Pulling rank with RNA: RANKL promotes the association of PGC-1β/RNA complexes with NCoR/HDAC3 to activate gene expression in osteoclasts

In this issue, Abe et al1 report a novel mechanism by which RANKL stimulates osteoclast differentiation and bone resorption through non-coding RNAs that bind PGC-1β and convert the NCoR/HDAC3 co-repressor complex into a co-activator of AP-1- and NFκB-regulated genes.

12 The incidence, clinical features, and management of essential infantile esotropia in the United Kingdom. A British Ophthalmology Surveillance Unit (BOSU) study - Final Report

Studies from the UK have reported declining rates of surgery for childhood esotropia. It is not known if this equates to a reduced incidence of essential infantile esotropia (EIE). A national study was undertaken through the British ophthalmology surveillance unit (BOSU) to determine the incidence presenting features and management of EIE in the UKData from a prospective national observational cohort of newly diagnosed EIE presenting to clinicians in the United Kingdom over a 12-month period was collected. Cases with a confirmed diagnosis by a clinician of a constant, non-accommodative esotropia ≥ 20 prism dioptres (PD), presenting at ≤ 12months, with no neurological or ocular abnormalities were identified through BOSU. Follow up data was collected at 12 months. Data was collected on the age, gender, ethnicity, birth history, age at diagnosis, age at intervention, angle of esotropia, refraction, associated features of amblyopia, overelevation in adduction (OEIA), latent nystagmus and dissociated vertical deviation (DVD), method of management and outcomes.During the period of observation between October 2017 to October 2018 a total of 57 cases were reported giving an incidence of EIE of 1 in 12,828 live births with a corrected incidence of 1 in 9027 live births allowing for estimated under reporting. The mean age of diagnosis and intervention were 7.05± 2.6 months (range 2 to 12 months) and 14.7± 4.9 (range 6.5-28.1 months) respectively. The majority were Caucasians 86.5% and 52.7% were female. Management was surgical in 59.6%, and botulinum toxin alone in 22.8%, 17.5% were observed. There was no significant difference in the age of presentation (P=0.6), gender (P=0.8), prematurity (P=0.5), deprivation indices (P=0.68), refraction (P=0.7), OEIA (P=0.6), DVD (P=0.7) or follow up (P=0.3) between the three groups. The preoperative angle of esotropia was smaller in the observation group (P=0.04). The post-operative angle of esotropia was not statistically significant between botulinum toxin or surgery (P=0.3) though the age of intervention was earlier in the botulinum group (P=0.007). Early intervention did not influence the motor post intervention outcomes between 0-10 prism dioptres of esotropia (P=0.78). Amblyopia (P=0.02) and latent nystagmus (P=0.009) was more common in the observation group.The incidence of EIE in the UK is considerably lower than reported in other population-based studies. The preferred method of treatment was surgical with earlier intervention in those treated with botulinum toxin. An early age of intervention did not influence motor outcomes. Parental choice and amblyopia treatment were reasons cited for conservative management in the observational group.

Exercise training attenuates pulmonary inflammation and mitochondrial dysfunction in a mouse model of high-fat high-carbohydrate-induced NAFLD

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) can lead to pulmonary dysfunction that is associated with pulmonary inflammation. Moreover, little is known regarding the therapeutic role of exercise training on pulmonary pathophysiology in NAFLD. The present study aimed to investigate the effect of exercise training on high-fat high-carbohydrate (HFHC)-induced pulmonary dysfunction in C57BL/6 mice.

METHODS

Male C57BL/6 mice (N = 40) were fed a standard Chow (n = 20) or an HFHC (n = 20) diet for 15 weeks. After 8 weeks of dietary treatment, they were further assigned to 4 subgroups for the remaining 7 weeks: Chow (n = 10), Chow plus exercise (Chow+EX, n = 10), HFHC (n = 10), or HFHC plus exercise (HFHC+EX, n = 10). Both Chow+EX and HFHC+EX mice were subjected to treadmill running.

RESULTS

Chronic exposure to the HFHC diet resulted in obesity with hepatic steatosis, impaired glucose tolerance, and elevated liver enzymes. The HFHC significantly increased fibrotic area (p < 0.001), increased the mRNA expression of TNF-α (4.1-fold, p < 0.001), IL-1β (5.0-fold, p < 0.001), col1a1 (8.1-fold, p < 0.001), and Timp1 (6.0-fold, p < 0.001) in the lung tissue. In addition, the HFHC significantly altered mitochondrial function (p < 0.05) along with decreased Mfn1 protein levels (1.8-fold, p < 0.01) and increased Fis1 protein levels (1.9-fold, p < 0.001). However, aerobic exercise training significantly attenuated these pathophysiologies in the lungs in terms of ameliorating inflammatory and fibrogenic effects by enhancing mitochondrial function in lung tissue (p < 0.001).

