Newly developed TGF-ß2 knock down transgenic mouse lines express TGF-ß2 differently and its distribution in multiple tissues varies.

BACKGROUND: Transforming growth factor-betas (TGF-ßs), including beta2 (TGF-ß2), constitute a superfamily of multifunctional cytokines with important implications in morphogenesis, cell differentiation and tissue remodeling. TGF-ß2 is thought to play important roles in multiple developmental processes and neuron survival. However, before we carried out these investigations, a TGF-ß2 gene down-regulated transgenic animal model was needed. In the present study, expressional silencing TGF-ß2 was achieved by select predesigning interference short hairpin RNAs (shRNAs) targeting mouse TGF-ß2 genes. RESULTS: Four homozygous transgenic offspring were generated by genetic manipulation and the protein expressions of TGF-ß2 were detected in different tissues of these mice. The transgenic mice were designated as Founder 66, Founder 16, Founder 53 and Founder 41. The rates of TGF-ß2 down-expression in different transgenic mice were evaluated. The present study showed that different TGF-ß2 expressions were detected in multiple tissues and protein levels of TGF-ß2 decreased at different rates relative to that of wild type mice. The expressions of TGF-ß2 proteins in transgenic mice (Founder 66) reduced most by 52%. CONCLUSIONS: The present study generated transgenic mice with TGF-ß2 down-regulated, which established mice model for systemic exploring the possible roles of TGF-ß2 in vivo in different pathology conditions.

WIF1 causes dysfunction of heart in transgenic mice.

Wnt activity is a key regulator of cardiac progenitor cell self-renewal, differentiation and morphogenesis. However, Wnt inhibitory factor 1 (WIF1), a antagonists of Wnt signaling activity, its potential effects on heart development has not yet been approached by either in vivo or in vitro studies. Here, the expression of WIF1 was regulated in a different way in the dilated and hypertrophic cardiomyopathy heart from transgenic mice by mutations in cardiac troponin T, cTnT(R141W) and cTnT(R92Q). The heart tissue specific transgenic mice of WIF1 was studied using M-mode echocardiography and histologic analyses. Production levels of an array of effectors and transcription factors that impact cellular organization and tissue morphology were measured. The effects of WIF1 on ß-catenin pathway could be reversed by LiCl regarding signaling pathways and effector and respondent molecules in H9c2 cells, consistent with the expression levels of c-myc, natriuretic peptide precursor type B and skeletal muscle actin α1. Among the most noteworthy findings were that WIF1 impaired the function and structure of heart, and the effects on ß-catenin pathway maybe the course of the former. It is anticipated that our findings will contribute to expansion of our understanding of WIF1 biological function on heart development and possible modes of treatment of heart diseases.

Establishing extended pluripotent stem cells from human urine cells.

BACKGROUND: Extended pluripotent stem cells (EPSCs) can contribute to both embryonic and trophectoderm-derived extraembryonic tissues. Therefore, EPSCs have great application significance for both research and industry. However, generating EPSCs from human somatic cells remains inefficient and cumbersome. RESULTS: In this study, we established a novel and robust EPSCs culture medium OCM175 with defined and optimized ingredients. Our OCM175 medium contains optimized concentration of L-selenium-methylcysteine as a source of selenium and ROCK inhibitors to maintain the single cell passaging ability of pluripotent stem cells. We also used Matrigel or the combination of laminin 511 and laminin 521(1:1) to bypass the requirement of feeder cells. With OCM175 medium, we successfully converted integration-free iPSCs from easily available human Urine-Derived Cells (hUC-iPSCs) into EPSCs (O-IPSCs). We showed that our O-IPSCs have the ability to form both intra- and extra- embryonic chimerism, and could contribute to the trophoblast ectoderm lineage and three germ layer cell lineages. CONCLUSIONS: In conclusion, our novel OCM175 culture medium has defined, optimized ingredients, which enables efficient generation of EPSCs in a feeder free manner. With the robust chimeric and differentiation potential, we believe that this system provides a solid basis to improve the application of EPSCs in regenerative medicine.

Cardioprotection by Hepc1 in cTnT(R141W) transgenic mice.

