Red blood cell and fibroblast membranes in Duchenne and myotonic muscular dystrophy

The literature concerning red blood cell and fibroblast protein studies in Duchenne and myotonic muscular dystrophy is critically reviewed. In this review, we emphasize methodological and technical considerations in order to promote an appreciation of the complexities of this area of research to clinical scientists interested in muscle disease.     

Nuclear alterations in autosomal-dominant Emery-Dreifuss muscular dystrophy

Electron microscopy study of muscle biopsies from patients with autosomal-dominant Emery-Dreifuss muscular dystrophy revealed nuclear alterations in about 10% of the preserved muscle fibers. The major findings consisted of peripheral heterochromatin loss or detachment from the nuclear envelope, and of interchromatin texture alterations. These abnormalities are similar to those reported in an animal model of the disease and to those found in the X-linked form of Emery-Dreifuss muscular dystrophy. These results suggest that an abnormal ultrastructural arrangement of the nuclear periphery is a common feature in the known forms of Emery-Dreifuss muscular dystrophy, and that several proteins of the nuclear scaffold are necessary in muscle cells to maintain the nuclear structural/functional integrity and a normal muscle cell metabolism.     

Vascular alterations in Fukuyama type congenital muscular dystrophy

Blood vessels in muscle biopsy specimens from 6 Fukuyama type congenital muscular dystrophy (FCMD) patients were examined by electron microscopy and compared with ones in non-diagnostic biopsy specimens from age-matched controls and patients with childhood neuromuscular disorders. The most striking feature was the blister-like swelling of vascular endothelial cells in the biopsied muscle specimens from 5 of the 6 patients with FCMD. Morphometric analysis of capillaries in biopsied muscles showed the extremely greater capillary, endothelial and pericyte areas in the FCMD patients than in controls. These phenomena are quite similar to those found in Duchenne muscular dystrophy (DMD) at the preclinical stage and suggest an as yet undetermined process in blood vessels in FCMD as well as DMD. An immunohistochemical study involving dystrophin antibodies showed positive staining in FCMD.     

Brain alterations in the classical form of congenital muscular dystrophy

In the classical form of congenital muscular dystrophy (CMD), subclinical brain involvement is frequent. In order to establish the natural evolution of CNS alterations in this type of CMD, the cerebral functions of 12 cases were examined longitudinally for a mean period of 8 years. There were 7 boys and 5 girls, with a mean age of 5 years at first evaluation and 13 at the last one. Merosin expression in muscle fiber basement membrane, evaluated in 10 of them, was normal in 6 and deficient in 4. CNS conditions were followed up by repeated neuropsychiatric examinations, intelligence tests, EEG and brain CT scan and/or MRI. Eight of the 12 patients (including the 4 with merosin-deficiency) had normal intelligence, while 4 had mild to moderate mental retardation: in all the intellectual ability was unchanged during the follow-up study. CT scan detected minor brain alterations in 9 patients: 6 of these, the 4 with merosin deficiency and 2 others in whom merosin was not evaluated, presented leukoencephalopathy: on neuroimaging reappraisal it was unchanged in 3, improved in 2 and worse in 1 (a merosin-deficient case). Cerebellar alterations or mild ventricular dilatation were detected in 8 cases, including 3 merosin-non-deficient ones: these abnormalities were unchanged at the last study by CT and MRI, as were the normal neuroimaging findings observed in 3 other cases. Overall, during our study the brain alterations found in classical CMD showed a stationary or an improving course; progressive worsening was observed only in 1 of 4 merosin-deficient cases with leukoencephalopathy.Preliminary data on some of the patients have been presented at the International Symposium on Congenital Muscular Dystrophies, Tokyo, Japan, 7–8 July 1994     

Red blood cell lipid alterations in type II diabetes mellitus

Alterations in blood rheological properties have been reported in diabetes mellitus. Changes in lipid composition of red blood cell (RBC) membranes resulting in an impairement of RBC deformability may play a role in the altered blood rheological pattern. The aim of this study was to investigate the lipid composition of RBC membrane in a group of patients affected by type II diabetes (age 21–45 years), selected on the basis of the absence of complications and good metabolic control, and in a group of suitable control subjects. Saturated fatty acid amounts in the different phospholipid fractions were significantly higher in diabetics than in controls (p<0.05), whereas polyunsaturated fatty acids were decreased (p<0.05). Cholesterol/phospholipid molar ratio was not altered. On the contrary, sphingomyelin/phosphatidylcholine ratio was higher in diabetics than in controls (1.10±0.08 vs 0.96±0.10, p相似文献   

