Effects of Alcohol and Estrogen Receptor Blockade Using ICI 182,780 on Bone in Ovariectomized Rats.

BACKGROUND: Estrogen signaling is essential for the sexual dimorphism of the skeleton, is required for normal bone remodeling balance in adults, and may influence the skeletal response to alcohol. High levels of alcohol consumption lower bone mass in ovary-intact but not ovariectomized (ovx) rats. However, the extremely rapid rate of bone loss immediately following ovx may obscure the effects of alcohol. We therefore determined (i) whether heavy alcohol consumption (35% caloric intake) influences bone in sexually mature ovx rats with established cancellous osteopenia and (ii) whether ICI 182,780 (ICI), a potent estrogen receptor signaling antagonist, alters the skeletal response to alcohol. METHODS: Three weeks following ovx, rats were randomized into 5 groups, (i) baseline, (ii) control + vehicle, (iii) control + ICI, (iv) ethanol (EtOH) + vehicle, or (v) EtOH + ICI, and treated accordingly for 4 weeks. Dual-energy X-ray absorptiometry, microcomputed tomography, blood measurements of markers of bone turnover, and gene expression in femur and uterus were used to evaluate response to alcohol and ICI. RESULTS: Rats consuming alcohol had lower bone mass and increased fat mass. Bone microarchitecture of the tibia and gene expression in femur were altered; specifically, there was reduced accrual of cortical bone, net loss of cancellous bone, and differential expression of 19/84 genes related to bone turnover. Furthermore, osteocalcin, a marker of bone turnover, was lower in alcohol-fed rats. ICI had no effect on weight gain, body composition, or cortical bone. ICI reduced cancellous bone loss and serum CTX-1, a biochemical marker of bone resorption; alcohol antagonized the latter 2 responses. Neither alcohol nor ICI affected uterine weight or gene expression. CONCLUSIONS: Alcohol exaggerated bone loss in ovx rats in the presence or absence of estrogen receptor blockade with ICI. The negligible effect of alcohol on uterus and limited effects of ICI on bone in alcohol-fed ovx rats suggest that estrogen receptor signaling plays a limited role in the action of alcohol on bone in a rat model for chronic alcohol abuse.

Heparan sulfotransferases Hs6st1 and Hs2st keep Erk in check for mouse corpus callosum development.

The corpus callosum (CC) connects the left and right cerebral hemispheres in mammals and its development requires intercellular communication at the telencephalic midline mediated by signaling proteins. Heparan sulfate (HS) is a sulfated polysaccharide that decorates cell surface and extracellular matrix proteins and regulates the biological activity of numerous signaling proteins via sugar-protein interactions. HS is subject to regulated enzymatic sulfation and desulfation and an attractive, although not proven, hypothesis is that the biological activity of HS is regulated by a sugar sulfate code. Mutant mouse embryos lacking the heparan sulfotransferases Hs2st or Hs6st1 have severe CC phenotypes and form Probst bundles of noncrossing axons flanking large tangles of midline glial processes. Here, we identify a precocious accumulation of Sox9-expressing glial cells in the indusium griseum region and a corresponding depletion at the glial wedge associated with the formation of Probst bundles along the rostrocaudal axis in both mutants. Molecularly, we found a surprising hyperactivation of Erk signaling in Hs2st(-/-) (2-fold) and Hs6st1(-/-) (6-fold) embryonic telencephalon that was most striking at the midline, where Erk signaling is lowest in wild-types, and a 2-fold increase in Fgf8 protein levels in Hs6st1(-/-) embryos that could underpin Erk hyperactivation and excessive glial movement to the indusium griseum. The tightly linked Hs6st1(-/-) CC glial and axonal phenotypes can be rescued by genetic or pharmacological suppression of Fgf8/Erk axis components. Overall, our data fit a model in which Hs2st and Hs6st1 normally generate conditions conducive to CC development by generating an HS-containing environment that keeps Erk signaling in check.

Assessment of the relationship between hypoglycaemia awareness and autonomic function following islet cell/pancreas transplantation.

