MYL9 deficiency is neonatal lethal in mice due to abnormalities in the lung and the muscularis propria of the bladder and intestine

Abstract

Class II myosin complexes are responsible for muscle contraction as well as other non-sarcomeric contractile functions in cells. Myosin heavy chain molecules form the core of these structures, while light chain molecules regulate their stability and function. MYL9 is a light chain isoform that is thought to regulate non-sarcomeric myosin. However, whether this in only in specific cell types or in all cells remains unclear. To address this, we generated MYL9 deficient mice. These mice die soon after birth with abnormalities in multiple organs. All mice exhibited a distended bladder, shortening of the small intestine and alveolar overdistension in the lung. The Myl9 allele in these mice included a LacZ reporter knockin that allowed for mapping of Myl9 gene expression. Using this reporter, we show that MYL9 expression is restricted to the muscularis propria of the small intestine and bladder, as well as in the smooth muscle layer of the bronchi in the lung and major bladder vessels in all organs. This suggests that MYL9 is important for the function of smooth muscle cells in these organs. Smooth muscle dysfunction is therefore likely to be the cause of the abnormalities observed in the intestine, bladder and lung of MYL9 deficient mice and the resulting neonatal lethality.

Exploring the material basis and mechanism of Moringa oleifera in alleviating slow transit constipation based on network pharmacology and animal models

“…The absence of MYL9 can cause diseases characterized by gastrointestinal functional obstruction [60]. MYL9 deficiency can also lead to smooth muscle dysfunction in many parts of the intestine [61]. Importantly, smooth muscle dysfunction is closely related to constipation [62].…”

Identification of Ancient Chinese Medical Prescriptions and Case Data Analysis Under Artificial Intelligence GPT Algorithm: A Case Study of Song Dynasty Medical Literature

“…These groups often have particular body deficiencies, so warm-natured drugs can help strengthen the "Qi." As stated in the Plain Questions • The Theory of Yin Yang Correspondence: "External deficiencies of the body can be treated by warming up the "QI" [38]. The phlegm obstructs the "QI," which leads to the stagnation of the "Qi" and tends to turn the depression into heat, so cold-natured drugs also account for a high proportion in treating pulmonary distension.…”