Myotonic muscular dystrophy. Time-dependent alterations in erythrocyte membrane fluidity

The muscle cell membrane may be the site of the basic molecular defect in myotonic muscular dystrophy. Many laboratories, including our own, have suggested that this defect may also be manifested in membrane of extraneural tissue. In previous studies, we found that electron spin resonance results suggested an increased membrane fluidity in erythrocyte membranes that had aged two days in buffer, but we and others could find no such changes in fresh erythrocyte membranes. To investigate these findings further, the results of an initial study of the time course of the membrane fluidity changes in erythrocytes in myotonic muscular dystrophy are given in the present report. They suggested that increased membrane fluidity changes in erythrocytes in myotonic muscular dystrophy are given in the present report. They suggested that increased membrane fluidity in myotonic dystrophy is manifested after two days of in vivo ageing and confirm our original findings. These results are discussed in relation to possible effects of metabolic deprivation or of protein-lipid alterations in erythrocytes.     

The role of corticosteroids in muscular dystrophy: a critical appraisal

Over the years various steroid trials have been conducted in Duchenne muscular dystrophy (DMD). In children who are still able to walk as well as in those who are wheelchair-bound, corticosteroids have been found to stabilize muscle strength for a period of time. Controlled clinical observations have shown that some boys remain ambulatory for years longer than reported in natural history data. The two main steroids used are prednisone/prednisolone and deflazacort. They are probably equally effective in stabilizing muscle strength but may have different side-effect profiles; for instance, deflazacort causes less weight gain. The exact mechanism by which steroids slow the dystrophic process is under investigation. DMD children treated long term also seem to develop other complications of the condition less frequently. For instance, they develop respiratory insufficiency later and have fewer cardiac symptoms. The therapeutic value of corticosteroids is limited, but these drugs represent the best treatment option currently available.     

Congenital muscular dystrophy: brain alterations in an unselected series of Western patients.

The typical form of congenital muscular dystrophy (CMD) described in Western countries is generally considered different from its Japanese variant because of the absence of CNS involvement. Evaluations from both a clinical and a neuroradiological point of view were made of the CNS functions of 12 unselected Western children affected by CMD. In five patients, clinical observation and intelligence tests showed a mild to severe mental retardation. One of these patients suffered also from a severe form of epilepsy. In the same five patients, various degrees of white matter hypodensity, ventricular enlargement and cerebral atrophy were also detected. Similar neuroradiological abnormalities were also found in five of the seven children who did not have clinical symptoms or signs of CNS involvement. In one of these cases, necropsy neuropathological examination showed the gyral anomalies characteristic of the Japanese type of CMD. This study clearly indicates the high frequency of subclinical CNS alterations in typical Western CMD, suggesting that it should be considered a type of myoencephalopathy like its Japanese counterpart.     

Stem cell based cell therapy for muscular dystrophy]

Stem cell-based cell therapy is one of attractive therapeutic approaches to muscular dystrophy. In transplantation into dystrophic skeletal muscle, muscle satellite cells and musclE side population (SP) cells are good candidates as sources of stem cells. We purified mouse satellite cells from adult C57B16 mice by FACS using a monoclonal antibody, SM/C-2.6, which can specifically recognize quiescent satellite cells. DNA micro-array analysis on both quiescent and activated satellite cells allowed us to distinguish novel quiescent satellite cell-specific genes. These genes may encode molecules that keep satellite cells in a dormant and undifferentiated state. We transplanted purified muscle satellite cells transduced with lentivirus vector, and found these cells were effectively incorporated into dystrophin-deficient skeletal muscle and expressed transduced dystrophin. We also identified a novel side population (SP) cells in uninjured and regenerating skeletal muscle. The majority of muscle-SP cells in uninjured stage showed endothelial cell-like properties. CD31 negative/CD45 negative SP cells were a minor population in normal conditions, but actively proliferate during muscle regeneration. Co-transplantation experiments showed that the SP cells synergistically promoted muscle regeneration with satellite cells. It is indispensable to study molecular basis of muscle stem cells and muscle regeneration to achieve effective stem cell-based cell therapy on muscular dystrophy.     