CONCLUSIONS

The current findings suggest that exercise training has a beneficial effect against pulmonary abnormalities in HFHC-induced NAFLD through improved mitochondrial function.

Protective Effects of Extra Virgin Olive Oil and Exercise Training on Rat Skeletal Muscle against High-fat Diet Feeding

A diet high in saturated fat leads to skeletal muscle deteriorations including insulin resistance, mitochondrial dysfunction and muscle fiber atrophy. Consumption of long-chain polyunsaturated fatty acids and exercise have shown promise in ameliorating high-fat diet (HFD)-induced oxidative stress and inflammation. However, the impact of extra virgin olive oil (EVOO) on mitochondrial homeostasis in muscle is largely unknown. This study aimed to investigate whether 12 weeks of EVOO feeding alone and in conjunction with endurance training could protect against metabolic and mitochondrial dysfunction rat muscle with HFD. Female Sprague-Dawley rats were divided into 4 groups fed a control diet (C), HFD, EVOO diet, and EVOO diet with training (EVOO+T). Mitochondrial enzyme activity and protein content decreased with HFD compared to C, but were restored with EVOO and EVOO+T. EVOO+T elevated muscle cytochrome c and PGC-1α levels. HFD increased muscle proteolytic markers and protein ubiquitination, whereas these effects were not seen in EVOO and EVOO+T. HFD suppressed mitochondrial fusion protein level while increasing fission protein levels, but were restored with EVOO and EVOO+T. Mitophagy marker PINK1 content decreased with HFD, but was unchanged in EVOO and EVOO+T. EVOO+T upregulated autophagy markers, along with decreased phosphorylated/dephosphorylated FoxO3 ratio. Antioxidants enzyme levels were upregulated by EVOO and EVOO+T, and EVOO+T reduced HFD-induced lipid peroxidation. In conclusion, HFD impaired muscle oxidative capacity, promoted protein ubiquitination and mitochondrial fission, and upregulated autophagy markers. Replacement of HFD with EVOO corrected the observed adverse effects, while exercise training in conjunction with EVOO provided additional protection to the muscle.

Echocardiographic global longitudinal strain as a marker of myocardial fibrosis predicts outcomes in aortic stenosis

Background

Left ventricular global longitudinal strain (LV-GLS) by speckle tracking echocardiography (STE) reflects intrinsic myocardial function, influenced by interstitial abnormalities. Cardiovascular magnetic resonance (CMR) detects myocardial fibrosis non-invasively, but it is limited for widespread use. We aim to establish LV-GLS as a marker of replacement myocardial fibrosis on CMR and validate the prognostic value of LV-GLS thresholds associated with fibrosis.

Methods

LV-GLS thresholds of replacement fibrosis were established in the derivation cohort: 151 patients (57±10 years; 58% males) with hypertension who underwent STE to measure LV-GLS and CMR for replacement myocardial fibrosis. Prognostic value of the thresholds was validated in a separate outcome cohort: 261 patients with moderate-severe aortic stenosis (AS; 71±12 years; 58% males; NYHA functional class I-II) and preserved LVEF ≥50%. Primary outcome was a composite of cardiovascular mortality, heart failure hospitalization, myocardial infarction and cerebrovascular events.

Results

In the derivation cohort, LV-GLS demonstrated good discrimination (c-statistics 0.74; 95% confidence interval: 0.66–0.83; P<0.001) and calibration (Hosmer-Lemeshow X2=6.37; P=0.605) for replacement fibrosis. In the outcome cohort, 52 events occurred over 16 [3.1, 42.0] months of follow-up. Patients with LV-GLS >−15.0% (corresponding to 95% specificity to rule-in myocardial fibrosis) had the worst outcomes compared to patients with LV-GLS <−21.0% (corresponding to 95% sensitivity to rule-out myocardial fibrosis) and those between −21.0 and −15.0% (log-rank P<0.001; Figure 1). Furthermore, LV-GLS offered independent prognostic value over clinical variables, AS severity, echocardiographic LVEF and E/e' (hazard ratio 1.18; 95% confidence interval: 1.07 to 1.30; P=0.001).

Conclusions

LV-GLS thresholds associated with replacement myocardial fibrosis is a novel approach to risk-stratify patients with AS and preserved LVEF (Figure 2).

