Epigenetic modifications such as DNA methylation, histone post-translational modifications, non-coding RNA are reversible, heritable alterations which are induced by environmental stimuli. Major risk factors of diabetes and diabetic complications including hyperglycemia, oxidative stress and advanced glycation end products, can lead to abnormal epigenetic modifications in retinal vascular endothelial cells and retinal pigment epithelium cells. Epigenetic mechanisms are involved in the pathogenesis of macular edema and neovascularization of diabetic retinopathy (DR), as well as diabetic metabolic memory. The heritable nature of epigenetic marks also playsakey role in familial diabetes mellitus. Further elucidation of epigenetic mechanisms in DR can open the way for the discovery of novel therapeutic targets to prevent DR progression.
OBJECTIVE: To investigate the expression and distribution of xenoantigen in intervertebral disk of Chinese banna minipig inbred line, and to study the availability of xenograft transplantation of intervertebral disk. METHODS: Samples of intervertebral disk were collected from six Banna pigs of 8 to 11-month-old. The fixation, embedment and slice were performed. α-Gal specific binding lection (BSI-B4) were used as affinity reagents and affinity-immunohistochemistry assays (SABC methods and DAB stain) were conducted to detect the expression and distribution of xenoantigen (α-Gal). RESULTS: alpha-Gal was found in chondrocyte cell and chondrocyte-like cell in intervertebral disk which have the positive yellow-stained particulate aggradation. There was no stain in the matrix, elastic fiber and collagen fiber. CONCLUSIONS: The distribution of xenoantigen is locally in the tissue of intervertebral disk and its expression is weak. This suggests that the intervertebral disk of Banna pig may be alternative donor for xenotransplantation.
In thiis study,we show thai carbachol stimulates the accumulation of inositol phosphates(InsPs)in human rellnal pigment epithelium (RPE)cells and atropine blocks the carbachol-induced effect ,suggesting the existence of musearinie acelyleholine receptors in human RPE cells. In contrast,noradrenaline,serotonin, cpidermal growth factor (EGF),isoproterenol,and
NECA (5'-[N-ethyl]-carboxamido-adenosine)do not influence the basal levels of InsPs.Moreover,isoprmerenol and NECA do not affect the carhaehol elevated levels of InsPs.EGF,howcvcr,does potentiate the carhaehol stimulated elevation of InsPs in a dose-dependent manner ,suggesting an interaction between EGF and musearinie receptors in cultured human RPE cells.
（Chin J Ocul Fundus Dis,1994,10:220-222）
Objective To investigate the effectiveness of the deep inferior epigastric perforator (DIEP) flap for extreme defects around the knee. Methods Between June 2017 and December 2018, 15 patients with the extreme defects around the knee were admitted. There were 9 males and 6 females with a median age of 36 years (range, 23-51 years). The etiology was the traffic accident in 7 cases, tumor in 5 cases, and burn in 3 cases. The injured location was left knee in 8 cases and right knee in 7 cases. The size of soft tissue defects ranged from 15 cm×10 cm to 30 cm×20 cm, and all defects complicated with exposure of blood vessels, nerves, tendons, and other tissues. Transverse DIEP flaps with 1-2 vascular pedicles were prepared according to the size of the defect, including 6 cases of single-pedicle flaps and 9 cases of double-pedicle conjoined flaps. According to the depth of the defect, 10 cases of skin flaps were thinned under microscope. The size of the DIEP flaps ranged from 16 cm×10 cm to 32 cm×20 cm; the average thickness was 1.5 cm (range, 0.8-1.8 cm); the average pedicle length was 7.5 cm (range, 5.0-9.0 cm). The donor site was directly sutured. Results One single-pedicle flap developed distal necrosis after operation, and healed after skin grafting; the other skin flaps survived, and the wounds at the donor and recipient sites healed by first intention. All patients were followed up 16-28 months (mean, 24 months). The shape and texture of the flap were satisfactory, and there was no abnormal hair growth or obvious pigmentation. There was only linear scar at the donor site and no complication such as abdominal hernia. The appearance and function of the knee were satisfactory. No recurred tumor was observed, and the scar contracture was released. At last follow-up, 13 cases were excellent and 2 cases were good, according to the Knee Society Score (KSS) criteria. Conclusion The DIEP flap is an ideal alternative for repairing the extreme defects around knee, with a concealed donor site, easy dissection, flexible design, as well as less complication.
OBJECTIVE: To isolate and characterize mesenchymal stem cells (MSCs) derived from bone marrow of Banna minipig inbred line (BMI). METHODS: BMI-MSCs was isolated from bone marrow by density gradient centrifugation and cultured in DMEM (containing 15% bovine serum) at 37 degrees C with humidified 5% CO2. These cultured stem cells were characterized in clonal growth, expression of specific markers and capability of differentiation. RESULTS: Mesenchymal stem cells were proliferative and could be expanded rapidly in vitro. Clonal growth of these cells can be observed when small amount of cells was inoculated. These cells were SH2, SH3, SH4, SB10 and SB21 positive. And it was proved that these cells possess osteo-differentiation ability, up-regulated alkaline phosphatase expression and calcium secretion after osteosupplement was added into the media for several days. CONCLUSION: Mesenchymal stem cells derived from bone marrow of BMI possess the general characters of stem cell.