Gene expression in blood of subjects with Duchenne muscular dystrophy

The objective of this study was to examine RNA expression in blood of subjects with Duchenne muscular dystrophy (DMD). Whole blood was collected into PAX gene tubes and RNA was isolated for 3- to 20-year-old males with DMD (n = 34) and for age- and gender-matched normal healthy controls (n = 21). DMD was confirmed by genetic testing in all subjects. RNA expression was measured on Affymetrix whole-genome human U133 Plus 2.0 GeneChips. Using a Benjamini–Hochberg false discovery rate of 0.05 to correct for multiple comparisons, an unpaired t test for DMD versus controls yielded 10,763 regulated probes with no fold change cutoff, 1,467 probes with >|1.5|-fold change, 191 probes with >|2.0|-fold change, and 59 probes with a >|2.5|-fold change. These genes (probes) separated DMD from controls using cluster analyses. Almost all of the genes regulated in peripheral blood were different from the genes reported to be regulated in diseased muscle of subjects with DMD. It is proposed that the genes regulated in blood of subjects with Duchenne muscular dystrophy are indicative, at least in part, of the immune response to the diseased DMD muscle. The regulated genes might be used to monitor therapy or provide novel targets for immune-directed therapy for DMD. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Serotonin uptake in blood platelets of Duchenne muscular dystrophy patients

Serotonin (5-HT) uptake was studied in the blood platelets of 10 patients with Duchenne-type muscular dystrophy (DMD) and 7 age-matched controls. Vmax (maximum number of uptake sites) of platelet 5-HT uptake in the DMD patients was significantly less than that of the normal controls. There was no difference in the affinity for 5-HT (Km) between the two groups. There was a significant negative correlation between serum creatine kinase activity and Km of 5-HT uptake in blood platelets of these patients. However, no correlation was found between Km or Vmax and ambulatory status of DMD.     

4000/脐血源间质干细胞移植治疗Emery-Dreifuss型肌营养不良

2008-02南京医科大学附属无锡第二医院神经内科收治的男性患者1例,32岁,体质量38 kg,四肢无力、肌萎缩18年,突发头晕、呕吐3 d后入院,经基因分析和肌肉活检确诊为Emery-Dreifus型肌营养不良并发小脑梗死。经HLA配型在上海市脐血库中寻找到一个与受者非血源相关、HIA全相合、Rh血型相合、ABO血型主侧不合的脐血供体,于入院后第9天采用白消安+环磷酰胺+兔抗胸腺淋巴细胞球蛋白预处理后,通过外周静脉移植异基因脐血间充质干细胞悬液40 mL,10滴/min,实际输入的有核细胞数为31.98×108。细胞移植5周后,患者头晕消失,吞咽困难、饮水呛咳症状明显好转,可连续饮水,双手协调动作较移植前好转,可操作电脑,体质量约增长4 kg;移植后半年,血清肌酸磷酸激酶由移植前35.79 μkat/L降至9.55 μkat/L,血清肌酸磷酸激酶同工酶由移植前18.20 μkat/L降至 4.78 μkat/L,肌红蛋白由移植前413.50 μg/L降至213.20 μg/L,功能独立性评分由71分提高至101分,未见免疫排斥反应及致瘤趋性。提示脐血间充质干细胞移植后能在短期内使血清肌酸磷酸激酶水平下降,改善运动功能,有助于Emery-Dreifuss型肌营养不良的治疗,近期安全性可靠。     

Blood-brain barrier alterations in MDX mouse, an animal model of the Duchenne muscular dystrophy

This article reviews recent studies on the alterations occurring in the brain vessel wall of the mdx mouse, an animal model with genetic defects in a region homologous with the human Duchenne muscular dystrophy (DMD) gene. These alterations affect both endothelial and astroglial cells and are associated with opened tight junctions, swollen perivascular astrocyte processes and a reduction in the expression of tight junctions associated proteins, ie. zonula occludens and of a specific water channel i.e. aquaporin-4, suggesting that some neurological dysfunctions of mdx mice and DMD patients could be associated with changes in brain osmotic equilibrium.     

