Increased circulating leukocyte numbers and altered macrophage phenotype correlate with the altered immune response to brain injury in metallothionein (MT) -I/II null mutant mice

<p>Abstract</p> <p>Background</p> <p>Metallothionein-I and -II (MT-I/II) is produced by reactive astrocytes in the injured brain and has been shown to have neuroprotective effects. The neuroprotective effects of MT-I/II can be replicated <it>in vitro </it>which suggests that MT-I/II may act directly on injured neurons. However, MT-I/II is also known to modulate the immune system and inflammatory processes mediated by the immune system can exacerbate brain injury. The present study tests the hypothesis that MT-I/II may have an indirect neuroprotective action via modulation of the immune system.</p> <p>Methods</p> <p>Wild type and MT-I/II^-/-mice were administered cryolesion brain injury and the progression of brain injury was compared by immunohistochemistry and quantitative reverse-transcriptase PCR. The levels of circulating leukocytes in the two strains were compared by flow cytometry and plasma cytokines were assayed by immunoassay.</p> <p>Results</p> <p>Comparison of MT-I/II^-/-mice with wild type controls following cryolesion brain injury revealed that the MT-I/II^-/-mice only showed increased rates of neuron death after 7 days post-injury (DPI). This coincided with increases in numbers of T cells in the injury site, increased IL-2 levels in plasma and increased circulating leukocyte numbers in MT-I/II^-/-mice which were only significant at 7 DPI relative to wild type mice. Examination of mRNA for the marker of alternatively activated macrophages, Ym1, revealed a decreased expression level in circulating monocytes and brain of MT-I/II^-/-mice that was independent of brain injury.</p> <p>Conclusions</p> <p>These results contribute to the evidence that MT-I/II^-/-mice have altered immune system function and provide a new hypothesis that this alteration is partly responsible for the differences observed in MT-I/II^-/-mice after brain injury relative to wild type mice.</p

Metallothionein (MT) -I and MT-II Expression Are Induced and Cause Zinc Sequestration in the Liver after Brain Injury

Experiments with transgenic over-expressing, and null mutant mice have determined that metallothionein-I and -II (MT-I/II) are protective after brain injury. MT-I/II is primarily a zinc-binding protein and it is not known how it provides neuroprotection to the injured brain or where MT-I/II acts to have its effects. MT-I/II is often expressed in the liver under stressful conditions but to date, measurement of MT-I/II expression after brain injury has focused primarily on the injured brain itself. In the present study we measured MT-I/II expression in the liver of mice after cryolesion brain injury by quantitative reverse-transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) with the UC1MT antibody. Displacement curves constructed using MT-I/II knockout (MT-I/II−/−) mouse tissues were used to validate the ELISA. Hepatic MT-I and MT-II mRNA levels were significantly increased within 24 hours of brain injury but hepatic MT-I/II protein levels were not significantly increased until 3 days post injury (DPI) and were maximal at the end of the experimental period, 7 DPI. Hepatic zinc content was measured by atomic absorption spectroscopy and was found to decrease at 1 and 3 DPI but returned to normal by 7DPI. Zinc in the livers of MT-I/II−/− mice did not show a return to normal at 7 DPI which suggests that after brain injury, MT-I/II is responsible for sequestering elevated levels of zinc to the liver. Conclusion: MT-I/II is up-regulated in the liver after brain injury and modulates the amount of zinc that is sequestered to the liver

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

The Daily Profiles of Circulating AMH and INSL3 in Men are Distinct from the Other Testicular Hormones, Inhibin B and Testosterone.