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Medical Research Council Figure 1Figure 2

The impact of impulsivity on weight loss after bariatric surgery: a systematic review

BACKGROUND

Impulsivity has been shown to be associated with obesity through links to pathological eating behavior such as binge eating. The recent literature suggests that impulsivity is linked to poorer outcomes post-bariatric surgery. Impulsivity can be measured in various ways and comprises of three broad domains: impulsive choice, impulsive action, and impulsive personality traits. The aim of this systematic review is to synthesize the current evidence on the impact of impulsivity on post-bariatric surgery weight loss.

METHODS

A literature review was performed in February 2020. Original studies investigating the relationship between impulsivity and weight loss post-bariatric surgery were evaluated.

RESULTS

Ten studies with a total of 1246 patients were analyzed. There were four case-control, four prospective observational and two retrospective observational studies. The postoperative follow-up ranged from 0.5 to 12 years. Eight studies measuring trait impulsivity did not show any association with weight loss post-bariatric surgery, although two studies reported an indirect effect of impulsivity on weight loss mediated via pathological eating behavior. Assessment of impulsive action by two studies showed that post-bariatric surgery weight loss is affected by impulsive action.

CONCLUSION

Impulsivity may adversely affect postoperative outcomes after bariatric surgery. However, this may be specific to state impulsivity or impulsive action rather than trait impulsivity. Patients with a higher state impulsivity may benefit from closer follow-up post-bariatric surgery, as well as cognitive behavioral therapies targeting cognitive control over food.

LEVEL OF EVIDENCE

Level I, systematic review.

Oxidative stress: an evolving definition

Thirty-five years ago, Sies and colleagues insightfully described the universal phenomenon that the generation of reactive oxygen species could modify macromolecules in living organisms, resulting in a wide range of measurable damage. They used the term "oxidative stress" to define the loss of the balance between oxidants and antioxidants in favor of the former. After decades of research, it became increasingly clear that cells are not simply passive receivers of oxidative modification but can act dynamically to resist and adapt to oxidants. Furthermore, many redox-sensitive pathways have been identified wherein certain oxidants (mainly hydrogen peroxide and nitric oxide) are used as messenger molecules to transduce the signals required for these adaptations. Since the turn of the century, redox signaling has developed into a vibrant multidisciplinary field of biology. To reflect the evolution of the study in this field, the definition of oxidative stress is postulated to define a state in which the pro-oxidative processes overwhelm cellular antioxidant defense due to the disruption of redox signaling and adaptation.

The role of mitochondria in redox signaling of muscle homeostasis

In the past, contraction-induced production of reactive oxygen species (ROS) has been implicated in oxidative stress to skeletal muscle. As research advances, clear evidence has revealed a more complete role of ROS under both physiologic and pathologic conditions. Central to the role of ROS is the redox signaling pathways that control exercise-induced major physiologic and cellular responses and adaptations, such as mitochondrial biogenesis, mitophagy, mitochondrial morphologic dynamics, antioxidant defense, and inflammation. The current review focuses on how muscle contraction and immobilization may activate or inhibit redox signalings and their impact on muscle mitochondrial homeostasis and physiologic implications.

Aging alters acetylation status in skeletal and cardiac muscles

During aging, organs such as skeletal muscle and heart require sufficient NAD+ both as a coenzyme for oxidative-reductive electron transfer and as a substrate for multiple signaling pathways. Sirtuins (SIRTs), a family of NAD+-dependent deacetylase, play an important role in regulating mitochondrial homeostasis and antioxidant defense by deacetylating transcription factors and enzymes such as PGC-1α, p65, GCN5, and SOD2. However, age-related DNA damage and increased SASP activate PARP-1 and CD38, the enzymes competing with SIRTs for NAD+. Thus, it is important to know how aging alters intracellular NAD+ status and NAD+-depending enzyme expression in muscles. In this study, we report that the acetylation level of muscle protein pool, as well as major SIRTs target proteins (PGC-1α, GCN5, p65, and SOD2), was significantly increased in hindlimb and cardiac muscles of 24-month old mice compared with their 6-month old counterparts, despite the fact that most members of the SIRT family were upregulated with aging. Aging increased the protein content of PARP-1 and CD38, whereas decreased NAD+ levels in both skeletal and heart muscles. Aged muscles demonstrated clear signs of mitochondrial dysfunction, oxidative stress, and inflammation. Taken together, our data suggest that despite the upregulation of SIRTs, aged muscles suffered from NAD+ deficit partly due to the competition of elevated CD38 and PARP-1. The enhanced acetylation of several key proteins involved in broad cellular functions may contribute to the age-related muscle deterioration.

