Intraperitoneal administration of cyclophosphamide 100 mg/kg and 200 mg/kg significantly lowered plasma sodium and significantly increased plasma potassium but did not result in saline preference in a strain of wild-derived house mice given a choice between water and saline (0.15M) to drink. Deoxycorticosterone acetate treatment in dosages up to 1.5 mg for four days also failed to increase salt intake. The data suggest a possible absence of a sodium appetite mechanism in this species.

Our purpose was to investigate the influence of in vitro oocyte aging on fertilization and subsequent embryonic development following subzonal sperm injection with reference to spontaneous zona hardening in the mouse.

Recent studies have shown that Toll-like receptors (TLRs) are involved in cerebral ischemia/reperfusion (I/R) injury. This study was to investigate the role of TLR2 and TLR4 in acute focal cerebral I/R injury. Cerebral infarct size, neurological function and mortality were evaluated. NFk{cyrillic}B binding activity, phosphorylation of Ik{cyrillic}Bα, Akt and ERK1/2 were examined in ischemic cerebral tissue by EMSA and Western blots. Compared to wild type (WT) mice, in TLR4 knockout (TLR4KO) mice, brain infarct size was decreased (2.6 ± 1.18% vs 11.6 ± 1.97% of whole cerebral volume, p < 0.05) and neurological function was maintained (7.3 ± 0.79 vs 4.7 ± 0.68, p < 0.05). However, compared to TLR4KO mice, TLR2 knockout (TLR2KO) mice showed higher mortality (38.2% vs 13.0%, p < 0.05), decreased neurological function (2.9 ± 0.53 vs 7.3 ± 0.79, p < 0.05) and increased brain infarct size (19.1 ± 1.33% vs 2.6 ± 1.18%, p < 0.05). NFk{cyrillic}B activation and Ik{cyrillic}Bα phosphorylation were attenuated in TLR4KO mice (1.09 ± 0.02 and 1.2 ± 0.04) compared to TLR2KO mice (1.31 ± 0.02 and 2.2 ± 0.32) after cerebral ischemia. Compared to TLR4KO mice, in TLR2KO mice, the phosphorylation of Akt (0.2 ± 0.03 vs 0.9 ± 0.16, p < 0.05) and ERK1/2 (0.8 ± 0.06 vs 1.3 ± 0.17) evoked by cerebral I/R was attenuated. The present study demonstrates that TLR2 and TLR4 play differential roles in acute cerebral I/R injury. Specifically, TLR4 contributes to cerebral I/R injury, while TLR2 appears to be neuroprotective by enhancing the activation of protective signaling in response to cerebral I/R.

A reproducible model of global cerebral ischemia in mice is essential for elucidating the molecular mechanism(s) of neuronal damage induced by cerebral ischemia/reperfusion injury. In the present study, we developed a mouse model of transient global ischemia induced by occlusion of the bilateral common carotid arteries and the left subclavian artery together with right subclavian artery (RSA) stenosis (CSOSS) under controlled ventilation in C57BL/10ScSn mice. The mean arterial blood pressure was maintained in the physiological range. The cortical cerebral blood flow was reduced to less than 10% of the pre-ischemic value. Twelve minutes of global ischemia induced brain damage in several brain structures. The neuropathological score in the hippocampus CA1 region was 1.7, 3.5 and 3.7 following reperfusion for 24, 48 and 72 h, respectively. Less extensive damage was seen in the dentate gyrus and cortical regions, compared with the CA1 region. Damage was observed in these regions 24 h after ischemia and was not different between 48 and 72 h post-ischemia. Results indicated that this global ischemia model possessed several advantages, including reproducible cerebral ischemic insult, sufficient reperfusion and low mortality rate (10%), and could be used for studies on cerebral ischemia/reperfusion injury in mice.

