scholarly journals Effect of dietary protein level on in vivo and in vitro vitamin A esterase activity in the chick

1967 ◽  
Vol 21 (3) ◽  
pp. 565-581 ◽  
Author(s):  
I. Nir ◽  
I. Bruckental ◽  
I. Ascarelli ◽  
A. Bondi
Keyword(s):  
Vitamin A ◽  
Oral Dose ◽  
Dietary Protein ◽  
Protein Level ◽  
Blood Stream ◽  
Duodenal Mucosa ◽  
Protein Levels ◽  
Temporary Decrease

1. The efficiency of absorption of and liver storage from a single oral dose of 10000 i.u. vitamin A palmitate decreased in chicks reared on a diet containing 10% protein as compared to the efficiency in chicks reared on a diet in which the protein level was adequate. When the chicks were given orally an equivalent dose of vitamin A alcohol, the absorption was equally efficient at both dietary protein levels.2. The vitamin A alcohol content of this intestine, plasma and liver of chicks dosed with vitamin A palmitate was decreased by protein restriction. The physiological change responsible for this decrease seems to be the lowering of the hydrolysing activity for vitamin A palmitate in pancreas and in the duodenal mucosa.3. The importance of the enzymic step in the absorption of an oral dose of vitamin A palmitate is shown by the finding that protein malnutrition reduced only slightly the final liver stores when vitamin A in its different forms (palmitate, acetate or alcohol) was injected directly into the blood stream.4. The uptake of injected vitamin A from the blood was much delayed when the vitamin was injected as palmitate, i.e. the ester of a long-chain fatty acid, instead of the acetate ester of the free alcohol.5. When vitamin A was injected, the liver content did not rise continuously with time, but showed a temporary decrease after a certain period. The phenomenon was apparently due to changes in the rate of the two inverse processes of uptake of the vitamin by the liver and liberation from it.

scholarly journals Prebiotics Inhibit Proteolysis by Gut Bacteria in a Host Diet-Dependent Manner: a Three-Stage Continuous In Vitro Gut Model Experiment

2020 ◽  
Vol 86 (10) ◽  
Author(s):  
Xuedan Wang ◽  
Glenn R. Gibson ◽  
Manuela Sailer ◽  
Stephan Theis ◽  
Robert A. Rastall
Keyword(s):  
Dietary Protein ◽  
Health Benefit ◽  
Distal Colon ◽  
High Protein ◽  
Model Systems ◽  
Dependent Manner ◽  
Bacterial Fermentation ◽  
Protein Levels

ABSTRACT Dietary protein residue can result in microbial generation of various toxic metabolites in the gut, such as ammonia. A prebiotic is “a substrate that is selectively utilised by host microorganisms conferring a health benefit” (G. R. Gibson, R. Hutkins, M. E. Sanders, S. L. Prescott, et al., Nat Rev Gastroenterol Hepatol 14:491–502, 2017, https://doi.org/10.1038/nrgastro.2017.75). Prebiotics are carbohydrates that may have the potential to reverse the harmful effects of gut bacterial protein fermentation. Three-stage continuous colonic model systems were inoculated with fecal samples from omnivore and vegetarian volunteers. Casein (equivalent to 105 g protein consumption per day) was used within the systems as a protein source. Two different doses of inulin-type fructans (Synergy1) were later added (equivalent to 10 g per day in vivo and 15 g per day) to assess whether this influenced protein fermentation. Bacteria were enumerated by fluorescence in situ hybridization with flow cytometry. Metabolites from bacterial fermentation (short-chain fatty acid [SCFA], ammonia, phenol, indole, and p-cresol) were monitored to further analyze proteolysis and the prebiotic effect. A significantly higher number of bifidobacteria was observed with the addition of inulin together with reduction of Desulfovibrio spp. Furthermore, metabolites from protein fermentation, such as branched-chain fatty acids (BCFA) and ammonia, were significantly lowered with Synergy1. Production of p-cresol varied among donors, as we recognized four high producing models and two low producing models. Prebiotic addition reduced its production only in vegetarian high p-cresol producers. IMPORTANCE Dietary protein levels are generally higher in Western populations than in the world average. We challenged three-stage continuous colonic model systems containing high protein levels and confirmed the production of potentially harmful metabolites from proteolysis, especially replicates of the transverse and distal colon. Fermentations of proteins with a prebiotic supplementation resulted in a change in the human gut microbiota and inhibited the production of some proteolytic metabolites. Moreover, we observed both bacterial and metabolic differences between fecal bacteria from omnivore donors and vegetarian donors. Proteins with prebiotic supplementation showed higher Bacteroides spp. and inhibited Clostridium cluster IX in omnivore models, while in vegetarian modes, Clostridium cluster IX was higher and Bacteroides spp. lower with high protein plus prebiotic supplementation. Synergy1 addition inhibited p-cresol production in vegetarian high p-cresol-producing models while the inhibitory effect was not seen in omnivore models.