Muscle Disuse Atrophy Caused by Discord of Intracellular Signaling

Significance: Regular contractile activity plays a critical role in maintaining skeletal muscle morphological integrity and physiological function. If the muscle is forced to stop contraction, such as during limb immobilization (IM), the IGF/Akt/mTOR signaling pathway that normally stimulates protein synthesis and inhibits proteolysis will be suppressed, whereas the FoxO-controlled catabolic pathways such as ubiquitin-proteolysis and autophagy/mitophagy will be activated and dominate, resulting in muscle fiber atrophy. Recent Advances: Mitochondria occupy a central position in the regulation of both protein synthesis and degradation through several redox-sensitive pathways, including peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), mitochondrial fusion and fission proteins, mitophagy, and sirtuins. Prolonged IM downregulates PGC-1α due to AMPK (5'-AMP-activated protein kinase) and FoxO activation, thus decreasing mitochondrial biogenesis and causing oxidative damage. Decrease of mitochondrial inner membrane potential and increase of mitochondrial fission can trigger cascades of mitophagy leading to loss of mitochondrial homeostasis (mitostasis), inflammation, and apoptosis. The phenotypic outcomes of these disorders are compromised muscle function and fiber atrophy. Critical Issues: Given the molecular mechanism of the pathogenesis, it is imperative that the integrity of intracellular signaling be restored to prevent the deterioration. So far, overexpression of PGC-1α via transgene and in vivo DNA transfection has been found to be effective in ameliorating mitostasis and reduces IM-induced muscle atrophy. Nutritional supplementation of select amino acids and phytochemicals also provides mechanistic and practical insights into the prevention of muscle disuse atrophy. Future Directions: In light of the importance of mitochondria in regulating the various critical signaling pathways, future work should focus on exploring new epigenetic strategies to restore mitostasis and redox balance.

Would a right shift of the oxy-hemoglobin dissociation curve improve exercise capacity in patients with heart failure?

Exercise intolerance is a hallmark of symptoms in patients with heart failure. In addition to reduced cardiac output, a series of impairments in pulmonary and vascular systems leads to decreases in oxygen delivery and availability in locomotor muscles. This contributes to exercise intolerance in heart failure. The oxy-hemoglobin dissociation curve is essentially a graph illustrating the relationship between the partial pressure of oxygen (PO₂, X-axis) and oxygen saturation (SaO₂, Y-axis) of hemoglobin. The rightward shift of the curve indicates that hemoglobin's affinity for oxygen decreases and in turn, it may allow the release of more oxygen to tissues. In the present study, we discuss the pathophysiological impairment, which causes exercise intolerance in heart failure patients and suggest a strategy to improve exercise capacity without altering cardiac output via modulating the oxy-hemoglobin dissociation curve.

Cellular mechanism of immobilization-induced muscle atrophy: A mini review

It is well-established that regular contraction maintains morphological and functional integrity of skeletal muscle, whereas rigorous exercise training can upregulate muscle metabolic and contractile function. However, when muscles stop contraction, such as during immobilization (IM) and denervation, withdrawal of IGF/Akt/mTOR signaling allows FoxO-controlled protein degradation pathways to dominate. Mitochondria play an important role in regulating both protein synthesis and degradation via several redox sensitive signaling pathways such as mitochondrial biogenesis, fusion and fission dynamics, ubiquitin-proteolysis, autophagy/mitophagy, and apoptosis. During prolonged IM, downregulation of PGC-1α and increased mitochondrial oxidative damage facilitate fission protein and inflammatory cytokine production and activate mitophagic process, leading to a vicious cycle of protein degradation. This “mitostasis theory of muscle atrophy” is the opposite pathway of hormesis, which defines enhanced muscle function with contractile overload. The demonstration that PGC-1α overexpression via transgene or in vivo DNA transfection can successfully restore mitochondrial homeostasis and reverse myocyte atrophy supports such a proposition. Understanding the mechanism governing mitostasis can be instrumental to the treatment of muscle atrophy associated with bedrest, cancer cachexia and sarcopenia.

Mitochondrial dysregulation and muscle disuse atrophy

It is well established that mitochondria play a critical role in the metabolic and physiological adaptation of skeletal muscle to enhanced contractile activity. Several redox-sensitive signaling pathways such as PGC-1α, AMPK, IGF/Akt/mTOR, SIRT, NFκB, and FoxO are involved with extensive crosstalk to regulate vital cellular functions such as mitochondrial biogenesis, mitochondrial fusion and fission dynamics, autophagy/mitophagy, and apoptosis under altered demand and stress. However, when muscles cease contraction, such as during immobilization and denervation, mitochondria undergo a series of detrimental changes characterized by downregulation of PGC-1α and antioxidant defense, increased ROS generation, activated FoxO, NFκB, and inflammation, enhanced ubiquitination, and finally mitophagy and apoptotic cascades. The phenotypic outcome of the discord of mitochondrial homeostasis is elevated proteolysis and muscle atrophy. The demonstration that PGC-1α overexpression via transgene or in vivo DNA transfection can restore mitochondrial homeostasis and reverse myocyte atrophy supports the "mitostasis theory of muscle atrophy".

