scholarly journals Robust Comparison of Protein Levels Across Tissues and Throughout Development Using Standardized Quantitative Western Blotting

Author(s):  
Yu-Ting Huang ◽  
Dinja van der Hoorn ◽  
Leire M. Ledahawsky ◽  
Anna A. L. Motyl ◽  
Crispin Y. Jordan ◽  
...  
2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ke Zhang ◽  
Zhuoying Li ◽  
Yunyang Lu ◽  
Linyi Xiang ◽  
Jiadong Sun ◽  
...  

Abstract Background The Wnt planar cell polarity (PCP) pathway is implicated in osteoarthritis (OA) both in animals and in humans. Van Gogh-like 2 (Vangl2) is a key PCP protein that is required for the orientation and alignment of chondrocytes in the growth plate. However, its functional roles in OA still remain undefined. Here, we explored the effects of Vangl2 on OA chondrocyte in vitro and further elucidated the molecular mechanism of silencing Vangl2 in Wnt5a-overexpressing OA chondrocytes. Methods Chondrocytes were treated with IL-1β (10 ng/mL) to simulate the inflammatory microenvironment of OA. The expression levels of Vangl2, Wnt5a, MMPs, and related proinflammatory cytokines were measured by RT-qPCR. Small interfering RNA (siRNA) of Vangl2 and the plasmid targeting Wnt5a were constructed and transfected into ATDC5 cells. Then, the functional roles of silencing Vangl2 in the OA chondrocytes were investigated by Western blotting, RT-qPCR, and immunocytochemistry (ICC). Transfected OA chondrocytes were subjected to Western blotting to analyze the relationship between Vangl2 and related signaling pathways. Results IL-1β induced the production of Vangl2, Wnt5a, and MMPs in a time-dependent manner and the significantly increased expression of Vangl2. Vangl2 silencing effectively suppressed the expression of MMP3, MMP9, MMP13, and IL-6 at both gene and protein levels and upregulated the expression of type II collagen and aggrecan. Moreover, knockdown of Vangl2 inhibited the phosphorylation of MAPK signaling molecules (P38, ERK, and JNK) and P65 in Wnt5a-overexpressing OA chondrocytes. Conclusions For the first time, we demonstrate that Vangl2 is involved in the OA process. Vangl2 silencing can notably alleviate OA progression in vitro by inhibiting the expression of MMPs and increasing the formation of the cartilage matrix and can inhibit the proinflammatory effects of Wnt5a via MAPK and NF-κB pathway. This study provides new insight into the mechanism of cartilage inflammation.


Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Rong Xie ◽  
Michelle Cheng ◽  
Mei Li ◽  
Robert Sapolsky ◽  
Heng Zhao

Background and Objective: Akt is a serine-threonine kinase that plays critical role in promoting cell survival. Akt consists of three isoforms (Akt1, 2, 3), with Akt3 predominantly expressed in the brain. Although Akt pathway has been shown to mediate neuronal survival in cerebral ischemic injury, it is unclear how these Akt isoforms contribute to neuronal protection, and whether exogenous Akt can protect the brain against ischemic injury or not. In this study, we over-expressed Akt isoforms and its downstream signaling proteins such as FKHR and PRAS40 to investigate the role of the Akt pathway along with its potential relationship with the mTOR pathway in stroke. Methods: Sprauge Dawley rats (250∼280g) were used for all studies. A lentiviral vector consists of a CMV promoter driving IRES-eGFP was used to clone an active Akt 1 and 3 (cAKt 1 and 3), dominant-negative Akt (AktDN), active FKHR (AAA FKHR), and PRAS40. Lentivirus expressing these genes were added to primary mixed cortical cultures for two days prior to oxygen glucose deprivation (OGD) (MOI=1:5). Neuronal survival was measured by LDH release. Lentivirus were stereotaxically injected into the cortex, and rats were subjected to focal ischemia induced by distal MCA occlusion combined with bilateral CCA occlusion. Western blotting and immunofluorescent confocal microscopy were used to detect the expression of Akt isoforms and other proteins in both the Akt and mTOR pathways. Results: Western blotting analysis showed that both endogenous Akt1 and 3 proteins degraded as early as 1 h after stroke, while Akt2 protein remained unchanged until 24 h after stroke. In vitro studies showed that over-expression of both constitutively active cAkt1 and cAkt3 decreased LDH release after OGD, while AktDN worsened neuronal death ( P <0.05). In vivo over-expression of cAkt1, cAkt3 and PRAS40 reduced infarct size after stroke ( P <0.01). Gene transfer of cAkt1 and 3 also promoted protein levels of pAkt (phosphorylated Akt), pPRAS40, pFKHR, pPTEN, pmTOR, but not pGSK3β. Both in vitro and in vivo studies showed that over-expression of cAkt3 resulted in a stronger protection than cAkt1 ( P <0.05). Interestingly, cAkt3 gene transfer preserved both endogenous protein levels of Akt1 and 3, whereas cAkt1 gene transfer only preserved endogenous Akt1. Furthermore, cAkt3 promoted higher pmTOR levels than cAkt1. Treatment of rapamycin, an mTOR inhibitor, blocked the protective effects of both cAkt1 and cAkt3 both in vitro and in vivo. Conclusion: Lentiviral-mediated overexpression of cAkt3 confers stronger protection than that of cAkt1, by maintaining both endogenous Akt1 and Akt3, as well as promoting higher mTOR activities after stroke.


Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Peng Wang ◽  
Rong Xie ◽  
Xunming Ji ◽  
Heng Zhao

Introduction: Ischemic postconditioning represents a series of brief occlusions of blood flow before complete restoration of reperfusion after brain stroke. We have shown that ischemic postconditioning reduces infarct size in focal ischemia in rats and improves neurological deficits, but the underlying protective mechanisms are not fully understood. The mammalian target of rapamycin (mTOR) pathway plays a key role in cell growth, differentiation and survival. We studied the hypothesis that the mTOR pathway is involved in the protective effect of ischemic postconditioning and brain recovery after stroke in rats. Methods: Focal ischemia was induced by 30 min of bilateral CCA occlusion and permanent distal MCA occlusion in rats. Ischemic postconditioning was induced by 3 cycles of 30 sec reperfusion and 10 sec occlusion at the end of stroke. Rapamycin, an mTOR inhibitor, was injected into the left lateral ventricle 1 hour before stroke onset. For the behavior test, home cage and vibrissa-elicited limb use tests were used and performed until 21d after stroke. Peri-infarct tissues were collected 1 and 3 weeks after stroke for Western blotting and immunostaining. Molecular markers related with synaptic transmission and neuronal growth and plasticity, including Gap-43, synaptophysin, MAP-2 and PSD-95 proteins were detected. Protein levels of phosphorylated mTOR (p-MTOR) and 4EPB-1 in the mTOR pathway, and the upstream molecule, Akt, were also measured. Results: Ischemic postconditioning improved neurological function when measured 2 weeks after stroke (n=6, p<0.05), and reduced brain injury size by 34.2% (P<0.05). These protective effects were abolished by rapamycin treatment. The results of Western blotting showed that postconditioning substantially promoted the protein level of Gap-43, MAP-2 and PSD-95, but not synaptophysin. Rapamycin significantly inhibited Gap-43 levels at 1 and 3 weeks after stroke, and inhibited Map-2 level at 1 week (P<0.05). Postconditioning significantly increased the protein levels of p-Akt, p-mTOR, p-4EBP-1 compared with control ischemia (p<0.05) at 1 week after stroke injury. Rapamycin attenuated p-mTOR levels 1 and 3 weeks after stroke, and inhibited p-4EBP-1 level at 1 week (p<0.05), but had no effects on the expression level of p-Akt and Akt. Conclusion: Ischemic postconditioning improved brain function, which is consistent with the improved expression of proteins related with synaptic function and brain plasticity. This protection appears to be achieved by the enhanced mTOR activity.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Akira Nishiyama ◽  
Juan Wang ◽  
Shinichi Yachida ◽  
Genevieve Nguyen ◽  
Takuo Hirose ◽  
...  

(Pro)renin receptor ((P)RR) is a component of the Wnt receptor complex (Science, 2010). We have recently demonstrated that (P)RR plays an important role in the tumorigenesis of pancreatic ductal adenocarcinoma via the activation of Wnt/β-catenin signaling pathway (Shibayama et al. Sci Rep. 2015). Since the patients with colon cancer often show aberrantly activated Wnt/β-catenin-dependent signaling pathway by the mutations of its components, we investigated the possible role of (P)RR and Wnt/β-catenin signaling pathway in carcinogenesis of colon cancer. Real-time PCR was used for measuring mRNA levels of (P)RR. Protein levels of (P)RR was determined by Western blotting and immunohistochemistry. Activated β-catenin levels were determined by Western blotting. Cell proliferative ability was evaluated by counting the cell number in cultured colon cancer cell lines, HCT116 and DLD-1 cells. As compared to normal colon tissues (n=6), mRNA and protein levels of (P)RR were increased by 2.6- and 2.2-fold, respectively, in colon cancer tissues (n=9), which were associated with increased activated β-catenin levels (by 2.8-fold, P<0.05). However, plasma soluble (P)RR levels were not changed in patients with colon cancer (n=9). (P)RR and activated β-catenin levels were also increased in HCT116 (by 2.2- and 2.7-fold, n=5, respectively) and DLD-1 cells (by 1.9- and 2.8-fold, n=5, respectively). In these cells, inhibiting (P)RR with an siRNA attenuated the activity of β-catenin and reduced the proliferative abilities (n=5, P<0.05, respectively). These data suggest that (P)RR contributes to the tumorigenesis of colon cancer through the activation of Wnt/β-catenin signaling pathway.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Huiling Zhang ◽  
Zhong-Sheng Li ◽  
Yong Ni ◽  
Xian-Yong Zhou ◽  
Shi-Gang Qiao

