Decreased drebrin mRNA expression in Alzheimer disease: correlation with tau pathology

To investigate the mRNA expression of the dendritic spine protein drebrin in Alzheimer's disease (AD), we performed post-mortem in situ hybridization studies in brain sections from 20 AD patients and 21 controls. AD diagnosis was confirmed by decreased drebrin protein and increased Abeta(40) (+464%; P < 0.05), Abeta(42) (+369%; P < 0.0001), Abeta(42/40) ratio (+226%; P < 0.01), total tau (+2,725%; P < 0.0001), and paired helical filament tau (PHFtau; +867%; P < 0.001) compared with controls. We found significant decreases in drebrin mRNA in the parietal cortex (-27%; P < 0.01), the temporal cortex (-22%; P < 0.05), and the hippocampus (-25%; P < 0.05) of AD patients compared with controls. Cortical levels of drebrin mRNA correlated positively with soluble total tau (r(2) = +0.244) but negatively with duration of symptoms (r(2) = -0.357) and PHFtau (r(2) = -0.248). Drebrin mRNA levels were correlated to a lesser degree with the drebrin protein content (r(2) = +0.136) and with sim2 (r(2) = +0.176), a potential modulator of drebrin transcription. Our results suggest that the down-regulation of drebrin mRNA expression plays an important role in AD and is closely related to the progression of the disease.

Guanosine reduces apoptosis and inflammation associated with restoration of function in rats with acute spinal cord injury

Spinal cord injury results in progressive waves of secondary injuries, cascades of noxious pathological mechanisms that substantially exacerbate the primary injury and the resultant permanent functional deficits. Secondary injuries are associated with inflammation, excessive cytokine release, and cell apoptosis. The purine nucleoside guanosine has significant trophic effects and is neuroprotective, antiapoptotic in vitro, and stimulates nerve regeneration. Therefore, we determined whether systemic administration of guanosine could protect rats from some of the secondary effects of spinal cord injury, thereby reducing neurological deficits. Systemic administration of guanosine (8 mg/kg per day, i.p.) for 14 consecutive days, starting 4 h after moderate spinal cord injury in rats, significantly improved not only motor and sensory functions, but also recovery of bladder function. These improvements were associated with reduction in the inflammatory response to injury, reduction of apoptotic cell death, increased sparing of axons, and preservation of myelin. Our data indicate that the therapeutic action of guanosine probably results from reducing inflammation resulting in the protection of axons, oligodendrocytes, and neurons and from inhibiting apoptotic cell death. These data raise the intriguing possibility that guanosine may also be able to reduce secondary pathological events and thus improve functional outcome after traumatic spinal cord injury in humans.

Donor non-specific IFN-gamma production by primed alloreactive cells as a potential screening test to predict the alloimmune response

In order to devise an in vitro experimental system that predicts the in vivo generation of T lymphocytes capable of initiating the rejection process and thereby to individualize the immunosuppressive strategy in a rational way, we studied the in vitro strength of alloresponses to non-specific donors as a surrogate tool to identify patients with heightened alloimmunity. We measured interferon gamma (IFN-gamma) produced by primed alloactivated peripheral blood lymphocytes (p-allo-PBL) against third party stimulator PBLs in four groups by the enzyme linked immunospot (Elispot) assay: 16 with excellent renal transplant function (group 1); nine with chronic rejection (group 2); 11 allo-sensitized (PRA>60%) by graft loss on dialysis (group 3) and 36 normal controls (group 4). The Elispot assay was performed using 10(6) irradiated stimulator PBLs and 10(5) responder PBLs for 24 and 48 h. Each responder was challenged by 2-4 independent stimulators.

RESULTS

At 24 h, mean+/-S.D. and 95% confidence intervals (CI) of spots/10(5) responder cells were 12.8+/-8.7 (10-15.5); 57.8+/-116 (11.9-103.7); 77.5+/-91.3 (39.8-115.2); and 20.7+/-17.9 (17.4-24.1) in groups 1-4, respectively. P<0.01 between groups 1 or 4 vs. 2 or 3. An arbitrary spot level of >or=30 has positive and negative predictive values of 58% and 95%, respectively, sensitivity of 94% and specificity of 65% to identify patients with enhanced immunity.

CONCLUSION

Chronic allogeneic stimulation is associated with enhanced p-allo-PBL. IFN-gamma producing frequencies against third party stimulators. Significant variation in IFN-gamma spots produced by p-allo-PBL may be useful to choose less allogeneic donors. Diminished p-allo-PBL alloresponse to third party stimulators may predict transplant patients with decreased alloresponses who may benefit from lesser immunosuppressive drugs.

