Quantitative trait loci for growth traits in C57BL/6J × DBA/2J mice

Quantitative trait loci (QTLs) for body weight and tail length are mapped in an F₂ population of 927 C57BL/6J × DBA/2J mice. We test the concordance between the locations of the mapped QTLs with those detected by changes of marker frequency under artificial selection in a previous experiment with the same base population. The directions of effects of the QTLs are generally in agreement, and in many cases significant QTLs are found in similar map positions, but there are also discrepancies between the two experiments. There are indications of age-specific QTL effects on growth. For body weight traits, the genetic variation in the F₂ appears to result from many loci with relatively small effects. For tail length at 10 weeks, however, a single QTL on Chromosome (Chr) 1 with a peak LOD score of ∼33 contributes most of the genetic variation detected, changes the trait value by about 6%, and explains about 20% of the phenotypic variance of the trait. Received: 4 August 1998 / Accepted: 17 November 1998     

Determination of RBC Survival in C57BL/6 and C57BL/6-Tg(UBC–GFP) Mice

Although several methods for determining erythrocyte lifespan are used in research studies that involve mice, all involve the alteration of RBC to allow for its tracking over time, which may affect overall RBC survival. The aims of this study were to determine 1) whether sex affects RBC survival; 2) whether RBC survival differs between the biotin method and an alternative method that uses GFP; and 3) whether repeat exposure of mice to biotin results in an antibiotin antibody response or decreased RBC survival. The results suggest no difference in the RBC half-life between male and female C57BL/6 mice (22.9 ± 1.2 and 22.4 ± 0.9 d, respectively). In addition, RBC half-life did not differ between the biotin- and GFP-based methods (20.5 ± 2.1 d and 22.7 ± 2.1 d, respectively). Finally, retransfusion of mice 90 d after an initial transfusion with biotin-labeled RBC did not induce detectable antibiotin antibodies nor alter the half-life of transfused biotin-labeled RBC (initial transfusion, 22.0 ± 1.2 d; subsequent transfusion, 23.4 ± 1.4 d, respectively).Abbreviations: T_1/2, half-lifeRBC lifespan and senescence are important parameters used both clinically and in research studies of hereditary disorders of erythrocyte metabolism, transfusion medicine, and sepsis.^{8,21,27,32,35} Labeling RBC with a biotinylating reagent is a common method used to determine their circulating lifespan. Other methods involve using radioactive isotopes, such as ⁵¹Cr and ⁵⁹Fe.^7,20 Biotinylating reagents are preferred for various research applications with humans,^8,23,24 and are used in a variety of animal models.^{1,25,33,34,37} Once biotin attaches to RBC surface proteins, streptavidin (a protein derived from Streptomyces avidinii) that is labeled with a fluorescent dye is used to form a strong and rapid complex with biotin, thereby allowing for its detection through flow cytometry. Blood samples analyzed sequentially over a period of weeks will show a linear decline in biotin–streptavidin signal as labeled cells age and are cleared from the circulation through the reticuloendothelial system.The characteristics of an ideal label for performing RBC survival studies include: 1) stable presence on or within the cell throughout its normal lifespan; 2) specificity for RBC; 3) inertness, such that the cell does not become prone to accelerated destruction; 4) nonrecycling (that is, the label does not reenter the circulation and bind to new cells after destruction of the labeled RBC); and 5) easy and accurate measurement by using available assays. Radioactive isotopes and other labels fulfill several of these criteria, but their limitations include elution from RBC as well as safety concerns.^7,22 In contrast, biotin poses little to no risk of accumulation or toxicity. The sulfo- N-hydroxysuccinimide–biotin ester used for RBC tracking studies in humans and animals can be administered directly or through the transfusion of biotinylated RBC. Although it is generally accepted that biotinylation of RBC does not affect their function, antibodies to biotin have been demonstrated in some human studies, posing the question of whether repeated administration of biotin ester or biotinylated RBC could interfere with subsequent results within the same subject.^4,20 Repeat transfusions of biotinylated RBC to mice have not been described in the literature. One aim of this study was to determine whether exposure to biotinylated RBC induces an antibiotin antibody response in mice. Furthermore, we tested whether the survival of biotinylated RBC changed after repeat exposure.Recently GFP-expressing RBC have been used to track the posttransfusion survival and recovery of stored RBC administered to nonGFP-expressing recipient mice.^9,12,36 The C57BL/6-Tg(UBC–GFP)30Scha/J mouse strain is characterized by GFP expression under the control of a human ubiquitin C promoter. All tissues of these mice express GFP, including blood.²⁶ GFP expression appears to be consistent throughout life and does not otherwise alter the normal structure, physiology, or function of RBC. In addition, GFP is unaffected by ambient light contamination or degradation, drawbacks that are associated with fluorescent dyes.¹⁵ In addition, GFP allows for the separation of cell populations through flow cytometry.^9,11 Many qualities of GFP suggest that it may serve as a useful surrogate marker in place of other labeling techniques in mice. Therefore, we sought to evaluate the utility of UBC–GFP transgenic mice as an alternative to labeling RBC with biotin esters. Our aim for this work was to determine the survival of RBC in wild-type C57BL/6 mice and in the UBC–GFP strain and to compare methods for determining RBC half-life (T_1/2).     