BACKGROUND: This study assesses the autonomic function of patients who have regained awareness of hypoglycaemia following islet cell or whole pancreas transplant. METHODS: Five patients with type 1 diabetes and either islet cell (four patients) or whole pancreas (one patient) transplant were assessed. These patients were age-matched and gender-matched to five patients with type 1 diabetes without transplant and preserved hypoglycaemia awareness and five healthy control participants without diabetes. All participants underwent (i) a battery of five cardiovascular autonomic function tests, (ii) quantitative sudomotor axonal reflex testing, and (iii) sympathetic skin response testing. RESULTS: Total recorded hypoglycaemia episodes per month fell from 76 pre-transplant to 13 at 0- to 3-month post-transplant (83% reduction). The percentage of hypoglycaemia episodes that patients were unaware of decreased from 97 to 69% at 0-3 months (p < 0.001, Fisher's exact test) and to 20% after 12 months (p < 0.0001, Fisher's exact test). This amelioration was maintained at the time of testing (mean time: 4.1 years later, range: 2-6 years). Presence of significant autonomic neuropathy was seen in all five transplanted patients (at least 2/3 above modalities abnormal) but in only one of the patients with diabetes without transplantation. CONCLUSIONS: The long-term maintenance of hypoglycaemia awareness that returns after islet cell/pancreas transplantation in patients with diabetes is not prevented by significant autonomic neuropathy and is better accounted for by other factors such as reversal of hypoglycaemia-associated autonomic failure.

Heparan sulfate sugar modifications mediate the functions of slits and other factors needed for mouse forebrain commissure development.

Heparan sulfate proteoglycans are cell surface and secretory proteins that modulate intercellular signaling pathways including Slit/Robo and FGF/FGFR. The heparan sulfate sugar moieties on HSPGs are subject to extensive postsynthetic modification, generating enormous molecular complexity that has been postulated to provide increased diversity in the ability of individual cells to respond to specific signaling molecules. This diversity could help explain how a relatively small number of axon guidance molecules are able to instruct the extremely complex connectivity of the mammalian brain. Consistent with this hypothesis, we previously showed that mutant mice lacking the heparan sulfotransferases (Hsts) Hs2st or Hs6st1 display major axon guidance defects at the developing optic chiasm. Here we further explore the role of these Hsts at the optic chiasm and investigate their function in corpus callosum development. Each Hst is expressed in a distinct pattern and each mutant displays a specific spectrum of axon guidance defects. Particular Hs2st(-/-) and Hs6st1(-/-) phenotypes closely match those of Slit1(-/-) and Slit2(-/-) embryos respectively, suggesting possible functional relationships. To test functional interactions between Hs2st or Hs6st1 and Slits we examined optic chiasm and corpus callosum phenotypes in a panel of genotypes where Hs2st or Hs6st1 and Slit1 or Slit2 function were simultaneously reduced or absent. We find examples of Hs2st and Hs6st1 having epistatic, synergistic, and antagonistic genetic relationships with Slit1 and/or Slit2 depending on the context. At the corpus callosum we find that Hs6st1 has Slit-independent functions and our data indicate additional roles in FGF signaling.

Examining the preparation and ongoing support of adults to take their medications as prescribed in kidney transplantation.

RATIONALE, AIMS AND OBJECTIVES: The shortage of kidney donors and benefits of kidney transplantation make graft success imperative. Medication adherence is critical to prevent the risk of graft rejection. This paper examines how adults are prepared and supported by renal transplant co-ordinators and pharmacists to take their medications as prescribed in kidney transplantation. METHODS: Renal transplant co-ordinators and pharmacists of all five hospitals offering adult kidney transplantation in Victoria, Australia, were interviewed between November 2013 and February 2014. All data underwent qualitative descriptive analysis. RESULTS: Nine renal transplant co-ordinators and six pharmacists were interviewed. Although there was no standardized approach to education or other evidence-based strategies to facilitate medication adherence, there were similarities between sites. These similarities included printed information, pre-transplant education sessions, the use of medication lists and medication administration aids, intensive education in hospital and ensuring an adequate supply of medications post-discharge. CONCLUSIONS: Renal transplant co-ordinators and pharmacists recognized the importance of early patient education concerning immunosuppressant medication. However, each site had developed their own way of preparing a patient for kidney transplantation and follow-up in the acute hospital setting based on experience and practice. Other non-educational strategies involving behavioural and emotional aspects were less common. Differences in usual care reinforce the necessity for evidence-based health care for best patient outcomes.