The testes secrete four hormones (anti-Müllerian hormone, insulin-like peptide 3, Inhibin B and testosterone) from two endocrine cell types. It is unknown whether anti-Müllerian hormone and insulin-like peptide 3 levels have a diurnal variation, and if so, whether they covary during the day with testosterone and InhB. Sera were obtained from 13 men at 00:00, 06:00, 09:00, 12:00, 14:00, 17:00 and 19:00 hours and the levels of their testicular hormones measured by ELISA. A second cohort of 20 men was similarly examined with blood drawn at 19:00 and the following 06:00. Anti-Müllerian hormone levels exhibited a subtle diurnal pattern with a 19:00 peak that was 4.9% higher on average than the 06:00 nadir (p = 0.004). The decrease in anti-Müllerian hormone coincided with a rise in testosterone and InhB, but there was no association between the person-to-person variation in the diurnal patterns of anti-Müllerian hormone and testosterone or Inhibin B. Insulin-like peptide 3 had no diurnal pattern, with only minor sporadic variation between time points being observed in some men. In conclusion, the diurnal and sporadic variation of each testicular hormone is distinct, indicating that the major regulation is at the level of the hormone rather than at the endocrine cell type. Consequently, the balance of the hormones being released by the testes has complex variation during the day. The physiological significance of this will vary depending on which combinations of testicular hormones that the target cells respond to

Covariation of the diurnal patterns of the hormones.

<p>The covariation between time points for each of the testicular hormones were calculated for 20 men using mixed model analysis, and expressed as the covariation <b>β</b> coefficient (p value). Note that the data is normalised to the daily mean, and is therefore independent of the absolute levels of the men’s hormones.</p><p>* indicates statistical significance.</p><p>Covariation of the diurnal patterns of the hormones.</p

Incidental neoplasms in renal biopsies

BACKGROUND: Incidental neoplastic lesions are occasionally found in renal biopsy specimens, but there is no evidence to indicate how they should be managed. METHODS: A retrospective review was made of the management and clinical course of patients in whom an unsuspected neoplasm had been found in a renal biopsy. RESULTS: In 11 880 biopsies taken over 22 years, there were incidental neoplasms in 25 (0.2%). Twenty-three of the 25 patients were men, and the median age was 59 years (range, 42-83 years). All had chronic renal damage, with a median index of chronic damage of 37% (range, 10-83%; normal=0%). Twenty-two neoplasms were papillary, two were clear cell renal carcinomas and one was in situ carcinoma in a collecting duct. The two clear cell carcinomas, three papillary neoplasms with residual masses after biopsy and the two papillary neoplasms in renal allografts were resected by nephrectomy or partial nephrectomy. Seven patients without resection were imaged with computerized tomography, six with magnetic resonance imaging and three with ultrasound scanning. Two were not imaged. None of the 11 patients who died, nor any of the other 14, had evidence of renal cell carcinoma at death or last follow-up respectively, at median 3.6 years after biopsy (range, 1 month-18.2 years). CONCLUSIONS: When an incidental neoplasm is found, the pathological type should be defined, and imaging should be performed. Surgery should be considered in patients in whom there is a neoplasm of any type detectable by imaging, and limited resection may be possible. Neoplasms that are undetectable with imaging cannot be resected as the site of the lesion is unknown. We suggest surveillance of these, but whether this is necessary is undetermined. There is no evidence whether neoplasms undetectable with imaging in renal allografts require aggressive treatment

Changes in serum testicular hormonal concentration between 19:00 and 06:00 (Study 2).

<p>(A) AMH, (B) INSL and (C) InhB and (D) testosterone levels were analysed in 20 men. AMH, on average declined by 4.9 ± 1.8%, (p = 0.004, paired Student t-test), whereas the levels of InhB and testosterone increased on average by 28 ± 4% (p<0.0005) and 41% (p = 0.011) respectively. There was no significant change in the levels of INSL3, on average (p = 0.78). The mean levels of the hormones at 19:00 and 06:00 were: AMH (57.9 ± 5.7, 55.0 ± 5.3 pM); InhB (147 ± 13, 189 ± 17 pg/ml); INSL3 (2.28 ± 0.20, 2.21 ± 0.24 ng/ml); testosterone (16.0 ± 1.9, 24.5 ± 2.0 nM).</p

Study 1: Daily trend of serum testicular hormones from 13 healthy men plotted individually.

<p>(A) AMH, (B) InhB, (C) INSL3 and (D) testosterone. The 00:00 data points are plotted at both 0:00 and 24:00, with the dashed line used to indicate this extrapolation.</p