scholarly journals Ets-1 expression and gemcitabine chemoresistance in pancreatic cancer cells

2011 ◽  
Vol 16 (1) ◽  
Author(s):  
Amit Khanna ◽  
Kulandaivelu Mahalingam ◽  
Debarshi Chakrabarti ◽  
Giridharan Periyasamy
Keyword(s):  
Pancreatic Cancer ◽  
Protein Expression ◽  
Western Blot ◽  
Cancer Cells ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Time Course ◽  
Target Genes ◽  
Fold Increase ◽  
Pancreatic Cancer Cells

AbstractGemcitabine, a novel pyrimidine nucleoside analog, has become the standard chemotherapeutic agent for pancreatic cancer patients. The clinical impact of gemcitabine remains modest owing to the high degree of inherent and acquired resistance. There are various lines of evidence that confirm the role of Ets-1, a proto-oncoprotein, in tumor invasion, progression, and chemoresistance. This study examines a hypothesis that implicates Ets-1 in the development of gemcitabine-resistance in pancreatic cancer cells. Ets-1 protein expression was assessed in parental pancreatic cancer cells and their gemcitabine-resistant clones. Western blot analysis revealed elevated levels of Ets-1 protein expression in gemcitabine-resistant PANC1GemRes (4.8-fold increase; P < 0.05), MIA PaCa2GemRes (3.2-fold increase; P < 0.05), and Capan2GemRes (2.1-fold increase; P < 0.05) cells as compared to their parental counterparts. A time course analysis was conducted to determine the change in Ets-1 expression in the parental cells after incubation with gemcitabine. Reverse transcriptase quantitative real-time PCR (RT-qPCR) and Western blot analysis revealed a significant increase in Ets-1 expression. All the three parental cells incubated with gemcitabine showed elevated Ets-1 protein expression at 6 h. By 24 h, the expression level had decreased. Using small interfering RNA (siRNA) against Ets-1 in gemcitabine-resistant cells, we demonstrated a reversal in gemcitabine chemosensitivity and also detected a marked reduction in the expression of the Ets-1 target genes MMP1 and uPA. Our novel finding demonstrates the significance of Ets-1 in the development of gemcitabine chemoresistance in pancreatic cancer cells. Based on these results, a new siRNA-based therapeutic strategy targeting the Ets-1 genes can be designed to overcome chemoresistance.

Effect of nicotine on chemoresistant phenotype as mediated through Src-dependent Id1 expression in pancreatic adenocarcinoma cells.

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 216-216
Author(s):  
J. G. Trevino ◽  
S. R. Pillai ◽  
S. P. Chellappan
Keyword(s):  
Pancreatic Cancer ◽  
Western Blot ◽  
Cell Viability ◽  
Cancer Cells ◽  
Signaling Pathways ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Pancreatic Tumor ◽  
Pancreatic Cancer Cells ◽  
Dependent Pathway

