In Vivo DYSF Gene Viral Delivery Provides a Histoprotective Effect in Skeletal Muscle Tissue in Dysferlin-Deficient Mice.

We studied the effects of a dual-vector DYSF gene delivery system based on adeno-associated virus serotype 9 capsids on pathological manifestations of dysferlinopathy in skeletal muscles of Bla/J mice lacking DYSF expression. The mice received intravenous injection of 3×1013 genomic copies of the virus containing the dual-vector system. M. gastrocnemius, m. psoas major, m. vastus lateralis, and m. gluteus superficialis were isolated for histological examination in 3, 6, and 12 weeks after treatment. Healthy wild-type (C57BL/6) mice served as positive control and were sacrificed 3 weeks after injection of 150 µl of 0.9% NaCl into the caudal vein. To detect dysferlin in muscle cryosections, immunohistochemical analysis with diagnostic antibodies was performed; paraffin sections were stained with hematoxylin and eosin for morphometric analysis. After administration of gene-therapeutic constructs, muscle fibers with membrane or cytoplasmic dysferlin location were detected in all examined muscles. The proportion of necrotic muscle fibers decreased, the number of muscle fibers with central location of the nucleus increased, and the mean cross-section area of the muscle fibers decreased.

Structural and ultrastructural changes in the skeletal muscles of dysferlin-deficient mice during postnatal ontogenesis.

A number of sarcolemma proteins are responsible for muscle fiber repair. Dysferlin encoded by the DYSF gene is one of these proteins. Dysferlin promotes membrane repair in striated muscle fibers (MFs). Mutations in DYSF lead to loss of or decreased dysferlin expression, impaired membrane repair in MF, and its destruction, clinically manifesting as dysferlinopathy. Preclinical studies of cell and gene therapies aimed at restoring impaired muscle regeneration require well-characterized small animal models. Our investigation aimed to distinguish the histopathological features of a mouse strain lacking dysferlin expression (Bla/J strain). Ultrastructural changes in the sarcolemma, mitochondria and contractile apparatus were observed. It was shown that postnatal histogenesis of skeletal muscles in genetically determined dysferlin deficiency is characterized by a higher proportion of necrotic muscle fibers, compensatory hypertrophy of muscle fibers with their subsequent atrophy, and decreases in proliferative activity and the level of myogenic differentiation of myogenic progenitor cells compared to wild-type mice (C57Bl/6).

[Pathohistological characteristics of muscles in patients with chronic lower limb ischemia]. / Patogistologicheskaya kharakteristika myshts u patsientov s khronicheskoi arterial'noi nedostatochnost'yu nizhnikh konechnostei.

Despite the widespread occurrence of ischemic diseases of the lower extremities, including atherosclerosis and diseases with an autoimmune component of their pathogenesis, the pathohistological signs of damage and concomitant chronic ischemia, compensatory tissue responses as intracellular and cellular regeneration remain out of the field of vision in researchers. OBJECTIVE: To assess the signs of damage (the extent of necrosis and apoptosis, capillary density (CD)) and regeneration (the cross-sectional muscle fiber area (CSMFA), the proportion of centrinucleated muscle fibers (CNMFs), and that of connective tissue), by using the gastrocnemius medial head biopsy specimens obtained from patients with heterogeneous forms of chronic lower limb obliterating diseases (CLLODs). SUBJECTS AND METHODS: The investigation included the biopsy specimens obtained from 44 men under 65 years of age (their mean age was 54±9.8 years) with Stage IIB-IV chronic limb ischemia (according to the A.V. Pokrovsky-Fontaine classification) with its history of at least six months. The nosological entities were atherosclerotic lesion in 33 patients (distal atherosclerosis n=13), multistage lesion (n=8), and Leriche's syndrome (n=12); autoimmune-mediated vascular injury in 11 patients (Buerger's disease (n=7) and nonspecific aortoarteritis (n=4)). The similar muscle fragments obtained during autopsy from the deceased without obvious signs of cardiovascular system diseases were examined as a control. RESULTS: It was found that there was a statistically significant difference between the nosological entities, as compared to the control in terms of CD and CSMFA (a decrease), the proportion of CNMFs and that of connective tissue (an increase). No substantial differences were found in the studied parameters between the nosological entities. CONCLUSION: The findings may suggest the universal mechanism for damage to striated muscle tissue because of circulatory hypoxia, regardless of its etiology and the common character of tissue compensatory-adaptive responses (regeneration).