During the recovery phase of ischemic stroke, one of the major barriers for the spontaneous neuronal axon regeneration is the formation of astrogliosis and glial scar, and targeting astrogliosis becomes a therapeutic strategy for ischemic stroke. However, the mechanism regulating the process of scar components after ischemia still remains poorly understood. The aim of this study was to observe the role of RIP1 kinase (RIP1K), the key regulator of necroptosis (programmed necrosis) in the brain functional recovery after ischemic stroke and in the ischemic stroke-induced astrogliosis and glial scar formation in both in vitro and in vivo glial scar models. The glial scar formation model in vitro or in vivo was established by using primary cultured astrocyte subjected to 6 hours of oxygen-glucose deprivation (OGD) following 12 hours or 24 hours reperfusion, or by 90 min of transient middle cerebral artery occlusion (tMCAO) and reperfusion in rats. Western blotting analysis and immunohistochemical assay showed that knockdown of RIP1K by lentivirally-delivered shRNAs against RIP1K (shRNA RIP1K) could decrease several protein levels of glial scar markers such as glial fibillary acidic protein (GFAP), neurocan and phosphacan both in in vitro and in vivo glial scar models. Furthermore, western blotting analysis showed that knockdown of RIP1K reduced the protein levels of VEGF-D receptor 3 in in vitro glial scar models. In addition, knockdown of RIP1K also notably reduced the shrinking volume and ameliorated the behavioral symptoms in the recovery phase of rats after tMCAO. And immunocytochemistry assay demonstrated that RIP1K knockdown promoted the neuronal axonal generation in a neuron and astrocyte co-culture system. Our data indicates that RIP1K might play an important role in the formation of glial scar after ischemic stroke via promoting the function of VEGF-D receptor 3 in astrocytes.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 383-383
Author(s):  
Luis Cordero-Monroy ◽  
Carla Taylor ◽  
Peter Zahradka

Abstract Objectives This study was designed to investigate whether unconventional prefoldin RPB5 interactor (URI)-1 mediates hepatic accumulation of triglyceride (TG) in response to a diet with trans-10,cis-12 conjugated linoleic acid (t10,c12 CLA) in lean or genetically obese mice. URI-1 belongs to the prefoldin family of proteins that have been shown to coordinate nutrient availablility by transcriptional regulation of genes involved in glucose and lipid metabolism. Thus, it was hypothesized that URI-1 in liver is involved in increased fatty acid uptake and accumulation leading to fatty liver. Methods C57BL/6 and db/db mice were randomly assigned to two diet groups, control (CTL) and t10,c12 CLA (0.4% w/w). After 4 weeks, the mice were weighed and euthanized. Livers were dissected, weighed and stored at –80°C. Liver lysates were prepared from the tissue for Western blotting to measure hepatic protein levels of URI-1 and FABP1. The amount of lipid in the livers was determined using the LabAssay™ Triglyceride kit, a colorimetric TG assay. Results The liver to body weight ratio of db/db and C57BL/6 mice fed t10,c12 CLA increased by 90% and 52%, respectively, compared to their counterparts fed the CTL diet. Likewise, the hepatic TG concentration (mg TG/mg protein) was increased 38% and 5-fold, respectively, in CLA-fed db/db and C57BL/6 mice compared to CTL db/db and C57BL/6 mice. Western blotting showed that FABP1 levels were approximately 2-fold greater in the db/db t10,c12 CLA group relative to the db/db CTL group, and may contribute to increased fatty acid uptake. Furthermore, URI-1 protein levels were elevated 4-fold in db/db and C57BL6 mice fed t10,c12 CLA compared to their respective CTL groups. Lastly, correlation analysis revealed that URI-1 levels were significantly correlated with hepatic TG concentrations (r = 0.61) and liver/body weight ratio (r = 0.64). Conclusions This study revealed a relationship between hepatic TG accumulation and URI-1, a protein associated with hepatocellular carcinoma (HCC) and cirrhosis. This study provides a basis for in vitro experiments exploring the causative role of URI-1 in propagating hepatic TG accumulation, and ultimately the progression of fatty liver disease to HCC and cirrhosis. Funding Sources University Collaborative Research Project, NSERC Discovery, and University of Manitoba Graduate Enhancement of Tri-Council Stipends.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yu Hu ◽  
JianHua Fu ◽  
XueYan Liu ◽  
XinDong Xue