scholarly journals Protective effects of piperine on the retina of mice with streptozotocin-induced diabetes by suppressing HIF-1/VEGFA pathway and promoting PEDF expression

2021 ◽  
Vol 14 (5) ◽  
pp. 656-665
Author(s):  
Pu Zhang ◽  
◽  
Yao Tan ◽  
Ling Gao ◽  
◽  
...  
Keyword(s):  
Protein Level ◽  
Pigment Epithelium ◽  
Hypoxia Inducible Factor ◽  
Protective Effects ◽  
Protein Levels ◽  
Chemical Hypoxia ◽  
Diabetic Retina ◽  
Streptozotocin Induced Diabetes

AIM: To evaluate the protective mechanisms of piperine in the retina of mice with streptozotocin-induced diabetes. METHODS: In experiments in vitro, stimulation by chemical hypoxia was established in ARPE-19 cells. Then, the expression of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor A (VEGFA), and pigment epithelium-derived factor (PEDF) was assessed at the mRNA and protein levels. In experiments in vivo, diabetes mellitus was established by intraperitoneally injecting 150 mg/kg streptozotocin once. After 3wk of the onset of diabetes, 15 mg/kg piperine was intraperitoneally injected once daily for 1 or 3wk. Then, the retinal morphology and mRNA and protein expression were assessed. RESULTS: In hypoxia, 1-100 μmol/L piperine significantly decreased the expression of VEGFA mRNA and increased the expression of PEDF mRNA without affecting HIF-1α mRNA. Meanwhile, 100 μmol/L piperine substantially decreased the protein level of VEGFA and increased the protein level of PEDF. The HIF-1α protein level was also hampered by piperine. In the diabetic retina of mice, the morphological damage was alleviated by piperine. Likewise, the retinal vascular leakage was substantially decreased by piperine. Further, the protein levels of HIF-1α and VEGFA were significantly reduced by piperine. Moreover, the level of the antiangiogenic factor of PEDF dramatically increased by piperine. CONCLUSION: Piperine may exert protective effects on the retina of mice with diabetes via regulating the pro-antiangiogenic homeostasis composed of HIF-1/VEGFA and PEDF.

The effect of excess vitamin A on cultures of embryonic chicken skin explanted at different stages of differentiation

1957 ◽  
Vol 146 (923) ◽  
pp. 242-256 ◽  
Keyword(s):  
Vitamin A ◽  
Culture Medium ◽  
Blood Stream ◽  
Watch Glass ◽  
Secretory Cells ◽  
Normal Medium ◽  
Mucous Metaplasia ◽  
Prolonged Contact