Hepcidin 1 (Hepc1) is a peptide hormone secreted by the liver in response to iron loading. It is expressed in the heart and is thought to play a role in the regulation of iron homeostasis in an autocrine and paracrine fashion. We have shown that expression of Hepc1 is strongly down-regulated in the heart of the cTnT(R141W) transgenic mouse model of dilated cardiomyopathy (DCM) at 3 months of age. Transgenic mice with heart tissue-specific Hepc1 expression alone or in combination with the cTnT(R141W) mutation were produced to study the effects of Hepc1 on DCM. Transgenic expression of Hepc1 was found to be nonlethal and resulted in decreased mortality in cTnT(R141W) transgenic mice, from 29.6 to 7.4%(n  = 27; P < 0.05), through 7 months of age. Expression of Hepc1 also brought about increases in the left ventricular wall, as well as ejection fraction and fractional shortening. In addition, the expression of Hepc1 inhibited the fibrosis and ultra-structural alterations seen in cTnT(R141W) transgenic mice. Furthermore, transgenic expression of Hepc1 restored the iron level and phosphorylation level of extracellular signal-regulated kinases 1/2 (ERK1/2) in the heart tissues of cTnT(R141W) transgenic mice. It was concluded that transgenic expression of Hepc1 compensated for the loss of Hepc1 expression and the release of iron and brought about a marked improvement in the pathologic phenotype of DCM, in which the ERK1/2 signal pathway might play an important role.

Transgenic expression of human P-selectin glycoprotein ligand-1 is not sufficient for enterovirus 71 infection in mice.

Human PSGL-1 is a receptor for EV71 that facilitates EV71 entry and replication in mouse cells. We have evaluated the role of human PSGL-1 in EV71 infection in vivo using a transgenic mouse line. Expression of human PSGL-1 failed to enhance infectivity of clinical EV71 strains in mice; however, it promoted replication and symptom severity at an earlier stage in mice upon infection with a mouse-adapted EV71 strain. We therefore conclude that human PSGL-1 alone is not sufficient to modulate infection with the clinical EV71 strains of genotype C4 in mice.

Evodiamine improves congnitive abilities in SAMP8 and APP(swe)/PS1(ΔE9) transgenic mouse models of Alzheimer's disease.

AIM: To investigate the effect of evodiamine (a quinolone alkaloid from the fruit of Evodia rutaecarpa) on the progression of Alzheimer's disease in SAMP8 and APP(swe)/PS1(ΔE9) transgenic mouse models. METHODS: The mice at age of 5 months were randomized into the model group, two evodiamine (50 mg·kg(-1)·d(-1) and 100 mg·kg(-1)·d(-1)) groups and an Aricept (2 mg·kg(-1)·d(-1)) group. The littermates of no-transgenic mice and senescence accelerated mouse/resistance 1 mice (SAMR1) were used as controls. After 4 weeks of treatment, learning abilities and memory were assessed using Morris water-maze test, and glucose uptake by the brain was detected using positron emission tomography/computed tomography (PET/CT). Expression levels of IL-1ß, IL-6, and TNF-α in brain tissues were detected using ELISA. Expression of COX-2 protein was determined using Western blot. RESULTS: In Morris water-maze test, evodiamine (100 mg·kg(-1)·d(-1)) significantly alleviated the impairments of learning ability and memory. Evodiamine (100 mg·kg(-1)·d(-1)) also reversed the inhibition of glucose uptake due to development of Alzheimer's disease traits in mice. Furthermore, the dose of evodiamine significantly decreased the expression of IL-1ß, IL-6, TNF-α, and COX-2 that were involved in the inflammation due to Alzheimer's disease. CONCLUSION: The results indicate that evodiamine (100 mg·kg(-1)·d(-1)) improves cognitive abilities in the transgenic models of Alzheimer's disease.

Sodium Channel Voltage-Gated Beta 2 Plays a Vital Role in Brain Aging Associated with Synaptic Plasticity and Expression of COX5A and FGF-2.

The role of sodium channel voltage-gated beta 2 (SCN2B) in brain aging is largely unknown. The present study was therefore designed to determine the role of SCN2B in brain aging by using the senescence-accelerated mice prone 8 (SAMP8), a brain senescence-accelerated animal model, together with the SCN2B transgenic mice. The results showed that SAMP8 exhibited impaired learning and memory functions, assessed by the Morris water maze test, as early as 8 months of age. The messenger RNA (mRNA) and protein expressions of SCN2B were also upregulated in the prefrontal cortex at this age. Treatment with traditional Chinese anti-aging medicine Xueshuangtong (Panax notoginseng saponins, PNS) significantly reversed the SCN2B expressions in the prefrontal cortex, resulting in improved learning and memory. Moreover, SCN2B knockdown transgenic mice were generated and bred to determine the roles of SCN2B in brain senescence. A reduction in the SCN2B level by 60.68% resulted in improvement in the hippocampus-dependent spatial recognition memory and long-term potential (LTP) slope of field excitatory postsynaptic potential (fEPSP), followed by an upregulation of COX5A mRNA levels and downregulation of fibroblast growth factor-2 (FGF-2) mRNA expression. Together, the present findings indicated that SCN2B could play an important role in the aging-related cognitive deterioration, which is associated with the regulations of COX5A and FGF-2. These findings could provide the potential strategy of candidate target to develop antisenescence drugs for the treatment of brain aging.

