Junctophilin-2 (JP2) is a structural protein required for normal excitation-contraction (E-C) coupling. Following cardiac stress, JP2 is cleaved by Ca2+-dependent protease calpain, which disrupts the E-C coupling ultrastructural machinery and drives heart failure progression. Here we demonstrate that stress-induced proteolysis of JP2 liberates an N-terminal fragment (JP2NT) that translocates to the nucleus, binds to genomic DNA and controls expression of a spectrum of genes in cardiomyocytes. Transgenic overexpression of JP2NT in mice modifies the transcriptional profile resulting in attenuated pathological remodeling in response to cardiac stress. Conversely, loss of JP2NT function accelerates stress-induced development of hypertrophy and heart failure in mutant mice. These data reveal a self-protective mechanism in failing cardiomyocytes that transduce mechanical information (E-C uncoupling) into salutary transcriptional reprogramming in the stressed heart.

Epithelial-mesenchymal transition (EMT) plays a critical role in the development of tumor metastases by enhancing migration/invasion. One of the hallmarks of EMT is loss of E-cadherin and gain of N-cadherin expression, which are regulated by the core EMT-inducing transcription factors (EMT-TFs), such as Zeb1/2, Snai1/2 and Twist1. Here, we find that EMT-TFs can be dynamically degraded by an atypical ubiquitin E3 ligase complex Skp1-Pam-Fbxo45 (SPFFbxo45) through the ubiquitin proteasome system (UPS). The key step is recognition of EMT-TFs by Fbxo45 through its SPRY domain for Zeb2, or F-box domain for the other three EMT-TFs Snai1, Snai2 and Twist1, respectively. The K48-linkaged ubiquitination capability on Zeb2 relies on its functional SBD domain. In addition, miR-27a* can directly down-regulate the expression of Fbxo45, preventing degradation of EMT-TFs and thus ensuring EMT phenotype. We suggest that Fbxo45 is a key node of the miR-27a*/Fbxo45/EMT-TFs signaling axis.

BackgroundGrb2 (Growth factor receptor-bound protein 2) is a key adaptor protein in maintaining the ERK activity via linking Sos1 (Son of sevenless homolog 1) or other proteins to activated RTKs, such as EGFR. Currently, little knowledge is available concerning the post-translational modification (PTM) of Grb2 except for its phosphorylation. Since emerging evidences have highlighted the importance of SUMOylation (Small ubiquitin-related modifier), a reversible PTM, in modulating protein functions, we wondered if Grb2 could be SUMOylated and thereby influences its functions especially involved in the Ras/MEK/ERK pathway.MethodsSUMOylation of Grb2 was analyzed with the in vivo SUMOylation assay using the Ni2+-NTA affinity pulldown and the in vitro E.coli-based SUMOylation assay. To test the ERK activity and cell transformation, the murine fibroblast cell line NIH/3T3 and the murine colon cancer cell line CMT-93 were used for the experiments including Grb2 knockdown, ectopic re-expression, cell transformation and migration. Immunoprecipitation (IP) was employed for seeking proteins that interact with SUMO modified Grb2. Xenograft tumor model in mice was conducted to verify that Grb2 SUMOylation regulated tumorigenesis in vivo.ResultsGrb2 can be SUMOylated by SUMO1 at lysine 56 (K56), which is located in the linker region between the N-terminal SH3 domain and the SH2 domain. Knockdown of Grb2 reduced the ERK activity and suppressed cell motility and tumorigenesis in vitro and in vivo, which were all rescued by stable ectopic re-expression of wild-type Grb2 but not the mutant Grb2K56R. Furthermore, Grb2 SUMOylation at K56 increased the formation of Grb2-Sos1 complex, which sequentially leads to the activation of Ras/MEK/MAPK pathway.ConclusionsOur results provide evidences that Grb2 is SUMOylated in vivo and this modification enhances ERK activities via increasing the formation of Grb2-Sos1 complex, and may consequently promote cell motility, transformation and tumorigenesis.

Abstract. This paper explains how an attacker can efficiently factor 184 distinct RSA keys out of more than two million 1024-bit RSA keys downloaded from Taiwan's national "Citizen Digital Certificate" database. These keys were generated by government-issued smart cards that have built-in hardware random-number generators and that are advertised as having passed FIPS 140-2 Level 2 certification.These 184 keys include 103 keys that share primes and that are efficiently factored by a batch-GCD computation. This is the same type of computation that was used last year by two independent teams (USENIX Security 2012: Heninger, Durumeric, Wustrow, Halderman; Crypto 2012: Lenstra, Hughes, Augier, Bos, Kleinjung, Wachter) to factor tens of thousands of cryptographic keys on the Internet.The remaining 81 keys do not share primes. Factoring these 81 keys requires taking deeper advantage of randomness-generation failures: first using the shared primes as a springboard to characterize the failures, and then using Coppersmith-type partial-key-recovery attacks. This is the first successful public application of Coppersmith-type attacks to keys found in the wild.

