Comparison of Telomere Length Between Buccal Cells and Blood Cells

Background Telomere length (TL) in blood has been extensively studied as a biomarker of aging and aging-associated disease. TL in blood cells is commonly used as a proxy for TL in other tissue types. The source of DNA of adequate quality and quantity is an important consideration in telomere length analysis. Compared to blood cells, buccal cells easy for genomic DNA preparation would facilitate the rapid and reliable telomere length analysis. However, the feasibility of buccal cells for TL analysis remains yet unestablished. Methods A total of 52 participants ranged in age from 18 to 80 years including 24 males and 28 females were included in this study. Both buccal and blood samples were taken at the same time by using buccal cell swabs and fingertip stick from each participant. Relative telomere length (RTL) was analyzed using the quantitative real-time polymerase chain reaction (qPCR) method. Results The results indicate that there is a strong positive correlation between buccal RTL and blood RTL and negative correlation between both buccal RTL and blood RTL with age. Conclusion The validity of sampling using buccal cell swabs provides simple operation and good reproducibility for telomere length analysis, which overcomes the discomfort and risk of infection caused by blood sampling.

Comparison of Telomere Length in Young and Master Endurance Runners and Sprinters

It is unclear how running modality influences telomere length (TL). This single laboratory visit study compared the TL of master sprinters and endurance runners with their young counterparts. The correlation between leukocyte and buccal cell TL in athletes was also explored. Participants consisted of 11 young controls, 11 young sprinters, 12 young endurance runners, 12 middle-aged controls, 11 master sprinters, and 12 master endurance runners. Blood and buccal samples were collected and randomized for analysis of TL by quantitative polymerase chain reaction. Young endurance runners displayed longer telomeres than master athletes (p < .05); however, these differences were not significant when controlled for covariates (p > .05). A positive correlation existed between leukocyte and buccal cell TL in athletes (r = .567, p < .001). In conclusion, young endurance runners possess longer telomeres than master endurance runners and sprinters, a consequence of lower body mass index and visceral fat.

Characterization of buccal cell DNA after exposure to azo compounds: a cross-sectional study

Background: Azo compounds, containing naphthol and diazonium salts, are synthetic dyes widely used in the batik industry. Azo compounds are considered toxic when they are exposed to human tissue. The purpose of this study was to analyze buccal cell DNA exposed to azo compounds in batik workers. Methods: A cross-sectional study involving 20 male subjects divided into two groups (n=10 group), namely azo-exposed and non-exposed (control group). Inclusion criteria were batik workers of the colouring division who have been exposed to azo for at least 5 years. Buccal cells were taken using cytobrush then DNA were isolated from buccal cell. DNA isolation was done by buccal DNA kit, while the purity and concentration of the DNA was determined using spectrophotometer and electrophoresis. Results: The azo-exposed group revealed higher purity DNA than those in the control group. The purity of the DNA in the azo-exposed group and control group was 0.61±0.93 and 0.21±0.09, respectively, while the concentration of DNA was of 59.02 and 19.35 ng/UL, respectively. The ratio at 260/280 nm was 1.84-1.94 (azo-exposed) and 1.85-1.92 (control). Principal component analysis using the first principle component (PC1) and second principle component (PC2) could successfully classify subjects in the control and azo-exposed groups. Conclusion: Characteristics of DNA could be used as an indication of exposure to azo compounds in workers of batik industries.

Characterization of buccal cell DNA after exposure to azo compounds: a cross-sectional study

Background: Azo compounds, containing naphthol and diazonium salts, are synthetic dyes widely used in the batik industry. Azo compounds are considered toxic when they are exposed to human tissue. The purpose of this study was to analyze buccal cell DNA exposed to azo compounds in batik workers. Methods: A cross-sectional study involving 20 male subjects divided into two groups (n=10 group), namely azo-exposed and non-exposed (control group). Inclusion criteria were batik workers of the colouring division who have been exposed to azo for at least 5 years. Buccal cells were taken using cytobrush then DNA were isolated from buccal cell. DNA isolation was done by buccal DNA kit, while the purity and concentration of the DNA was determined using spectrophotometer and electrophoresis. Results: The azo-exposed group revealed higher purity DNA than those in the control group. The purity of the DNA in the azo-exposed group and control group was 0.61±0.93 and 0.21±0.09, respectively, while the concentration of DNA was of 59.02 and 19.35 ng/UL, respectively. The ratio at 260/280 nm was 1.84-1.94 (azo-exposed) and 1.85-1.92 (control). Principal component analysis using the first principle component (PC1) and second principle component (PC2) could successfully classify subjects in the control and azo-exposed groups. Conclusion: Characteristics of DNA could be used as an indication of exposure to azo compounds in workers of batik industries.

