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.
ObjectiveTo investigate the current status of research in gene therapy for retinitis pigmentosa (RP) from 2005 to 2024. MethodsThe literature related to gene therapy for RP included in the Web of Science Core Collection dataset from January 1, 2005 to September 15, 2024 was retrieved and screened. The bibliometrix package of R software was used to analyze the annual trend of the number of publications, citation frequency, distribution of countries/regions of the literature, and distribution of journals containing the articles. CiteSpace software was used to perform keyword clustering analysis and the keywords bursts analysis. ResultsA total of 209 articles were included. There was an overall fluctuating upward trend of annual publications from 2005 to 2024, with the highest number of publications in 2023 at 26 (12.4%, 26/209), and the lowest number of publications in 2006 at 2 (0.9%, 2/209). There was an overall increasing trend in the frequency of citations to relevant literature. Corresponding authors from the United States had the highest total number of publications with 98 (46.9%, 98/209). Among authors, Hauswirth from the University of Florida, USA, had the most with 25 (12.0%, 25/209). Among institutions, Columbia University, USA, had the most with 55 (26.3%, 55/209). Among journals, Mol Ther had the most with 25 (12.0%, 25/209), and it had the highest 2023 impact factor of 12.1. Keyword clustering analysis yielded eight valid clusters, namely #0 P23H, #1 AAV, #2 PDE6B, #3 CRB1, #4 RPGR, #5 antisense oligonucleotide, #6 NR2E3, and #7 NRL, which intersected with each other with good continuity. The keywords bursts analysis showed that the keyword with the longest emergence time was RNAi, followed by PDE and PDE6. USH2A, CRB1, CRISPR Cas9, base editing, and ORF15 were keywords that emerged in recent years and were continuously studied. ConclusionsRP gene therapy research literature has shown an increasing trend from 2005 to 2024, with the highest number of publications from research organizations and scholars in the United States. Currently, studies focus on RHO, PDE6B, CRB1, RPGR, NR2E3, and NRL gene. In recent years, there has been a gradual increase in studies on USH2A, CRB1 genes, and the RPGR ORF15 region. CRISPR Cas9 and base editing gene therapy strategies are being developed.
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.
Torpedo maculopathy is a rare, congenital lesion of RPE, which locates temporal to the macula and along the horizontal raphe. The lesion is torpedo-shaped with its torpedo-like tip pointing towards the fovea. As an incidental finding, it often affects only one eye with no damage to central visual acuity. According to its characteristics on OCT, it is divided into 2 types: typeⅠ, attenuation of outer retinal structures without outer retinal cavitation; typeⅡ, those with both attenuation of outer retinal structures and outer retinal cavitation. Diseases with pigment changes in the RPE layer similar to torpedo maculopathy include congenital hypertrophy of the RPE, RPE lesions in Gardner syndrome, etc. The main point to distinguish the disease from other diseases is its unique location and shape. Most of the torpedo maculopathy lesions are stable and do not require special treatment, but the disease can be complicated by neurosensory retinal detachment, choroidal neovascularization and so on, and symptomatic treatment is needed if necessary.
OBJECTIVE: To observe the heart anatomic and histological structure of the Banna mini-pig inbred-lined and to provide the morphological data for heart xenotransplantation and breeding transgens pig. METHODS: Ten Banna mini-pigs (12-18 months old) were affused and fixed by common coratid artery. The heart were observed and measured by gross anatomy and histology. RESULTS: There were many similarities between the Banna pig heart and the human heart in anatomy and histology. However, the following differences were observed in the Banna pig heart: 1. Azygos vein directly drew into right atrium cordis. 2. The intercalated disk of cardiac muscle was less than that of human. 3. The Purkinje’s fibre was bigger than that of human. CONCLUSION: On the morphology and histology, the structure of Banna pig heart is similar to the heart of human being. It is possible that Banna minipig heart becomes organ donors for xenotransplantation.
