TTTCA repeat expansion causes familial cortical myoclonic tremor with epilepsy.

BACKGROUND AND PURPOSE: The aim was to investigate whether abnormal TTTTA and TTTCA repeat expansions in introns of SAMD12, TNRC6A and RAPGEF2 are involved in the pathogenesis of familial cortical myoclonic tremor with epilepsy (FCMTE). METHODS: Five families diagnosed with FCMTE were included in the current genetic analysis. Whole-exome sequencing was performed in selected patients of each family. TTTTA and TTTCA expansions were examined by repeat-primed polymerase chain reaction. The clinical features of FCMTE were elicited as defined by the common genetic mechanism of 14 patients. RESULTS: Abnormal TTTCA expansion was identified and co-segregated in all five FCMTE families, four inserted in SAMD12 and one in RAPGEF2. The insertion of expanded TTTCA was not found in 116 control alleles. TTTTA expansion in SAMD12 was detected in 90.9% (10/11) of patients or mutation carriers; TTTTA expansion in RAPGEF2 was not found. The onset age of myoclonic tremor was 27.4 ± 5.9 (19-37) and epilepsy usually presented around age 34. Focal and generalized seizures were witnessed with various origins recorded by electroencephalogram. Cognitive deficits were not common within the first 3 years after epilepsy onset. Emotional instability was reported by most patients. No patients showed any cerebellar deficits. Valproate added with clonazepam is effective in controlling seizures but cannot guarantee a complete remission of tremor. Repeat length showed intergenerational instability and was inversely correlated with age at onset of myoclonic tremor and epilepsy. CONCLUSIONS: TTTCA expansion insertion is associated with FCMTE in Chinese families. The homogenous genetic mechanism allowed for a higher precision of FCMTE description.

[Effects of human adipose-derived mesenchymal stem cells and platelet-rich plasma on healing of wounds with full-thickness skin defects in mice].