Added value of buccal cell FISH analysis in the diagnosis and management of Turner syndrome

STUDY QUESTION Is there an added diagnosis value of buccal cell FISH analysis compared with blood lymphocyte chromosomal investigations in patients with Turner syndrome (TS)? SUMMARY ANSWER Buccal cell FISH analysis, a non-invasive technique, modified the chromosomal results obtained with the blood karyotype in 17 patients (12%) of our cohort. WHAT IS KNOWN ALREADY Few studies have evaluated buccal cell FISH analysis and compared them with blood karyotype in patients with TS. STUDY DESIGN, SIZE, DURATION A prospective, monocentric cohort study was conducted in a rare diseases centre (CMERC) between July 2017 and August 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS In total, 142 adult patients with TS, and at least 5% 45,X cells in a previous blood karyotype, were recruited. All the patients’ files were included in the CEMARA database. This national database has been declared to the French data protection agency (CNIL approval number 1187326). In compliance with French law, consent regarding non-opposition to collect and use the data was obtained from each patient. A FISH analysis on a buccal smear was performed. MAIN RESULTS AND THE ROLE OF CHANCE The percentage of 45,X cells was identical between the two tissues in only 32.4% of cases. The discrepancy was higher than 41% for 12% of the cohort. The percentage of 45,X cells was higher in blood in 53 (37.3%) patients, and higher in buccal cells in 43 (30.3%) of cases. In 17 (12%) cases, the blood karyotype had to be reconsidered in regard to the buccal cell analysis. LIMITATIONS, REASONS FOR CAUTION It would have been interesting to evaluate karyotypes in cells from other tissues such as cells from skin biopsy or from the urinary tract and even from blood vessels or gonads in case of surgery and to compare them with each patient’s phenotype. However, most of the time, these tissues are not available. WIDER IMPLICATIONS OF THE FINDINGS Although blood lymphocyte karyotype remains the gold standard for the diagnosis of TS, buccal cell FISH analysis is an efficient tool to evaluate the global chromosomal constitution in these patients, thus allowing them to have better care and follow-up. For instance, identifying a Y chromosome can prevent the occurrence of a gonadoblastoma, as gonadectomy should be discussed. On the other hand, finding normal XX cells in a patient with a previous diagnosis of homogenous 45,X TS, may be psychologically helpful and relevant for gynaecological care. STUDY FUNDING/COMPETING INTEREST(S) No specific funding was sought for the study. The authors declare no competing interests. TRIAL REGISTRATION NUMBER N/A

Evaluation of GammaH2AX in Buccal Cells as a Molecular Biomarker of DNA Damage in Alzheimer’s Disease in the AIBL Study of Ageing

In response to double-stranded breaks (DSBs) in chromosomal DNA, H2AX (a member of histone H2A family) becomes phosphorylated to form γH2AX. Although increased levels of γH2AX have been reported in the neuronal nuclei of Alzheimer’s disease (AD) patients, the understanding of γH2AX responses in buccal nuclei of individuals with mild cognitive impairment (MCI) and AD remain unexplored. In the current study, endogenous γH2AX was measured in buccal cell nuclei from MCI (n = 18) or AD (n = 16) patients and in healthy controls (n = 17) using laser scanning cytometry (LSC). The γH2AX level was significantly elevated in nuclei of the AD group compared to the MCI and control group, and there was a concomitant increase in P-trend for γH2AX from the control group through MCI to the AD group. Receiver-operating characteristic curves were carried out for different γH2AX parameters; γH2AX in nuclei resulted in the greatest area under the curve value of 0.7794 (p = 0.0062) with 75% sensitivity and 70% specificity for the identification of AD patients from control. In addition, nuclear circularity (a measure of irregular nuclear shape) was significantly higher in the buccal cell nuclei from the AD group compared with the MCI and control groups. Additionally, there was a positive correlation between the nuclear circularity and γH2AX signals. The results indicated that increased DNA damage is associated with AD.