In earlier experiments, Fell & Mellanby (1953) showed that the simple, two-layered epidermis of the 7-day embryonic chick underwent mucous metaplasia when grown in medium containing excess vitamin A. The present investigation was undertaken to see whether epidermis at more advanced stages of development would undergo a similar transformation in vitro under the influence of vitamin A. Skin from the shank and foot of 13-, 14- and 18-day chick embryos was grown on rayon acetate cloth by Shaffer’s modification of the watch-glass method, in medium (cock plasma and embryo extract) to which natural or synthetic vitamin A alcohol had been added. For purposes of comparison, one experiment was made with skin from the trunk and limbs of 7-day embryos. A dose of 1500 i. u. vitamin A /100 ml. of culture medium completely inhibited keratinization in all the + A explants, whatever the age of the embryo from which they were obtained. This concentration induced mucous metaplasia in all the explants from 7- and 13-day chicks, and in a minority of those from 18-day embryos. In the 13- and 18-day explants, the outer strata of epidermal cells degenerated and were sloughed, and the secretory epithelium was formed from the deepest and least differentiated layers. The dermis also was affected by the vitamin. When the explants were transferred from + A to normal medium, mucin secretion at first increased, often becoming astonishingly copious; later the mucous tissue was shed and the deeper cells regenerated a squamous, keratinizing epidermis. In all the controls grown on normal medium, the epidermis retained its squamous structure and formed increasing amounts of keratin, except at the margin of the 7- and 13-day cultures; here the newly formed epithelium, which had spread beyond or below the dermis, often failed to cornify and in one 7-day control, which elsewhere was heavily keratinized, it even developed some secretory cells. This peripheral effect is thought to be due to the close and prolonged contact of the outwandering epithelium with the fairly high level of vitamin A normally present in fowl blood plasma. The concentrations of vitamin A used in the present experiments were much less than those that can be produced in the blood of fowls fed on a high vitamin A diet. The vitamin A in the culture medium, however, may be much more readily available to the epidermis than the same concentrations of vitamin in the blood stream of a hypervitaminotic bird. It is also probable that the vitamin is in a more active state in the culture medium than it is in vivo (cf. Fell & Mellanby 1952).

scholarly journals Schlafen 12 Interaction with SerpinB12 and Deubiquitylases Drives Human Enterocyte Differentiation

2018 ◽  
Vol 48 (3) ◽  
pp. 1274-1290 ◽  
Author(s):  
Marc D. Basson ◽  
Qinggang Wang ◽  
Lakshmi S. Chaturvedi ◽  
Shyam More ◽  
Emilie E. Vomhof-DeKrey ◽  
...  
Keyword(s):  
Duodenal Mucosa ◽  
Intestinal Epithelial ◽  
Putative Promoter ◽  
Protein Levels ◽  
Human Enterocyte ◽  
Laser Capture ◽  
Enterocyte Differentiation ◽  
Enterocytic Differentiation

Background/Aims: Human enterocytic differentiation is altered during development, fasting, adaptation, and bariatric surgery, but its intracellular control remains unclear. We hypothesized that Schlafen 12 (SLFN12) regulates enterocyte differentiation. Methods: We used laser capture dissection of epithelium, qRT-PCR, and immunohistochemistry to evaluate SLFN12 expression in biopsies of control and fasting human duodenal mucosa, and viral overexpression and siRNA to trace the SLFN12 pathway in human Caco-2 and HIEC6 intestinal epithelial cells. Results: Fasting human duodenal mucosa expressed less SLFN12 mRNA and protein, accompanied by decreases in enterocytic markers like sucrase-isomaltase. SLFN12 overexpression increased Caco-2 sucrase-isomaltase promoter activity, mRNA, and protein independently of proliferation, and activated the SLFN12 putative promoter. SLFN12 coprecipitated Serpin B12 (SERPB12). An inactivating SLFN12 point mutation prevented both SERPB12 binding and sucrase-isomaltase induction. SERPB12 overexpression also induced sucrase-isomaltase, while reducing SERPB12 prevented the SLFN12 effect on sucrase-isomaltase. Sucrase-isomaltase induction by both SLFN12 and SERPB12 was attenuated by reducing UCHL5 or USP14, and blocked by reducing both. SERPB12 stimulated USP14 but not UCHL5 activity. SERPB12 coprecipitated USP14 but not UCHL5. Moreover, SLFN12 increased protein levels of the sucrase-isomaltase-promoter-binding transcription factor cdx2 without altering Cdx2 mRNA. This was prevented by reducing UCHL5 and USP14. We further validated this pathway in vitro and in vivo. SLFN12 or SERPB12 overexpression induced sucrase-isomaltase in human non-malignant HIEC-6 enterocytes. Conclusions: SLFN12 regulates human enterocytic differentiation by a pathway involving SERPB12, the deubiquitylases, and Cdx2. This pathway may be targeted to manipulate human enterocytic differentiation in mucosal atrophy, short gut or obesity.

