Cholestasis commonly arises from mechanical obstruction of the biliary tract or genetic defects, resulting in the accumulation of bile substances in both the blood and liver (Squires and McKiernan, 2018). Among the pediatric population, cholestasis predominantly affects neonates and infants (Tessitore et al., 2021). Infants with cholestasis typically present with jaundice, pale stools, dark yellow urine, hepatomegaly, and conjugated hyperbilirubinemia (Venigalla and Gourley, 2004). Biliary atresia (BA) is a severe cholestatic liver disease during infancy, characterized by extrahepatic and/or intrahepatic obstructive cholestasis (Feldman and Sokol, 2020, Feldman and Sokol, 2021). Prompt identification and determination of the causative factor are crucial for formulating an effective treatment plan; however, further enhancement is still required for diagnosing and treating BA.

Neurotensin (NTS) is a 13 endogenous amino-acid peptide that is predominantly present in the central nervous system and the gastrointestinal tract. It exerts its effects through NTS receptors (NTSRs), namely NTSR1, NTSR2, and NTSR3, which are cell surface receptors. These physiological functions encompass dopamine transmission, feeding behavior regulation, analgesia induction, and antipyretic activity (Barchetta, 2023a, Barchetta et al., 2022, Li et al., 2021, Li et al., 2016, Torruella-Suárez and McElligott, 2020, Vincent et al., 1999). Moreover, NTS plays a role in inhibiting gastric acid secretion to safeguard the gastrointestinal mucosa. Additionally, it participates in the hepatic-intestinal circulation of bile, facilitating the secretion of bile from the liver and its absorption in the ileum. Furthermore, there have been implications of NTS involvement in tumorigenesis and tumor progression (Christou et al., 2020). Elevated expression of NTS has been observed in gastrointestinal tumors such as pancreatic and colorectal cancer. Notably, the use of SR48692 as an antagonist for NTSR1 has demonstrated potential in mitigating NTS-mediated tumorigenicity (Ehlers et al., 2000, Maoret et al., 1999, Takahashi et al., 2021). The expression of NTS is initially observed during the early stages of rat liver development, but undergoes suppression in adulthood. However, it can be re-expressed during malignant transformation of the liver, such as in nonalcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC) (Barchetta, 2023b, Evers et al., 1993, Tang et al., 2012).

Using a combination of cell lines, organoids and mouse models, this study aimed to explore the pathological effects of NTS on the cholestasis liver. The findings revealed an increased expression of NTS in the blood of BA patients, suggesting its potential as a predictive biomarker. Furthermore, this study observed that NTS was localized in the bile ducts and promoted their differentiation. Additionally, NTS influenced energy metabolism and facilitated metalloproteinase-7 (MMP7) and interleukin-8 (IL8) through the regulation of the calmodulin-dependent kinase kinase 2-AMP-activated protein kinase (CaMKK2-AMPK) signaling pathway upon binding to NTSR1 and NTSR3.