216 Background: The signaling pathways contributing to DNA-binding protein inhibitor Id1 expression and chemoresistance in pancreatic cancer remain unknown. Id1 plays a role in pancreatic tumor progression with tumor-promoting effects of nicotine regulating protein tyrosine kinase Src activation and Id1 expression, both associated with chemoresistance in other systems. We hypothesize Id1 expression regulates chemoresistance in pancreatic cancer through a nicotine-promoting Src-dependent pathway. Methods: We probed pancreatic cancer cell lines (L3.6pl, PANC-1, Mia-PaCa-2) for innate gemcitabine chemoresistance with cell viability MTT assay and western blot analysis of PARP cleavage programmed cell death. Gemcitabine-sensitive cells were exposed to rising gemcitabine concentrations to establish a resistant subtype, L3.6plGemRes. Protein analysis and mRNA expression were determined by western blot analysis and RT-PCR respectively. Induction of Src phosphorylation or Id1 expression was performed with nicotine (1 μM). Results: Inhibition of c-Src expression was performed with short-interfering RNA (siRNA). Nicotine-induced Src phosphorylation and Id1 expression. Inhibition of Src by siRNA resulted in decreased nicotine-induced Id1 expression. Inhibition of Src and Id1 expression by siRNA in innate or established gemcitabine resistant pancreatic cancer cells resulted in gemcitabine sensitization. To determine if nicotine contributes to gemcitabine chemoresistance, we exposed gemcitabine-sensitive cells to nicotine with subsequent exposure to gemcitabine IC50, 250 ng/ml, and cell viability assays confirmed a 2-fold increase in cell prolilferation and a 4.5-fold reduction in apoptosis. Further, nicotine induced phosphorylation of key signaling enzymes involved in proliferation and apoptosis, Erk1/2 and Akt respectively. Conclusions: In summary, we demonstrate that Id1, through a nicotine-promoting Src-dependent pathway, is necessary for establishment of a chemoresistant phenotype in pancreatic cancer cells. Understanding the signaling pathways involved in pancreatic tumor chemoresistance will lead to therapies resulting in improved tumor responses. No significant financial relationships to disclose.

scholarly journals DDX31: A Novel Functional Oncogene Promotes Migration and Proliferation of Pancreatic Cancer

2021 ◽  
Author(s):  
Yang Liu ◽  
Yongjie Xie ◽  
Jinsheng Ding ◽  
Liangliang Wu
Keyword(s):  
Pancreatic Cancer ◽  
Western Blot ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Cancer Cells ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Ductal Adenocarcinoma ◽  
Rna Helicases ◽  
Pancreatic Cancer Cells

Abstract Purpose: Pancreatic cancer is one of the most malignant cancers with rapid disease progression. Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% in exocrine pancreatic cancer. DDX31 is one of the Asp-Glu-Ala-Asp (DEAD)-box RNA helicases (DDX) family member, which has never been reported in pancreatic ductal adenocarcinoma. Through comprehensive analysis of bioinformatics screening, clinical pathological data and experiment results verification, we found DDX31 may be a promising oncogene.Patients and methods: The potential correlation between DDX3 expression and clinical feature of PDAC was analyzed, which revealed that patients with high DDX31 expression may have a poor prognosis. Elevated expression levels of DDX31 in PDAC compared with adjacent normal tissues were determined by immunohistochemical and Western blot analyses. Western blot analysis of N-cadherin, Snail, transwell, and wound healing assays was carried out to evaluate the pro-metastasis effects of DDX31 in PDAC. In vitro experiments included colony formation assay. Edu labeling assay, CCK-8, western blot analysis of Ki67, PCNA, and an in vivo subcutaneous mouse model were used to analyze the role of DDX31 in PDAC proliferation.Results: In our research, integrated bioinformatics analysis of the TCGA and GEO databases was performed to identify the metastasis and proliferation-related differentially expressed genes (DEG). DDX31 predicts strong metastasis and proliferation capacity of PDAC, was finally screened. Then, the clinical data identified that highexpression-DDX31 was correlated with pancreatic tumor size, pathological grade, and lymph node metastasis. The in vitro and vivo experiments revealed that overexpression-DDX31 promoted the migration, proliferation and cell viability of pancreatic cancer cells, these functions of DDX31 had also been proved in the knockdown results. Moreover, the EMT related markers and proliferation markers were identified to be positively regulated by DDX31 in pancreatic cancer cells.Conclusion: Thus, our work uncovered that DDX31 promotes migration and proliferation in PDAC and might be a promising therapeutic target in pancreatic cancer.