scholarly journals All-Trans Retinoic Acid Increases DRP1 Levels and Promotes Mitochondrial Fission

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1202
Author(s):  
Bojjibabu Chidipi ◽  
Syed Islamuddin Shah ◽  
Michelle Reiser ◽  
Manasa Kanithi ◽  
Amanda Garces ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Mitochondrial Fission ◽  
Normal Function ◽  
Mitochondrial Network ◽  
Protein Levels ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Area And Perimeter

In the heart, mitochondrial homeostasis is critical for sustaining normal function and optimal responses to metabolic and environmental stressors. Mitochondrial fusion and fission are thought to be necessary for maintaining a robust population of mitochondria, and disruptions in mitochondrial fission and/or fusion can lead to cellular dysfunction. The dynamin-related protein (DRP1) is an important mediator of mitochondrial fission. In this study, we investigated the direct effects of the micronutrient retinoid all-trans retinoic acid (ATRA) on the mitochondrial structure in vivo and in vitro using Western blot, confocal, and transmission electron microscopy, as well as mitochondrial network quantification using stochastic modeling. Our results showed that ATRA increases DRP1 protein levels, increases the localization of DRP1 to mitochondria in isolated mitochondrial preparations. Our results also suggested that ATRA remodels the mitochondrial ultrastructure where the mitochondrial area and perimeter were decreased and the circularity was increased. Microscopically, mitochondrial network remodeling is driven by an increased rate of fission over fusion events in ATRA, as suggested by our numerical modeling. In conclusion, ATRA results in a pharmacologically mediated increase in the DRP1 protein. It also results in the modulation of cardiac mitochondria by promoting fission events, altering the mitochondrial network, and modifying the ultrastructure of mitochondria in the heart.

scholarly journals TRIM27 interacts with Iκbα to promote the growth of human renal cancer cells through regulating the NF-κB pathway

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chengwu Xiao ◽  
Wei Zhang ◽  
Meimian Hua ◽  
Huan Chen ◽  
Bin Yang ◽  
...  
Keyword(s):  
Cell Lines ◽  
Prognostic Indicator ◽  
The Cancer Genome Atlas ◽  
Mrna Levels ◽  
Loss Of Function ◽  
Protein Levels ◽  
Kaplan Meier ◽  
Cancer Genome Atlas

Abstract Background The tripartite motif (TRIM) family proteins exhibit oncogenic roles in various cancers. The roles of TRIM27, a member of the TRIM super family, in renal cell carcinoma (RCC) remained unexplored. In the current study, we aimed to investigate the clinical impact and roles of TRIM27 in the development of RCC. Methods The mRNA levels of TRIM27 and Kaplan–Meier survival of RCC were analyzed from The Cancer Genome Atlas database. Real-time PCR and Western blotting were used to measure the mRNA and protein levels of TRIM27 both in vivo and in vitro. siRNA and TRIM27 were exogenously overexpressed in RCC cell lines to manipulate TRIM27 expression. Results We discovered that TRIM27 was elevated in RCC patients, and the expression of TRIM27 was closely correlated with poor prognosis. The loss of function and gain of function results illustrated that TRIM27 promotes cell proliferation and inhibits apoptosis in RCC cell lines. Furthermore, TRIM27 expression was positively associated with NF-κB expression in patients with RCC. Blocking the activity of NF-κB attenuated the TRIM27-mediated enhancement of proliferation and inhibition of apoptosis. TRIM27 directly interacted with Iκbα, an inhibitor of NF-κB, to promote its ubiquitination, and the inhibitory effects of TRIM27 on Iκbα led to NF-κB activation. Conclusions Our results suggest that TRIM27 exhibits an oncogenic role in RCC by regulating NF-κB signaling. TRIM27 serves as a specific prognostic indicator for RCC, and strategies targeting the suppression of TRIM27 function may shed light on future therapeutic approaches.

