Digestive Diseases and Sciences (2018) 63:619–627
Neuronal Nitric Oxide Synthase Is a Novel Biomarker for the Interstitial
Cells of Cajal in Stress‑Induced Diarrhea‑Dominant Irritable Bowel
Da Eun Jang
· Ji Hyun Bae
· Yoo Jin Chang
· Yoon Hoo Lee
· Ki Taek Nam
· Il Yong Kim
· Je Kyung Seong
Yong Chan Lee
· Su Cheong Yeom
Received: 6 March 2017 / Accepted: 16 January 2018 / Published online: 25 January 2018
© Springer Science+Business Media, LLC, part of Springer Nature 2018
Background Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder involving changes in normal bowel
movements. The pathophysiology of IBS is not clearly understood owing to the lack of identiﬁable pathological abnormali-
ties and reliable biomarkers.
Aim The aim of this study was to discover the novel and reliable biomarker for IBS.
Method In this study, neonatal maternal separation (NMS) stress model was used for the IBS mouse model. Further assess-
ment was conducted with whole gastrointestinal transit test, quantitative RT-PCR, histological examination, and western blot.
Results Male pups developed symptoms similar to those of human IBS with diarrhea (IBS-D), such as low-grade inﬂamma-
tion, stool irregularity, and increased bowel motility. NMS stress inﬂuenced to the interstitial cells of Cajal (ICC) and induced
altered bowel motility, resulting in IBS-D-like symptoms. In addition, we found neuronal nitric oxide synthase (nNOS) to
be a novel biomarker for ICC under NMS stress. nNOS expression was only observed in the ICC of the submucosal plexus
of IBS-D mice, and the inhibition of nNOS changed the phenotype from IBS-D to IBS with constipation.
Conclusion Our study demonstrates that early-life stress can inﬂuence to ICC and modulate bowel activity and that nNOS
might be used as a biomarker for ICC stimulation in IBS.
Keywords Interstitial cells of Cajal · irritable bowel syndrome · Neonatal maternal separation · Neuronal nitric oxide
Irritable bowel syndrome (IBS) is a functional gastrointesti-
nal (GI) disorder associated with alterations in normal bowel
movements, with an estimated prevalence of 11% . The
clinical symptoms of IBS include abdominal pain or dis-
comfort; stool irregularities and bloating; and other somatic,
visceral, and psychiatric comorbidities . The diagnosis
of IBS mainly depends on the symptom-based diagnostic
criteria of Manning et al. and the Rome criteria, which have
been widely used to identify IBS patients. At present, IBS is
considered to be a disorder without any organic lesions [3,
4]. Although IBS is not life-threatening, it causes a heavy
economic burden owing to increased work absenteeism,
impaired quality of life, and increased use of healthcare
The pathophysiology of IBS is not completely under-
stood because of the lack of clearly identiﬁed pathological
abnormalities and reliable biomarkers. However, the pos-
sible causes of IBS include physical stressors; infection;
inﬂammation; and psychological disorders such as anxiety,
depression, and negative coping mechanism in response to
emotional trauma . A distinguishing feature of IBS, vis-
ceral sensitivity, is often triggered or sustained by stress .
Stress disrupts homeostasis and causes changes in intesti-
nal motility, visceral perception, and gut barrier function.
Recently, there has been an increasing interest in stress-
related neural and immunological networks within the gut
Electronic supplementary material The online version of this
article (http s://doi.org/10.1007 /s106 20-018-4933 -7) contains
supplementary material, which is available to authorized users.
* Su Cheong Yeom
Extended author information available on the last page of the article