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

Psychological Stress, Inflammation, and Coronary Heart Disease.

PURPOSE OF REVIEW In this review, we summarize evidence on the risk factor psychological stress in the context of coronary heart disease (CHD) in humans and explore the role of inflammation as a potential underlying mechanism. RECENT FINDINGS While chronic stress increases the risk of incident CHD and poor cardiovascular prognosis, acute emotional stress can trigger acute CHD events in vulnerable patients. Evidence supporting a potential role for inflammation as a promising biological mechanism comes from population-based studies showing associations between chronic stress and increased inflammation. Similarly, experimental studies demonstrate acute stress-induced increases in inflammatory markers and suggest modulatory potential for pharmacological and biobehavioral interventions. So far, studies investigating patients with cardiovascular disease are few and the full sequence of events from stress to inflammation to CHD remains to be established. Psychological stress is an independent CHD risk factor associated with increased inflammation. Although promising, causality needs to be further explored