Effect of KRAS and P-STAT3 inhibition by SBT-100 on gemcitabine and pancreatic cancer growth in vivo.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15727-e15727
Author(s):  
Sunanda Singh ◽  
Genoveva Murillo ◽  
Avani Singh ◽  
Samara Singh ◽  
Meenakshi S Parihar ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Targeted Therapy ◽  
Western Blot ◽  
Cancer Cells ◽  
Mtt Assay ◽  
Blot Analysis ◽  
Cancer Growth ◽  
Pancreatic Cancers ◽  
Pancreatic Cancer Cells

e15727 Background: Over 90% of pancreatic cancers have KRAS mutations and hyper-expression of P-STAT3 oncoproteins, which if specifically targeted may help treatment of pancreatic cancers. Singh Biotechnology’s proprietary technology engineered SBT-100, a single domain antibody that is bispecific for KRAS & STAT3, which can cross the cell membranes and bind to these intracellular oncoproteins. Combining this targeted therapy with an established chemotherapy, such as gemcitabine, may improve patient’s response to treatment. Methods: Human pancreatic cancer cells (PANC-1 and BX-PC3) were used. Biacore assay demonstrates SBT-100 binding to KRAS, KRAS (G12D), and STAT3. Immunoprecipitation (IP) and western blot analysis confirmed binding to STAT3 by SBT-100. Pancreatic cancer cells were treated at varying doses of SBT-100 ranging from 0µg/ml to 200µg/ml ± gemcitabine, and after 72 hours growth inhibition was determined by a MTT assay. PANC-1 tumors were grown in athymic nude mice, divided into four groups and staged to a range of 100-150mm3 before treatment. Groups were: vehicle only, SBT-100, gemcitabine, and SBT-100 & gemcitabine. Animals received treatments for 14 days, then monitored for 7 days. Results: Biacore study shows SBT-100 binds KRAS with an affinity of 10-9M, KRAS (G12D) with 10-8M, and STAT3 with 10-8M. IP and western blot analysis demonstrates that SBT-100 binds P-STAT3. MTT assay demonstrates SBT-100 inhibits the growth of PANC-1 and BX-PC3 (p < 0.001). In PANC1 cells a combination of SBT-100 & gemcitabine demonstrates synergism in inhibiting growth of PANC-1, even at 1/8th the gemcitabine IC50 concentration. PANC-1 xenograft study demonstrates that combination therapy of SBT-100 & gemcitabine is superior to either SBT-100 or gemcitabine alone. Compared to the vehicle group, SBT-100 & gemcitabine is far superior (p < 0.001) and gives statistically significant suppression of pancreatic cancer growth in vivo. Conclusions: Targeted therapy for KRAS and P-STAT3 expressing tumors with SBT-100 & gemcitabine is synergistic for the treatment of pancreatic cancer. This study suggests that synergism maybe achieved with lower doses of gemcitabine, thereby reducing toxicity in patients.

scholarly journals Aquaporin-8 is a novel marker for progression of human cervical cancer cells

2021 ◽  
pp. 1-10
Author(s):  
Weibo Li ◽  
Yizuo Song ◽  
Chunyu Pan ◽  
Junhui Yu ◽  
Jianan Zhang ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Protein Expression ◽  
Western Blot ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Siha Cells ◽  
Potential Marker ◽  
Cervical Cancer Cells

BACKGROUND: Role of aquaporin-8 (AQP8) in cervical cancer has not been fully elucidated. OBJECTIVE: We aim to explore the impacts of AQP8 on viability, apoptosis and metastasis in cervical cancer cells. METHODS: AQP8 protein expression in cervical carcinoma specimens and cell lines was detected by IHC and western blot analysis. Lentivirus-mediated transfection was used to upregulate and knockdown AQP8 in cells. Cell viability and apoptosis were assessed by CCK-8 and flow cytometry assays, respectively. Transwell experiments were conducted to investigate cell invasive and migratory capabilities. EMT-related markers were detected by western blot analysis. RESULTS: A strong positive of AQP8 protein expression was observed in cervical cancer tissues. Western blot analysis confirmed overexpression and knockdown of AQP8 in SiHa cells. AQP8-overexpressed SiHa cells displayed an enhanced viability, reduced apoptotic rate, increased invasive and migratory abilities. Knockdown of AQP8 inhibited the viability, promoted the apoptosis, and suppressed invasion and migration. Furthermore, AQP8 overexpression significantly upregulated vimentin and N-cadherin, and downregulated E-cadherin, which were reversed by AQP8 knockdown. CONCLUSIONS: AQP8 increases viability, inhibits apoptosis, and facilitates metastasis in SiHa cells. This may be associated with EMT-related markers regulated by AQP8. AQP8 could serves as a potential marker for cervical cancer progression.