Bias in the αβ T-cell repertoire: implications for disease pathogenesis and vaccination

The na?ve T-cell repertoire is vast, containing millions of unique T-cell receptor (TCR) structures. Faced with such diversity, the mobilization of TCR structures from this enormous pool was once thought to be a stochastic, even chaotic, process. However, steady and systematic dissection over the last 20 years has revealed that this is not the case. Instead, the TCR repertoire deployed against individual antigens is routinely ordered and biased. Often, identical and near-identical TCR repertoires can be observed across different individuals, suggesting that the system encompasses an element of predictability. This review provides a catalog of αβ TCR bias by disease and by species, and discusses the mechanisms that govern this inherent and widespread phenomenon.     

Sex-restricted non-Mendelian inheritance of mouse Chromosome 11 in the offspring of crosses between C57BL/6J and (C57BL/6J × DBA/2J)F1 mice

We report on the observation of sex-restricted, non-Mendelian inheritance over a region of mouse Chromosome (Chr) 11, occurring in the offspring of crosses between two commonly used Mus musculus-derived inbred strains, C57BL/6J and DBA/2J. In the surviving backcross progeny of reciprocal matings between (C57BL/6J × DBA/2J)F₁ hybrids and the C57BL/6J parental strain, we observed the preferential appearance of C57BL/6J alleles along a region of Chr 11. The deviation from Mendelian predictions was observed only in female offspring from both reciprocal backcrosses, and not in males from either cross. The sex-specificity of the observed non-Mendelian inheritance points to an explanation based on embryonic or neonatal lethality. Our data add to previously obtained evidence for a Chr 11 locus or loci with sex-specific and allele-specific effects on viability. Received: 19 December 1997 / Accepted: 10 June 1998     

Short-term protection conferred by Leishvacin® against experimental Leishmania amazonensis infection in C57BL/6 mice

To date, there is no vaccine available against human leishmaniasis. Although some vaccination protocols can induce immunity in murine models, they fail to induce protection in humans. The reasons for that remain unclear. The aim of the present study was to characterize the changes in the pattern of the immune response during subcutaneous vaccination with Leishvacin® in mice. We also investigated whether IFN-γ and nitric oxide synthase are indispensable for the protection elicited by the vaccine. C57BL/6 WT vaccinated mice showed smaller lesions and fewer numbers of parasites in footpads until 8 weeks post-infection. Up to this time, they produced higher levels of IFN-γ, IL-2, IL-4, IL-17A and IL-10 and higher specific antibody response than control non-vaccinated mice. Moreover, we showed that IFN-γ, most likely by induction of iNOS expression, is essential for immunity. However, after 12 weeks of infection, we observed loss of difference in lesion size and parasite burden between the groups. Loss of resistance was associated with the disappearance of differences in cytokine patterns between vaccinated and control mice, but not of antibody response, which remained different until a later time of infection. The reversal of resistance to L. amazonensis could not be explained by upregulation of regulatory cytokines. Our data point to a subversion of the host immune response by L. amazonensis even when a protective response was previously induced.     

