphocytes' response significantly increased the former parameters in DS patients compared to their level before irradiation, except for Bcl-2, which was significantly decreased. In conclusion: increased telomerase activity associated with increased activity and overexpression of ETS-2 on chromosome 21 in DS patients may contribute to the increased rate of early senescence in circulating lymphocytes, which consequently contributes to the abnormalities of the immune system observed in DS. Increased apoptosis is due to increased oxidative stress, which induces an increase in the apoptotic genes Bax, Fas and FasL accompanied by a decrease in the antiapoptotic gene Bcl-2

Assessment of immune function in down syndrome patients

In Down syndrome [DS], trisomy 21 leads to overexpression of gene coding for specific enzymes. This overexpression translates directly into biochemical aberrations that affect multiple interacting metabolic pathways which culminates in cellular dysfunction and contributes to the unique pathogenesis of DS. The aim of this study is to evaluate parameters of immune response in terms of cytokines [tumor necrosis factor-alpha [TNF-alpha] and interlukin-2 [IL-2]] together with the quantitative expression of cystathionine beta synthase [CBS], whose transsulfuration pathway generates cysteine and hydrogen sulfide [H[2]S]. H[2]S is known to boost host defense at physiological concentrations and to display cytotoxic activity at higher concentrations. Calcineurin activity [CAN] was also measured as its dysregulation has been shown to cause immune suppression. Subjects were 60 DS patients vs. 30 age and socioeconomic matching healthy controls. In their blood, the cytokines: TNF-alpha and IL-2, together with CBS and its by product H[2]S as well as CAN activity, were measured. Results showed that CBSmRNA relative expression [0.56 +/- .06 vs. 0.32 +/- .02], plasma H[2]S [72 +/- 8.5 vs. 50.8 +/- 4.1] and TNF-alpha [8.11 +/- .01 vs. 3.6 +/- 0.9] were significantly higher among DS patients compared to controls, while CAN [0.27 +/- 0.1 vs. 0.45 +/- 0.2 units], was significantly decreased in blood of DS patients compared to controls. IL-2 [36.4 +/- 2.6 vs. 37.4 +/- 0.9] showed no significant difference between DS patients and controls. Accordingly it can be concluded that excessive synthesis of multiple gene products derived from overexpression of the genes present on chromosome 21 may be the cause for decreased immunity in DS patients compared to controls

Cytokines and growth factors in Duchene muscular dystrophy patients

Dystrophin deficiency associated with Duchene muscular dystrophy [DMD] results in chronic inflammation and severe skeletal muscle degeneration, where the extent of muscle fibrosis contributes to disease severity. The microenvironment of dystrophic muscles is associated with variation in levels of cytokine and growth factors. Most of the current researches test for such cytokines and growth factors in tissue biopsies, which is an invasive technique. Of the present study is to investigate whether cytokines and growth factors, as indicators of inflammatory response, can be detected in blood of DMD patients as non-invasive technique. Accordingly the cytokine tumor necrosis factor alpha [TNF TNF-alpha], as well as the growth factors basic fibroblast growth factor [bFGF] and vascular endothelial growth factor [VEGF] were measured in blood of 24 boys with DMD diagnosed clinically and at the molecular level versus 20 age matching healthy boys. Showed a significant increases in TNF-alpha [30.2 +/- 9.5 vs. 3.6 +/- 0.9 pg/ml] and bFGF [21.7 +/- 10.3 vs. 4.75 +/- 2.2 pg/ml.], while VEGF was significantly decreased [190 +/- 115 vs. 210 +/- 142 pg/ml] in blood of DMD patients compared to controls. Results provide further proof that inflammatory response is associated with DMD pathogenesis and favours the use of biomarkers in blood of such patients as a non invasive technique

Indicators of apoptosis in Duchenne muscular dystrophy patients

Tissue sections of dystrophic muscle demonstrate apoptotic myonuclei in degenerating muscle fibers of Duchene muscle dystrophy [DMD] patients. The apoptosis cascade can be triggered by 2 main pathways, via an intrinsic, endogenous system such as the mitochondrial Bax/Bcl-2 or via an extrinsic system involving transmembrane receptors of the death receptor family Fas and Fas Ligand [FasL]. The present study is an attempt to demonstrate the levels of Fas and FasL and Bax/Bcl-2 in DMD pathogenesis. Subjects were 16 boys with DMD diagnosed clinically and at the molecular level versus 20 age and socioeconomic matching healthy boys. Plasma DNA fragmentation [0.38% +/- 0.12 vs. 0.2% +/- 0.15] and Fas [9.9 +/- 2.8 vs. 2 +/- 0.1, p < 0.001] together with FasL mRNA expression in circulating lymphocytes [0.47 +/- .09 vs. 0.24 +/- .04, p <0.001] were significantly increased in DMD patients compared to controls. There was a significant increase in Bax mRNA relative concentration [0.19 +/- 0.07 vs. 0.05 +/- 0.01, p <0.00001] accompanied by a significant decrease in Bcl-2 protein in circulating lymphocytes [6.4 +/- 1.6 vs l0 +/- 2.8, p <0.0001] both compared to controls. Indicate that apoptosis and its markers determined in blood of DMD patients can replace the invasive technique of tissue biopsy