Synthesis and Characterization of Quinoline-3-Carboxamide Derivatives as Inhibitors of the ATM Kinase

2020 ◽  
Vol 20 (23) ◽  
pp. 2070-2079
Author(s):  
Srimadhavi Ravi ◽  
Sugata Barui ◽  
Sivapriya Kirubakaran ◽  
Parul Duhan ◽  
Kaushik Bhowmik
Keyword(s):  
Western Blot ◽  
Cancer Cells ◽  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Cancer Cell Lines ◽  
Atm Kinase ◽  
Cytotoxicity Studies

Background: The importance of inhibiting the kinases of the DDR pathway for radiosensitizing cancer cells is well established. Cancer cells exploit these kinases for their survival, which leads to the development of resistance towards DNA damaging therapeutics. Objective: In this article, the focus is on targeting the key mediator of the DDR pathway, the ATM kinase. A new set of quinoline-3-carboxamides, as potential inhibitors of ATM, is reported. Methods: Quinoline-3-carboxamide derivatives were synthesized and cytotoxicity assay was performed to analyze the effect of molecules on different cancer cell lines like HCT116, MDA-MB-468, and MDA-MB-231. Results: Three of the synthesized compounds showed promising cytotoxicity towards a selected set of cancer cell lines. Western Blot analysis was also performed by pre-treating the cells with quercetin, a known ATM upregulator, by causing DNA double-strand breaks. SAR studies suggested the importance of the electron-donating nature of the R group for the molecule to be toxic. Finally, Western-Blot analysis confirmed the down-regulation of ATM in the cells. Additionally, the PTEN negative cell line, MDA-MB-468, was more sensitive towards the compounds in comparison with the PTEN positive cell line, MDA-MB-231. Cytotoxicity studies against 293T cells showed that the compounds were at least three times less toxic when compared with HCT116. Conclusion: In conclusion, these experiments will lay the groundwork for the evolution of potent and selective ATM inhibitors for the radio- and chemo-sensitization of cancer cells.

scholarly journals Proteolytic cleavage and truncation of NDRG1 in human prostate cancer cells, but not normal prostate epithelial cells

2013 ◽  
Vol 33 (3) ◽  
Author(s):  
Mohammad K. Ghalayini ◽  
Qihan Dong ◽  
Des R. Richardson ◽  
Stephen J. Assinder
Keyword(s):  
Prostate Cancer ◽  
Epithelial Cells ◽  
Western Blot ◽  
Cancer Cells ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Metastasis Suppressor ◽  
Normal Prostate ◽  
Truncated Protein ◽  
Prostate Epithelial Cells

NDRG1 (N-myc downstream regulated gene-1) is a metastasis suppressor that is down-regulated in prostate cancer. NDRG1 phosphorylation is associated with inhibition of metastasis and Western blots indicate two bands at ~41 and ~46 kDa. Previous investigations by others suggest the higher band is due to NDRG1 phosphorylation. However, the current study using a dephosphorylation assay and the Phos-tag (phosphate-binding tag) SDS/PAGE assay, demonstrated that the 46 kDa NDRG1 protein band was not due to phosphorylation. Further experiments showed that the NDRG1 protein bands were not affected upon glycosidase treatment, despite marked effects of these enzymes on the glycosylated protein, fetuin. Analysis using RT–PCR (reverse transcriptase–PCR) demonstrated only a single amplicon, and thus, the two bands could not result from an alternatively spliced NDRG1 transcript. Western-blot analysis of prostate cancer cell lysates identified the 41 kDa band to be a truncated form of NDRG1, with MS confirming the full and truncated proteins to be NDRG1. Significantly, this truncated protein was not present in normal human PrECs (prostate epithelial cells). Western-blot analysis using anti-NDRG1 raised to its N-terminal sequence failed to detect the truncated protein, suggesting that it lacked N-terminus amino acids (residues 1–49). Sequence analysis predicted a pseudotrypsin protease cleavage site between Cys49–Gly50. Such cleavage of NDRG1 in cancer cells may result in loss of NDRG1 tumour suppressive activity.

