Increased Myosin light chain 9 expression during Kawasaki disease vasculitis

Network pharmacology combined with an animal model to reveal the material basis and mechanism of Amomum villosum in alleviating constipation in mice

Constipation is a prevalent gastrointestinal disorder, with its prevalence showing an annual upward trend. There are many factors involved in the occurrence of constipation, such as abnormal smooth muscle contraction and disorders of gastrointestinal hormone secretion. Amomum villosum (A. villosum) has been proven to be effective in improving digestive system diseases, but there is no report on improving constipation. Therefore, we used network pharmacology prediction combined with animal experiments to explore the key active components of A. villosum and their pharmacological mechanisms. The results of network pharmacological prediction showed that β-sitosterol was the key laxative compound of A. villosum, which may play a laxative role by activating the adrenoceptor alpha 1 A-myosin light chain (ADRA1A-MLC) pathway. Further animal experiments showed that β-sitosterol could significantly shorten the time to first black stool; increase faecal weight, faecal number, and faecal water content; and promote gastrointestinal motility. β-sitosterol may promote intestinal motility by upregulating the expression of ADRA1A and myosin light chain 9 (Myl9) mRNA and protein in the colon, thereby activating the ADRA1A-MLC signalling pathway. In addition, it is possible to improve constipation symptoms by regulating serum neurotransmitters and gastrointestinal motility-related factors, such as the serum content of 5-hydroxytryptamine (5-HT) and acetylcholinesterase (AchE) and the mRNA expression of 5-hydroxytryptamine receptor 4 (5-HT4), stem cell factor (SCF), stem cell factor receptor (c-Kit) and smooth muscle myosin light chain kinase (smMLCK) in the colon. These results lay a foundation for the application of A. villosum and β-sitosterol in constipation.

Plasma anti-myosin autoantibodies in the diagnosis of necrotizing enterocolitis

We aimed to assess whether autoantibodies can be used as biomarkers for necrotizing enterocolitis (NEC) and applied for its early diagnosis. A prospective observational study was conducted in neonates with suspected NEC abdominal distension (the developmental study), which consisted of 50 neonates finally divided into NEC (n = 24) and non-NEC (n = 26) cohorts based on follow-up results. Serum samples were collected within 48 h of illness onset and used for screening NEC-associated plasma autoantibodies by autoantigen microarray. Additionally, we validated anti-myosin autoantibodies by enzyme-linked immunosorbent assay (ELISA) in an independent validation study, for which we selected plasma samples within 48 h of onset of NEC (n = 38) and samples of gestational age- and weight-matched controls (n = 13). Autoantigen microarray revealed that both IgG and IgM anti-myosin autoantibodies in plasma from neonates with NEC were significantly higher than those in neonates with other diagnoses. ELISA showed that plasma anti-myosin autoantibodies increased in the NEC cohort, with 1.5-fold higher levels than in the non-NEC cohort. Anti-myosin autoantibodies were able to distinguish NEC from non-NEC, achieving an area under the curve (AUC) of 0.8856 (95% confidence interval (CI): 0.7918-0.9795), with sensitivity of 81.58% and specificity of 76.93%. Plasma anti-myosin autoantibodies were significantly higher in all three subtypes of NEC (P < 0.0001 for NEC I; P = 0.0018 for NEC II; P = 0.0011 for NEC III), especially in NEC stage I than that in the non-NEC controls.

CONCLUSION

Anti-myosin autoantibodies may be applied as a promising diagnostic marker for NEC, especially for NEC stage I.

WHAT IS KNOWN

• Intestinal damage and self-antigen exposure may lead to increased autoantibodies, and they are widely used as biomarkers for diagnosing inflammatory bowel disease. • Necrotizing enterocolitis (NEC) is a devastating disease with overwhelming inflammation and immune dysregulation.

WHAT IS NEW

• Increased autoantibodies were present in patients with NEC, even before typical X-ray manifestations. • Anti-myosin autoantibodies may be applied as a promising diagnostic marker for NEC.