The impact of pulsed electromagnetic field therapy on blood pressure and circulating nitric oxide levels: a double blind, randomized study in subjects with metabolic syndrome

Purpose: Regulation of blood pressure (BP) is important in reducing the risk for cardiovascular disease. There is growing interest in non-pharmacological methods to treat BP including a novel approach using pulsed electromagnetic field therapy (PEMF). PEMF therapy has been proposed to impact physiological function at the cellular and tissue level and one possible mechanism is through an impact on endothelial function and nitric oxide (NO) related pathways. The focus of the present study was to evaluate the effect of PEMF on BP and NO in subjects with mild to moderate metabolic syndrome.Materials and methods: For 12 weeks, 23 subjects underwent PEMF therapy and 21 subjects underwent sham therapy. BP was measured at rest and near the end of submaximal exercise pre- and 12 week post-therapy. Additionally, plasma NO was measured at similar time points.Results: The PEMF demonstrated an increase in NO after therapy (p = .04) but SHAM did not (p = .37). For resting BP, there were no differences in systolic BP (SBP), diastolic BP (DBP) or mean arterial pressure (MAP) between groups (p > .05). During exercise, PEMF had a reduction in peak SBP (p = .04), but not SHAM (p = .57). PEMF demonstrated significant relationships between baseline SBP and change in SBP following therapy (r = -0.71, p < .01) and between MAP and change in MAP following therapy (r = -0.60, p < .01), but no such relationships were found in SHAM. Subjects with resting hypertension (SBP ≥140 mmHg) in PEMF (n = 11) had significant reductions in SBP, DBP and MAP when compared to SHAM with hypertension (n = 9) (p < .05). In this sub-group analysis, PEMF demonstrated lowered peak SBP (p = .04) at a given exercise load (p = .40) but SHAM did not (p > .05).Conclusion: PEMF may increase plasma NO availability and improve BP at rest and during exercise. However, this beneficial effect appears to be more pronounced in subjects with existing hypertension.

Avenanthramides attenuate inflammation and atrophy in muscle cells

BACKGROUND

Chronic inflammation is an important etiologic mechanism for muscle atrophy. Oat-derived phytochemical avenanthramides (AVAs) have been shown to suppress inflammatory responses in human clinical studies and in several cell lines in vitro, but their role in skeletal muscle is unclear. The aim of this study was to investigate whether AVA treatment can prevent tumor necrosis factor (TNF)-α-induced muscle fiber atrophy in C2C12 cells.

METHODS

We treated 70% confluent cells for 24 h with AVA. Then, TNF-α was added to cell-cultured medium. Subsequently, cells were harvested at different time points. The cells were examined using various biochemical techniques for measuring protein, messenger RNA levels, nuclear binding activity, and viability. Fluorescence microscope was used for analysis of the myotube morphology.

RESULTS

Cells treated with TNF-α significantly increased nuclear factor κB activation, indicated by a marked decrease of IκB (p < 0.05) and a 6.6-fold increase in p65-DNA binding (p < 0.01); however, 30 μmol of AVA-A, -B, and -C treatment reduced the binding by 33%, 18%, and 19% (p < 0.01), respectively, compared with cells treated with TNF-α without AVA. The interleukin-6 level increased by 2.5 fold (p < 0.01) with TNF-α, but decreased by 24%, 32%, and 28% (p < 0.01), respectively, with AVA-A, -B, and -C. The interleukin-1β level also showed a 47% increase with TNF-α (p < 0.01), whereas this increment was abolished in all AVA-treated cells. Reactive oxygen species production was 1.3-fold higher in the TNF-α-treated group (p < 0.01) but not in the TNF-α + AVAs groups. Messenger RNA levels of muscle-specific E3 ubiquitin ligase atrogin-1 increased 23% in TNF-α vs. control (p < 0.05) but was decreased by 46%, 34%, and 53% (p < 0.01), respectively, with treatment of AVA-A, -B, and -C. Moreover, TNF-α treatment increased the muscle RING finger 1 messenger RNA level by 76% (p < 0.01); this change was abolished by AVAs. Cells treated with TNF-α demonstrated a reduced proliferation compared with control cells (p < 0.01), but this effect was not seen in TNF-α + AVAs cells. The diameter of the C2C12 myotube decreased by 28% (p < 0.01) with TNF-α, whereas it showed no change when AVAs were included in the cell media.

