Hippocampal damage in mouse and human forms of systemic autoimmune disease

Systemic lupus erythematosus (SLE) is frequently accompanied by neuropsychiatric (NP) and cognitive deficits of unknown etiology. By using autoimmune MRL-lpr mice as an animal model of NP-SLE, we examine the relationship between autoimmunity, hippocampal damage, and behavioral dysfunction. Fluoro Jade B (FJB) staining and anti-ubiquitin (anti-Ub) immunocytochemistry were used to assess neuronal damage in young (asymptomatic) and aged (diseased) mice, while spontaneous alternation behavior (SAB) was used to estimate the severity of hippocampal dysfunction. The causal relationship between autoimmunity and neuropathology was tested by prolonged administration of the immunosuppressive drug cyclophosphamide (CY). In comparison to congenic MRL +/+ controls, SAB acquisition rates and performance in the "reversal" trial were impaired in diseased MRL-lpr mice, suggesting limited use of the spatial learning strategy. FJB-positive neurons and anti-Ub particles were frequent in the CA3 region. Conversely, CY treatment attenuated the SAB deficit and overall FJB staining. Similarly to mouse brain, the hippocampus from a patient who died from NP-SLE showed reduced neuronal density in the CA3 region and dentate gyrus, as well as increased FJB positivity in these regions. Gliosis and neuronal loss were observed in the gray matter, and T lymphocytes and stromal calcifications were common in the choroid plexus. Taken together, these results suggest that systemic autoimmunity induces significant hippocampal damage, which may underlie affective and cognitive deficits in NP-SLE.     

Focused motor stereotypies do not require enhanced activation of neurons in striosomes

Stereotypic motor behavior is a widespread phenomenon of many neurologic and psychiatric disorders. Studies on the mechanisms controlling motor stereotypies have focused on the role of dopamine in modulating the activity of basal ganglia neuronal circuits, and recent results demonstrated that stereotypic motor responses characteristic of psychomotor stimulant sensitization correlate with an enhanced activation of neurons located in striatal striosomes that substantially exceeds that of the surrounding matrix. The present study tested whether predominant striosomal activation is a general predictor for stereotypy. Wild-type and dopamine D(2) and D(3) receptor knockout mice were treated either three times with methamphetamine (METH; 3 x 5 mg/kg every 2 hours) or once with a full D(1) agonist. Depending on the genotype, both treatments elicit the same focused stereotypy (taffy pulling). Repeated METH-treatment elicits intense stereotypy in wild-type and D(3) mutants but not in D(2) single and D(2)/D(3) double mutants. The stereotypic response of wild-type and D(3) mutants correlates with a predominant activation of neurons located in striosomes. No striosomal predominance is detected in METH-treated D(2) single and D(2)/D(3) double mutants. In contrast, D(2) single and D(2)/D(3) double mutants exhibited the most severe stereotypic response to D(1)-agonist treatment. However, this treatment did not result in enhanced striosomal activation. Thus, whereas the expression of stereotypy in response to repeated METH treatment requires D(2) receptor expression, D(2) receptor expression diminishes stereotypic responses to an acute dose of a D(1) agonist. Enhanced striosomal activation, however, is a reliable indicator of D(1)- and D(2)-receptor coactivation but not a predictor for repetitive motor behavior in general.     

