Project description:Background: Cardiac kinases play a critical role in the development of heart failure, and represent potential tractable therapeutic targets. However, only a very small fraction of the cardiac kinome has been investigated. To identify novel cardiac kinases involved in heart failure, we employed an integrated transcriptomics and bioinformatics analysis and identified Homeodomain-Interacting Protein Kinase 2 (HIPK2) as a novel candidate kinase. The role of HIPK2 in cardiac biology is unknown. Methods: We used the Expression2Kinase algorithm for the screening of kinase targets. To determine the role of HIPK2 in the heart, we generated cardiomyocyte-specific HIPK2 knockout (CM-KO) and heterozygous (CM-Het) mice. Heart function was examined by echocardiography and related cellular and molecular mechanisms were examined. Adeno-associated virus serotype 9 (AAV9) carrying cardiac-specific constitutively active MEK1 (TnT-MEK1-CA) were administrated to rescue cardiac dysfunction in CM-KOs. Results: To our knowledge, this is the first study to define the role of HIPK2 in cardiac biology. Using multiple HIPK2 loss-of-function mouse models, we demonstrated that reduction of HIPK2 in cardiomyocytes leads to cardiac dysfunction—suggesting a causal role in heart failure. Importantly, cardiac dysfunction in HIPK2 KOs developed with advancing age, but not during development. In addition, CM-KO and CM-Het exhibited a gene dose-response relationship of cardiomyocyte HIPK2 on heart function. HIPK2 expression in the heart was significantly reduced in human end-stage ischemic cardiomyopathy compared to non-failing myocardium, suggesting a clinical relevance of HIPK2 in cardiac biology. In vitro studies with neonatal rat ventricular cardiomyocytes corroborated the in vivo findings. Specifically, adenovirus-mediated overexpression of HIPK2 suppressed the expression of heart failure markers, NPPA and NPPB, at basal condition and abolished phenylephrine-induced pathological gene expression. An array of mechanistic studies revealed impaired ERK1/2 signaling in HIPK2 deficient hearts. In vivo rescue experiment with AAV9 TnT-MEK1-CA nearly abolished the detrimental phenotype of KOs suggesting that impaired ERK signaling mediated apoptosis as the key factor driving the detrimental phenotype in CM-KO hearts. Conclusions: Taken together, these findings suggest that cardiomyocyte HIPK2 is required to maintain normal cardiac function via ERK signaling
Project description:In this experiment, we determined the differences in the transcriptomes of freshly isolated murine small intestine and colon derived crypts. The data shows that the mRNA profiles of the two tissues significantly differ in their ground state. Interestingly, we found that the expression levels of ERK pathway components as well as their positive and negative regulators significantly differ between small intestinal and colonic crypts. This observation indicates that the ERK pathway displays higher basal activity in the small intestine compared to the colon.
Project description:We used an integrated computational/experimental systems biology approach to identify upstream protein kinases that regulate gene expression changes in kidneys of HIV-1 transgenic mice (Tg26), which have significant tubulo-interstitial fibrosis (TIF) and glomerulosclerosis (GS). We identified the homeo-domain interacting protein kinase 2 (HIPK2) as a key regulator of TIF and GS. HIPK2 was upregulated in kidneys of Tg26 and patients with various kidney diseases. HIV infection increased the protein level of HIPK2 by promoting oxidative stress, which inhibited Siah1-mediated proteasomal degradation of HIPK2. The data contain two sets: kidney corticies from WT and Tg26 mice and HEK293 transfected with HIPK2, HIPK2-DN and wild type.
Project description:HIPK2, a member of the homeodomain-interacting protein kinase family, is a transcriptional corepressor whose activity inhibits tumor progression and allows tumor cell apoptosis in response to chemotherapy. HIPK2 regulates the function of numerous molecules and its inhibition by siRNA, hypoxia or mutations, strongly favours molecular pathways involved in tumor progression, angiogenesis, invasion and chemoresistance. Hence the identification of novel molecules regulated by HIPK2 may be beneficial for better understanding tumor progression and for evaluating targeted antitumor therapies.
Project description:HIPK2, a member of the homeodomain-interacting protein kinase family, is a transcriptional corepressor whose activity inhibits tumor progression and allows tumor cell apoptosis in response to chemotherapy. HIPK2 regulates the function of numerous molecules and its inhibition by siRNA, hypoxia or mutations, strongly favours molecular pathways involved in tumor progression, angiogenesis, invasion and chemoresistance. Hence the identification of novel molecules regulated by HIPK2 may be beneficial for better understanding tumor progression and for evaluating targeted antitumor therapies. By using microarray analysis, derived from HIPK2 overexpression (that mimics HIPK2 activation) in colon cancer RKO cells, we aim at evaluating the HIPK2 modulated gene expression involved in tumor progression.
Project description:Homeodomain-interacting protein kinase 2 (HIPK2), a well-known tumor suppressor, exhibits contradictory expression patterns in different cancers. This study was performed to reveal the potential mechanism of HIPK2 involvement in oral squamous cell carcinoma (OSCC) metastasis. High throughput RNA-sequencing was used to detect the dysregulated signaling pathways in HIPK2 deficiency OSCC cells. Transwell assay and lymphatic metastatic orthotopic mouse model assay were performed to identify the effect of HIPK2 on tumor invasion. Western blotting and luciferase reporter assay were performed to examine the HIPK2/P53/E-Cadherin axis in OSCC. We observed that depletion of HIPK2 promoted tumor cell invasion in vitro and facilitated cervical lymph node metastasis in vivo. According to mRNA-sequencing, pathways closely related to tumor invasion were notably activated. HIPK2 was found to trigger E-Cadherin expression by mediating P53, which directly targets the CDH1 (coding E-Cadherin) promoter. Restoring P53 expression rescued the E-Cadherin suppression induced by HIPK2 deficiency. Together, the depletion of HIPK2 expression promoted OSCC metastasis by suppressing the P53/E-Cadherin axis, which might be a promising target for anti-cancer therapies.
Project description:We used an integrated computational/experimental systems biology approach to identify upstream protein kinases that regulate gene expression changes in kidneys of HIV-1 transgenic mice (Tg26), which have significant tubulo-interstitial fibrosis (TIF) and glomerulosclerosis (GS). We identified the homeo-domain interacting protein kinase 2 (HIPK2) as a key regulator of TIF and GS. HIPK2 was upregulated in kidneys of Tg26 and patients with various kidney diseases. HIV infection increased the protein level of HIPK2 by promoting oxidative stress, which inhibited Siah1-mediated proteasomal degradation of HIPK2. The data contain two sets: kidney corticies from WT and Tg26 mice and HEK293 transfected with HIPK2, HIPK2-DN and wild type. Gene expression comparison between kidney cortecies of Tg26 HIV mouse model and wild type. Gene expression comparison between 293 HEK cells with HIPK-DN, HIPK-KO and normal.
Project description:We use Affymetrix Gene Chip Array to screen the targets of HIPK2 in heart. Total RNA was extracted from 8-week-old HIPK2-knockout and Wild Type (WT) mice.