维生素B12支持雄性小鼠骨肌肉的氧化酸化能力
bioRxiv : the preprint server for biology
|September 5, 2025
概括
维生素B12缺乏导致线粒体DNA中的 uracil 积累,并损害骨肌肉功能. 补充剂改善了老鼠的能量产生,突出了B12
科学领域:
- 线粒体生物学
- 营养生物化学
- 分子遗传学
背景情况:
- 维生素B12对于叶酸介导的单碳代谢 (FOCM) 至关重要,影响核酸合成.
- 损坏的FOCM导致DNA中的 uracil 积累,尤其是线粒体DNA (mtDNA) 的敏感性.
- 乌拉在mtDNA中的功能影响和B12缺乏对骨肌肉的影响尚不清楚.
研究的目的:
- 调查功能和饮食维生素B12缺乏如何影响骨肌肉中的mtDNA完整性和线粒体功能.
- 确定B12缺乏对肌肉组织中 uracil 含量和氧化酸化的影响.
主要方法:
- 使用Mtr+/-小鼠 (功能性B12缺乏) 和小鼠B12缺乏饮食.
- 向老年小鼠提供B12补充剂.
- 评估肌肉重量,mtDNA uracil 含量,mtDNA 含量和氧化化复合体容量.
主要成果:
- 在Mtr+/-小鼠中,前肌的最大呼吸能力有所降低.
- 缺乏B12的饮食增加了mtDNA uracil水平 (约10倍),并降低了红骨肌的复合I能力.
- 补充B12增强了老鼠胃膜复合体的活性.
结论:
- 饮食维生素B12缺乏导致mtDNA中的 uracil 积累,并损害骨肌肉的氧化能力.
- 维生素B12缺乏会影响能量密集组织中的线粒体功能.
- 维生素B12补充可以恢复特定肌肉类型的线粒体功能.
相关概念视频
01:23Bone as Supporting Connective Tissue
Bone tissue forms the internal skeleton of vertebrate animals, providing structure to the body.
Bone Matrix
Bone, or osseous tissue, is a connective tissue that has a large amount of two different types of matrix material. The organic matrix is similar to the matrix material found in other connective tissues, including some amount of collagen and elastic fibers. This gives strength and flexibility to the tissue. The inorganic matrix consists of mineral salts— mostly calcium salts— that give the...
Bone Matrix
Bone, or osseous tissue, is a connective tissue that has a large amount of two different types of matrix material. The organic matrix is similar to the matrix material found in other connective tissues, including some amount of collagen and elastic fibers. This gives strength and flexibility to the tissue. The inorganic matrix consists of mineral salts— mostly calcium salts— that give the...
01:18The Bone Matrix
Bone contains a relatively small number of cells entrenched in a matrix of collagen fibers that provide an adherent surface for inorganic salt crystals. Both components of the matrix, organic and inorganic, contribute to the unusual properties of bone. Without collagen, bones would be brittle and shatter easily. Without mineral crystals, bones would flex and provide little support. This can be observed by an experiment: when the minerals of a bone are dissolved by soaking the bone in acid or...
01:29Blood and Nerve Supply to the Bones
Bones are dynamic organs that require a rich supply of oxygen and nutrients. Around 5% to 10% of the cardiac output supplies blood to the bones. A typical long bone has three main sources: the nutrient artery, the metaphyseal and epiphyseal arteries, and the periosteal arteries.
Nutrient Artery
The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This...
Nutrient Artery
The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This...
01:31Essential Minerals for Bone Health
The minerals contained in all of the food we consume are essential for our organ systems. However, certain essential minerals, such as calcium, phosphorus, magnesium, manganese, and fluoride, largely affect bone health.
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...
01:25Role of Vitamins in Maintaining Bone Health
The growth and maintenance of bone are regulated by a combination of nutritional factors, including vitamins, such as vitamin A, B12, C, D, and K.
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
01:20Sulfur Assimilation
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to become...