Effect of resistance training on arterial wave reflection and brachial artery reactivity in normotensive postmenopausal women.

Large elastic artery stiffness increases with age and menopause is a mitigating factor in women. High-intensity resistance training (RT) increases arterial stiffness in young men and women. However, the effects of moderate intensity RT on central aortic pressure wave reflection in healthy postmenopausal women are unknown. Healthy sedentary normotensive postmenopausal women were randomly assigned to either 18 weeks (2 days/week) of RT (RES n = 13) or aerobic training (AER n = 10). Central aortic pressure wave reflection and brachial artery reactivity were assessed before and after training. Central aortic pressure wave reflection was evaluated by measuring aortic augmentation index (AI(a)) and round trip travel time (Deltat (p)) of the reflected arterial pressure wave using applanation tonometry. Brachial artery reactivity was assessed using brachial artery flow mediated dilation (FMD). Eighteen weeks of RT did not change AI(a) (28.9 +/- 1.9 vs. 28.5 +/- 1.9%; mean +/- S.E.M.) or Deltat (p) (140.6 +/- 2.4 vs. 141.2 +/- 2.1 ms). In contrast, the AER group showed a decrease in AI(a) from 28.8 +/- 2.1 to 25.1 +/- 1.4% (P < 0.05) and an increase in Deltat (p) from 137.3 +/- 2.5 to 144.6 +/- 2.9 ms (P < 0.05). Brachial FMD did not significantly change in either group following training. This prospective, randomized study demonstrated that moderate intensity whole body RT in previously sedentary, normotensive postmenopausal women does not alter central aortic pressure wave reflection.

Comparison of alendronate vs alendronate plus mechanical loading as prophylaxis for osteoporosis in lung transplant recipients: a pilot study.

BACKGROUND: Osteoporosis is known to complicate outcomes after lung transplantation (Tx). METHODS: To determine the efficacy of bisphosphonate therapy combined with the osteogenic stimulus of mechanical loading, 30 lung transplant recipients (LTRs) were randomly assigned either to alendronate (10 mg/day; n = 10), alendronate (10 mg/day) + resistance exercise (n = 10) or to a control group (n = 10). Alendronate was initiated at 7 days after Tx. Bone mineral density (BMD) of the lumbar spine was measured by dual-energy X-ray absorptiometry before and 2 and 8 months after Tx. Resistance training was initiated at 2 months after Tx and consisted of lumbar extension exercise performed 1 day/week for 6 months. RESULTS: Lumbar BMD decreased significantly to below pre-transplant baseline at 2 months after Tx in controls (-12.5 +/- 2.1%), but not in the alendronate (1.5 +/- 1.2%) or alendronate + training (1.5 +/- 0.9%) groups. At 8 months after Tx, lumbar BMD in controls was 14.1 +/- 3.9% below baseline (p < or = 0.05), but was 1.4 +/- 1.1% above baseline in alendronate recipients (p > or = 0.05). The alendronate + training group showed a significantly increased lumbar BMD with values 10.8 +/- 2.3% greater than before Tx. CONCLUSIONS: These results suggest that resistance exercise plus alendronate is more effective than alendronate alone in restoring BMD. Anti-osteoporosis therapy in LTRs should include both an anti-resorptive agent and an osteogenic stimulus, such as mechanical loading.

The role of integrins and coreceptors in refining thresholds for B-cell responses.

Despite compelling evidence that a large proportion of antigens encountered in vivo by B cells are membrane bound, the general view is that B cells are mainly activated by soluble antigens. This notion may have been biased somewhat over the years because the high affinity of the B-cell receptor (BCR) for soluble intact ligands allows efficient B-cell stimulation in vitro. In vivo, however, even soluble antigens are likely to be deposited on the surface of antigen-presenting cells, either by complement or Fc receptors in the form of immune complexes, thus becoming more potent stimulators of B-cell activation. In this framework, the BCR works in a complex environment of integrins and coreceptors, as well as the B-cell cytoskeleton. Over the last few years, we have focused on B-cell membrane-bound antigen recognition. Here, we discuss some of our findings in the context of what is currently known in this exciting new field.

