1.IPA and its precursors differently modulate the proliferation, differentiation, and integrity of intestinal epithelial cells
Shámila ISMAEL ; Catarina RODRIGUES ; Gilberto Maia SANTOS ; Inês CASTELA ; Inês BARREIROS-MOTA ; Maria João ALMEIDA ; Conceição CALHAU ; Ana FARIA ; João Ricardo ARAÚJO
Nutrition Research and Practice 2023;17(4):616-630
BACKGROUND/OBJECTIVES:
Indole-3-propionic acid (IPA) is a tryptophan-derived microbial metabolite that has been associated with protective effects against inflammatory and metabolic diseases. However, there is a lack of knowledge regarding the effects of IPA under physiological conditions and at the intestinal level.MATERIALS/METHODS: Human intestinal epithelial Caco-2 cells were treated for 2, 24, and/ or 72 h with IPA or its precursors – indole, tryptophan, and propionate – at 1, 10, 100, 250, or 500 μM to assess cell viability, integrity, differentiation, and proliferation.
RESULTS:
IPA induced cell proliferation and this effect was associated with a higher expression of extracellular signal-regulated kinase 2 (ERK2) and a lower expression of c-Jun. Although indole and propionate also induced cell proliferation, this involved ERK2 and c-Jun independent mechanisms. On the other hand, both tryptophan and propionate increased cell integrity and reduced the expression of claudin-1, whereas propionate decreased cell differentiation.
CONCLUSIONS
In conclusion, these findings suggested that IPA and its precursors distinctly contribute to the proliferation, differentiation, and barrier function properties of human intestinal epithelial cells. Moreover, the pro-proliferative effect of IPA in intestinal epithelial cells was not explained by its precursors and is rather related to its whole chemical structure.Maintaining IPA at physiological levels, e.g., through IPA-producing commensal bacteria, may be important to preserve the integrity of the intestinal barrier and play an integral role in maintaining metabolic homeostasis.
2.Does the prosthesis weight matter? 3D finite element analysis of a fixed implant-supported prosthesis at different weights and implant numbers
João Paulo Mendes TRIBST ; Amanda Maria de Oliveira Dal PIVA ; Alexandre Luiz Souto BORGES ; Vinicius Anéas RODRIGUES ; Marco Antonio BOTTINO ; Cornelis Johannes KLEVERLAAN
The Journal of Advanced Prosthodontics 2020;12(2):67-74
PURPOSE:
. This study evaluated the influence of prosthesis weight and number of implants on the bone tissue microstrain.
MATERIALS AND METHODS:
. Fifteen (15) fixed full-arch implant-supported prosthesis designs were created using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15, 20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elements formed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior. The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implant interface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along the Z-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria.
RESULTS:
. The prosthesis weight was related to the bone strain. The more implants installed, the less the amount of strain generated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with the largest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce bone remodeling simply due to the prosthesis weight.
CONCLUSION
. Heavier prostheses under the effect of gravity force are related to more strain being generated around the implants. Installing more implants to support the prosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generate harmful values of peri-implant bone strain.
3. Unlocking the in vitro anti-Trypanosoma cruzi activity of halophyte plants from the southern Portugal
Marta OLIVEIRA ; Maria João RODRIGUES ; Luísa BARREIRA ; Luísa CUSTÓDIO ; Policarpo Ademar SALES JUNIOR ; Silvane Maria Fonseca MURTA ; Alvaro José ROMANHA ; Marina DELLAGRECA
Asian Pacific Journal of Tropical Medicine 2016;9(8):735-741
Objective To evaluate the in vitro anti-Trypanosoma cruzi (T. cruzi) activity of organic extracts prepared from halophyte species collected in the southern coast of Portugal (Algarve), and chemically characterize the most active samples. Methods Acetone, dichloromethane and methanol extracts were prepared from 31 halophyte species and tested in vitro against trypomastigotes and intracellular amastigotes of the Tulahuen strain of T. cruzi. The most active extract was fractionated by preparative HPLC-DAD, affording 11 fractions. The most selective fraction was fully characterized by