ABSTRACT
Background@#Sarcopenia is commonly found in the elderly due to a decline in muscle mass.Many researchers have performed genome-wide association studies (GWAS) to find genetic risk factors of sarcopenia. Although many studies have discovered sarcopenia associated single nucleotide polymorphisms (SNPs), most of them are studies targeting Caucasians. The purpose of this study was to evaluate genetic correlation according to muscle mass in middle aged Koreans using data of the Korean Genome and Epidemiology Study (KOGES), a large population-based genomic cohort study. @*Methods@#Baseline participants were 10,030 subjects aged 40 to 69 years who were from Ansan or Anseong in Gyeonggi-do, South Korea. Among them, 9,351 subjects with laboratory data available were included in this study. To identify sarcopenia associated variants, those in the top 30% and bottom 30% of muscle mass index (MMI) were compared. A total of 7,452 people with an MMI of 30-70% were excluded. A total of 1,004 people were also excluded due to missing data. Finally, 895 people were selected for this study. The Korea Biobank Array generated 500,568 SNPs for this dataset. @*Results@#When subjects were divided into top 30% and bottom 30% of MMI, the top 30% had 169 men and 308 women and the bottom 30% had 220 men and 198 women. In men, age, body mass index (BMI), waist and hip were significantly (P < 0.005) different between top 30% and bottom 30% MMI groups. In women, age, BMI, waist, hip, and hypertension history were significantly different between the two MMI groups. There were 13 significant SNPs in men and 14 significant SNPs in women. Genes associated with variants in men based on the single-nucleotide polymorphism database (dbSNP) were LRP1B containing rs11679458 and RGS6 containing rs11848300. A gene associated with variants in women was Pi4K2A, which contained rs1189312 as a variant. In addition, rs11189312 was associated with expression quantitative trait loci (eQTL) of ZFYVE27 in skeletal muscles and other SNPs of ZFYVE27 (rs10882883, rs17108378, rs35077384) known to be associated with spastic paraplegia. The eQTL analysis revealed that rs11189312 was a variant associated with SNPs of ZFYVE27. @*Conclusions@#In the demographic study, significant results were found in BMI, waist, hip, history of hyperlipidemia, and sedentary life status in male group, and significant results were found in BMI, waist, hip, and hypertension history in female group. Variant rs11189312 was found to be a novel variant affecting ZFYVE27 expressed in skeletal muscles, suggesting that rs11189312 might be related to sarcopenia as a novel discovery of this study. Further study is needed to determine the association between sarcopenia and ZFYVE27 known to be associated with spastic paraplegia.
ABSTRACT
Semisulcospira libertina, a species of freshwater snail, is widespread in East Asia. It is important as a food source. Additionally, it is a vector of clonorchiasis, paragonimiasis, metagonimiasis, and other parasites. Although S. libertina has ecological, commercial, and clinical importance, its whole-genome has not been reported yet. Here, we revealed the genome of S. libertina through de novo assembly. We assembled the whole-genome of S. libertina and determined its transcriptome for the first time using Illumina NovaSeq 6000 platform. According to the k-mer analysis, the genome size of S. libertina was estimated to be 3.04 Gb. Using RepeatMasker, a total of 53.68% of repeats were identified in the genome assembly. Genome data of S. libertina reported in this study will be useful for identification and conservation of S. libertina in East Asia.
ABSTRACT
Sarcopenia leads to loss of skeletal muscle mass, quality, and strength due to aging; it was recently given a disease code (International Classification of Diseases, Tenth Revision, Clinical Modification, M62.84). As a result, in recent years, sarcopenia-related research has increased. In addition, various studies seeking to prevent and treat sarcopenia by identifying the various mechanisms related to the reduction of skeletal muscle properties have been conducted. Previous studies have identified muscle synthesis and breakdown; investigating them has generated evidence for preventing and treating sarcopenia. Mouse models are still the most useful ones for determining mechanisms underlying sarcopenia through correlations and interventions involving specific genes and their phenotypes. Mouse models used to study sarcopenia often induce muscle atrophy by hindlimb unloading, denervation, or immobilization. Though it is less frequently used, the senescence-accelerated mouse can also be useful for sarcopenia research. Herein, we discuss cases where senescence-accelerated and genetically engineered mouse models were used in sarcopenia research and different perspectives to use them.
ABSTRACT
Sarcopenia leads to loss of skeletal muscle mass, quality, and strength due to aging; it was recently given a disease code (International Classification of Diseases, Tenth Revision, Clinical Modification, M62.84). As a result, in recent years, sarcopenia-related research has increased. In addition, various studies seeking to prevent and treat sarcopenia by identifying the various mechanisms related to the reduction of skeletal muscle properties have been conducted. Previous studies have identified muscle synthesis and breakdown; investigating them has generated evidence for preventing and treating sarcopenia. Mouse models are still the most useful ones for determining mechanisms underlying sarcopenia through correlations and interventions involving specific genes and their phenotypes. Mouse models used to study sarcopenia often induce muscle atrophy by hindlimb unloading, denervation, or immobilization. Though it is less frequently used, the senescence-accelerated mouse can also be useful for sarcopenia research. Herein, we discuss cases where senescence-accelerated and genetically engineered mouse models were used in sarcopenia research and different perspectives to use them.
