Double benefit of long-acting somatostatin analogs in a patient with coexistence of acromegaly and ulcerative colitis

Machine learning-based algorithms applied to drug prescriptions and other healthcare services in the Sicilian claims database to identify acromegaly as a model for the earlier diagnosis of rare diseases

Acromegaly is a rare disease characterized by a diagnostic delay ranging from 5 to 10 years from the symptoms' onset. The aim of this study was to develop and internally validate machine-learning algorithms to identify a combination of variables for the early diagnosis of acromegaly. This retrospective population-based study was conducted between 2011 and 2018 using data from the claims databases of Sicily Region, in Southern Italy. To identify combinations of potential predictors of acromegaly diagnosis, conditional and unconditional penalized multivariable logistic regression models and three machine learning algorithms (i.e., the Recursive Partitioning and Regression Tree, the Random Forest and the Support Vector Machine) were used, and their performance was evaluated. The random forest (RF) algorithm achieved the highest Area under the ROC Curve value of 0.83 (95% CI 0.79-0.87). The sensitivity in the test set, computed at the optimal threshold of predicted probabilities, ranged from 28% for the unconditional logistic regression model to 69% for the RF. Overall, the only diagnosis predictor selected by all five models and algorithms was the number of immunosuppressants-related pharmacy claims. The other predictors selected by at least two models were eventually combined in an unconditional logistic regression to develop a meta-score that achieved an acceptable discrimination accuracy (AUC = 0.71, 95% CI 0.66-0.75). Findings of this study showed that data-driven machine learning algorithms may play a role in supporting the early diagnosis of rare diseases such as acromegaly.

Somatostatin as an Active Substance in the Mammalian Enteric Nervous System

Somatostatin (SOM) is an active substance which most commonly occurs in endocrine cells, as well as in the central and peripheral nervous system. One of the parts of the nervous system where the presence of SOM has been confirmed is the enteric nervous system (ENS), located in the wall of the gastrointestinal (GI) tract. It regulates most of the functions of the stomach and intestine and it is characterized by complex organization and a high degree of independence from the central nervous system. SOM has been described in the ENS of numerous mammal species and its main functions in the GI tract are connected with the inhibition of the intestinal motility and secretory activity. Moreover, SOM participates in sensory and pain stimuli conduction, modulation of the release of other neuronal factors, and regulation of blood flow in the intestinal vessels. This peptide is also involved in the pathological processes in the GI tract and is known as an anti-inflammatory agent. This paper, which focuses primarily on the distribution of SOM in the ENS and extrinsic intestinal innervation in various mammalian species, is a review of studies concerning this issue published from 1973 to the present.

Molecular mechanisms of somatostatin-mediated intestinal epithelial barrier function restoration by upregulating claudin-4 in mice with DSS-induced colitis

Intestinal barrier dysfunction plays a crucial role in the pathogenesis of ulcerative colitis (UC). Previous studies have shown somatostatin (SST) can protect intestinal barrier structure possibly through upregulating tight junction (TJ) protein expression, but the mechanisms of this upregulation remain undefined. This study aimed to investigate the molecular mechanisms of interaction of SST with its downstream regulatory elements in DSS-induced colitis mice. In DSS-induced colitis mice, exogenous SST supplement (octreotide) effectively ameliorated disease progression, restored colonic barrier structure and function, and stimulated claudin-4 expression. Similar effects were also observed for SST on Caco-2 cells intervened by TNF-α. SST receptor 5 (SSTR5) agonist L-817,818 upregulated the claudin-4 expression whereas the SSTR2 agonist seglitide could not reverse TNF-α-induced reduction of claudin-4. SST treatment significantly decreased the phosphorylation levels of ERK1/2 and p38 induced by TNF-α. PD-98059 (ERK1/2 pathway inhibitor) but not SB-202190 (p38 pathway inhibitor) could reverse TNF-α-induced suppression of claudin-4 expression. Both inhibitors could improve the TJ barrier function damaged by TNF-α. Our studies suggest that the protective effect of SST on intestinal barrier achieved by upregulating claudin-4 expression through activation of SSTR5 and suppression of the ERK1/2 pathways. These findings will benefit the development of novel treatment regimens for UC.