Inhibition of Insulin Degrading Enzyme and Insulin Degradation by UV-Killed Lactobacillus acidophilus.

Probiotics have beneficial effects on management of type 2 diabetes (T2D). The major hallmarks of T2D are insulin deficiency and insulin resistance which emphasize insulin therapy in onset of disease. Lactobacilli such as Lactobacillus acidophilus (L. acidophilus) have well known properties on prevention of T2D and insulin resistance but not on insulin degradation. Insulin-degrading enzyme (IDE) degrades insulin in the human body. We studied the effects of cell-free supernatant (CFS) and ultraviolet (UV)-killed L. acidophilus (ATCC 314) on IDE activity and insulin degradation in vitro. Cell growth inhibition by CFS and UV-killed L. acidophilus (ATCC 314) was studied and Western blotting and a fluoregenic assay was performed to determine IDE expression and its activity, respectively. Insulin degradation was evaluated by sandwich enzyme-linked immunosorbent assay(ELISA). IDE expression and activity was reduced by CFS and UV-killed L. acidophilus (ATCC 314). Although, decreased enzyme expression and activity was not significant for CFS in contrast to MRL (MRS with same pH as CFS). Also, reduction in IDE activity was not statistically considerable when compared to IDE expression. Insulin degradation was increased by CFS but decreased by UV-killed L. acidophilus (ATCC 314).

Effect of Passage Number and Culture Time on the Expression and Activity of Insulin-Degrading Enzyme in Caco-2 Cells

Background: Insulin-degrading enzyme (IDE) is a conserved zinc metallopeptidase. Here, we have evaluated the effect of passage number and culture time on IDE expression and activity in colorectal adenocarcinoma cell line (Caco-2). Methods: Caco-2 cells were cultured with different passage ranges of 5-15, 25-35, 52-63 for 48, 72, and 120 hours. Subsequently, IDE expression and enzyme activity were assessed by Western blot analysis and fluorescent assay, respectively. Results: Our results confirmed that the amount of IDE was higher in cell extract compared to supernatant, and different passage numbers and culture times had small effect on IDE expression. However, when cells were cultured in the passage number range of 5-15 for 72 hours, the IDE activity was 35% higher compared to other passage numbers (p < 0.05). Conclusion: The use of Caco-2 cells at passage number range of 5-15 and culture time of 72 hours provides proper conditions for IDE-related studies.

Truncated forms of RUNX3 Unlike Full Length Protein Alter Cell Proliferation in a TGF-ß Context Dependent Manner.

The Runt related transcription factors (RUNX) are recognized as key players in suppressing or promoting tumor growth. RUNX3, a member of this family, is known as a tumor suppressor in many types of cancers, although such a paradigm was challenged by some researchers. The TGF-ß pathway governs major upstream signals to activate RUNX3. RUNX3 protein consists of several regions and domains. The Runt domain is a conserved DNA binding domain and is considered as the main part of RUNX proteins. Herein, we compared the effects of Runt domains and full-Runx3 in cell viability by designing two constructs of Runx3, including N-terminal region and Runt domain. We investigated the effect of full-Runx3, N-t, and RD on growth inhibition in AGS, MCF-7, A549, and HEK293 cell lines which are different in TGF-ß sensitivity, in the absence and presence of TGF-ß. The full length RUNX3 did not notably inhibit growth of these cell lines while, the N-t and RD truncates showed different trends in these cell lines. Cell proliferation in the TGF-ß impaired context cell lines (AGS and MCF-7) significantly decrease while in the A549 significantly increase. On the other hand, transfection of N-t and RD did not considerably affect the cell proliferation in the HEK293.Our results show that full-lenght RUNX3 did not affect the cell viability. Conversely, the N-t and RD constructs significantly changed cell proliferation. Therefore, therapeutic potentials for these truncated proteins are suggested in tumors with RUNX proteins dysfunction, even in the TGF-ß impair context.

Potential efficacy of Lactobacillus casei IBRC_M10711 on expression and activity of insulin degrading enzyme but not insulin degradation.

Type 2 diabetes (T2D) is a condition with insufficient insulin production or in the setting of insulin resistance with many origins including intestinal microbiota-related molecular mechanism. Insulin-degrading enzyme (IDE) is responsible for insulin breakdown in various tissues and is known as a potential drug target for T2D. Here, we assessed the effects of cell-free supernatant (CFS) and UV-killed Lactobacillus casei IBRC_M10711 on IDE expression, IDE activity, and insulin degradation in Caco-2 cell line. It was found that CFS and UV-killed L. casei IBRC_M10711 led to lower expression of IDE. UV-killed L. casei IBRC_M10711 significantly inhibited IDE activity but CFS did not. Insulin degradation was affected with none of them. In conclusion, L. casei IBRC_M10711 is effective on IDE expression and its activity, but not on insulin degradation. Future studies are recommended to explore the effect of this probiotic on other substrates of IDE.

Biomolecular markers in assessment and treatment of asthma.

Asthma is a chronic and heterogeneous inflammatory disorder with several different phenotypes. Whereas clinical features of asthma are non-specific and pulmonary function tests are often insensitive, further development is needed for efficient treatment or even early diagnosis. Recently, several airway inflammatory biomarkers have emerged as valuable tools in diagnosis and management of asthma. The analysis of molecular markers of airways inflammation has provided promising and non-invasive techniques that facilitate the detection of disease phenotypes as well as measurement of therapeutic efficacy. Although conventional treatments remain the preferred therapy, they do not adequately control some severe cases of asthma. Novel therapeutic agents have been developed to target various biomarkers involved in the inflammatory responses and have been investigated in patients with asthma. In this article, we summarized the most studied asthma biomarkers, derived from a variety of biological sources including exhaled gases, induced sputum, serum and urine. Likewise, the effects of current anti-inflammatory asthma treatments on inflammatory biomarkers and some promising biomarkers for developing new targeted therapies are also discussed.