RNA can be labeled by more than 170 chemical modifications after transcription, and these chemical modifications are collectively referred to as RNA modifications. It opened a new chapter of epigenetic research and became a major research hotspot in recent years. RNA modification regulates the expression of genes from the transcriptome level by regulating the fate of RNA, thus participating in many biological processes and disease occurrence and development. With the deepening of research, the diversity and complexity of RNA modification, as well as its physiological significance and potential as a therapeutic target, can not be ignored.
Objective To observe the expression of cyclin dependent kinase 5 (Cdk5) and p25 in the pathogenesis of retinitis pigmentosa (RP) in Royal College of Surgeon (RCS) rats and its relationships with apoptosis. To explore the mechanism of Cdk5 and p25 induced photoreceptor apoptosis in the pathogenesis of RP. Methods Retinas of RCS and RCS-rdy+ rats were obtained at the ages of postnatal day 17, 25, 35, 60. The retinal structure and thickness of outer nuclear layer were measured by optical microscopy. The expression of Cdk5, p25, cleave-caspase 3 in the retina was evaluated by immunohistochemistry. The protein expression of cleave-caspase 3 in the retina was determined by Western blot. The apoptosis of retinal cells was examined by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The mean absorbance value of apoptotic cells was analyzed by SPSS 17.0 software. Results The retinal thickness of the RCS rats was significantly reduced in comparison to the RCS-rdy+ rats as the postnatal days progressed, particularly in the layer of rods and cones and the outer nuclear layer. The expression level of Cdk5, p25, cleave-caspase 3 of RCS rats increased from postnatal 17 days to postnatal 35 days, while decreased on postnatal 60 days; but there was no obvious change of above indexes in RCS-rdy+ rats. The protein expression of cleave-caspase 3 in the RCS rats was significantly increased with progression of postnatal days to postnatal 35; but there was no obvious similar change in RCS-rdy+ rats. The results of TUNEL showed that the apoptotic cells significantly increased in the outer nuclear layer of RCS rats from postnatal 17 days to postnatal 35 days, while decreased on postnatal 60 days; but there was no obvious change of above index in RCS-rdy+ rats. This study showed that there were significant correlations between the following variables: Cdk5 expression and p25 expression, Cdk5 expression and cleave-caspase 3 expression, Cdk5 expression and apoptotic cells, p25 expression and cleave-caspase 3 expression, p25 expression and apoptotic cells, cleave-caspase 3 expression and apoptotic cells. The partial correlation coefficients were 0.949, 0.808, 0.959, 0.887, 0.979, 0.852, respectively and the P value was 0.000. Conclusions The apoptotic cells significantly increases and the expression level of Cdk5, p25, cleave-caspase 3 of RCS rats increases from postnatal 17 days to postnatal 35 days. The tendency of apoptotic cells to increase is consistent with the change of Cdk5, p25, cleave-caspase 3 expression. The apoptosis of photoreceptor cells is related to increasing expression of Cdk5 and p25 in RCS rats. Cdk5 may be involved in the development of RP in RCS rats.
Retinitis pigmentosa is a hereditary disease which is characterized by damage in retinal photoreceptor cells and retinal pigment epithelium. Its main clinical features include low vision with night blindness, progressive visual field defects, and abnormal electroretinograms. The development of gene sequencing, the diagnosis and treatment methods of retinitis pigmentosa update year by year, including gene therapy, stem cell therapy, optogenetic therapy, etc. However, there is still a big gap in these treatments from laboratory technology into effective clinical treatment drugs. Some problems which include immune response, potential mutagenesis and tumorigenesis of the inserted region, genetic toxicity, quality and stability of gene technology and stem cell technology, mass production and promotion of clinical grade drugs, and optimization of the effectiveness of drugs and surgery, etc, remain to be solved by researchers.
Epigenetics refers to the modification effect of external and internal environmental factors on genes under the premise of the unaltered genetic sequence, leading to changes in gene expression level or function, and thereby affecting various phenotypes or disease outcomes. In recent years, epigenetics has attracted increasing attention. Among them, DNA methylation has been shown to be closely related to human development and the development of disease. However, the high-dimensional omics data generated by genome-wide methylation detection can comprehensively reflect the overall and local epigenetic modifications at the genome level, which has become one of the main research contents in this field. Based on genome-wide methylation chip data, this paper summarized the quality control process of this omics data, common epigenetic omics correlation statistical analysis methods and ideas, and visualization realization of main results based on SAS JMP Genomics 10 software, so as to provide reference for similar studies.
The ultra.structural changes of photic injury to the retina of two patients caused by indirect ophthalmoscope were studied.The duration of exposure was 20 minutes. Under transmission electron microscope, dilation of the choroidal vessels,swelling and vacule formation at all retinal layers,
disparsed pyknotic nuclei among the outer nuclear layer and swelling of the nerve fibers were found,The retina of the pregnant woman was injured more severely than that of the male patient.
（Chin J Ocul Fundus Dis,1994,10:77-79）