Abstract WP433: Targeting Organic Anion Transporting Polypeptide 1a4 (Oatp1a4) Expression at the Blood-brain Barrier: Implications for Treatment of Ischemic Stroke

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Wazir Abdullahi ◽  
Hrvoje Brzica ◽  
Patrick Ronaldson
Keyword(s):  
Protein Expression ◽  
Western Blot ◽  
Rat Brain ◽  
Blood Brain Barrier ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Organic Anion ◽  
Stroke Treatment ◽  
Brain Microvessels ◽  
Cns Delivery

Introduction: Stroke is a leading cause of mortality and morbidity. Several drugs with neuroprotective properties have been proposed for stroke treatment but many have failed in clinical trials. These failures may be due to limited drug permeability across the blood-brain barrier (BBB). Targeting endogenous BBB uptake transporters (i.e., organic anion transporting polypeptides (Oatps)) is a novel approach that can improve CNS delivery of drugs relevant to stroke therapy (i.e., statins). Optimal CNS drug delivery via Oatp in the setting of stroke requires characterization of regulatory pathways such as transforming growth factor (TGF)-β signaling. The goal of the present study was to investigate, in vivo , involvement of TGF-β signaling via the activin-like kinase (ALK)-1 receptor on Oatp1a4 expression at the BBB. Methods: Female Sprague-Dawley rats (200-250 g) were administered bone morphogenic protein-9 (BMP-9; 0-5 μg/kg, i.p.), an ALK1 agonist, or vehicle (i.e., 0.9% saline). Inhibition experiments were performed using LDN193189 (0-5 mg/kg, i.p.), an ALK1 antagonist. Western blot analysis and fluorescence microscopy of isolated brain microvessels were used to determine protein expression and localization in rat brain microvessels respectively. Results: Fluorescence staining demonstrated localization of Oatp1a4 and ALK1 in rat brain microvessels. Western blot analysis showed a dose dependent increase in Oatp1a4 protein expression in brain microvessels isolated from BMP-9 treated rats as compared to controls. Treatment with 0.5 μg/kg and 5 μg/kg BMP-9 resulted in a 55% and 116% increase in Oatp1a4 protein expression, implying that activation of ALK1 signaling can up-regulate Oatp1a4 at the brain microvasculature. In contrast, 6 h treatment with LDN193189 did not alter Oatp1a4 expression across a dose range of 0-5 mg/kg, suggesting that ALK1 inhibition does not modulate basal Oatp1a4 expression at the BBB. Conclusions: Taken together, our data implies that TGF-β/ALK1 signaling may play a role in altering Oatp1a4 protein expression at the BBB. Studies are currently being undertaken in our laboratory to fully characterize the role of TGF-β/ALK1 signaling in determining CNS delivery of drugs relevant to stroke treatment (i.e., statins).