Objective: To investigate the effects of human adipose-derived mesenchymal stem cells (ADSCs) and platelet-rich plasma (PRP) on healing of wounds with full-thickness skin defects in mice. Methods: ADSCs were isolated from the lumbar and abdominal fat donated voluntarily by a healthy woman undergoing liposuction in the Department of Plastic Surgery of Guangzhou General Hospital of Guangzhou Military Area Command, and the cells were cultured and identified. ADSCs of the second passage were used in the following experiments. The venous blood of the volunteer was taken, and PRP was obtained by secondary centrifugation. Thirty-six C57BL/6 mice were divided into simple injury group (n=12), simple ADSCs treatment group (n=12), and ADSCs+ PRP treatment group (n=12) according to the random number table. Each mouse was inflicted with a 1 cm×1 cm wound with full-thickness skin defect on the back. Immediately after injury, the wounds of mice in simple injury group were subcutaneously injected with 1 mL normal saline, the wounds of mice in simple ADSCs treatment group were subcutaneously injected with 1 mL phosphate buffer solution-blended ADSCs suspension (with concentration of 5×10(5) /mL, the same below), and the wounds of mice in ADSCs+ PRP treatment group were subcutaneously injected with 1 mL mixture of PRP and ADSCs (1∶2 volume ratio). Three mice in each group were taken on post injury day (PID) 3, 5, 7, and 14 to observe the gross condition of wound, and the wound healing rate was calculated. On PID 3, 5, and 7, the non-healing wound tissue and 0.5 cm normal skin tissue around the wound margin were taken after gross observation. The inflammation, re-epithelialization, and angiogenesis of tissue were observed by hematoxylin and eosin staining, and the re-epithelialization rate was calculated. The collagen synthesis of tissue was observed by masson staining. Immunohistochemistry was used to observe the expression of macrophages of tissue samples collected on PID 3 and 5. Data were processed with analysis of variance of factorial design and Least-Significant Difference test. Results: (1) On PID 3, the wounds of mice in ADSCs+ PRP treatment group were with granulation tissue regeneration, redness, and swelling, and the wounds of mice in the other two groups were ruddy and with effusion. On PID 5, the wounds of mice in ADSCs+ PRP treatment group had less redness and swelling, which were dry with obvious scab, and wounds of mice in the other two groups were obviously red and swollen. On PID 7, scab formed basically on wounds of mice in the three groups. On PID 14, the wounds of mice in the three groups basically healed, and their crusts were off. On PID 3, 5, 7, and 14, the wound healing rates of mice in ADSCs+ PRP treatment group were obviously higher than those of the other two groups (P<0.05 or P<0.01). On PID 5 and 7, the wound healing rates of mice in simple ADSCs treatment group were obviously higher than those of simple injury group (P<0.01). (2) On PID 3, granulation tissue regeneration of wounds in ADSCs+ PRP treatment group was more than that in the other two groups. On PID 5, inflammatory reaction of wounds of mice was mild in ADSCs+ PRP treatment group, which was severe in the other two groups. On PID 7, the re-epithelialization process of wounds of mice was almost completed in ADSCs+ PRP treatment group, and the number of new vessels was more in ADSCs+ PRP treatment group than in the other two groups. The migration distance of regenerated epithelia around the wound edge in simple injury group and simple ADSCs treatment group was short. On PID 3, 5, and 7, the re-epithelialization rates of wounds of mice in ADSCs+ PRP treatment group were (37.6±4.5)%, (59.1±1.3)%, and (89.2±4.3)%, respectively, significantly higher than (25.7±1.5)%, (34.5±4.4)%, and (50.8±2.7)% in simple injury group and (29.1±0.8)%, (42.6±2.9)%, and (72.9±3.0)% in simple ADSCs treatment group (P<0.01). On PID 5 and 7, the re-epithelialization rates of wounds of mice in simple ADSCs treatment group were significantly higher than those in simple injury group (P<0.05 or P<0.01). (3) On PID 3 and 5, a quite large number of new collagen fibers appeared in granulation tissue of wounds of ADSCs+ PRP treatment group, while the collagen fibers in the other two groups were less. On PID 7, the granulation tissue of mice in ADSCs+ PRP treatment group decreased, and a large number of new collagen fibers appeared. The collagen fibers in wounds tissue of mice in simple ADSCs treatment group increased, while the collagen fibers deposited in wounds tissue of mice in simple injury group was still less. (4) On PID 3 and 5, the numbers of macrophages in wounds tissue of mice in simple ADSCs treatment group were 4.7±0.6 and 5.3±0.6 respectively, obviously lower than 6.3±0.6 and 7.7±0.6 in injury group (P<0.05 or P<0.01); the numbers of macrophages in wounds tissue of mice in ADSCs+ PRP treatment group were 3.0±1.1 and 2.7±0.5, significantly lower than those in the other two groups (P<0.05 or P<0.01). Conclusions: Human PRP and ADSCs are involved in the early inflammation, metaphase of tissue proliferation, and re-epithelialization and shaping process of late stage of wounds with full-thickness skin defects in mice. The combination of ADSCs and PRP may be a comparatively good combination to improve the speed and quality of wound healing.

Biomechanics of cell rolling: shear flow, cell-surface adhesion, and cell deformability.

The mechanics of leukocyte (white blood cell; WBC) deformation and adhesion to endothelial cells (EC) has been investigated using a novel in vitro side-view flow assay. HL-60 cell rolling adhesion to surface-immobilized P-selectin was used to model the WBC-EC adhesion process. Changes in flow shear stress, cell deformability, or substrate ligand strength resulted in significant changes in the characteristic adhesion binding time, cell-surface contact and cell rolling velocity. A 2-D model indicated that cell-substrate contact area under a high wall shear stress (20 dyn/cm2) could be nearly twice of that under a low stress (0.5 dyn/cm2) due to shear flow-induced cell deformation. An increase in contact area resulted in more energy dissipation to both adhesion bonds and viscous cytoplasm, whereas the fluid energy that inputs to a cell decreased due to a flattened cell shape. The model also predicted a plateau of WBC rolling velocity as flow shear stresses further increased. Both experimental and computational studies have described how WBC deformation influences the WBC-EC adhesion process in shear flow.