Molecular Characterization of Constipation Disease as Novel Phenotypes in CRISPR-Cas9-Generated Leptin Knockout Mice with Obesity

Abstract

(1) Background: We characterized a novel animal model with obesity-induced constipation because constipation is rarely known in genetically engineered mice (GEM); (2) Methods: The changes in the constipation parameters and mechanisms were analyzed in CRISPR-Cas9-mediated leptin (Lep) knockout (KO) mice from eight to 24 weeks; (3) Results: Significant constipation phenotypes were observed in the Lep KO mice since 16 weeks old. These mice showed a significant decrease in the gastrointestinal motility, mucosal layer thickness and ability for mucin secretion as well as the abnormal ultrastructure of Lieberkühn crypts in the transverse colon. The density or function of the enteric neurons, intestinal Cajal cells (ICC), smooth muscle cells, and the concentration of gastrointestinal (GI) hormones for the GI motility were remarkably changed in Lep KO mice. The downstream signaling pathway of muscarinic acetylcholine receptors (mAChRs) were activated in Lep KO mice, while the expression of adipogenesis-regulating genes were alternatively reduced in the transverse colon of the same mice; (4) Conclusions: These results provide the first strong evidence that Lep KO mice can represent constipation successfully through dysregulation of the GI motility mediated by myenteric neurons, ICC, and smooth muscle cells in the transverse colon during an abnormal function of the lipid metabolism.

Network-Based Elaboration of the Efficacy of the Dachangshu (BL25) and Tianshu (ST25) Points in the Treatment of Functional Constipation in Children through Inflammation, Adipocytokine, or Leptin Pathways

“…IBD is a chronic nonspecific inflammatory disease involving the gastrointestinal tract that is recurring and difficult to treat [ 17 ]. In addition, the adipocytokine signaling pathway [ 18 , 19 ], Th17-cell differentiation [ 20 ], NF-kappa B signaling pathway [ 21 ], and Toll-like receptor signaling pathway [ 22 ] may also be closely related to FCC.…”

Dysregulation of the Enteric Nervous System in the Mid Colon of Complement Component 3 Knockout Mice with Constipation Phenotypes

“…Furthermore, a similar decrease pattern was detected in constipated animal models. The levels of NSE, PGP9.5, and C-kit expression were statistically significantly lower in the mid colon of 16 week old Lep KO mice with the constipation phenotypes [ 32 ]. ICR mice and SR rats with loperamide (Lop)-induced constipation exhibited a decrease in the level of two ICC markers (C-kit and SCF) and the other enteric nerve-related factors (PGP9.5, brain-derived neurotrophic factor (BDNF), and GNDT) [ 33 , 34 ].…”

“…Significant alterations in ACh concentration, AChE activity, and AChR downstream signaling were detected. Lop-induced constipation rat and CRISPR/Cas9-generated Lep KO mice with obesity-induced constipation exhibited a decrease in mAChRM2 and M3 expression level, as well as activation of their downstream signaling [ 32 , 43 , 44 ]. In addition, the AChE activity was statistically significantly lower in the colon tissue of Lop-induced constipation rats and the serum of activated carbon-induced constipation mice than their untreated counterparts [ 44 , 45 ].…”

The anti-inflammatory effects of Akkermansia muciniphila and its derivates in HFD/CCL4-induced murine model of liver injury

“…Liver and colon specimens were immediately fixed in 10% neutral buffered formalin. Paraffin-embedded liver and colon tissues were stained with hematoxylin and eosin (H&E) method 28 . The thickness of the epithelium and mucosal layer were then evaluated by an expert pathologist, blind to the study groups.…”