Improvement of experimental allergic encephalomyelitis (EAE) by thymoquinone; an oxidative stress inhibitor

Experimental Allergic Encephalomyelitis (EAE) is an autoimmune demyelinating disease of the central nervous system that is widely accepted as an animal model for the human multiple sclerosis. Oxidative stress appears to play a role in the onset and progression of EAE. We reasoned that decreasing oxidative stress might ameliorate symptoms and signs of EAE. Thymoquinone is reported to inhibit oxidative stress. One way of decreasing oxidative stress is to induce glutathione (GSH). We tested the impact of Thymoquinone (1 mg/kg, injected at tail vein) in our EAE model. We induced (EAE) in female Lewis rats using myelin basic protein emulsified with complete Freund's adjuvant. 24 animals were placed into three groups: A) Rats with EAE B) EAE rats with concomitant five day injection of Thymoquinone days 1-5, C) EAE rats with five doses of Thymoquinone injected at day 12-17. Twenty-eight days later, animals were sacrificed; spinal cord tissues collected for glutathione (GSH).

RESULTS

63% of animals in group "A" developed hind limb weakness and/or paralysis while 37% developed mild tail weakness, perivascular inflammation and low spinal cord GSH level. 25% of animals in group "B" exhibited mild tail and hind limb weakness and 75% animals had no symptoms, no perivascular inflammation and high spinal cord GSH level. 63% of animals of group "C" showed improving symptoms following Thymoquinone injections, no perivascular inflammation and higher GSH level while 37% of animals showed no symptoms prior and post Thymoquinone injections. Clinical symptoms correlated well with perivascular inflammation and GSH level. Animals received Thymoquinone at day 12-17 had higher GSH level, no perivascular inflammation and no symptoms compared with other groups.

CONCLUSION

Thymoquinone inhibited oxidative stress which leads into improvement in our EAE animals. Thymoquinone may have a role in treatment of Multiple Sclerosis.

Detection of ICAM-1 in experimentally induced colitis of ICAM-1-deficient and wild-type mice: an immunohistochemical study

Adhesion molecules (e.g. ICAM-1, CD 54) are known to be upregulated on activated vascular endothelial cells during inflammatory reactions. To study the role of ICAM-1 in intestinal inflammation in vivo, we induced acute experimental colitis in wild-type (C57BL/6) mice and ICAM-1-deficient mice, by feeding the animals with 3% dextran sodium sulphate (DSS) in drinking water for 7 days. In the control strain the immunohistochemical staining showed a very pronounced endothelial upregulation of ICAM-1 after the DSS treatment observed in areas of inflammatory infiltrate, especially in venules or arterioles of the propria and submucosa, and partly in the mesocolon. DSS-fed ICAM-1-deficient mice showed no endothelial enhancement and only faint staining of venules or capillaries approaching that encountered in the control ICAM-1-deficient animals. Our data indicate that ICAM-1 may play a crucial role in the development of acute intestinal inflammation, consistent with our finding that ICAM-1 deficiency can obviate severe forms of experimentally induced colitis in mice.

Intercellular adhesion molecule-1 (ICAM-1) deficiency protects mice against severe forms of experimentally induced colitis

ICAM-1 (CD54), the ligand for LFA-1 and Mac-1, is up-regulated during inflammatory reaction on the activated vascular endothelium. To determine its role in intestinal inflammation, we induced acute experimental colitis in mice with a deleted ICAM-1 gene, by feeding them with 3% dextran sodium sulphate (DSS) in drinking water for 7 days. Chronic colitis was elicited by DSS similarly, followed by 2 weeks with water. In the acute phase of inflammation, ICAM-1-deficient mice exhibited a significantly lower mortality rate (5%) than control C57Bl/6J mice (35%). Control animals, but not the ICAM-1-deficient mice, exhibited diarrhoea and rectal bleeding. Histological examination of large-bowel samples evaluated the intensity of inflammatory changes, and type and extent of mucosal lesions. In the acute phase, 33.3% of samples from ICAM-1-deficient mice exhibited mucosal defects (flat and fissural ulcers), predominantly mild to moderate inflammatory infiltrate within the lamina propria mucosae and lower grades of mucosal lesions. Much stronger inflammatory changes were present in control animals, flat ulcers (sometimes multiple) and fissural ulcers being observed in 62.5% of samples. Mucosal inflammatory infiltrate was moderate to severe, typically with higher grades of mucosal lesions. In chronic colitis, smaller inflammatory changes were found in the large bowel. The two mouse strains differed, the chronic colitis being accompanied by an increased serum level of anti-epithelial IgA autoantibodies in C57Bl/6 control mice but not in ICAM-1-deficient mice. These findings provide direct evidence of the participation of ICAM-1 molecule in the development of experimentally induced intestinal inflammation.