A minimal dose of electrically induced muscle activity regulates distinct gene signaling pathways in humans with spinal cord injury.

Paralysis after a spinal cord injury (SCI) induces physiological adaptations that compromise the musculoskeletal and metabolic systems. Unlike non-SCI individuals, people with spinal cord injury experience minimal muscle activity which compromises optimal glucose utilization and metabolic control. Acute or chronic muscle activity, induced through electrical stimulation, may regulate key genes that enhance oxidative metabolism in paralyzed muscle. We investigated the short and long term effects of electrically induced exercise on mRNA expression of human paralyzed muscle. We developed an exercise dose that activated the muscle for only 0.6% of the day. The short term effects were assessed 3 hours after a single dose of exercise, while the long term effects were assessed after training 5 days per week for at least one year (adherence 81%). We found a single dose of exercise regulated 117 biological pathways as compared to 35 pathways after one year of training. A single dose of electrical stimulation increased the mRNA expression of transcriptional, translational, and enzyme regulators of metabolism important to shift muscle toward an oxidative phenotype (PGC-1α, NR4A3, IFRD1, ABRA, PDK4). However, chronic training increased the mRNA expression of specific metabolic pathway genes (BRP44, BRP44L, SDHB, ACADVL), mitochondrial fission and fusion genes (MFF, MFN1, MFN2), and slow muscle fiber genes (MYH6, MYH7, MYL3, MYL2). These findings support that a dose of electrical stimulation (∼10 minutes/day) regulates metabolic gene signaling pathways in human paralyzed muscle. Regulating these pathways early after SCI may contribute to reducing diabetes in people with longstanding paralysis from SCI

Choriocapillaris Vascular Dropout Related to Density of Drusen in Human Eyes with Early Age-Related Macular Degeneration

Morphologic studies of human eyes reveal that vascular loss occurs early in the pathogenesis of AMD and is related to the cross-sectional area of drusen, supporting the concept that vascular changes may lead to drusen formation in AMD

A representative example of the phenotype for a trained and untrained human paralyzed muscle.

<p>(A) A representative example of the torque produced during the stimulation of a chronically paralyzed human soleus muscle, contractions 1, 15, 60, and 120 during the first bout of electrical stimulation are illustrated. (B) The ratio of muscle to adipose tissue from several MR images slices of the proximal shank and distal thigh after >7 years of unilateral soleus electrical stimulation training in subject 1. A representative MR Image slice of the trained and untrained lower leg before (C) and after (D) implementing the muscle and fat tissue segmentation algorithm. Immunofluorescence stain for collagen IV (green) in a chronically trained (E) and untrained (F) paralyzed muscle. Note the loss of collagen IV (green) in the chronically trained muscle. Immunofluorescence stain (green) for mitochondrial distribution in a trained (G) and untrained (H) paralyzed muscle.</p

Top 10 Repressed mRNA Gene Transcripts Following an Acute Dose of Electrical Muscle Stimulation.

a<p>mRNA expression levels reported as group mean ± standard deviation of fold-change relative to the control limb.</p><p>Top 10 Repressed mRNA Gene Transcripts Following an Acute Dose of Electrical Muscle Stimulation.</p

Top 10 Expressed mRNA Gene Transcripts Following an Acute Dose of Electrical Muscle Stimulation.

a<p>mRNA expression levels reported as group mean ± standard deviation of fold-change relative to the control limb.</p><p>Top 10 Expressed mRNA Gene Transcripts Following an Acute Dose of Electrical Muscle Stimulation.</p

Expression of transcription factor, fast-twitch fiber, and slow-twitch fiber genes following acute or chronic stimulation.

<p>PGC-1α was increased 3 hours after a dose of muscle stimulation (5.46±0.64, p<0.001) and after >1 year of muscle training (1.73±0.09, p<0.002) (A). NR4A3 was increased 3 hours after a dose of muscle stimulation (12.45±2.36, p<0.001), while it was decreased after >1 year of muscle training (0.79±0.06, p = 0.046) (B). ABRA was increased after a single dose of muscle stimulation (5.98±0.40, p<0.001), but was unchanged after >1 year of soleus training (0.66±0.18, p<0.16) (C). MSTN was decreased 3 hours after a dose of muscle stimulation (0.56±0.06, p = 0.002) and after >1 year of muscle training (0.33±0.03, p<0.001) (D). MYL5 (0.040±0.07, p = 0.013), MYL6 (0.84±0.038, p = 0.030), and ACTN3 (0.12±0.025, p = 0.003) were all decreased after >1 year of muscle training (E, F, and G). There was no difference detected 3 hours after a dose of muscle stimulation for MYL5 (1.09±0.083, p = 0.45). MYL6 (0.95±0.048, p = 0.32), and ACTN3 (0.99,0.095, p = 0.72) (E, F, and G). PVALB was increased after a single dose of muscle stimulation (1.47±0.22, p = 0.074), but was decreased after >1 year of muscle training (0.26±0.19, p = 0.047) (H). MYH6 (6.76±2.50, p = 0.030), MYH7 (11.69±4.93, p = 0.025), MYL2 (2.78±0.80, p = 0.063), and MYL3 (9.07±3.75, p = 0.046) were increased after >1 year of muscle training, while they were decreased 3 hours after single session of muscle stimulation (0.81±0.04, p = 0.0073, 0.77±0.073, p = 0.030, 0.92±0.036, p = 0.066, 0.76±0.078, p = 0.037; respectively) (I, J, K, and L). † indicates a p-value <0.05 for a within group paired t-test. ‡ indicates a p-value <0.10 for a within group paired t-test.</p

Top 10 Repressed mRNA Gene Transcripts Following Chronic Training of Electrical Muscle Stimulation.

a<p>mRNA expression levels reported as group mean ± standard deviation of fold-change relative to the control limb.</p><p>Top 10 Repressed mRNA Gene Transcripts Following Chronic Training of Electrical Muscle Stimulation.</p

Localization of complement 1 inhibitor (C1INH/SERPING1) in human eyes with age-related macular degeneration

Age-related macular degeneration (AMD) is a common degenerative disease resulting in injury to the retina, retinal pigment epithelium and choriocapillaris. Recent data from histopathology, animal models and genetic studies have implicated altered regulation of the complement system as a major factor in the incidence and progression of this disease. A variant in the gene SERPING1, which encodes C1INH, an inhibitor of the classical and lectin pathways of complement activation, was recently shown to be associated with AMD. In this study we sought to determine the localization of C1INH in human donor eyes. Immunofluorescence studies using a monoclonal antibody directed against C1INH revealed localization to photoreceptor cells, inner nuclear layer neurons, choriocapillaris, and choroidal extracellular matrix. Drusen did not exhibit labeling. Genotype at rs2511989 did not appear to affect C1INH abundance or localization, nor was it associated with significant molecular weight differences when evaluated by Western blot. In a small number of eyes (n = 7 AMD and n = 7 control) AMD affection status was correlated with increased abundance of choroidal C1INH. These results indicate that C1INH protein is present in the retina and choroid, where it may regulate complement activation