Suppression of MAPK11 or HIPK3 reduces mutant Huntingtin levels in Huntington's disease models.

Most neurodegenerative disorders are associated with accumulation of disease-relevant proteins. Among them, Huntington disease (HD) is of particular interest because of its monogenetic nature. HD is mainly caused by cytotoxicity of the defective protein encoded by the mutant Huntingtin gene (HTT). Thus, lowering mutant HTT protein (mHTT) levels would be a promising treatment strategy for HD. Here we report two kinases HIPK3 and MAPK11 as positive modulators of mHTT levels both in cells and in vivo. Both kinases regulate mHTT via their kinase activities, suggesting that inhibiting these kinases may have therapeutic values. Interestingly, their effects on HTT levels are mHTT-dependent, providing a feedback mechanism in which mHTT enhances its own level thus contributing to mHTT accumulation and disease progression. Importantly, knockout of MAPK11 significantly rescues disease-relevant behavioral phenotypes in a knockin HD mouse model. Collectively, our data reveal new therapeutic entry points for HD and target-discovery approaches for similar diseases

LSL-KrasG12D; LSL-Trp53R172H/+; Ink4flox/+; Ptf1/p48-Cre mice are an applicable model for locally invasive and metastatic pancreatic cancer.

Pancreatic cancer (PC) accumulates multiple genetic mutations, including activating KRAS mutations and inactivating TP53, SMAD4 and CDKN2A mutations, during progression. The combination of mutant KRAS with a single inactivating TP53, SMAD4 or CDKN2A mutation in genetically engineered mouse models (GEMMs) showed that these mutations exert different synergistic effects in PC. However, the effect of the combination of TP53, CDKN2A and KRAS mutations on the trajectory of PC progression is unknown. Here, we report a GEMM that harbors KRAS (KrasG12D), TP53 (Trp53R172H/+), CDKN2A (Ink4flox/+) and Ptf1/p48-Cre (KPIC) mutations. Histopathology showed that KPIC mice developed adenocarcinoma that strongly resembled the pathology of human PC, characterized by rich desmoplastic stroma and low microvascularity. The median survival of KPIC mice was longer than that of LSL-KrasG12D; Ink4flox/flox; Ptf1/p48-Cre mice (KIC) (89 vs 62 days) and shorter than that of KRAS (KrasG12D), TP53 (Trp53R172H/+) and Ptf1/p48-Cre (KPC) mice. Moreover, the neoplastic cells of KPIC mice were epithelial, highly proliferative tumor cells that exhibited ERK and MAPK pathway activation and high glucose uptake. Isolated neoplastic cells from spontaneous KPIC tumors showed all molecular profiles and cellular behaviors of spontaneous KPIC tumors, including epithelial-mesenchymal transition (EMT) under drug stress as well as tumorigenic, metastatic and invasive abilities in immunocompetent mice. Furthermore, orthotopic and metastatic tumors of KPIC cells almost recapitulated the pathology of spontaneous KPIC tumors. These data show that in addition to spontaneous KPIC tumors, KPIC cells are a valuable tool for preclinical studies of locally invasive and metastatic PC

KPIC cells are tumorigenic in immunocompetent mouse.

<p>(A) The gross pathology of an orthotopic KPIC cell tumor showed that the orthotopic tumor invaded the spleen and liver (white circle, orthotopic tumor; green line, liver invasion; yellow line, spleen invasion). (B) H&E staining, Mason Trichrome and Ki67 immunostaining of orthotopic KPIC tumors showed that the orthotopic tumors are invasive, and contain desmoplastic stroma and highly proliferative cells. (C) H&E staining, p53 and CK antibodies immunohistochemistry of the orthotopic tumor of KPIC cells showed the invasion of orthotopic KPIC tumor to liver. These KPIC cells are ductal epithelial cells and accumulate p53. (D, E) H&E staining showed the orthotopic tumor invasion to spleen and lymph node. White dotted lines (B-D), the boundary between tumor and normal tissue. Ca, cancer; Pan, pancreas. (F) Histology of original spontaneous tumor of KPIC. Scale bar, 100μm.</p

The proliferative and glucose uptake ability and microvasculature characteristics of KPIC tumors.