Protective effect of sesamol against 60Co γ-ray-induced hematopoietic and gastrointestinal injury in C57BL/6 male mice

Abstract

Protection of γ-ray-induced injury in hematopoietic and gastrointestinal (GI) systems is the rationale behind developing radioprotectors. The objective of this study, therefore, was to investigate the radioprotective efficacy and mechanisms underlying sesamol in amelioration of γ-ray-induced hematopoietic and GI injury in mice. C57BL/6 male mice were pre-treated with a single dose (100 or 50 mg/kg, 30 min prior) of sesamol through the intraperitoneal route and exposed to LD_50/30 (7.5 Gy) and sublethal (5 Gy) dose of γ-radiation. Thirty-day survival against 7.5 Gy was monitored. Sesamol (100 mg/kg) pre-treatment reduced radiation-induced mortality and resulted survival of about 100% against 7.5 Gy of γ-irradiation. Whole-body irradiation drastically depleted hematopoietic progenitor stem cells in bone marrow, B cells, T cell subpopulations, and splenocyte proliferation in the spleen on day 4, which were significantly protected in sesamol pre-treated mice. This was associated with a decrease of radiation-induced micronuclei (MN) and apoptosis in bone marrow and spleen, respectively. Sesamol pre-treatment inhibited lipid peroxidation, translocation of gut bacteria to spleen, liver, and kidney, and enhanced regeneration of crypt cells in the GI system. In addition, sesamol pre-treatment reduced the radiation-induced pattern of expression of p53 and Bax apoptotic proteins in the bone marrow, spleen, and GI. This reduction in apoptotic proteins was associated with the increased anti-apoptotic-Bcl-x and PCNA proteins. Further, assessment of antioxidant capacity using ABTS and DPPH assays revealed that sesamol treatment alleviated total antioxidant capacity in spleen and GI tissue. In conclusion, the results of the present study suggested that sesamol as a single prophylactic dose protects hematopoietic and GI systems against γ-radiation-induced injury in mice.     

Doxorubicin plus tumor necrosis factor α combination treatments in EL4-lymphoma-bearing C57BL/6 mice

 The therapeutic efficacy of a total of 42 single-agent or combination protocols involving doxorubicin (Adriamycin, ADM) and tumor necrosis factor α (TNFα) were evaluated in the syngeneic murine lymphoma model, C57BL/6-EL4. Combination treatments were the most effective and the therapeutic effects were schedule-dependent; e.g. it was generally advantageous for ADM to precede TNFα administration. Two protocols selected for further study were 4 mg/kg ADM i.v. on days 1 and 8 plus TNFα, i.v., at either 16 000 U (7 μg)/injection, on days 1 and 8 or 4000 U (1.7 μg)/injection, on days 11–15. Survival of mice bearing one of four EL4 sublines having different in vitro drug sensitivities was assessed. These sublines were E10 (ADM-sensitive/TNFα-resistant), E16 (sensitive/sensitive), ER2 (ADM-resistant/TNFα-sensitive) and ER13 (resistant/resistant). Between 80% and 100% long-term survivors (i.e. tumor free on day 60) were obtained with the two treatments in mice bearing ADM-sensitive sublines, even though one of these sublines, E10, was resistant to TNFα in vitro. Induction of long-term survival appeared, therefore, to correlate with in vitro defined sensitivity/resistance to ADM, but not to TNFα. Treatment-induced modulations of tumoricidal immune effector functions were also examined. Taken together, the results indicated that induction of long-term survival involved complex interactions of: (1) ADM-induced tumor modifications, including, but not limited to, tumor debulking, (2) combination-treatment-induced modifications of splenic cytolytic T cell and macrophage activities, and (3) the restoration of thymus cellularity. Finally, when long-term survivors resulting from treatment of E10- or E16-bearing mice were implanted with ER2 on day 120, the majority survived, indicating that long-term immune memory, capable of recognizing drug resistant variants, had been established. Received: 14 August 1997 / Accepted: 2 October 1997     

