Lack of association between increased mitochondrial DNA(4977) deletion and ATP levels of sputum cells from chronic obstructive pulmonary disease patients versus healthy smokers

WOS: 000397858400027PubMed ID: 26713688In this study we looked at smokers with and without chronic obstructive pulmonary disease (COPD) patients in order to evaluate the incidence of 4977 base pair (bp) mtDNA (mtDNA(4977)) deletion and mtDNA copy number in sputum cells and in peripheral blood leukocytes (PBLs) in relation to mitochondrial function and oxidative stress status. Twenty-five COPD patients who were current smokers, 22 smokers and 23 healthy nonsmokers (for only PBLs studies) participated in this study. The 4977-bp deletion was detected in all examined samples within 40 cyles of PCR amplification, using a quantitative real time PCR. The frequency of the mtDNA(4977) was significantly higher in the sputum cells of patients with COPD compared to smokers without COPD (p<0.0001). This difference was not observed in PBLs. Levels of cellular oxidative stress were significantly higher in the sputum cells of subjects with COPD than in the smoker group. However, mtDNA copy number, mitochondrial membrane potential (Delta Psi m) and cellular ATP levels in PBLs and sputum cells were not significantly different between the studied groups. The Pearson analysis revealed no correlations between the accumulation of mtDNA(4977), and intracellular ATP content and Delta Psi m values of the sputum cells, although there was a positive correlation between the increase in the percentage of deleted mtDNA(4977) and the levels of cellular oxidative stress in COPD patients (r = 0.80, p<0.0001). Our studies may suggest that the accumulation of mtDNA(4977) in the sputum cells of smokers with COPD does not seem to have an important impact on mitochondrial dysfunction in relation to ATP production and Delta Psi m when compared to those of healthy smokers.Research Fund of Istanbul University [T81/12122006]There is no conflict of interest among the author. This work was supported by the Research Fund of Istanbul University (project number: T81/12122006)

HLA-B*51 ekspresyonundaki artış endoplazmik retikulum stresi ile ilişkili olabilir

Amaç: Endoplazmik retikulum, hücre içi proteinlerinin katlan-di¤› ve paketlendi¤i organeldir. Proteinlerin katlanmas› ile ilgi-li sorunlar ER stresine yol açarak, katlanmam›fl protein yan›t›-na ve “unfolded protein response” (UPR) molekullerinin art›fl›-na yol acar. HLA-B*27’nin yavafl katlanmas›n›n ER strese yolact›¤›na dair kan›tlar mevcuttur. HLA-B*51 de HLA-B*27 ileortak olarak HLA-Bw4 yap›s› içerdi¤inden, ayn› katlanma pa-ternine sahip olabilir. HLA-B*51’in ER stres ile iliflkisi bilinme-mektedir. Bu cal›flmada HLA-B51’in ER stres ile iliflkisininaraflt›r›lmas› hedeflenmifltir.Yöntem: HLA-B*51 eksprese Th1 monosit hücre dizisinde ba-zal ve stimule koflullarda (tunikamisin, LPS, ATP, LPS+ATP,IFN, LPS+IFN) ER stres ile iliflkili IRE1, PERK, ATF6, BIPve XBP1’in rt-PCR ile ekspresyon düzeylerine bak›lm›flt›r. Ay-r›ca HLA-B*51 (+) ve negatif PBMC kültürlerinde ve pozitifkontrol olarak HLA-B*27 (+) ve negatif PBMC kültürlerindeUPR moleküllerinin uyaranlarla olan de¤iflimine bak›lm›flt›r.Ek olarak Th1 hücre dizisi ve PBMC kültürlerinde makrofajdönüflümü sa¤land›ktan sonra UPR yan›t› de¤erlendirilmifltir.Bulgular: Monosit hücre dizisinde HLA-B*51 ekspresyonun-daki artisin UPR moleküllerinden IRE1(r(12)=0.957.P.0.01),PERK (r(12)=0.974.p.0,01), ATF6(r(12)=0.952, p&lt;0.01),BIP(r(12)= 0.610, p&lt;0.05) molekülleri ile korelasyon gösterdi¤isaptand›. Makrofajlarda, HLA-B*51 ile BIP (r(12)=0.808,p&lt;0.01) ve ATF6 (r(12)=0.626, p&lt;0.05) aras›nda iliflki bulundu.HLA-B*51 (+) PBMC kültüründe HLA-B*51 ile PERK(r(12)=0.535, p&lt;0.05) ve ATF6 (r(12)= 0.622, p&lt;0.05) aras›ndakorelasyon saptand›. HLA-B*51 (-) PBMC kültüründe, HLA-B*51 (+) PBMC kültüründeki kuvvetli UPR yan›t› saptanmad›.HLA-B*51 (+) PBMC kültüründen elde edilen makrofajlarda,HLA-B*51 ile IRE1 (r(12)= 0.746, p&lt;0.01), PERK (r(12)=0.696, p&lt;0.01) ve ATF6 (r(12)= 0.558, p&lt;0.05) aras›nda iliflkisaptand›. Pozitif kontrol olan HLA-B*27 (+) PBMC kültürün-de, HLA-B*27 ile PERK (r(12)= 0.903, p&lt;0.01) ve ATF6(r(12)= 0.706, p&lt;0.01) aras›nda korelasyon saptand›. HLA-B*51ve HLA-B*27 (-) kültürlerde, uyaranlara kuvvetli UPR yan›t›gözlenmedi.Sonuç: Th1 hücre dizisi monositlerinde uyaranlarla kuvvetliHLA-B*51 ekspresyon art›fl› ve korele olarak IRE1, PERK,ATF6 ve BIP düzeylerinde art›fl saptanm›flt›r. Makrofajlarda iseB51 ekspresyonunu ile birlikte BIP ve ATF6 düzeylerinde art›flsaptanm›flt›r. HLA-B*51 (+) PBMC’de (-) PBMC’ye göre uya-ranlarla kuvvetli UPR yan›t› izlenmistir. HLA-B*51 ekspresyo-nu ile PERK ve ATF6 aras›nda korelasyon saptanm›flt›r. Ma