Abstract 234: Interleukin 2 Promotes Proliferation and Migration in Vascular Smooth Muscle Cells

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Spencer Barnhill ◽  
Prakash Arumugam ◽  
John Matsuura ◽  
Scott Berceli ◽  
Katie Carroll ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Protein Expression ◽  
Western Blot ◽  
Vascular Smooth Muscle Cells ◽  
Blot Analysis ◽  
Intimal Hyperplasia ◽  
Western Blot Analysis ◽  
Interleukin 2 ◽  
And Migration ◽  
Proliferation And Migration

Interleukin-2 (IL-2) is primarily known as a soluble cytokine that regulates T cell responses. We previously reported, however, that IL-2 is retained in the extracellular matrix by association with perlecan, a heparan sulfate proteoglycan (HSPG). Perlecan is the main HSPG in vascular basement membranes, and previous studies from our laboratory demonstrated that, in human arteries, vascular smooth muscle cells (VSMC) are surrounded by perlecan-bound IL-2. We also noted that IL-2 deficient mice lose SMCs with age, leading to widened esophagi and aortic aneurysms. Given this information, we hypothesized that IL-2 has a direct impact on VSMC, and that VSMC express functional IL-2 receptors (IL-2R). We therefore examined both protein and mRNA expression of each of the three IL-2R subunits (alpha, beta, gamma) on human VSMC grown from arterial explants. These VSMC expressed SMC actin, smooth muscle myosin heavy chain, and when quiescent, smoothelin. Protein expression was assessed by in cell Western and by Western blot analysis. Receptor expression was evaluated under distinct culture conditions, which yielded highly proliferative, intermediate, or quiescent VSMC. Contractile protein expression was low, intermediate, or high, respectively, consistent with the characteristics of proliferating vs quiescent SMCs. Each phenotype expressed all 3 subunits of the IL-2R. IL-2 subunits appeared to follow a cytoskeletal pattern in cells expressing high levels of contractile proteins. Western blot analysis of VSMC lysates revealed expression of all 3 receptors at molecular weights identical to lysates from a T cell line. VSMCs also expressed mRNA for each receptor subunit. Functionally, IL-2 promoted migration (using a Boyden chamber assay) and proliferation in a dose dependent fashion. Because excess proliferation and migration are critical to intimal hyperplasia, we asked whether IL-2 levels change under conditions known to generate intimal hyperplasia. In a rabbit model, IL-2 mRNA increased in venous grafts exposed to high flow for 2h. IL-2 levels, by Western blot, were also increased in human hyperplastic veins. In conclusion, these data show that VSMC have functional IL-2R, and suggest that IL-2 may contribute to the development of intimal hyperplasia.

scholarly journals Proteomic profiles of unilateral cryptorchidism in pigs at different ages using MALDI-TOF mass spectrometry and in-gel digestion coupled with mass spectrometry (GeLC-MS/MS) approaches

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Nathamon Yimpring ◽  
Sittiruk Roytrakul ◽  
Janthima Jaresitthikunchai ◽  
Narumon Phaonakrop ◽  
Sucheewin Krobthong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Protein Expression ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Expression Profiles ◽  
Tumor Necrosis Factor Receptor ◽  
Principal Component ◽  
Peptide Mass ◽  
Different Ages

Abstract Background Cryptorchidism is a condition that occurs when one or both testes fail to descend into the scrotum. It is a common congenital disorder, causing economic loss in pig production. However, there have been only limited studies of differential protein expression profiles in undescended testes (UDTs) in the abdomen and descended testes (DTs) in cryptorchid pigs, especially at the peptidome and proteome levels. The present study aimed to analyze the peptidome of UDTs and DTs in unilateral cryptorchid pigs aged 1–2, 6, 15 and 20 weeks and in normal testes of healthy pigs aged 1–2 and 12 weeks, using peptide mass fingerprinting and three-dimensional principal component analysis (3D-PCA) with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and to identify potential protein candidates, using in-gel digestion coupled with mass spectrometry (GeLC-MS/MS). Western blot analysis was used to verify protein expression. Protein sequence was affirmed by liquid chromatography–tandem mass spectrometry. Results A PCA plot showed a discrete cluster for each sample group. Peptide mass fingerprints (PMFs) demonstrated unique peptide fragments in UDTs at different ages. A number of markedly expressed proteins from GeLC-MS/MS were identified, including the multifunctional tumor necrosis factor receptor superfamily member 18 (TNFRSF18), in DTs at 1–2 and 6 weeks and in UDTs at 15 and 20 weeks of age. Using western blot analysis, high expression of TNFRSF18 was observed in the UDTs at 15 weeks. Using the STITCH database, this protein was found to be related to apoptosis, corresponding to the previous report in the UDTs at the same age. Conclusions The present study revealed the specific PMFs and clusters for porcine cryptorchidism, and a novel protein, TNFRSF18, associated with the disease mechanism. These results could provide further insights into the pathogenesis of the disease.