Expressional difference, distributions of TGF-ß1 in TGF-ß1 knock down transgenic mouse, and its possible roles in injured spinal cord.

Transforming growth factor ß1 (TGF-ß1) is a multi-functional cytokine implicated in many aspects of mammalian wound healing and scar tissue formation. However, few experiments have so far addressed the potential biological effects of TGF-ß1 in the nervous system after injury, in addition to the immune system. In the present study, expressional silencing TGF-ß1 was achieved by selecting predesigning hairpins targeting mouse TGF-ß1 genes. Four homozygous transgenic offspring were generated and designed as Founder 90, Founder 12, Founder 41 and Founder 46. The down-regulated rates of TGF-ß1 in different transgenic mice were also determined. To investigate the potential roles of TGF-ß1, we observed changes in the neurological behavior of TGF-ß1-knockdown (TGF-ß1-kd) mice after spinal cord transection (SCT). Moreover, mRNA levels of inflammatory cytokines, including IL-1, IL-6, IL-10, NF-κB and TNF, were also detected in nucleate cells from blood by real-time PCR. Consequently, different TGF-ß1 expressions were detected in multiple tissues, and protein levels of TGF-ß1 decreased at different rates relative to that of wild type (WT) ones. The levels of TGF-ß1 proteins in TGF-ß1-kd mice decreased at most by 57% in Founder 90, which showed a significant recovery in Basso, Beattie, Bresnahan (BBB) scores after SCT compared with that of WT. However, expressions of immune relative genes showed no dramatic difference compared with WT ones. This study is the first to generate TGF-ß1 down regulated mice and determine the possible roles of TGF-ß1 in vivo in different conditions.

Expression of CYP2E1 increases oxidative stress and induces apoptosis of cardiomyocytes in transgenic mice.

Cytochrome P450 2E1 (CYP2E1) is an effective generator of reactive oxygen species. Marked expression of CYP2E1 occurs in the heart and it is known to be regulated in the course of progression of myocardial ischemia and cardiomyopathy. We provide evidence that the expression of CYP2E1 is strongly up-regulated in cTnT(R141W) transgenic mice with dilated cardiomyopathy. Heart tissue-specific CYP2E1 transgenic mice were produced to study the effects of CYP2E1 overexpression on the heart. Increased mortality, chamber dilation and contractile dysfunction, as well as myocyte disarray, interstitial fibrosis, ultrastructural degeneration with myofibrillar disorganization and mitochondria damage, were observed in CYP2E1 transgenic mice and cTnT(R141W) transgenic mice. In addition, levels of H(2) O(2) and malondialdehyde were increased and levels of glutathione and total antioxidant capability were strongly reduced in CYP2E1 transgenic mice and cTnT(R141W) transgenic mice. Myocyte apoptosis was significantly increased by 19-fold in CYP2E1 transgenic mice and by 11-fold in cTnT(R141W) transgenic mice, respectively, compared to wild-type mice. Mitochondrial-dependent apoptotic signal transduction events, such as cytochrome c release from mitochondria into the cytosol and the expression of cleaved (active) caspases 3 and 9, were significantly increased in CYP2E1 transgenic mice and cTnT(R141W) transgenic mice. These results demonstrate that CYP2E1 over-expression produces apoptosis and that the up-regulation of CYP2E1 in cTnT(R141W) transgenic mice also correlates with apoptosis in this model.

miR-29c regulates BACE1 protein expression.

Recently, BACE1 expression was shown to be regulated by microRNAs, small endogenous RNA molecules that regulate protein expression through sequence-specific interaction with messenger RNA. Here, we showed that microRNA-29c (miR-29c), a miRNA that is enriched in the brain and highly expressed in the APPswe/PSΔE9 mouse lowers BACE1 protein in vitro and in transgenic miR-29c mice. In silico analysis identified two putative target sites in the BACE1 mRNA for the miR-29c family. We chose SH-SY5Y, HEK-293T cell lines and miR-29c transgenic mice for these studies to validate our hypothesis. Significantly, over-expression of miR-29c in SH-SY5Y, HEK-293T cell lines and miR-29c transgenic mice downregulated BACE1 protein levels. Our findings suggest that miR-29c may be an endogenous regulator of BACE1 protein expression.