Objective To evaluate a new alternative method for thereconstruction of vagina with deep inferior epigastric perforator(DIEP) flap. Methods From January 2004 to May 2005, DIEP flaps were used for vaginal reconstruction in 5 patients(19 to 40 years), including 4 cases of congenital vaginal agenesis and 1 case of vaginal tumor. Before operation, the perforators were detected by theDoppler and the flaps based on the perforators ranged from 10 cm×9 cm to 12 cm×11 cm. DIEP flaps were elevated and then transferred to reconstruct the vagina. Results Deep inferior epigastric perforator flaps were used in 5 patients. Only 1 patient developed haematoma in the posterior aspect of thereconstructed vagina, but the flap was viable. The wounds healed secondarily after conservative therapy. All the flaps survived completely. No complication occurred at donor site of abdominal wall. Conclusion Despite technical difficulties in elevatingthe deep inferior epigastric perforator flap, the flap is a good choice for vaginal reconstruction.
OBJECTIVE The major obstacle in pig to human transplantation is acute and hyperacute rejection (HAR) triggered mainly by alpha-galactosyl residues(alpha-Gal) in donor. Since the inbred-line Banna pig(IBNP) and Wuzhishan pig (IWZSP) are highly inbred and may be the potential donor for xenotransplantation, it is important to investigate the reaction between human serum and inbred-line pig tissues as well as the distribution of alpha-Gal in these tissues. METHODS Samples from heart, liver, spleen, lung, kidney, pancreas, small intestine, thymus, skin, lymph node and blood vessels at all levels were collected from four 8 to 11-month-old male IBNPs and one IWZSP. Affinity-immunohistochemistry assays were conducted following routine procedures on paraffin sections with normal human sera of blood type A, B, O, AB and BSI-B4(alpha-Gal specific binding lectin) as the primary antibodies or affinity reagents. Sections digested by alpha-galactosidase were also examined as control. RESULTS Parallel results were obtained from these pig tissues stained against human sera and BSI-B4. There was no significant difference both in the antigens recognized by sera of different blood types or BSI-B4 and in the distribution of alpha-Gal. The best alpha-Gal positive staining was appeared in vascular endothelial cells at all levels and partial parenchyma cells. However, tissues of cartilage, peripheral nerve and muscle were negative. After digested by alpha-Galactosidase, all samples were negative against BSI-B4 and human sera except few positions that showed different staining. CONCLUSION The distribution of target antigen is similar in various tissues of the two kinds of pigs. Though alpha-Gal is the major xenoantigen in IBNP and IWZSP, there may be some unknown antigens related to pig to human transplantation. Possibly the level and distribution of antigen expression in pig tissues are not the first affair to be considered, and these pigs should be genetically modified in order to eliminate rejection in pig to human xenotransplantation.
Objective To investigate whether mutations exist in codon 58 and codon 347 of the rhodopsin gene in patients with autosomal dominant retinitis pigmentosa(ADRP)． Methods Point mutations at codons 58 and 347 were detected by restriction endonuclease digestion of exons 1 and 5 amplified by polymerase chain reaction(PCR)．This method was applied to screen genomic DNAs from 57 patients of 38 families with ADRP and 60 normal controls． Results Four patients from one family of ADRP were confirmed to have a point mutation at the second nucleotide of codon 58,and 6 patients from two families of ADRP were found to have a mutation at codon 347．None of these mutations were found in 60 normal subjects． Conclusion It is suggested that molecular genetic heterogeneity exists within ADRP and some subtypes of ADRP are caused by points mutations of the rhodopsin gene． (Chin J Ocul Fundus Dis,1998,14:108-110)
Severely coagulated retinae by argon laser of 20 Chinese hamsters were investigated with transmission electron-microscopy. The results revealed destruction of retinal pigment epithelium-Bruch's membrane-choroid capillary complex at the coagulated foci, and leakage of fluid and blood cells through the choroidal vessels into the subretinal space. Several days after laser burn the subretinal fluid was found to subside and the RPE cells surrounding the burned lesions started to proliferate. The smaller lesions were covered by the proliferating RPE 10 days after coagulation, but poor regeneration of RPE in large necrotic areas. Neovascularization was usually associated with obvious defect of Bruch's membrane and restoration of RPE barrier was most likely impossible. （Chin J Ocul Fundus Dis,1992,8:14-16）