Indiana University-Purdue University Indianapolis (IUPUI) / Current interventions used to reduce skeletal fragility are insufficient at enhancing bone across multiple hierarchical levels. Bisphosphonates, such as Zoledronate (ZOL), treat a variety of bone disorders by increasing bone mass and bone mineral density to decrease fracture risk. Despite the mass-based improvements, bisphosphonate use has been shown to compromise bone quality. Alternatively, Raloxifene (RAL) has recently been demonstrated to improve tissue quality and overall mechanical properties by binding to collagen and increasing tissue hydration in a cell-independent manner. We hypothesized that a combination of RAL and ZOL would improve mechanical and material properties of bone more than either monotherapy alone by enhancing both quantity and quality of bone. In this study, wildtype (WT) and heterozygous (OIM+/-) male mice from the Osteogenesis Imperfecta (OI) murine model were treated with either RAL, ZOL, or RAL and ZOL from 8 weeks to 16 weeks of age. Combination treatment resulted in higher trabecular architecture, cortical mechanical properties, and cortical fracture toughness in diseased mouse bone. Two fracture toughness properties, direct measures of the tissue’s ability to resist the initiation and propagation of a crack, were significantly improved with combination treatment in OIM+/- compared to control. There was no significant effect on fracture toughness with either monotherapy alone in either genotype. Following the mass-based effects of ZOL, bone volume fraction was significantly higher with combination treatment in both genotypes. Similar results were seen in trabecular number. Combination treatment resulted in higher ultimate stress in both genotypes, with RAL additionally increasing ultimate stress in OIM+/-. RAL and combination treatment in OIM+/- also produced a higher resilience compared to the control. Given no significant changes in cortical geometry, these mechanical alterations were likely driven by the quality-based effects of RAL. In conclusion, this study demonstrates the beneficial effects of using combination therapy to increase bone mass while simultaneously improving tissue quality, especially to enhance the mechanical integrity of diseased bone. Combination therapies could be a future mechanism to improve bone health and combat skeletal fragility on multiple hierarchical levels.

During mouse development, the primordia of the posterior body including the trunk and tail tissues of the embryo forms largely from a bipotential cell population that resides in the posterior growth zone in vertebrate embryos. This bipotential cell population contains neuromesodermal progenitors (NMP) which are found in the tail bud which replaces the primitive streak after gastrulation and contributes to axial elongation by the formation of both the spinal cord and paraxial mesoderm derivatives. The three vertebrate Cdx genes, Cdx1, Cdx2 and Cdx4, encode transcription factors that play important roles in axial elongation since the triple Cdx mutant embryos fail to generate any tissue posterior to the occipital primordia. A comparison of Cdx mutant phenotypes suggests that Cdx2 is the most important contributor to axial elongation since Cdx2 heterozygous mutants exhibit foreshortened tails and Cdx2 conditional mutants exhibit axial truncation and complete loss of tail bud structures. Cdx2 target genes, such as Wnt3a, Cyp26a1 and T, are also essential for axial elongation. Cdx1 null mutants are viable and exhibit homeosis of cervical and anterior thoracic vertebrae, while Cdx4 null mutants are phenotypically normal. In addition, it has been shown that simultaneous loss of multiple copies of Cdx alleles disrupts axial elongation more severely than each single mutation which suggests there is overlapping function among the Cdx family. The genetic network underlying regulation of axial elongation by the Cdx family is not fully understood due in part to this functional overlap. In this thesis, I employed a conditional Cre-loxP system to derive conditional mutants lacking all Cdx functions. Additionally, Pax2-GFP transgenic mice where GFP is expressed under the control of Pax2 locus were used to enrich tail bud NMP cells for RNA-seq and ChIP-seq analysis for Cdx2. Using this approach, I revealed new target genes and pathways that are regulated by Cdx members and likely involved in axial elongation.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12802号 / 論医博第2074号 / 新制||医||1001(附属図書館) / 80846 / 京都大学大学院医学研究科医学専攻 / (主査)教授 妻木 範行, 教授 戸口田 淳也, 教授 松田 秀一 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18171号 / 医博第3891号 / 新制||医||1003(附属図書館) / 31029 / 京都大学大学院医学研究科医学専攻 / (主査)教授 三森 経世, 教授 生田 宏一, 教授 河本 宏 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

During neural development, nearly 50% of all newly generated neurons undergo cell death after making provisional contact with their target cells. The functional consequences of eliminating this neuronal cell death are not known. Bax, a pro-apoptotic protein, is required for cell death in many neural regions. A null mutation of the Bax gene in mice has been shown to increase overall cell number and eliminate the sex differences in neuron number in the anteroventral periventricular nucleus (AVPV) and the principal nucleus of the bed nucleus of the stria terminalis (BNSTp). The aim of my Master’s thesis was to study male and female sexual behaviors and motor behavior in Bax -/- mice and their wild-type siblings. Animals were gonadectomized in adulthood and provided with ovarian hormones or with testosterone for tests of female and male sexual behaviors, respectively. Wild-type mice exhibited a sex difference in feminine sexual behavior, with high lordosis scores in females and low scores in males. This sex difference was eliminated by Bax deletion, with very low receptivity exhibited by both male and female Bax -/- mice. Male sexual behavior was not sexually dimorphic among wild-type mice, but mounts and pelvic thrusts were nearly absent in Bax -/- mice of both sexes. The knockouts did not display deficient motor strength or performance at low speeds on a RotaRod apparatus compared to wild type mice. At high speeds, however, Bax -/- animals exhibited impairments on the RotaRod. Therefore, developmental cell death may be required for exhibition of male and female sexual behaviors, and for coordination of relatively difficult motor tasks.