CONCLUSION

These results indicated that AVAs can reduce proinflammatory cytokine and reactive oxygen species production and ameliorate TNF-α-induced myotube atrophy in muscle cells.

A Deep Learning-Based Approach to Reduce Rescan and Recall Rates in Clinical MRI Examinations

BACKGROUND AND PURPOSE

MR imaging rescans and recalls can create large hospital revenue loss. The purpose of this study was to develop a fast, automated method for assessing rescan need in motion-corrupted brain series.

MATERIALS AND METHODS

A deep learning-based approach was developed, outputting a probability for a series to be clinically useful. Comparison of this per-series probability with a threshold, which can depend on scan indication and reading radiologist, determines whether a series needs to be rescanned. The deep learning classification performance was compared with that of 4 technologists and 5 radiologists in 49 test series with low and moderate motion artifacts. These series were assumed to be scanned for 2 scan indications: screening for multiple sclerosis and stroke.

RESULTS

The image-quality rating was found to be scan indication- and reading radiologist-dependent. Of the 49 test datasets, technologists created a mean ratio of rescans/recalls of (4.7 ± 5.1)/(9.5 ± 6.8) for MS and (8.6 ± 7.7)/(1.6 ± 1.9) for stroke. With thresholds adapted for scan indication and reading radiologist, deep learning created a rescan/recall ratio of (7.3 ± 2.2)/(3.2 ± 2.5) for MS, and (3.6 ± 1.5)/(2.8 ± 1.6) for stroke. Due to the large variability in the technologists' assessments, it was only the decrease in the recall rate for MS, for which the deep learning algorithm was trained, that was statistically significant (P = .03).

CONCLUSIONS

Fast, automated deep learning-based image-quality rating can decrease rescan and recall rates, while rendering them technologist-independent. It was estimated that decreasing rescans and recalls from the technologists' values to the values of deep learning could save hospitals $24,000/scanner/year.

PGC-1α Overexpression via Local In Vivo Transfection in Mouse Skeletal Muscle

The overexpression of a specific protein is a common method for investigating the specific biological function of the substance and the mechanism of action. In vivo electrotransfer has been confirmed to be one of the most reliable, efficient and cost-effective way to overexpress a protein in a select biological tissue. Typically, this technique involves a physical injection of plasmid DNA followed by electric pulses across the injection site. Here, we introduce this method that we used to transfect green fluorescent protein (GFP)-tagged PGC-1α plasmid DNA into mouse tibialis anterior (TA) muscle, which attained high transfection efficiency with no muscle damage. To quantify the transfection efficiency, we also demonstrate the visualization of plasmid DNA transfected fibers via immunohistochemical staining on muscle cross sections.

Intensified mitophagy in skeletal muscle with aging is downregulated by PGC-1alpha overexpression in vivo

Mitochondrial dysfunction plays an important role in the etiology of age-related muscle atrophy known as sarcopenia. PGC-1α is positioned at the center of crosstalk in regulating mitochondrial quality control, but its role in mitophagy in aged skeletal muscle is currently unclear. The present study investigated the effects of aging and PGC-1α overexpression via in vivo DNA transfection on key mitophagy protein markers, as well as mitochondrial dynamics related proteins, metabolic function and antioxidant capacity in mouse muscle. C57BL/6J mice at the age of 2 mo (young, Y; N = 14) and 24 mo (old, O; N = 14) were transfected in vivo with either PGC-1α DNA (OE, N = 7) or GFP (N = 7) into the tibialis anterior (TA) muscle followed by electroporation. PINK1 and Parkin protein contents were 3.6 and 1.4-fold higher (P < 0.01), whereas mitochondrial ubiquitination (Ub) increased 1.5-fold (P < 0.05), in O vs. Y mice. PGC-1 OE suppressed PINK and Parkin protein levels by 50-60% (P < 0.01), and decreased Ub by 20% (P < 0.05) in old mice. Aging significantly increased the protein content of LC3II (30%, P < 0.05), p62 (42%, P < 0.05), RheB (5.5-fold, P < 0.01), Beclin-1 (3-fold, P < 0.01) and Mfn2 (~4-fold, P < 0.01) in the TA muscle. However, these age-related increases in mitophagy markers were attenuated by PGC-1α OE. Furthermore, aging dramatically increased Fis-1 protein content by 14-fold (P < 0.01), along with a severe reduction of citrate synthase activity (64%, P < 0.01) and cytochrome c oxidase subunit IV (COXIV) protein content (85%, P < 0.01). PGC-1α OE mitigated the age effects on Fis-1 and Drp-1 (P < 0.05). Moreover, PGC-1α OE enhanced mitochondrial oxidative function and antioxidant enzyme activities, and decreased lipid peroxidation and inner membrane damage found in old mice (P < 0.01). In summary, our data demonstrate that mitophagy protein expression in skeletal muscle was enhanced at old age driven possibly by increased mitochondrial dysfunction, damage, and fission. PGC-1α OE was effective in ameliorating mitochondrial deficits but did not restore muscle fiber atrophy.