Inhibition of NF-κB activation by diethylcarbamazine prevents alcohol-induced liver injury in C57BL/6 mice

Induction of NF-κB-mediated gene expression has been identified in the pathogenesis of alcoholic liver disease (ALD). Diethylcarbamazine (DEC) is a piperazine derivative drug with anti-inflammatory properties. The present study was designed to evaluate the effect of DEC on NF-κB pathways in mice undergoing alcoholism induced hepatic inflammation. Forty male C57BL/6 mice were divided equally into four groups: control group (C); DEC-treated group, which received 50 mg/kg (DEC50); alcoholic group (EtOH), submitted to chronic alcohol consumption and the alcohol-DEC treated group (EtOH50), submitted to chronic alcoholism consumption plus DEC treatment. Histological analysis of the alcoholic group showed evident hepatocellular damage which was reduced in EtOH50 group. Immunohistochemistry and western blot results showed elevated expression of inflammatory markers such as MDA, TNF-α, IL-1β, COX-2 and iNOS in hepatocytes of EtOH group. However, low immunopositivity for these markers was detected following DEC treatment. In the EtOH group the activation of NF-κB was observed by an increase in the expression of both NF-κB and pNF-κB in hepatocytes. This expression was significantly reduced in livers of EtOH50 group. Protein expression of Iκβα was measured to determine whether activation of NF-κB might be the result of Iκβα degradation. It was observed that expression of this protein was low in EtOH group, while animals treated with DEC had a high expression of Iκβα. The results of the present study indicate that DEC alleviates alcoholic liver injury, in part by the inhibiting activation of NF-κB and by suppressing the induction of NF-κB-dependent genes.     

Why does a sucrose choice reduce the consumption of alcohol in C57BL/6J mice?

To determine why animals reject alcohol when offered palatable solutions of sucrose, male C57BL/6J mice were challenged first with 5% sucrose then with 10% sucrose, while given continuous free-access to alcohol and water. The 5% sucrose dramatically reduced the intake of alcohol and increased the intake of total fluid by an average of 7.3 ml/day. The suppression of alcohol intake could not be attributed to a volumetric ceiling since access to 10% sucrose produced a further large increase in total intake (8.8 ml/day). The results support the interpretation that animals consume alcohol for characteristics it shares with sucrose.     

Cytochemical localization of β-galactosidase in resident and inflammatory peritoneal macrophages from C57BL mice

Summary A cytochemical method for the detection of -galactosidase (-Gase) in mouse peritoneal macrophages was used to study the ultrastructural localization of this enzyme in these cells. It was found that the reaction product for -Gase was localized in the perinuclear cisternae, the endoplasmic reticulum, the Golgi complex, lysosomes, vesicles and on the cell surface of peritoneal macrophages from untreated C57BL mice. When examined by X-ray microanalysis the crystalline reaction product was found to contain bromine, an element present in the indolyl substrate which was used to identify -Gase. Injection of Proprionibacterium acnes (P. acnes) intraperitoneally or BCG intravenously caused a visible loss in -Gase from all the organelles and from the cell surface of the macrophages.Abbreviations used -Gase -galactosidase - RP reaction product - PNC perinuclear cisternae - RER rough endoplasmic reticulum     

Diversity of the mouse T cell receptor Cγ1 gene: structural analysis in C57BL/Ka

We have isolated an unusual T cell receptor chain cDNA clone (7.1) from a library made from RNA derived from adult thymus of C57BL/Ka mice. This cDNA clone corresponds to the appropriately processed C1 constant region exons preceded by 1.5 kb of J-C1 intron. The 7.1 coding region is extremely homologous to the C1 gene of BALB/c mice, differing at the protein level by a single deletion (alanine 139) and a single substitution. This latter change eliminates the sole N-linked sugar attachment site, providing a basis for strain-specific glycosylation patterns. The J-C1 intronic region contains two DNA segments (termed J1 and J2) that are highly reminiscent of joining (J) segments; both have potentially functional recombination and donor splice sequences flanking an open reading frame. Northern analysis suggests that 7.1 may be derived from a large, variable region-containing precursor.     

