Transglutaminase 3 expression in C57BL/6J mouse embryo epidermis and the correlation with its differentiation

Epidermal-type transglutaminase 3 (TGM3) is involved in the cross-linking of structural proteins to form the cornifiedenvelope in the epidermis. In the present study, we detected the expression of TGM3 in the mouse embryo using RT-PCR.TGM3 mRNA is weakly presented from E11.5 to E14.5 and increases significantly from E15.5 to birth. Then wedetermined the spatial and temporal expression pattern of TGM3 in the skin and other organs by in situ hybridization. Wefound a deprivation of TGM3 in skin at E11.5, while a rich supply in periderm cells and a weak expression in basal cellsfrom E12.5 to E14.5. From the period of E15.5 to E16.5, after keratinization in the epidermis, TGM3 was expressed inthe granular and cornified layers. The electron microscopic observation of the C57BL/6J mouse limb bud skin develop-ment provided several morphological evidences for the epidermal differentiation. The above findings suggest that theexpression of TGM3 plays a important role in the epidermis differentiation in embryogenesis.

Axonal damage in myelin oligodendrocyte glycoprotein peptide-induced experimental autoimmune encephalomyelitis in a C57BL/6 mouse model may be not secondary to inflammatory demyelination

The present study established a chronic experimental autoimmune encephalomyelitis model in C57BL/6 mice induced by myelin oligodendrocyte glycoprotein peptides and complete Freund＇s adjuvant. Onset latency was 12 days, with an incidence rate of 100%. Neuropathological characteristics included perivascular inflammatory cell infiltration, demyelination, neuronal degeneration, and axonal damage within cerebral and myelic white matter. Electron microscopy revealed swollen mitochondria, complete organ disappearance, and fused or broken myelin sheath structure, which were accompanied by myelin sheath reconstruction. Moreover, axonal damage was not consistent with demyelination distribution, and severity of axonal damage did not correlate with demyelination. Results suggested that axonal damage in an experimental autoimmune encephalomyelitis model is not secondary to inflammatory demyelination.

Changes of the intestinal endocrine cells in the C57BL/6 mouse after implantation of murine lung carcinoma (3LL): An immunohistochemical quantitative study

AIM: To study the distributions and frequencies of intestinal endocrine cells in the C57BL/6 mouse with immunohistochemical method using seven types of specific antisera against chromogranin A (CGA), serotonin,somatostatin, glucagons, gastrin, cholecystokinin (CCK)-8 and human pancreatic polypeptide (hPP) after abdominal subcutaneous implantation of murine lung carcinoma (3LL).METHODS: The experimental animals were divided into two groups, one is non-implanted Sham and the other is 3LL-implanted group. Samples were collected from six regions of intestinal tract at 28th d after implantation of 3LL cells (1×105 cell/mouse).RESULTS: In this study, five types of immunoreactive (IR) cells were identified except for gastrin and hPP. The regional distributions of the intestinal endocrine cells in the 3LL-implanted group were similar to those of the non-implanted Sham. However, significant decreases of IR cells were detected in 3LL-implanted group compared to those of non-implanted Sham. CGA- and serotonin-IR cells significantly decreased in 3LL-implanted groups compared to that of non-implanted Sham. Somatostatin-IR cells in the jejunum and ileum and CCK-8-IR cells in the jejunum of 3LL-implanted groups significantly decreased compared to that of non-implanted Sham. In addition,glucagon-IR cells were restricted to the ileum and colon of non-implanted Sham.CONCLUSION: Implantation of tumor cell mass (3LL)induced severe quantifiable changes of intestinal endocrine cell density and the abnormality in density of intestinal endocrine cells may contribute to the development of gastrointestinal symptoms such as anorexia and indigestion, frequently encountered in patients with cancer.

Study on the Gene Transcription Level of Hippocampus NGF in C_(57) Mouse Development

β-Nerve growth factor (β NGF) mRNA levels in hippocampa from C57BL/6J mice of different ages were compared by semi-quantitative RT-PCR method, taking β-actin gene as an internal control. The levels of 6-and 12-month-old C57 mice were much lower compared with that of the l-month-old mouse. However, there was no significant difference between these two groups. This result suggests that gene transcription level of hippocampus β NGF in a C57, mouse descends evidently as it grows up. Base T at Site 294 of β NGF cDNA was substituted by C in the C57, mouse, as revealed by DNA sequencing for the first time. Nevertheless, this polymorphism of nucleotide did not make any difference in amino acid composition.