Data on in vivo PGC-1alpha overexpression model via local transfection in aged mouse muscle

The data presented in this article are related to the research paper entitled "Intensified mitophagy in skeletal muscle with aging is downregulated by PGC-1alpha overexpression in vivo" (Yeo et al., 2019). The data explained the surgical procedure of in vivo local transfection by electroporation method in aged mouse tibialis anterior muscle, and plasmid DNA preparation and verification protocol. The data also showed the transfection efficiency levels of GFP or GFP-tagged PGC-1alpha through immunohistochemistry method for frozen muscle cross-sections.

Anti-inflammatory effect of avenanthramides via NF-κB pathways in C2C12 skeletal muscle cells

Avenanthramides (Avns), the polyphenol compounds found only in oats, have been shown to exhibit anti-inflammatory effects mainly by inhibiting nuclear factor (NF)-κB activation in select cell lines. However, the molecular mechanism by which Avns regulate the NF-κB pathway is still unclear. The purpose of this study was to investigate (1) the molecular mechanism by which three main fractions of Avns (AvnA, AvnB and AvnC) interact with IκB Kinase β (IKKβ); and (2) whether this interaction results in reduced inflammatory responses in skeletal muscle cells. The protein-ligand docking and molecular dynamics simulation studies suggest that Avns acted as an allosteric inhibitor for modulating IKKβ's affinity for the NF-κB complex. Thus, Avns reduced IKKβ kinase activity in response to tert-butyl hydroperoxide (tBHP) stimulation and attenuated tBHP-induced TNFα and IL-1β mRNA expression. Furthermore, the three-fold increases in cyclooxygenase-2 (COX-2) protein and luciferase activity with tBHP treatment were reduced by 50% with Avns (P < .01), along with decreased prostaglandin E2 levels (P < .01). These data indicate that Avns are potent inhibitors of NFκB-mediated inflammatory response due to the downregulation of IKKβ activity in C2C12 cells.

The Rey Figure Copy as a Screening Instrument for Perceptual Deficits after Stroke

The aim of the study was to investigate the use of the Rey figure for screening patients for perceptual impairment following stroke. Stroke patients in a trial of a stroke unit were assessed using the Rey figure copy at entry to the study. Those admitted to the stroke unit were also assessed on the Rivermead Perceptual Assessment Battery (RPAB). In 61 patients assessed consecutively on both tests, using conventional clinical cut-off points the Rey figure copy was impaired in 31 out of 32 patients who were impaired on the RPAB. Fifteen patients who failed the Rey figure did not have perceptual problems on the RPAB, indicating that deficits on the Rey figure are not only due to perceptual problems. A receiver operating characteristic curve was plotted to compare different cut-off points. The Rey figure may be used as a brief screening assessment for perceptual deficits following stroke.

Muscle immobilization activates mitophagy and disrupts mitochondrial dynamics in mice

AIM

Skeletal muscle atrophy following prolonged immobilization (IM) is a catabolic state characterized by increased proteolysis and functional deterioration. Previous research indicates that discord of mitochondrial homoeostasis plays a critical role in muscle atrophy. We hypothesized that muscle IM would activate the ubiquitin-proteolysis, autophagy-lysosome (mitophagy) pathway, mitochondrial dynamics remodelling and apoptosis partially controlled by the FoxO signalling pathway.

METHODS

Female FVB/N mice were randomly divided into five groups (n = 8 each): control (CON), IM with banding of one of the hindlimbs for 1, 2 and 3 weeks (1w-, 2w- and 3w-IM) and 2w-IM followed by 1 week of remobilization (RM).

