OUP accepted manuscript

Interstitial cystitis (IC) is a bladder syndrome of unclear etiology with no generally accepted treatment. Growing evidence suggest that periostin (POSTN) is an important homeostatic component in the tissue repair and regeneration in adulthood, but its function in urinary bladder regeneration is still unknown. Here we investigate whether POSTN is involved in bladder tissue repair in a cyclophosphamide (CYP)-induced interstitial cystitis model. POSTN is primarily expressed in bladder stroma (detrusor smooth muscle and lamina propria) and upregulated in response to CYP-induced injury. POSTN deficiency resulted in more severe hematuria, aggravated edema of the bladder, and delayed umbrella cell recovery. Besides, less proliferative urothelial cells (labeled by pHH3, Ki67, and EdU) and lower expression of Krt14 (a urothelial stem cell marker) were detected in POSTN^−/− mice post CYP exposure, indicating a limited urothelial regeneration. Further investigations revealed that POSTN could induce Wnt4 upregulation and activate AKT signaling, which together activates β-catenin signaling to drive urothelial stem cell proliferation. In addition, POSTN can promote resident macrophage proliferation and polarization to a pro-regenerative (M2) phenotype, which favors urothelial regeneration. Furthermore, we generated injectable P-GelMA granular hydrogel as a biomaterial carrier to deliver recombinant POSTN into the bladder, which could increase urothelial stem cells number, decrease umbrella cells exfoliation, and hence alleviate hematuria in a CYP-induced interstitial cystitis model. In summary, our findings identify a pivotal role of POSTN in bladder urothelial regeneration and suggest that intravesical biomaterials-assisted POSTN delivery may be an efficacious treatment for interstitial cystitis.

Forecasting sensitive targets of the kynurenine pathway in pancreatic adenocarcinoma using mathematical modeling

In this study, a new mathematical model was established and validated to forecast and define sensitive targets in the kynurenine pathway (Kynp) in pancreatic adenocarcinoma (PDAC). Using the Panc-1 cell line, genetic profiles of Kynp molecules were tested. qPCR data were implemented in the algorithm programming (fmincon and lsqnonlin function) to estimate 35 parameters of Kynp variables by Matlab 2017b. All tested parameters were defined as non-negative and bounded. Then, based on experimental data, the function of the fmincon equation was employed to estimate the approximate range of each parameter. These calculations were confirmed by qPCR and Western blot. The correlation coefficient (R) between model simulation and experimental data (72 hours, in intervals of 6 hours) of every variable was >0.988. The analysis of reliability and predictive accuracy depending on qPCR and Western blot data showed high predictive accuracy of the model; R was >0.988. Using the model calculations, kynurenine (x3, a6), GPR35 (x4, a8), NF-kβp105 (x7, a16), and NF-kβp65 (x8, a18) were recognized as sensitive targets in the Kynp. These predicted targets were confirmed by testing gene and protein expression responses. Therefore, this study provides new interdisciplinary evidence for Kynp-sensitive targets in the treatment of PDAC.