Identification of candidate genes for nicotine withdrawal in C57BL/6J × DBA/2J recombinant inbred mice

Nicotine is the reinforcing ingredient in tobacco. Following chronic exposure, sudden cessation of nicotine use produces negative symptoms of withdrawal that contribute to dependence. The molecular mechanisms underlying nicotine withdrawal behaviors, however, are poorly understood. Using recombinant inbred mice, chronic nicotine was delivered by minipump and withdrawal induced using mecamylamine. Somatic signs of withdrawal, and anxiety-like behavior using elevated plus maze, were then assessed. Interval mapping was used to identify associations between genetic variation and withdrawal behaviors, and with basal gene expression. Differential gene expression following nicotine exposure and withdrawal was also assessed in progenitor mice using microarrays. Quantitative trait loci mapping identified chromosome intervals with significant genetic associations to somatic signs of withdrawal or withdrawal-induced anxiety-like behavior. Using bioinformatics, and association with basal gene expression in nucleus accumbens, we implicated Rb1, Bnip3l, Pnma2, Itm2b, and Kif13b as candidate genes for somatic signs of withdrawal, and Galr1, which showed trans-regulation from a region of chromosome 14 that was associated with somatic signs of withdrawal. Candidate genes within the chromosome 9 region associated with anxiety-like withdrawal behavior included Dixdc1, Ncam1, and Sorl1. Bioinformatics identified six genes that were also significantly associated with nicotine or alcohol traits in recent human genome-wide association studies. Withdrawal-associated somatic signs and anxiety-like behavior had strong non-overlapping genetic associations, respectively, with regions of chromosome 14 and chromosome 9. Genetic, behavioral and gene expression correlations, and bioinformatics analysis identified several candidate genes that may represent novel molecular targets for modulating nicotine withdrawal symptoms.     

Leishmanicidal activity of amphotericin B encapsulated in PLGA–DMSA nanoparticles to treat cutaneous leishmaniasis in C57BL/6 mice

The major goal of this work was to design a new nanoparticle drug delivery system for desoxycholate amphotericin B (D-AMB), based on controlled particle size, looking for the most successful release of the active agents in order to achieve the best site-specific action of the drug at the therapeutically optimal rate and dose regimen. For this, AMB nanoencapsulated in poly(lactic-co-glycolic acid) (PLGA) and dimercaptosuccinic acid (DMSA) nanoparticles (Nano-D-AMB) has been developed, and its efficacy was evaluated in the treatment of experimental cutaneous leishmaniasis in C57BL/6 mice, to test if our nano-drug delivery system could favor the reduction of the dose frequency required to achieve the same therapeutic level of free D-AMB, and so, an extended dosing interval. Magnetic citrate-coated maghemite nanoparticles were added to this nanosystem (Nano-D-AMB-MG) aiming to increase controlled release of AMB by magnetohyperthermia. Female mice (N = 6/group) were infected intradermally in the right footpad with promastigotes of Leishmania amazonensis in the metacyclic phase, receiving the following intraperitoneal treatments: 1% PBS for 10 consecutive days; D-AMB at 2 mg/kg/day for 10 days (totalizing 20 mg/kg/animal); Nano-D-AMB and Nano-D-AMB-MG at 6 mg/kg on the 1st, 4th and 7th days and at 2 mg/kg on the 10th day, also totalizing 20 mg/kg/animal by treatment end. The Nano-D-AMB-MG group was submitted to an AC magnetic field, allowing the induction of magnetohyperthermia. The evaluations were through paw diameter measurements; parasite number and cell viability were investigated by limiting dilution assay. D-AMB-coated PLGA–DMSA nanoparticles showed the same efficacy as free D-AMB to reduce paw diameter; however, the Nano-D-AMB treatment also promoted a significantly greater reduction in parasite number and cell viability compared with free D-AMB. The nano-drug AMB delivery system appeared more effective than free D-AMB therapy to reduce the dose frequency required to achieve the same therapeutic level. It thus favors a longer interval between doses, as expected with development of a new nano drug delivery system, and may be useful in the treatment of many different pathologies, from cancer to neurodegenerative diseases.     