Covalent organic frameworks (COFs) with efficient charge transport and exceptional chemical stability are emerging as an importance class of semiconducting materials for opto-/electronic devices and energy related applications. However, the limited synthetic chemistry to access such materials and the lack of mechanistic understanding of carrier mobility greatly hinder their practical applications. Herein, we report the synthesis of three chemically stable polyarylether-based metallophthalocyanine (PAE-PcM, M = Cu, Ni, and Co) COFs and facile in-situ growth of their thin films on various substrates (e.g., SiO2/Si, ITO, quartz) under solvothermal conditions. We show that PAE-PcM COFs thin films with van der Waals layered structures exhibit p-type semiconducting properties with the intrinsic mobility up to ~19.4 cm 2 V -1 s -1 and four orders of magnitude of increase in conductivity (0.2 S m -1 ) after iodine doping. Density functional theory (DFT) calculations reveal that the carrier transporting in the framework is anisotropic, with the out-of-plane hole transporting along columnar stacked phthalocyanine more favorable. Furthermore, PAE-PcCo shows the redox behavior maximumly contributes ~88.5% of its capacitance performance, yielding a high surface area normalized capacitance of ~19 μF cm -2 . Overall, this work not only deepens the understanding of electronic properties of polyarylether-based 2D COFs and but also opens new opportunities for their integration into various microdevices for energy storage applications.

The potential of increasing bone mass and preventing fractures in osteoporosis using stem cell therapy is currently an area of intense focus. However, there are very little data available regarding the postfracture bony defect healing efficacy under osteoporotic conditions. This study aims to investigate whether critical-sized segmental bone defects in a rabbit model of osteoporosis could be repaired using an allogenic stem cell-based tissue engineering (TE) approach and to investigate the potential influence of osteoporosis on the treatment efficacy. Rabbit fetal bone marrow mesenchymal stem cells (BMSCs) were harvested and expanded in vitro. Decalcified bone matrix (DBM) scaffolds were then seeded with allogenic fetal BMSCs and cultivated in osteogenic media to engineer BMSC/DBM constructs. Critical-sized radial defects were created in ovariectomized (OVX) rabbits and the defects were repaired either by insertion of BMSC/DBM constructs or by DBM scaffolds alone. Also, nonovariectomized age-matched (non-OVX) rabbits were served as control. At 3 months post-treatment under the osteoporotic condition (OVX rabbits), the BMSC/DBM constructs inserted within the defect generated significantly more bone tissue when compared to the DBM scaffold as demonstrated by the X-ray, microcomputed tomography, and histological analyses. In addition, when compared to a normal nonosteoporotic condition (age-matched non-OVX rabbits), the defect treatment efficacy was adversely affected by the osteoporotic condition with significantly less bone regeneration. This study demonstrated the potential of allogenic fetal BMSC-based TE strategy for repairing bone defects in an osteoporotic condition. However, the treatment efficacy could be considerably compromised in the OVX animals. Therefore, a more sophisticated strategy that addresses the complicated pathogenic conditions associated with osteoporosis is needed.

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Metformin is an antidiabetic drug. However, the pleiotropic beneficial effects of metformin in nondiabetic models still need to be defined. The objective of this study is to investigate the effect of metformin on angiotensin II (Ang II)-induced hypertension and cardiovascular diseases. Mice were infused with Ang II (400 ng/kg per min) with or without metformin for 2 weeks. Mice infused with angiotensin II displayed an increase in blood pressure associated with enhanced vascular endoplasmic reticulum (ER) stress markers, which were blunted after metformin treatment. Moreover, hypertension-induced reduction in phosphorylated AMPK, endothelial nitric oxide synthase (eNOs) phosphorylation, and endothelium-dependent relaxation (EDR) in mesenteric resistance arteries (MRA) were rescued after metformin treatment. Infusion of ER stress inducer (tunicamycin, Tun) in control mice induced ER stress in MRA and reduced phosphorylation of AMPK, eNOS synthase phosphorylation, and EDR in MRA without affecting systolic blood pressure (SBP). All these factors were reversed subsequently with metformin treatment. ER stress inhibition by metformin improves vascular function in hypertension. Therefore, metformin could be a potential therapy for cardiovascular diseases in hypertension independent of its effects on diabetes.