Reactive Changes in Elements of Stromal-Vascular Differons of Dysferlin-Deficient Skeletal Muscles after Procaine Injection.

The study assessed reactivity of stromal-vascular skeletal muscle differons to acute chemical injury. Dysferlin-deficient Bla/J mice and the wild-type С57BL/6 mice were intramuscularly injected with 100 µl of 0.5% procaine solution. The middle segment of gastrocnemius muscle was taken on postsurgery days 2, 4, 10, and 14 for routine histological examination. To evaluate proliferation and vascularization, the paraffin sections were stained immunohistochemically with antibodies to α-smooth muscle actin and Ki-67. The connective tissue was stained according to Mallory. The study revealed diminished proliferative activity of stromal-vascular differons and decreased vascular density in muscles of Bla/J mice. Thus, mutations in the DYSF gene coding dysferlin down-regulate the reparation processes in all differons of skeletal muscle.

Early ultra- and microstructural alterations in rat pancreas in alloxan-induced diabetes mellitus.

An adequate experimental model is important to understand pathophysiological processes ongoing in the pancreas with diabetes mellitus. Our study was aimed to describe early ultra- and microstructural changes in the rat pancreas in 12-48 h after alloxan administration in a dose of 180 mg/kg. A histopathological examination of the endocrine pancreas revealed the loss of borders between endocrine cells, granular dystrophy and degranulation, sings of necrosis in central cells of the Langerhans islets and apoptosis of their peripheral ones manifested as DNA fragmentation and an increased expression of apoptosis markers. There was a gradual increase of a Langerhans islet area, a decreased percentage of insulin+ cells and an increased one of glucagon+ cells, as well as the presence of proliferating islet cells were found. Structural changes of the exocrine pancreas included fatty degeneration, signs of exocrine cell mitochondrial damage, increased acini, which are located mainly around the Langerhans islets, as well as perivascular edema and leukocytic infiltration. Described ultra- and microstructural alterations suggest a significant contribution of apoptosis to death of endocrine cells exposed to alloxan. Coexisting damage of the exocrine pancreas with its stroma involvement is for the first time described.

[Outcomes of using autologous peripheral-blood stem cells in patients with chronic lower arterial insufficiency].

Presented herein are the outcomes of using autologous peripheral blood stem cells (SCs) in patients with stage II В lower limb chronic obliterating diseases (according to A.V. Pokrovsky's classification). Autologous SCs had previously been stimulated by means of the recombinant granulocytic colony stimulating factor (G-CSF) for five days. On day six, we performed mobilization of the peripheral blood stem cells on the MSC+ unit by means of leukopheresis followed by intramuscular administration of half of the obtained dose into the affected extremity. The mean number of the transplanted mononuclears amounted to 6.73 ± 2.2 x 10(9) cells, with the number of CD34+ cells averaging 2.94 ± 2.312 x 10(7). Assessing the therapeutic outcomes at 3 and 6 months of follow-up showed a statistically significant increase in the ankle-brachial pressure index (ABPI) [being at baseline 0.59 ± 0.04, at 3 months - 0.66 ± 0.04 (P=0.001), and after 6 months - 0.73 ± .08 (P=0.035)], accompanied and followed by improved measures of the treadmill test, with the pain-free walking distance at baseline equalling 102.2 ± 11.55 m, after 3 months - 129 ± 11.13 m (P<0.001), and after 6 months - 140 ± 13.11 m=0.021 vs baseline). The findings of the immunohistochemical study confirmed the development of neoangiogenesis in the skeletal muscle and a 25 percent increase in the capillary-network density following administration of autologous stem cells into the muscle. The method of transplanting peripheral-blood autologous stem cells for treatment of patients presenting with distal forms of chronic obliterating insufficiency of the lower limbs proved safe and efficient. The findings obtained during this study made it possible to recommend extending the indications for its application at the expense of patients with critical ischaemia.