scholarly journals Long noncoding RNA SNHG14 promotes hepatocellular carcinoma progression by regulating miR-876-5p/SSR2 axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zhibin Liao ◽  
Hongwei Zhang ◽  
Chen Su ◽  
Furong Liu ◽  
Yachong Liu ◽  
...  
Keyword(s):  
Noncoding Rna ◽  
Animal Experiments ◽  
Luciferase Reporter ◽  
Western Blot Assay ◽  
Downstream Target ◽  
Protein Levels ◽  
Elevated Expression ◽  
Rna Immunoprecipitation

Abstract Background Aberrant expressions of long noncoding RNAs (lncRNAs) have been demonstrated to be related to the progress of HCC. The mechanisms that SNHG14 has participated in the development of HCC are obscure. Methods Quantitative real-time PCR (qRT-PCR) was used to measure the lncRNA, microRNA and mRNA expression level. Cell migration, invasion and proliferation ability were evaluated by transwell and CCK8 assays. The ceRNA regulatory mechanism of SNHG14 was evaluated by RNA immunoprecipitation (RIP) and dual luciferase reporter assay. Tumorigenesis mouse model was used to explore the roles of miR-876-5p in vivo. The protein levels of SSR2 were measured by western blot assay. Results In this study, we demonstrated that SNHG14 was highly expressed in HCC tissues, meanwhile, the elevated expression of SNHG14 predicted poor prognosis in patients with HCC. SNHG14 promoted proliferation and metastasis of HCC cells. We further revealed that SNHG14 functioned as a competing endogenous RNA (ceRNA) for miR-876-5p and that SSR2 was a downstream target of miR-876-5p in HCC. Transwell, CCK8 and animal experiments exhibited miR-876-5p inhibited HCC progression in vitro and in vivo. By conducting rescue experiments, we found the overexpression of SSR2 or knocking down the level of miR-876-5p could reverse the suppressive roles of SNHG14 depletion in HCC. Conclusion SNHG14 promotes HCC progress by acting as a sponge of miR-876-5p to regulate the expression of SSR2 in HCC.

Phospholipase D1b and D2a generate structurally identical phosphatidic acid species in mammalian cells

2001 ◽  
Vol 360 (3) ◽  
pp. 707-715 ◽  
Author(s):  
Trevor R. PETTITT ◽  
Mark McDERMOTT ◽  
Khalid M. SAQIB ◽  
Neil SHIMWELL ◽  
Michael J. O. WAKELAM
Keyword(s):  
Liquid Chromatography ◽  
Phosphatidic Acid ◽  
Phospholipase D ◽  
Mammalian Cells ◽  
Inducible Promoter ◽  
In Vitro Assays ◽  
Protein Levels ◽  
Intracellular Messenger

Mammalian cells contain different phospholipase D enzymes (PLDs) whose distinct physiological roles are poorly understood and whose products have not been characterized. The development of porcine aortic endothelial (PAE) cell lines able to overexpress PLD-1b or −2a under the control of an inducible promoter has enabled us to characterize both the substrate specificity and the phosphatidic acid (PtdOH) product of these enzymes under controlled conditions. Liquid chromatography–MS analysis showed that PLD1b- and PLD2a-transfected PAE cells, as well as COS7 and Rat1 cells, generate similar PtdOH and, in the presence of butan-1-ol, phosphatidylbutanol (PtdBut) profiles, enriched in mono- and di-unsaturated species, in particular 16:0/18:1. Although PtdBut mass increased, the species profile did not change in cells stimulated with ATP or PMA. Overexpression of PLD made little difference to basal or stimulated PtdBut formation, indicating that activity is tightly regulated in vivo and that factors other than just PLD protein levels limit hydrolytic function. In vitro assays using PLD-enriched lysates showed that the enzyme could utilize both phosphatidylcholine and, much less efficiently, phosphatidylethanolamine, with slight selectivity towards mono- and di-unsaturated species. Phosphatidylinositol was not a substrate. Thus PLD1b and PLD2a hydrolyse a structurally similar substrate pool to generate an identical PtdOH product enriched in mono- and di-unsaturated species that we propose to function as the intracellular messenger forms of this lipid.