Background. Bronchopulmonary dysplasia (BPD) is a common and serious complication in premature infants. Lung fibroblasts (LFs) are present in the extracellular matrix and participate in pulmonary development in response to BPD. The aim of this study was to investigate the effect of extracellular signal-regulated kinase (ERK) on LFs cultured from newborn rats. Material and Methods. Primary LFs were isolated and treated with epidermal growth factor (EGF, 20 ng/mL) in the presence or absence of an ERK inhibitor, PD98059 (10 μmol/L). Phosphorylated ERK1/2 (p-ERK1/2) protein levels were determined using immunocytochemistry, western blotting, and real-time reverse transcription quantitative (RT–q)PCR. LF proliferation was examined by flow cytometry and a cell counting kit-8 assay. LF transdifferentiation was examined by protein and mRNA expression of α-smooth muscle actin (α-SMA) by immunocytochemistry, western blotting, and RT–qPCR. LF migration was examined by the transwell method. Results. Phosphorylated ERK1/2, which was activated by EGF, promoted LF proliferation by accelerating cell-cycle progression from the G1 to S phase. After treatment with PD98059, the expression of p-ERK1/2 in LFs, cellular proliferation, and the percentage of cells in S phase were significantly decreased. Phosphorylated ERK1/2 also promoted the differentiation of LFs into myofibroblasts through increased α-SMA synthesis and migration. Conclusion. The activation of ERK promotes proliferation, transdifferentiation, and migration of lung fibroblasts from newborn rats.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 346-346
Author(s):  
Elaine Y. Chung ◽  
Diana Cozma ◽  
Duonan Yu ◽  
Michael Dews ◽  
Erik A. Wentzel ◽  
...  

Abstract We have recently demonstrated that Pax5 promotes B-lymphomagenesis by upregulating key components of B-cell receptor signaling [Cozma et al, J Clin Inv, 117 (8), 2007]. Gene regulation by Pax5 often involves complex formation with other oncogenic transcription factors of the Ets family, namely Myb and Ets1. We determined that expression of these proteins themselves depends on the presence of Pax5, as seen in human diffuse large B-cell lymphomas with Pax5 knockdown and murine lymphomas with epigenetic silencing of Pax5 [Yu et al, Blood, 101:1950–1955, 2003; Johnson et al, Nat Immunol, 5:853–861, 2004]. Upon reconstitution with the Pax5 gene, Myb and Ets1 levels increase sharply. This occurs with little increase in steady-state mRNA levels, suggesting post-transcriptional regulation, possibly by microRNAs. To test this hypothesis, we compared miRNA profiles of Pax5-deficieint and sufficient cells and discovered that several miRNAs are indeed repressed by Pax5. Among them is the miR-15a/16-1 cluster whose predicted targets include both Myb and Ets1. Consistent with this prediction, forced expression of miR-15a/16 brings down Myb and Ets1 protein levels. This is accompanied by impaired Pax5 function and overall suppression of B-lymphomagenesis. Thus, Ets family members (along with previously identified bcl-2) are key targets of the miR-15a/16 locus, a tumor suppressor in chronic lymphocytic leukemia. Interplay between Pax5, Myb/Ets1, and miR-15a/16-1. (A) Upregulation of Myb and Ets 1 in tumors over-expressing Pax5ER fusion, as compared to control GFP-only neoplasms. (B) Down-regulation of Myb and Ets1 in Pax5 tumors engineered to over-express the miR-15a/16-1 cluster. All panels depict Western blotting. Interplay between Pax5, Myb/Ets1, and miR-15a/16-1. (A) Upregulation of Myb and Ets 1 in tumors over-expressing Pax5ER fusion, as compared to control GFP-only neoplasms. (B) Down-regulation of Myb and Ets1 in Pax5 tumors engineered to over-express the miR-15a/16-1 cluster. All panels depict Western blotting.


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