RESULTS

Mitochondrial density and DNA copies in tibialis anterior (TA) muscle were reduced by approx. 80% (P < 0.05 for 2w-IM; P < 0.01 for 3w-IM), along with activation of FoxO3a, atrogin-1 and MuRF1 following 2w- and 3w-IM (P < 0.01). Protein markers of autophagy/mitophagy, such as beclin 1 (approx. 2.7-fold; P < 0.01), LC3, ubiquitin-binding adaptor (approx. 1.47-fold; P < 0.01), Rheb (approx. 1.9-fold; P < 0.05) and parkin (approx. 70%; P < 0.05), were all increased by IM and remained activated after RM, whereas BNIP3 and PINK1 levels were decreased by IM (P < 0.05), but elevated upon RM (P < 0.01). IM decreased Mfn2 expression (approx. 50%; P < 0.01) and increased Fis-1 expression (approx. 2.4-fold; P < 0.05). Muscle apoptosis indicator Bax/Bcl2 ratio was elevated at 2w- to 3w-IM (approx. 3.7-fold; P < 0.01), whereas caspase-3 activity was five- to sixfold higher (P < 0.01) and remained threefold higher above CON (P < 0.05).

CONCLUSION

Our data indicate that IM-induced mitochondrial deterioration is associated with altered protein expressions in the autophagic/mitophagic pathway, more fragmented mitochondrial network and activation of apoptosis partly under the influence of FoxO3 activation.

Perovskite BiFeO3 thin film photocathode performance with visible light activity

Perovskite materials are now an important class of materials in the application areas of photovoltaics and photocatalysis. Inorganic perovskites such as BiFeO3 (BFO) are promising photocatalyst materials with visible light activity and inherent stability. Here we report the large area sol-gel synthesis of BFO films for solar stimulated water photo oxidation. By modifying the sol-gel synthesis process we have produced a perovskite material that has p-type behaviour and a flat band potential of ∼1.15 V (versus NHE). The photocathode produces a density of -0.004 mA cm(-2) at 0 V versus NHE under AM1.5 G illumination. We further show that 0.6 μmol h(-1) of O2 was produced at an external bias of -0.5 V versus Ag/AgCl. The addition of a non-percolating conducting network of Ag increases the photocurrent to -0.07 mA cm(-2) at 0 V versus NHE (at 2% Ag loading) with an increase to 2.7 μmol h(-1) for O2 production. We attribute the enhancement in photoelectrochemical performance to increased light absorption due light scattering by the incorporated Ag particles, improved charge transfer kinetics at the Ag/BFO interface and reduced over potential losses. We support these claims by an observed shift in flat band and onset potentials after Ag modification through UV-vis spectroscopy, Mott-Schottky plots and j-v curve analysis.

Barthel ADL Index: a comparison of administration methods

The Barthel ADL Index is routinely used to assess elderly patients after discharge from hospital. Its inter-rater reliability and criterion validity have been well established. However, the inter-method reliability in administering this scale has not been sufficiently documentated. This study compares post, telephone and interview (visit) methods of administration to investigate their agreement. The index was administered by the three methods in random order after patients were discharged from acute geriatric wards. Results suggest that these three methods are reliable and agree well with each other in the total scores obtained. Analyses of individual item scores indicate poor agreement on one item (stairs). Suggestions on improving the guidelines for this item are outlined.

Clinical associations of anosognosia in mild cognitive impairment and Alzheimer's disease

AIMS AND OBJECTIVE

While loss of insight of cognitive deficits is a common phenomenon in patients with Alzheimer's disease (AD), there is a lack of consensus regarding the presence of impaired insight among patients with mild cognitive impairment (MCI). We aim to investigate the clinical, cognitive, and behavioral associations of anosognosia in AD and MCI subjects.

METHODS

A consecutive series of 87 subjects (30 healthy older patients, 21 MCI, and 36 AD) each accompanied by a caregiver, underwent clinical assessment including the evaluation of insight using the Anosognosia Questionnaire for Dementia (AQD). We also separately assessed Intellectual Function (AQD-IF) and Behavior domains of the AQD scale. Regression models were subsequently used to investigate associations of AQD scores with cognitive and other neuropsychiatric symptoms, including depression and apathy.

RESULTS

Both AD and MCI groups demonstrated significant anosognosia compared with the healthy control group. In the AD group, 55.6% had "Mild Anosognosia," and 27.8% had "Severe Anosognosia." In the MCI group, 42.9% showed "Mild Anosognosia," and 9.5% had "Severe Anosognosia." Greater levels of AQD-Total and AQD-IF were associated with lower Mini-mental state examination and higher apathy scores in the AD group. In the MCI group, caregiver burden was significantly associated with AQD-Total (p = 0.016) and AQD-IF (p = 0.039).

CONCLUSION

The results indicated that anosognosia is common in both AD and MCI patients and associated with cognitive dysfunction and apathy in AD. The findings of this study warrant further research to delineate the mechanisms of anosognosia as it poses a challenge to treatment outcomes.