Regulation of carbohydrate metabolism by indole-3-carbinol and its metabolite 3,3′-diindolylmethane in high-fat diet-induced C57BL/6J mice

Indole glucosinolates, present in cruciferous vegetables have been investigated for their putative pharmacological properties. The current study was designed to analyse whether the treatment of the indole glucosinolates—indole-3-carbinol (I3C) and its metabolite 3,3′-diindolylmethane (DIM) could alter the carbohydrate metabolism in high-fat diet (HFD)-induced C57BL/6J mice. The plasma glucose, insulin, haemoglobin (Hb), glycosylated haemoglobin (HbA1c), glycogen and the activities of glycolytic enzyme (hexokinase), hepatic shunt enzyme (glucose-6-phosphate dehydrogenase), gluconeogenic enzymes (glucose-6-phosphatase and fructose-1,6-bisphosphatase) were analysed in liver and kidney of the treated and HFD mice. Histopathological examination of liver and pancreases were also carried out. The HFD mice show increased glucose, insulin and HbA1c and decreased Hb and glycogen levels. The elevated activity of glucose-6-phosphatase and fructose-1,6-bisphosphatase and subsequent decline in the activity of glucokinase and glucose-6-phosphate dehydrogenase were seen in HFD mice. Among treatment groups, the mice administered with I3C and DIM, DIM shows decreased glucose, insulin and HbA1c and increased Hb and glycogen content in liver when compared to I3C, which was comparable with the standard drug metformin. The similar result was also obtained in case of carbohydrate metabolism enzymes; treatment with DIM positively regulates carbohydrate metabolic enzymes by inducing the activity of glucokinase and glucose-6-phosphate dehydrogenase and suppressing the activity of glucose-6-phosphatase and fructose-1,6-bisphosphatase when compared to I3C, which were also supported by our histopathological observations.     

Do sires and juvenile male mice (C57BL/6) contribute to the rearing of the offspring?

Copulation and/or cohabitation with a pregnant female facilitate paternal behavior in male mice. However, their contribution to the rearing of the offspring is still not well understood. Our aims were to investigate the behavior of sires toward own or alien pups; the immediate consequences of the presence of fathers on the offspring and the behavior of the mother; and whether the exposure of juvenile males to newborn siblings, in an overlapping litters context, facilitates paternal behavior in C57BL/6 mice. We found that sires behaved paternally toward alien pups at both postpartum days 3 and 7; did not affect the behavior of the mother (e.g., licking and grooming, retrieval behavior, time in the nest, and crouching postures); and reduced the time offspring stayed alone in the nest. The exposure to newborn siblings did not promote paternal behavior in juvenile males. Therefore, sires are more paternal than usually described in the literature for laboratory mice, suggesting a facultative role in the rearing of the offspring. However, juvenile male mice, in contrast to juvenile females, could be adapted to leave the nest earlier without major contribution to the offspring.     

A comparison between intratracheal and inhalation delivery of Aspergillus fumigatus conidia in the development of fungal allergic asthma in C57BL/6 mice

Allergic asthma is a debilitating disease of the airways characterized by airway hyperresponsiveness, eosinophilic inflammation, goblet cell metaplasia with associated mucus hypersecretion,?and airway wall remodelling events, particularly subepithelial fibrosis and smooth muscle cell hyperplasia. Animal models that accurately mimic these hallmarks of allergic airways disease are critical for studying mechanisms associated with the cellular and structural changes that lead to disease pathogenesis. Aspergillus fumigatus, is a common aeroallergen of human asthmatics. The intratracheal (IT) delivery of A. fumigatus conidia into the airways of sensitized mice has been described as a model of allergic disease. Here, we compared the IT model with a newly developed inhalation (IH) challenge model. The IH model allowed multiple fungal exposures, which resulted in an exacerbation to the allergic asthma phenotype. Increased recruitment of eosinophils and lymphocytes, the hallmark leukocytes of asthma, was noted with the IH model as compared to the IT model in which macrophages and neutrophils were more prominent. Immunoglobulin E (IgE) production was significantly greater after IH challenge, while that of IgG(2a) was higher after IT challenge. Airway wall remodelling was pronounced in IH-treated mice, particularly after multiple allergen challenges. Although the IT model may be appropriate for the examination of the played by innate cells in the acute response to fungus, it fails to consistently reproduce the chronic remodelling hallmarks of allergic asthma. The ability of the IH challenge to mimic these characteristics recommends it as a model suited to study these important events.     