scholarly journals In Vitro and In Vivo Effects of Fermented Oyster-Derived Lactate on Exercise Endurance Indicators in Mice

2020 ◽  
Vol 17 (23) ◽  
pp. 8811
Author(s):  
Storm N. S. Reid ◽  
Joung-Hyun Park ◽  
Yunsook Kim ◽  
Yi Sub Kwak ◽  
Byeong Hwan Jeon
Keyword(s):  
Lactate Dehydrogenase ◽  
Protein Expression ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Biochemical Analysis ◽  
Positive Control ◽  
Exercise Endurance

Exogenous lactate administration has more recently been investigated for its various prophylactic effects. Lactate derived from potential functional foods, such as fermented oyster extract (FO), may emerge as a practical and effective method of consuming exogenous lactate. The current study endeavored to ascertain whether the lactate derived from FO may act on muscle cell biology, and to what extent this may translate into physical fitness improvements. We examined the effects of FO in vitro and in vivo, on mouse C2C12 cells and exercise performance indicators in mice, respectively. In vitro, biochemical analysis was carried out to determine the effects of FO on lactate content and muscle cell energy metabolism, including adenosine triphosphate (ATP) activity. Western blot analysis was also utilized to measure the protein expression of total adenosine monophosphate-activated protein kinase (AMPK), p-AMPK (Thr172), lactate dehydrogenase (LDH), succinate dehydrogenase (SDHA) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in response to FO administration. Three experimental groups were formed: a positive control (PC) treated with 1% horse serum, FO10 treated with 10 μg/mL and FO50 treated with 50 μg/mL. In vivo, the effects of FO supplementation on exercise endurance were measured using the Rota-rod test, and Western blot analysis measured myosin heavy-chain 2 (MYH2) to assess skeletal muscle growth, alongside p-AMPK, total-AMPK, PGC-1α, cytochrome C and UCP3 protein expression. Biochemical analysis was also performed on muscle tissue to measure the changes in concentration of liver lactate, lactate dehydrogenase (LDH), glycogen and citrate. Five groups (n = 10/per group) consisted of a control group (CON), exercise group (Ex), positive control treated with Ex and 500 mg/kg Taurine (Ex-Tau), Ex and 100 mg/kg FO supplementation (Ex-FO100) and Ex and 200 mg/kg FO supplementation (Ex-FO200) orally administered over the 4-week experimental period.FO50 significantly increased PGC-1α expression (p < 0.001), whereas both FO10 and FO50 increased the expression of p-AMPK (p < 0.001), in C2C12 muscle cells, showing increased signaling important for mitochondrial metabolism and biogenesis. Muscle lactate levels were also significantly increased following FO10 (p < 0.05) and FO50 (p < 0.001). In vivo, muscle protein expression of p-AMPK (p < 0.05) and PGC-1α were increased, corroborating our in vitro results. Cytochrome C also significantly increased following FO200 intake. These results suggest that the effects of FO supplementation may manifest in a dose-response manner. FO administration, in vitro, and supplementation, in vivo, both demonstrate a potential for improvements in mitochondrial metabolism and biogenesis, and even for potentiating the adaptive effects of endurance exercise. Mechanistically, lactate may be an important molecule in explaining the aforementioned positive effects of FO.

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