<p>(A) Immuostaining of KPIC tumor and typical human PC with Ki67 antibody showed that the neoplastic cells of KPIC tumor are highly proliferative, and similar to the highly proliferative neoplastic cells in human PC. Scale bar, 50μm. n, sample size. (B) CD34 immunofluorescent staining showed that KPIC tumor has a “hairy” microvasculature with basal microvilli that is rarely branched and similar to the typical “hairy” microvasculature in human PC (Human PC, Age 69, Male, tumor in head of pancreas). Scale bar, 20μm. (C) Accumulations of 2-NBDG-Alex 488 and Lectin-Alex-633 in KPIC tumors. First panel shows a panIN lesion; Second panel shows a typical adenocarcinoma. Scale bar, 20μm. (D) Accumulations of 2-NBDG-Alex 633 and Lectin-Alex 488 in the neoplastic cells of KIC tumors. Scale bar, 20μm.</p

KPIC cells are metastatic in immunocompetent mouse.

<p>(A) Orbital intravenous injection of KPIC cells to immunocompetent mice formed multiple metastatic lesions in the lung (19 days). Metastatic KPIC cells are proliferative and Sox-9- and p53-positive. Scale bars, 500μm and 100μm. (B) KPIC cells formed an <i>in situ</i> tumor at the injection site which also invaded to the muscles of eye. KPIC tumor cells are proliferative and Sox-9- and p53- positive. (yellow arrow, tumor in eye; green arrows, muscle; white arrows, tumor cells). Scale bar, 100μm.</p

KPIC mice formed a local invasive tumor with 3-months mean survival.

<p>(A) The gross anatomy of PC in a KPIC mouse showed cancer in the tail and body of pancreas, and the swelling of small intestine. The KPIC tumor locally invaded the neighboring organs (In, intestine; ki, kidney; yellow circle, tumor region). (B) Kaplan-Merrier curves of KPIC and KIC mice. Log-rank test. (C) H&E and Mason Trichrome staining of KPIC and KIC tumors. Both KPIC and KIC tumors showed a character of typical adenocarcinoma that tumor cells grow in a ductal manner. (D) Mason Trichrome staining showed the dense desmoplastic stroma of KPIC and KIC tumors. (E) Sox-9 immuostaining of KPIC and KIC tumors. Scale bar, 100μm.</p

Isolation and characterization of novel human short-chain dehydrogenase/reductase SCDR10B which is highly expressed in the brain and acts as hydroxysteroid dehydrogenase*

Hydroxysteroid dehydrogenase belongs to the subfamily of short-chain dehydrogenases/reductases (SDR), and 11-β-hydroxysteroid dehydrogenase catalyzes the interconversion of inactive glucocorticoids (cortisone in human, dehydrocorticosterone in rodents) and active glucocorticoids (cortisol in human, corticosterone in rodents). We report here the cloning and characterization of a novel human SDR gene SCDR10B which encodes a protein with similarity to 11β-hydroxysteroid dehydrogenase 1. SCDR10B was isolated from a human brain cDNA library, and was mapped to chromosome 19p13.3 by browsing the UCSC genomic database. It contains an ORF with a length of 858 bp, encoding a protein with a transmembrane helix and SDR domain. Its molecular mass and isoelectric point are predicted to be 30.8 kDa and 10.3 kDa, respectively. SCDR10B protein is highly conserved in mammals and fish. Phylogenetic tree analysis indicated that SCDR10B stands for a new subgroup in the 11β-hydroxysteroid dehydrogenase family. Northern blot analysis showed that SCDR10B was highly expressed in brain, and a strong expression signal was detected in hippocampal neurons by immunohistochemical analysis. RT-PCR and immunohistochemical analysis showed that SCDR10B was up-regulated in lung-cancer cell lines and human lung cancer. SCDR10B can catalyze the dehydrogenation of cortisol in the presence of NADP+, and therefore it is a hydroxysteroid dehydrogenase

The Correct Localization of Borealin in Midbody during Cytokinesis Depends on IQGAP1

Borealin is a key component of chromosomal passenger complex, which is vital in cytokinesis. IQ domain-containing GTPase-activating protein 1 (IQGAP1) also participates in cytokinesis. The correlation between Borealin and IQGAP1 during cytokinesis is not yet clear. Here, we used mass spectrometry and endogenous coimmunoprecipitation experiments to investigate the interaction between IQGAP1 and Borealin. Results of the current study showed that Borealin interacted directly with IQGAP1 both in vitro and in vivo. Knockdown of IQGAP1 resulted in an abnormal location of Borealin in the midbody. Knocking down Borealin alone, IQGAP1 alone, or Borealin and IQGAP1 at the same time inhibited the completion of cytokinesis and formed multinucleated cells. Our results indicated that IQGAP1 interacts with Borealin during cytokinesis, and the correct localization of Borealin in the midbody during cytokinesis is determined by IQGAP1, and IQGAP1 may play an important role in regulating Borealin function in cytokinesis