Study on the Gene Transcription Level of Hippocampus NGF in C57 Mouse Development

β-Nerve growth factor (β NGF) mRNA levels in hippocampa from C57BL/6J mice of different ages were compared by semi-quantitative RT-PCR method, taking β-actin gene as an internal control. The levels of 6-and 12-month-old C57 mice were much lower compared with that of the l-month-old mouse. However, there was no significant difference between these two groups. This result suggests that gene transcription level of hippocampus β NGF in a C57, mouse descends evidently as it grows up. Base T at Site 294 of β NGF cDNA was substituted by C in the C57, mouse, as revealed by DNA sequencing for the first time. Nevertheless, this polymorphism of nucleotide did not make any difference in amino acid composition.

Establishment of an orthotopic pancreatic cancer mouse model: Cells suspended and injected in Matrigel

AIM: To establish an orthotopic mouse model of pancreatic cancer that mimics the pathological features of exocrine pancreatic adenocarcinoma.

Expression ofα2-Na/K-ATPase in C57BL/6J Mice Inner Ear and Its Relationship with Age-related Hearing Loss

K^(+)cycling in the cochlea is critical to maintain hearing.Many sodium-potassium pumps are proved to participate in K^(+)cycling,such as Na/K-ATPase.Theα2-Na/K-ATPase is an important isoform of Na/K-ATPase.The expression ofα2-Na/K-ATPase in the cochlea is not clear.In this study,we used C57BL/6 mice as a model of presbycusis and implemented immunohistochemistry staining and quantitative real time-PCR,and theα2-Na/K-ATPase expression pattern was confirmed in the inner ear.It was foundα2-Na/K-ATPase was expressed widely in cochlea and its mRNA and protein expression was gradually reduced with aging(4-,14-,26-and 48-weeks old mice).We suspected that,the down-regulation ofα2-Na/K-ATPase expression might be associated with the remodeling of K^(+)cycling,degeneration of morphological structure and decrease of hearing function in aging C57 mice.In conclusion,we speculated that the reduction ofα2-Na/K-ATPase might play an important role in the pathogenesis of age-related hearing loss.

Establishment of Embryonic Stem Cell Lines from C57BL/6J Mice and Generation of Chimeras

Four embryonic stem (ES) cell lines, designated CE1, CE2, CE3 and CE4, were isolated from C57BL/6J blastocysts. The ratio of normal diploid composition of these cell lines is above 70%. To examine the differentiation potential of the ES cells, the CE2 cells were injected subcutaneously into syngenic mice, and many kinds of differentiated cells were observed on the sections of the teratoma derived from this ES cell line. On the other hand, to test the chimeric ability of the ES cells, the CE2 cells were microinjected into the blastocysts of ICR mice, and a chimera was obtained among living pups. These results show that CE2 ES cells are pluripotent stem cells, which can differentiate into many kinds of cell types, and can be used as a cell system for further research.

One extraction tool for in vitro-in vivo extrapolation?SPME-based metabolomics of in vitro 2D,3D,and in vivo mouse melanoma models

Solid phase microextraction(SPME)in combination with high-resolution mass spectrometry was employed for the determination of metabolomic profile of mouse melanoma growth within in vitro 2D,in vitro 3D,and in vivo models.Such multi-model approach had never been investigated before.Due to the low-invasiveness of SPME,it was possible to perform time-course analysis,which allowed building time profile of biochemical reactions in the studied material.Such approach does not require the multiplication of samples as subsequent analyses are performed from the very same cell culture or from the same individual.SPME already reduces the number of animals required for experiment;therefore,it is with good concordance with the 3Rs rule(replacement,reduction,and refinement).Among tested models,the largest number of compounds was found within the in vitro 2D cell culture model,while in vivo and in vitro 3D models had the lowest number of detected compounds.These results may be connected with a higher metabolic rate,as well as lower integrity of the in vitro 2D model compared to the in vitro 3D model resulting in a lower number of compounds released into medium in the latter model.In terms of in vitro-in vivo extrapolation,the in vitro 2D model performed more similar to in vivo model compared to in vitro 3D model;however,it might have been due to the fact that only compounds secreted to medium were investigated.Thus,in further experiments to obtain full metabolome information,the intraspheroidal assessment or spheroid dissociation would be necessary.

