Dechsupa Sinsuda, Yingsakmongkol Wicharn, Limthongkul Worawat, Singhatanadgige Weerasak, Honsawek Sittisak
Osteoarthritis and Musculoskeleton Research Unit, Department of Biochemistry, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn University, Bangkok, Thailand.
Department of Orthopaedics, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn University, Bangkok, Thailand.
PeerJ. 2018 Aug 9;6:e5381. doi: 10.7717/peerj.5381. eCollection 2018.
Lumbar spinal stenosis (LSS) is a common cause of low back pain with degenerative spinal change in older adults. Telomeres are repetitive nucleoprotein DNA sequences of TTAGGG at the ends of chromosomes. Oxidative stress originates from an imbalance in pro-oxidant and antioxidant homeostasis that results in the production of reactive oxygen species (ROS). The purpose of this study was to investigate relative telomere length (RTL) and oxidative DNA damage in ligamentum flavum (LF) tissue from LSS patients.
Forty-eight patients with LSS participated in this study. Genomic DNA from non-hypertrophic and hypertrophic LF tissue were analyzed by real-time polymerase chain reaction for relative telomere length (RTL). 8-hydroxy 2'-deoxygaunosine (8-OHdG) levels were determined by using enzyme-linked immunosorbent assay. We cultivated LF fibroblast cells from patients in different ages (61, 66, and 77 years). After each cultivation cycle, we examined RTL and senescence-associated β-galactosidase (SA-β-gal) expression.
The hypertrophic LF had significantly lower RTL than non-hypertrophic LF ( = 0.04). The levels of 8-OHdG were significantly higher in hypertrophic LF compared to non-hypertrophic LF ( = 0.02). With advancing cell culture passage, the number of cells in each passage was significantly lower in hypertrophic LF fibroblast cells than non-hypertrophic LF fibroblast cells. When evaluated with SA-β-gal staining, all senescent LF fibroblast cells were observed at earlier passages in hypertrophic LF compared with non-hypertrophic LF fibroblast cells.
Our results showed that patients with LSS displayed an accelerated RTL shortening and high oxidative stress in hypertrophic LF. These findings implied that telomere shortening and oxidative stress may play roles in the pathogenesis of hypertrophic LF in lumbar spinal stenosis.
腰椎管狭窄症（LSS）是老年人下腰痛伴脊柱退变的常见原因。端粒是染色体末端TTAGGG的重复核蛋白DNA序列。氧化应激源于促氧化剂和抗氧化剂稳态失衡，导致活性氧（ROS）的产生。本研究的目的是调查LSS患者黄韧带（LF）组织中的相对端粒长度（RTL）和氧化性DNA损伤。
48例LSS患者参与本研究。通过实时聚合酶链反应分析非肥厚性和肥厚性LF组织中的基因组DNA，以测定相对端粒长度（RTL）。采用酶联免疫吸附测定法测定8-羟基-2'-脱氧鸟苷（8-OHdG）水平。我们培养了不同年龄（61岁、66岁和77岁）患者的LF成纤维细胞。在每个培养周期后，我们检测了RTL和衰老相关β-半乳糖苷酶（SA-β-gal）的表达。
肥厚性LF的RTL显著低于非肥厚性LF（P = 0.04）。与非肥厚性LF相比，肥厚性LF中的8-OHdG水平显著更高（P = 0.02）。随着细胞培养传代次数的增加，肥厚性LF成纤维细胞每代的细胞数量显著低于非肥厚性LF成纤维细胞。当用SA-β-gal染色评估时，与非肥厚性LF成纤维细胞相比，在肥厚性LF中更早的传代中观察到所有衰老的LF成纤维细胞。
我们的结果表明，LSS患者在肥厚性LF中表现出RTL加速缩短和高氧化应激。这些发现暗示端粒缩短和氧化应激可能在腰椎管狭窄症中肥厚性LF的发病机制中起作用。
