Muscle Quality in Relation to Prediabetes Phenotypes: A Population-Based Study With Mediation Analysis

CONTEXT

Prediabetes is associated with an increased risk of physical disability, yet no studies have assessed the extent to which muscle quality, a measure reflecting muscle functionality, was altered in prediabetes and its specific phenotype.

OBJECTIVE

We evaluated their associations in a general US population with mediation analysis.

METHODS

This was a cross-sectional study based on the National Health and Nutrition Examination Survey 2011-2014. Participants with prediabetes were stratified as having an isolated defect (impaired fasting glucose [IFG], impaired glucose tolerance [IGT], or impaired hemoglobin A1c [IA1c]), 2 defects (IFG + IGT, IFG + IA1c, or IGT + IA1c), or all defects (IFG + IGT + IA1c). Muscle quality was calculated as dominant grip strength divided by dominant arm muscle mass measured by dual-energy X-ray absorptiometry.

RESULTS

We included 2351 participants (938 with prediabetes and 1413 with normoglycemia). Despite higher grip strength and larger arm muscle mass, arm muscle quality was lower in prediabetes and all prediabetes phenotypes (except for IGT) than normoglycemia (all P < .04), and was unrelated to prediabetes awareness. Arm muscle quality was decreased and the odds of low arm muscle quality was increased in prediabetes with increasing numbers of glucometabolic defects (both P < .001), with insulin resistance being the predominant mediator. HbA1c-defined prediabetes (IA1c) had lower arm muscle quality and higher odds of low arm muscle quality than blood glucose-defined prediabetes (IFG, IGT, or IFG + IGT).

CONCLUSION

Muscle quality was impaired in prediabetes and its specific phenotype. Relative to blood glucose, elevated HbA1c might be a better predictor of reduced muscle quality.

Genetic Origin and Introgression Pattern of Pingliang Red Cattle Revealed Using Genome-Wide SNP Analyses

The Pingliang red cattle, an outstanding indigenous resource in China, possesses an exceptional breeding value attributed to its tender meat and superior marbling quality. Currently, research efforts have predominantly concentrated on exploring its maternal origin and conducting conventional phenotypic studies. However, there remains a lack of comprehensive understanding regarding its genetic basis. To address this gap, we conducted a thorough whole-genome analysis to investigate the population structure, phylogenetic relationships, and gene flows of this breed using genomic SNP chip data from 17 bovine breeds. The results demonstrate that Pingliang red cattle have evolved distinct genetic characteristics unique to this breed, clearly distinguishing it from other breeds. Based on the analysis of the population structure and phylogenetic tree, it can be classified as a hybrid lineage between Bos taurus and Bos indicus. Furthermore, Pingliang red cattle display a more prominent B. taurus pedigree in comparison with Jinnan, Qinchuan, Zaosheng, Nanyang, and Luxi cattle. Moreover, this study also revealed closer genetic proximity within the Chinese indigenous cattle breed, particularly Qinchuan cattle, which shares the longest identical by descent (IBD) fragment with Pingliang red cattle. Gene introgression analysis shows that Pingliang red cattle have undergone gene exchange with South Devon and Red Angus cattle from Europe. Admixture analysis revealed that the proportions of East Asian taurine and Chinese indicine in the ancestry of Pingliang red cattle are approximately 52.44% and 21.00%, respectively, while Eurasian taurine, European taurine, and Indian indicine account for approximately 17.55%, 7.27%, and 1.74%. Our findings unveil distinct genetic characteristics in Pingliang red cattle and attribute their origin to B. taurus and B. indicus ancestry, as well as contributions from Qinchuan cattle, South Devon, and Red Angus.

A High-Performance Anti-Corrosive Epoxy Coating Based on Ultra-Thin Hydroxyapatite Nanosheets with pH-Responsive Functions

The changes in the working environment have necessitated greater requirements in terms of the long-term anti-corrosion ability of metal anti-corrosion coatings, and the emergence of intelligent coatings has met this demand. A nanocontainer with a hydrophobic inner cavity and hydrophilic outer cavity called β-cyclodextrin (β-CD) was grafted onto the surface of hydroxyapatite (HAp) with a silane coupling agent, encapsulating benzotriazole (BTA) and embedded in epoxy resin to improve the coating anticorrosion performance. The excellent corrosion resistance of the coating in immersion and scratch experiments was derived from the inert protective layer formed by the reaction of the rapidly released corrosion inhibitor with the corrosion products on the metal surface. After 30 days of immersion experiment, the coating could still maintain the low-frequency impedance value of 6.28 × 107 Ω cm2. In this work, the enhancement of the physical barrier function of HAp nanoparticle and the pH-response function conferred by β-cyclodextrin provided the coating with good passive and active acting abilities in corrosive environments, respectively.

CRISPR-Cas12a-based genome editing and transcriptional repression for biotin synthesis in Pseudomonas mutabilis

AIMS

To establish a dual-function clustered regularly interspaced short palindromic repeats (CRISPR)-Cas12a system combined genome editing and transcriptional repression for multiplex metabolic engineering of Pseudomonas mutabilis.

MATERIALS AND RESULTS

This CRISPR-Cas12a system consisted of two plasmids that enabled single gene deletion, replacement, and inactivation with efficiency >90% for most targets within 5 days. With the guidance of truncated crRNA containing 16 bp spacer sequences, a catalytically active Cas12a could be employed to repress the expression of the reporter gene eGFP up to 66.6%. When bdhA deletion and eGFP repression were tested simultaneously by transforming a single crRNA plasmid and Cas12a plasmid, the knockout efficiency reached 77.8% and the expression of eGFP was decreased by >50%. Finally, the dual-functional system was demonstrated to increase the production of biotin by 3.84-fold, with yigM deletion and birA repression achieved simultaneously.

CONCLUSIONS

This CRISPR-Cas12a system is an efficient genome editing and regulation tool to facilitate the construction of P. mutabilis cell factories.