Nuclear proteome profile of C57BL/6J mouse liver

The liver proteome can serve as a reference to better understand both disease mechanisms and possible therapeutics,since the liver is an important organ in the body that performs a large number of tasks.Here we identify the organelle proteome of C57BL/6J mouse liver nuclei as a promising strategy to enrich low abundance proteins,in the sense that analysis of whole liver cells is rather complex for current techniques and may not be suitable for proteins with low abundance.Evaluation of nucleus integrity and purity was performed to demonstrate the effectiveness of the optimized isolation procedure.The extracted nuclear proteins were identified by 2-DE MS analyses,and a total of 748 proteins were identified.Bioinformatic analyses were performed to demonstrate the physicochemical properties,cellular locations and functions of the proteins.

Establishment of a C57BL/6N mouse model of giardiasis

To establish a C57BL/6N mouse model infected with Giardia lamblia ( G lamblia ) isolates from human origin Method Two groups of C57BL/6N mouse were inoculated with purified cysts of two G lamblia isolates (CD and XZ) by gavage separately Patterns and curves of cyst excretion of the infected mice were observed and summarized Histopathological changes of the small intestines of the infected mice were observed Results Thirty six mice receiving 1×10 4 cysts each were all infected The C57BL/6N mouse showed high susceptibility to G lamblia infection There was no notable distinction between the two groups of the mice infected by the cysts of CD and XZ isolates Cyst excretion occurred with intermittence Of 36 infected mice, 32 (89%) passed cysts intermittently and 4 (11%) others persistently The latent period of cyst excretion was 0-3 days p i (post inoculation) The interruption of cyst excretion ranged from 12 to 20 days p i The fastigium of the cyst excretion was on day 6 p i The peak count of the cysts passed during a 2 h collection period was 2 3×10 7 /g fecal specimen Edema, inflammation, cell infiltration, small blood vessels congestion, mitotic figures and mucosa necrosis appeared in sections of intestines Conclusion C57Bl/6N mouse is a suitable animal model of G lamblia

I_κB kinase-beta inhibitor attenuates hepatic fibrosis in mice

AIM: To investigate the anti-fibrosis effect of IκB kinase-beta inhibitor (IKK2 inhibitor IMD0354) in liver fibrosis. METHODS: Twenty male C57BL6 mice were divided into four groups. Five high-fat fed mice were injected with lipopolysaccharide (LPS, 10 mg/kg) intraperitoneally and five high-fat fed mice were without LPS injection to build models of liver injury, and the intervention group (five mice) was injected intraperitoneally with IKK2 inhibitor (IMD 30 mg/kg for 14 d), while the remaining five mice received a normal diet as controls. Hepatic function, pathological evaluation and liver interleukin-6 (IL-6) expression were examined. Western blotting and real-time polymerase chain reaction were used to detect the expressions of nuclear factor-κB (NF-κB), alpha-smooth muscle actin (α-SMA), tumor growth factor-beta1 (TGF-β1), tumor necrosis factor-alpha (TNF-α), typeⅠand type Ⅲ collagen proteins and mRNA. RESULTS: A mouse model of liver injury was successfully established, and IMD decreased nuclear transloca-tion of NF-κB p65 in liver cells. In the IMD-treated group, the levels of alanine aminotransferase (103 ± 9.77 μ/L vs 62.4 ± 7.90 μ/L, P < 0.05) and aminotransferase (295.8 ± 38.56 μ/L vs 212 ± 25.10 μ/L, P < 0.05) were significantly decreased when compared with the model groups. The histological changes were significantly ameliorated. After treatment, the expressions of IL-6 (681 ± 45.96 vs 77 ± 7.79, P < 0.05), TGF-β1 (Western blotting 5.65% ± 0.017% vs 2.73% ± 0.005%, P < 0.05), TNF-α (11.58% ± 0.0063% vs 8.86% ± 0.0050%, P < 0.05), typeⅠcollagen (4.49% ± 0.014% vs 1.90% ± 0.0006%, P < 0.05) and type Ⅲ collagen (3.46% ± 0.008% vs 2.29% ± 0.0035%, P < 0.05) as well as α-SMA (6.19 ± 0.0036 μ/L vs 2.16 ± 0.0023 μ/L, P < 0.05) protein and mRNA were downregulated in the IMD group compared to the fibrosis control groups (P < 0.05). CONCLUSION: IKK2 inhibitor IMD markedly improved non-alcoholic fatty liver disease in mice by lowering NF-κB activation, which could become a remedial target for liver fibrosis.

