1.Genetic study of a case with abnormal hemoglobin Ta-li combined with hereditary persistence of fetal hemoglobin
Zongping MO ; Ling ZHANG ; Zhaohui HU ; Wenli FENG
Chinese Journal of Laboratory Medicine 2012;35(2):170-173
ObjectiveTo investigate the genotype of a case with abnormal hemoglobin combined with hereditary persistence of fetal hemoglobin (HPFH).Methods Male patient,26 years old,were suspected abnormal hemoglobin combined with HPFH after receiving medical examination including hematology exmination,hemoglobin electrophoresis,erythrocyte osmotic fragility analysis in Guangzhou Kingmed Diagnostics in September 2010.Routine examination of anemia and hemoglobin electrophoresis at alkaine pH on agarose gels were applied to analyze the phenotype.Direct sequencing of the complete HBB gene was utilized to identify the hemoglobin variant.Multiplex ligation-dependent probe amplification (MLPA) assay was used to identify the presence of β-globin gene cluster deletion.Gap polymerase chain reaction (gap-PCR) was used to amplify the HBB gene fragment across the breakpoint,and the deletion breakpoint was characterized by direct sequencing the gap-PCR product and comparing the sequencing result with the reference sequence NC_000011.9.ResultsBy direct sequencing of the complete HBB gene,the patient in this study was found to carry a hemoglobin Ta-Li (HBB:c.250G > T) mutation.By combining use of MLPA and gap-PCR with gene sequencing,we found that it had a gross deletion in the β-globin gene cluster,the deletion region was NC_000011.9:g.5222878_5250288del.Therefore,the genotype of this subject was SEA-HPFH combined with abnormal hemoglobin Ta-li.ConclusionCombining application of MLPA and gap-PCR with gene sequencing can help to make sure the genotype.
2.Moderate cyclic compressive stress accelerates anabolism of articular chondrocytes by affecting cytoskeleton
Jun MO ; Ying CHEN ; Dongyan ZHONG ; Huilin YANG ; Zongping LUO
Chinese Journal of Tissue Engineering Research 2016;20(37):5511-5517
BACKGROUND:Different mechanical stimulations may have an effect on the level of metabolism of chondrocytes, but the effect is not clear.
OBJECTIVE:To investigate expression level changes in metabolic genes that participate in cartilage cel decomposition and synthesis under compressive stress and tensile stress conditions.
METHODS:We obtained articular chondrocytes from 2-week-old Sprague-Dawley rats. Primary cultured chondrocytes were identified. Passage one chondrocytes received cyclic tensile stress and cyclic compressive stress of 3%and 7%, respectively, so as to measure articular changes in chondrocytes-related genes.
RESULTS AND CONCLUSION:When chondrocytes were subjected to cyclic tensile stress of 3%, synthetic metabolic gene col agen types I and II and proteoglycan mRNA expression levels were decreased. If 3%cyclic compressive stress was applied, proteoglycan mRNA expression levels were increased, and type I col agen mRNA expression levels were decreased (P<0.001), and matrix metal oproteinase-13 mRNA expression levels were reduced (P<0.01). When strain reached 7%, cyclic tensile stress and compressive stress could lead to a general decrease in anabolism-related genes. The former could also make matrix metal oproteinase-13 mRNA expression levels increased (P<0.05). 3%cyclic compression ratio and 3%cyclic stretch made cytoskeleton become oval. These results indicated that in vitro, proper cyclic compressive stress is beneficial to maintain the growth characteristics of articular chondrocytes in rats. Smal tensile stress can decrease the synthesis ability of chondrocytes. The effect of stress may be caused by changing the cytoskeleton.
3.Effects of static traction on the nucleus pulposus and annulus fibrosus of the rat intervertebral disc
Chinese Journal of Tissue Engineering Research 2024;28(8):1180-1185
BACKGROUND:Traction is clinically used for the early treatment of intervertebral disc degeneration,but its effect on the normal intervertebral disc remains unknown.Whether it directly causes intervertebral disc degeneration or has a positive effect is the key point of this study. OBJECTIVE:To design a static traction model and observe the effect of static traction on the nucleus pulposus and annulus fibrosus of the intervertebral disc METHODS:Twenty Sprague-Dawley rats,3 months of age,were included in the study.The intervertebral disc spaces between 7/8,8/9 and 9/10 were stretched by 1 mm,and the intervertebral disc spaces between 6/7 and 10/11 were used as control.Five rats were randomly selected at 2,4,6,and 8 weeks of traction to perform MRI T2-weighted scans of the caudal vertebra,tissue section staining,and RT-PCR gene assays for anabolic metabolism to observe the effects of static traction on the nucleus pulposus and annulus fibrosus of the intervertebral disc. RESULTS AND CONCLUSION:After short-term static traction of the rat caudal vertebra,the T2-weighted image signal in the nucleus pulposus region was enhanced.During the traction period,nucleus pulposus cells grew well,the intercellular matrix was abundant,and the annulus fibrosus arranged regularly.The RT-PCR results showed that after traction,the mRNA expression of proteoglycan increased,the expression of matrix metalloproteinase-3 decreased,the expression of type Ⅰ and Ⅱ collagen decreased,and the expression of matrix metalloproteinase-13 increased and tissue inhibitor of matrix metalloproteinase 1 increased.These gene results also indicated that traction made proteoglycan more inclined to an anabolic state,and type Ⅰ and Ⅱ collagen more inclined to a catabolic state.To conclude,static traction promotes proteoglycan anabolism making the nucleus pulposus moist.