骨髓和脐血间充质干细胞联合移植治疗杜氏型肌营养不良

背景：杜氏型肌营养不良的肌细胞损伤并非单一细胞受损,而是多因素缺陷导致肌细胞进行性萎缩的严重后果,患儿一经确诊即被告之无法医治。近年来国内外学者把目光转向具有修复和再生功能的干细胞,研究发现干细胞技术可以改善肌营养不良的运动功能。 目的：首次采用骨髓和脐血间充质干细胞联合移植方法,首次采用静脉注射和局部2种治疗途径,观察治疗杜氏型肌营养不良患者的安全性和有效性。 设计：自身前后对照。 对象：2007-06/2008-09解放军第四六三医院细胞治疗中心应用骨髓和脐血间充质干细胞联合移植方案治疗杜氏型肌营养不良患者31例,男29例,女2例(双胞胎),平均年龄9.7岁,平均病程5.1年,阳性家族史11例,均经临床症状、酶学、肌电图、基因分析、肌肉活检、肌肉核磁共振检查确诊。 方法：经双侧髂后上棘抽取患者自体骨髓80~150 mL,采用Ficoll密度梯度离心法分离单个核细胞,并诱导分化为骨髓间充质干细胞,调整细胞悬液浓度为1×1010 L-1,采用多点注射法移植于患者四肢肌肉内,移植细胞数为(1.5~6.0)×108个。选择健康足月产妇脐带血80~145 mL,同法制备脐血间充质干细胞,经静脉植入(1.0~4.8) ×107个细胞,1次/周,共3次。 主要观察指标：干细胞移植前后患者日常生活活动能力评价,临床分级评价,以及酶学、肌电图、肌肉MRI变化。 结果：31例患者均完成15个月随访,中途无脱落。与移植前比较,干细胞移植后3,6,9,12,15个月,26例(84.7%)动作灵活度增强,运动功能改善,日常生活活动能力评分升高(P < 0.05);干细胞移植后6个月,血清肌酸肌酶、乳酸脱氢酶水平降低11例,升高8例;5例复查肌电图,波幅改善2例;5例复查MRI,肌肉轮廓较前清晰2例。临床分级评定显效12例(38.7%),有效14例(45.2%),无效5例(16.1%),总有效率为83.9%,未发生不良反应及并发症。 结论：骨髓和脐血间充质干细胞联合移植治疗杜氏型肌营养不良可使83.9%患者获得临床症状改善,运动功能及肌力提高,6个月后部分患者血清酶学、肌电图及肌肉MRI轻度改善,安全性好,无排斥反应,是一种治疗杜氏型肌营养不良的新手段。     

The allure of stem cell therapy for muscular dystrophy

Duchenne muscular dystrophy (DMD) is a lethal muscle disease for which an effective treatment is urgently needed. The use of stem cells to produce normal muscle cells to replace the missing dystrophin protein has attracted much attention. Claims of success using stem cell treatment in animal models of human muscle diseases require careful evaluation and are not necessarily easily extrapolated to the clinical situation. Recent studies in the dystrophic dog model have been claimed to show that injected mesangioblasts, stem cells derived from blood vessels, reduce the severity of the disease. However, the authors' interpretation of the results did not consider that benefits might arise from the concomitant use of immunosuppressive drugs alone.     

Inefficient dystrophin expression after cord blood transplantation in Duchenne muscular dystrophy

We report a boy who received two allogeneic stem cell transplantations from umbilical cord donors to treat chronic granulomatous disease (CGD). The CGD was cured after the second transplantation, but 2.5 years later he was diagnosed with Duchenne muscular dystrophy (DMD). Examinations of his DNA, muscle tissue, and myoblast cultures derived from muscle tissue were performed to determine whether any donor dystrophin was being expressed. The boy was found to have a large‐scale deletion on the X chromosome that spanned the loci for CYBB and DMD. The absence of dystrophin led to muscle histology characteristic of DMD. Analysis of myofibers demonstrated no definite donor cell engraftment. This case suggests that umbilical cord–derived hematopoietic stem cell transplantation will not be efficacious in the therapy of DMD without additional interventions that induce engraftment of donor cells in skeletal muscle. Muscle Nerve, 2010