Beneficial effects of losartan or telmisartan on the local hepatic renin-angiotensin system to counter obesity in an experimental model

BACKGROUND Obesity has been associated with hepatic overexpression of the renin-angiotensin system(RAS).AIM To evaluate the action of two angiotensin II(ANGII) receptor blockers(losartan or telmisartan) on the modulation of local hepatic RAS and the resulting metabolic effects in a diet-induced obesity murine model.METHODS Twenty C57 BL/6 mice were randomly divided into two nutritional groups for 10 wk: control group(C, n = 5, 10% of energy as fat) or high-fat group(HF, n = 15,50% of energy as fat). After treatment started, the HF group was randomly divided into three groups: untreated HF group(n = 5), HF treated with losartan(HFL, n = 5) and HF treated with telmisartan(HFT, n = 5). The treatments lasted for 5 wk, and the dose was 10 mg/kg body mass.RESULTS HF diet induced body mass gain(+28%, P < 0.0001), insulin resistance(+69%, P =0.0079), high hepatic triacylglycerol(+127%, P = 0.0004), and overexpression of intrahepatic angiotensin-converting enzyme(ACE) 1/ANGII type 1 receptor(AT1 r)(+569.02% and +141.40%, respectively, P < 0.0001). The HFL and HFT groups showed higher ACE2/rMAS gene expression compared to the HF group(ACE2: +465.57%, P = 0.0002 for HFL and +345.17%, P = 0.0049 for HFT; rMAS:+711.39%, P < 0.0001 for HFL and +539.75%, P < 0.0001 for HFT), followed by reduced insulin/glucose ratio(-30% for HFL and-33% for HFT, P = 0.0181),hepatic triacylglycerol levels(-28%, P = 0.0381 for HFL; and-45%, P = 0.0010 for HFT, and Plin2 expression.CONCLUSION Modulation of the intrahepatic RAS, with favored involvement of the ACE2/rMAS axis over the ACE1/AT1 r axis after losartan or telmisartan treatments, caused hepatic and metabolic beneficial effects as demonstrated by reduced hepatic triacylglycerol levels coupled with reduced PLIN 2 expression and improved glycemic control.

Downregulation of Cav3.1 T-type Calcium Channel Expression in Age-related Hearing Loss Model

Objective Age-related hearing loss(AHL),characterized by degeneration of cochlea structures,is the most common sensory disorder among the elderly worldwide.The calcium channel is considered to contribute to normal hearing.However,the role of the T-type voltage-activated calcium channel,Cav3.1,remains unclear in AHL.Here,we investigate the age-related change of Cav3.1 expression in the cochlea and D-gal-induced senescent HEI-OC1 cells.Methods Cochleae from C57BL/6 mice at 2 months and 12 months of age were assessed.Senescence in House Ear Institute-Organ of Corti 1(HEI-OC1)cells was induced by D-gal treatment.The immunofluorescence technique was employed to investigate the distribution of Cav3.1 in vivo and in vitro.Quantitative assessment was achieved by Western blotting and real-time PCR.Results In comparison with 2-month-old animals,12-month old C57BL/6 mice exhibited great loss of hair cells and elevated auditory brainstem threshold.The Cav3.1 was located in hair cells,spiral ganglion cells,lateral walls,and the expression of Cav3.1 protein and mRNA decreased in the aged cochleae.D-gal-induced senescence assay confirmed the down-regulation of Cav3.1 expression in senescent HEI-OC1 cells.Conclusion Our results show that age-related down-regulated expression of Cav3.1 in the cochleae is associated with AHL and may contribute to the pathogenesis of AHL.

The metabolite, alpha-ketoglutarate inhibits non-alcoholic fatty liver disease progression by targeting lipid metabolism

Background:Non-alcoholic liver disease is of increased concern and contributing to economic burdens not only in developing countries but in developed countries as well.Identifying the biomarker of early diagnosis and early intervention approaches for non-alcoholic liver disease is unmet and required further investigation.Although the alpha-ketoglutarate(a-KG)is recently proposed to be a potential biomarker in differentiating patients with obesity from those with non-alcoholic liver disease,how a-ketoglutatate is involved in the fatty liver progression is not clear.Methods:A high-fat diet(HFD)feeding animal model,liver functional assays,and molecular approaches were adopted to clarify the impact of a-KG in fatty liver progression.Results:In the current study,it was found that dietary a-KG would inhibit weight gain in male and female mice fed with a normal chew or HFD.HFD feeding caused fatty liver in male mice,but a-KG treatment could substantially inhibit hepatic steatosis progression.Biochemical studies revealed the possible linkage of a-KG protective functions to lipid metabolism.Further analysis identified the important role of peroxisome proliferator-activated receptors in beneficial a-KG-mediated effects on fatty liver progression.Conclusions:The current study demonstrates the therapeutic potential of a-KG and how it may be used,via dietary supplementation,as a preventive intervention for non-alcoholic liver disease in obese patients.