NBR1 interacts with fasciculation and elongation protein zeta-1 (FEZ1) and calcium and integrin binding protein (CIB) and shows developmentally restricted expression in the neural tube.

NBR1 (named as next to BRCA1) was originally cloned as a candidate gene for the ovarian cancer antigen CA125, using expression cloning with the anti-CA125 Ig, OC125. NBR1 has been of interest due to its position close to BRCA1, although no involvement in breast or ovarian cancer has been demonstrated. Recently, the antigen CA125 has been cloned, and identified as a new mucin, MUC16, entirely different from NBR1. The function of NBR1 remains unknown. To investigate its function, a yeast two-hybrid study was performed to identify interacting protein partners that may reflect a biological role for this protein. Here, we show that NBR1 interacts with two proteins; fasciculation and elongation protein zeta-1 (FEZ1), a PKCzeta interacting protein, and calcium and integrin binding protein (CIB), which is associated with polo-like kinases Fnk/Snk and the Alzheimer's disease presenilin 2 protein. Co-transfection of FEZ1 and NBR1 showed overlapping localization in the cytoplasm, whereas coexpression of NBR1 and CIB resulted in a shift of CIB protein expression from the nucleus to the perinuclear compartment. FEZ1 is highly expressed in the brain and in situ hybridization analysis of Nbr1 showed that its expression is also regulated in the murine brain during development. These data suggest that NBR1 may function, through interaction with CIB and FEZ1 in cell signalling pathways, with a developmentally restricted expression suggesting a possible role in neural development.

HLS5, a novel RBCC (ring finger, B box, coiled-coil) family member isolated from a hemopoietic lineage switch, is a candidate tumor suppressor.

Hemopoietic cells, apparently committed to one lineage, can be reprogrammed to display the phenotype of another lineage. The J2E erythroleukemic cell line has on rare occasions developed the features of monocytic cells. Subtractive hybridization was used in an attempt to identify genes that were up-regulated during this erythroid to myeloid transition. We report here on the isolation of hemopoietic lineage switch 5 (Hls5), a gene expressed by the monocytoid variant cells, but not the parental J2E cells. Hls5 is a novel member of the RBCC (Ring finger, B box, coiled-coil) family of genes, which includes Pml, Herf1, Tif-1alpha, and Rfp. Hls5 was expressed in a wide range of adult tissues; however, at different stages during embryogenesis, Hls5 was detected in the branchial arches, spinal cord, dorsal root ganglia, limb buds, and brain. The protein was present in cytoplasmic granules and punctate nuclear bodies. Isolation of the human cDNA and genomic DNA revealed that the gene was located on chromosome 8p21, a region implicated in numerous leukemias and solid tumors. Enforced expression of Hls5 in HeLa cells inhibited cell growth, clonogenicity, and tumorigenicity. It is conceivable that HLS5 is one of the tumor suppressor genes thought to reside at the 8p21 locus.

Expression of a truncated Brca1 protein delays lactational mammary development in transgenic mice.

To address the hypothesis that certain disease-associated mutants of the breast-ovarian cancer susceptibility gene BRCA1 have biological activity in vivo, we have expressed a truncated Brca1 protein (trBrca1) in cell-lines and in the mammary gland of transgenic mice. Immunofluorescent analysis of transfected cell-lines indicates that trBRCA1 is a stable protein and that it is localized in the cell cytoplasm. Functional analysis of these cell-lines indicates that expression of trBRCA1 confers an increased radiosensitivity phenotype on mammary epithelial cells, consistent with abrogation of the BRCA1 pathway. MMTV-trBrca1 transgenic mice from two independent lines displayed a delay in lactational mammary gland development, as demonstrated by altered histological profiles of lobuloalveolar structures. Cellular and molecular analyses indicate that this phenotype results from a defect in differentiation, rather than altered rates of proliferation or apoptosis. The results presented in this paper are consistent with trBrca1 possessing dominant-negative activity and playing an important role in regulating normal mammary development. They may also have implications for germline carriers of BRCA1 mutations.