scholarly journals BIOM-55. DGKζ-TARGETED REGULATION OF MIR-34A IN THE PROLIFERATION AND TUMORIGENICITY OF HUMAN GLIOBLASTOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii13-ii13
Author(s):  
Wangxian Gu ◽  
Guoqing Wan ◽  
Yanjun Zheng ◽  
Xintong Yang ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Precancerous Lesions ◽  
Lipid Kinase ◽  
Human Glioblastoma ◽  
Kinase Substrate ◽  
Downstream Target ◽  
Protein Levels ◽  
Type Iv

Abstract Diacylglycerol kinase (DGK) is a lipid kinase that catalyzes the phosphorylation of diacylglycerol (DAG) to produce phosphatidic acid (PA), which uses ATP as a phosphate donor. Diacylglycerol kinases ζ(DGKζ) is characterized as specific type IV due to its myristoylated alanine-rich C-kinase substrate (MARCKS), ankyrin, and PDZ binding domain. Similar to other DGKs, DGKζ is also reported to be abnormally expressed in human colorectal cancer cells, and it is indispensable for the proliferation of cancer cells. However, its implications in human glioblastoma (GBM) is largely unknown. Both the mRNA and protein levels of DGKζ were significantly higher in GBM tissues than in precancerous lesions. Knockdown of DGKζ inhibited GBM cell proliferation, cell cycle and promoted apoptosis of GBM cells. Moreover, down-regulation of DGKζ markedly reduced in vitro colony formation and in vivo tumorigenic capability. Furthermore, we confirmed that DGKζ was the downstream target of miR-34a. The expression level of DGKζ was negatively correlated with miR-34a in GBM tissues. Overexpression of DGKζ reversed the tumor suppressive roles of miR-34a in GBM cells. Taken together, DGKζ can act as a potential prognostic biomarker for GBM patients and promote the growth of GBM cells was regulated by miR-34a, and it may represent a promising therapeutic target for patients with GBM.

scholarly journals EXTH-51. ANTI-INVASIVE EFFICACY AND SURVIVAL BENEFIT OF THE YAP-TEAD INHIBITOR VERTEPORFIN IN PRECLINICAL GLIOBLASTOMA MODELS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii98-ii98
Author(s):  
Anne Marie Barrette ◽  
Alexandros Bouras ◽  
German Nudelman ◽  
Zarmeen Mussa ◽  
Elena Zaslavsky ◽  
...  
Keyword(s):  
Survival Benefit ◽  
De Novo ◽  
Epithelial Mesenchymal Transition ◽  
Intraperitoneal Administration ◽  
Standard Of Care ◽  
Tumor Burden ◽  
Mesenchymal Transition ◽  
Protein Levels

Abstract Glioblastoma (GBM) remains an incurable disease, in large part due to its malignant infiltrative spread, and current clinical therapy fails to target the invasive nature of tumor cells in disease progression and recurrence. Here, we use the YAP-TEAD inhibitor Verteporfin to target a convergence point for regulating tumor invasion/metastasis and establish the robust anti-invasive therapeutic efficacy of this FDA-approved drug and its survival benefit across several preclinical glioma models. Using patient-derived GBM cells and orthotopic xenograft models (PDX), we show that Verteporfin treatment disrupts YAP/TAZ-TEAD activity and processes related to cell adhesion, migration and epithelial-mesenchymal transition. In-vitro, Verteporfin impairs tumor migration, invasion and motility dynamics. In-vivo, intraperitoneal administration of Verteporfin in mice with orthotopic PDX tumors shows consistent drug accumulation within the brain and decreased infiltrative tumor burden, across three independent experiments. Interestingly, PDX tumors with impaired invasion after Verteporfin treatment downregulate CDH2 and ITGB1 adhesion protein levels within the tumor microenvironment. Finally, Verteporfin treatment confers survival benefit in two independent PDX models: as monotherapy in de-novo GBM and in combination with standard-of-care chemoradiation in recurrent GBM. These findings indicate potential therapeutic value of this FDA-approved drug if repurposed for GBM patients.

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