CYP2E1 and Parkinson’s disease in a MPTP-induced C57BL/6 mouse model

Background

A proline-to-serine substitution at position-56 (P56S) of vesicle-associated membrane protein-associated protein B (VAPB) causes a form of dominantly inherited motor neuron disease (MND), including typical and atypical amyotrophic lateral sclerosis (ALS) and a mild late-onset spinal muscular atrophy (SMA). VAPB is an integral endoplasmic reticulum (ER) protein and has been implicated in various cellular processes, including ER stress, the unfolded protein response (UPR) and Ca²⁺ homeostasis. However, it is unclear how the P56S mutation leads to neurodegeneration and muscle atrophy in patients. The formation of abnormal VAPB-positive inclusions by mutant VAPB suggests a possible toxic gain of function as an underlying mechanism. Furthermore, the amount of VAPB protein is reported to be reduced in sporadic ALS patients and mutant SOD1G93A mice, leading to the hypothesis that wild type VAPB plays a role in the pathogenesis of ALS without VAPB mutations.

Results

To investigate the pathogenic mechanism in vivo, we generated human wild type (wtVAPB) and mutant VAPB (muVAPB) transgenic mice that expressed the transgenes broadly in the CNS. We observed robust VAPB-positive aggregates in the spinal cord of muVAPB transgenic mice. However, we failed to find an impairment of motor function and motor neuron degeneration. We also did not detect any change in the endogenous VAPB level or evidence for induction of the unfolded protein response (UPR) and coaggregation of VAPA with muVAPB. Furthermore, we crossed these VAPB transgenic mice with mice that express mutant SOD1G93A and develop motor neuron degeneration. Overexpression of neither wtVAPB nor muVAPB modulated the protein aggregation and disease progression in the SOD1G93A mice.

Conclusion

Overexpression of VAPBP56S mutant to approximately two-fold of the endogenous VAPB in mouse spinal cord produced abundant VAPB aggregates but was not sufficient to cause motor dysfunction or motor neuron degeneration. Furthermore, overexpression of either muVAPB or wtVAPB does not modulate the course of ALS in SOD1G93A mice. These results suggest that changes in wild type VAPB do not play a significant role in ALS cases that are not caused by VAPB mutations. Furthermore, these results suggest that muVAPB aggregates are innocuous and do not cause motor neuron degeneration by a gain-of-toxicity, and therefore, a loss of function may be the underlying mechanism.     

Attenuation of hyperglycemia-mediated oxidative stress by indole-3-carbinol and its metabolite 3, 3′- diindolylmethane in C57BL/6J mice

In this study, we have investigated the effect of the nutritive phytochemicals, indole-3-carbinol (I3C) and its metabolite, 3, 3′- diindolylmethane (DIM) on oxidative stress developed in type 2 diabetes mellitus (T2DM). This work was carried out in the genetically modified mouse (C57BL/6J mice) that closely simulated the metabolic abnormalities of the human disease after the administration of high fat diet (HFD). Glucose, insulin, hemoglobin (Hb), glycated hemoglobin (HbA1c), thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH), conjugated dienes (CD), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), vitamin C, vitamin E, and reduced glutathione (GSH) levels were monitored in all the groups. Treatments positively modulate the glucose, insulin, and Hb and HbA1c levels in HFD mice. TBARS, LOOH, and CD were decreased in treatment groups when compared to the HFD group. Treatments increase SOD, CAT, GPx levels (erythrocyte, liver, kidney, and heart) and vitamin C, vitamin E, and GSH levels (plasma, liver, kidney, and heart) in diabetic mice. From the study, it was clear that the antioxidant-scavenging action were accelerated in mice treated with DIM than the I3C treatment group which was comparable with the standard drug metformin.