ABSTRACT
The hallmark symptom of sarcopenia is the loss of muscle mass and strength without the loss of overall body weight. Sarcopenia patients are likely to have worse clinical outcomes and higher mortality than do healthy individuals. The sarcopenia population shows an annual increase of ~0.8% in the population after age 50, and the prevalence rate is rapidly increasing with the recent worldwide aging trend. Based on International Classification of Diseases, Tenth Revision, a global classification of disease published by the World Health Organization, issued the disease code (M62.84) given to sarcopenia in 2016. Therefore, it is expected that the study of sarcopenia will be further activated based on the classification of disease codes in the aging society. Several epidemiological studies and meta-analyses have looked at the correlation between the prevalence of sarcopenia and several environmental factors. In addition, studies using cell lines and rodents have been done to understand the biological mechanism of sarcopenia. Laboratory rodent models are widely applicable in sarcopenia studies because of the advantages of time savings, cost saving, and various analytical applications that could not be used for human subjects. The rodent models that can be applied to the sarcopenia research are diverse, but a simple and fast method that can cause atrophy or aging is preferred. Therefore, we will introduce various methods of inducing muscular atrophy in rodent models to be applied to the study of sarcopenia.
ABSTRACT
Background@#As an instrument for measuring body composition in experimental animals, dual energy X-ray absorptiometry (DXA) is ideal for accuracy, cost, and measurement efficiency. However, there is too little insight into the effectiveness of the various aspects of applying DXA to experimental animals. We investigated whether to compare and verify the precision and accuracy of DXA and nuclear magnetic resonance (NMR) animal body composition analyzers. @*Methods@#We used 30 Institution of Cancer Research mice in the study. First, in order to evaluate the reproducibility of DXA and NMR, we did repeated measurements by repositioning each mouse in anesthesia and euthanasia states. Subsequently, the accuracy of each device was evaluated by comparing the weight measured before the experiment, the weight of the tissue extracted from the mice after the experiment, and the measured DXA and NMR. In addition, when measuring the body composition of animals, we compared the time and the measurable body composition parameters and summarized the advantages and disadvantages of the 2 devices. @*Results@#Compared to NMR, DXA had the advantage of a fast measurement of bone composition and rapid image analysis. In addition, DXA showed a higher correlation (>95%) with fat mass, lean mass baseline than did NMR (>85%). @*Conclusions@#In conclusion, DXA was confirmed to have higher precision and measurement accuracy than did NMR. Therefore, DXA is an effective method for evaluating the body composition of experimental animals.
ABSTRACT
Background@#As an instrument for measuring body composition in experimental animals, dual energy X-ray absorptiometry (DXA) is ideal for accuracy, cost, and measurement efficiency. However, there is too little insight into the effectiveness of the various aspects of applying DXA to experimental animals. We investigated whether to compare and verify the precision and accuracy of DXA and nuclear magnetic resonance (NMR) animal body composition analyzers. @*Methods@#We used 30 Institution of Cancer Research mice in the study. First, in order to evaluate the reproducibility of DXA and NMR, we did repeated measurements by repositioning each mouse in anesthesia and euthanasia states. Subsequently, the accuracy of each device was evaluated by comparing the weight measured before the experiment, the weight of the tissue extracted from the mice after the experiment, and the measured DXA and NMR. In addition, when measuring the body composition of animals, we compared the time and the measurable body composition parameters and summarized the advantages and disadvantages of the 2 devices. @*Results@#Compared to NMR, DXA had the advantage of a fast measurement of bone composition and rapid image analysis. In addition, DXA showed a higher correlation (>95%) with fat mass, lean mass baseline than did NMR (>85%). @*Conclusions@#In conclusion, DXA was confirmed to have higher precision and measurement accuracy than did NMR. Therefore, DXA is an effective method for evaluating the body composition of experimental animals.
ABSTRACT
Malarial infection induces tissue hypoxia in the host through destruction of red blood cells. Tissue hypoxia in malarial infection may increase the activity of HIF1α through an intracellular oxygen-sensing pathway. Activation of HIF1α may also induce vascular endothelial growth factor (VEGF) to trigger angiogenesis. To investigate whether malarial infection actually generates hypoxia-induced angiogenesis, we analyzed severity of hypoxia, the expression of hypoxia-related angiogenic factors, and numbers of blood vessels in various tissues infected with Plasmodium berghei. Infection in mice was performed by intraperitoneal injection of 2×10⁶ parasitized red blood cells. After infection, we studied parasitemia and survival. We analyzed hypoxia, numbers of blood vessels, and expression of hypoxia-related angiogenic factors including VEGF and HIF1α. We used Western blot, immunofluorescence, and immunohistochemistry to analyze various tissues from Plasmodium berghei-infected mice. In malaria-infected mice, parasitemia was increased over the duration of infection and directly associated with mortality rate. Expression of VEGF and HIF1α increased with the parasitemia in various tissues. Additionally, numbers of blood vessels significantly increased in each tissue type of the malaria-infected group compared to the uninfected control group. These results suggest that malarial infection in mice activates hypoxia-induced angiogenesis by stimulation of HIF1α and VEGF in various tissues.