Histological Study on Mast Cells in Conjunctiva of NC/Nga Mice

Purpose To investigate the pathological findings in conjunctiva of NC/Nga mice, which develop atopic dermatitis spontaneously, we focused our study on the density of mast cells as determined by histological methods.Methods NC/Nga mice were divided into five groups; the 4W-group comprised four 4-week-old mice without treatment, the 10W-group comprised four 10-week-old mice without treatment, the 16W-group comprised four 16-week-old mice without treatment, the Dx group comprised three 16-week-old mice undergoing topical 0.1% dexamethasone (Dx) ointment treatment, and the FK506 group comprised three 16-week-old mice undergoing topical 0.1% FK506 ointment treatment. For the histological examination, the lids and eyeballs of the mice were removed and fixed with Carnoys solution and thin sections were made. The Carnoy-fixed specimens were stained with toluidine blue or H&E and examined histologically. Toluidine blue-stained tissue sections were examined for the density per square millimeter of mast cells, which were identified as metachromatic cells in the conjunctival tissue and lid cutaneous tissue by light microscopy.Results Mast cell density in the conjunctiva was 8.6 ± 8.2 cells/mm² in the 4W-group, 29.2 ± 22.0 cells/mm² in the 10W-group, 41.0 ± 21.1 cells/mm² in the 16W-group, 22.7 ± 17.1 cells/mm² in the Dx group, and 33.6 ± 27.7 cells/mm² in the FK506 group. Mast cell density increased significantly with age among the 4W-, 10W-, and 16W-groups (P < 0.001). The mast cell density of lid cutaneous tissue was higher than the conjunctival mast cell density. Mast cell density was significantly higher in the 16W-group than in the Dx group, but not significantly higher than in the FK506 group.Conclusions An increase in mast cell density with age indicates that NC/Nga mice develop atopic keratoconjunctivitis-like signs. Dexamethasone ointment has a suppressive effect on the increase in mast cell density. Jpn J Ophthalmol 2004;48:189–194 © Japanese Ophthalmological Society 2004     

A comprehensive guide to antibody and T-cell responses in type 1 diabetes

Type 1 diabetes (T1D) is an organ-specific autoimmune disease in which the insulin-producing beta cells in the pancreatic islets are selectively eliminated. T cells specific for beta-cell antigens are the mediators of this precise cellular destruction. However, antibodies to beta-cell proteins are also generated and may be used for predicting disease in at-risk populations. Over the past two decades, numerous beta-cell proteins and lipids have been implicated as autoantigens in patients or in non-obese diabetic (NOD) mice, a well-studied animal model of T1D. Here, we present a review of these antigens, accompanied by their T-cell epitopes, where known, and a discussion of our current understanding of why particular self-proteins become disease-inciting antigens. Although two dozen beta-cell antigens have been identified to date, few of these have been confirmed to be recognized by pathogenic T cells early in the disease process. Further identification and characterization of initiating beta-cell antigens targeted by pathogenic T cells should be a priority for future studies.     

Sensitivity of immunocompetent cells of DBA/2 and C57Bl/6 mice to cyclophosphamide

T cells were most sensitive to cyclophosphamide in DBA/2 mice, while in C57Bl/6 mice both T and B cells were sensitive. The formation of antibody-producing cells and the production of specific antibodies were delayed in DBA/2 mice immunized after pretreatment with antitumor drug. Accumulation of antibody-producing cells in the spleen was more active in immunized C57Bl/6 mice treated with cyclophosphamide compared to animals not treated with cyclophosphamide.     

Role of endocrine status and cell type in adhesion of human endometrial cells to the peritoneum in nude mice

OBJECTIVE: To investigate the role of different cellular types (epithelial and stromal endometrial cells and peritoneal cells) in the ectopic implantation of endometrium and to evaluate the importance of endocrine environment on the adhesion of endometrial cells to the peritoneum. DESIGN: Experimental prospective study. SETTING: University hospital, department of cell biology. ANIMAL(S): One hundred one nude mice. INTERVENTION(S): Monolayer culture of human epithelial and stromal endometrial cells obtained from patients undergoing hysterectomy or laparoscopy for benign disease. Intraperitoneal injection of cells into nude mice. MAIN OUTCOME MEASURE(S): Two weeks after cell injection, adhesion of endometrial cells was evaluated by histological and immunohistochemical examination. RESULT(S): Mixed cultures of stromal and epithelial cells, but not purified epithelial or stromal cells alone, adhered to the mouse peritoneum and led to endometriotic-like nodules. Pretreatment of cells with estrogen alone or with estrogen and progestin resulted in a higher percentage of animals developing endometriotic-like nodules, whereas treatment with progestin alone did not affect endometriotic implantation. CONCLUSION(S): Our data indicate that the success of endometrial cell implantation is dependent on the cooperativeness between stromal and epithelial endometrial cells, as well as on the endocrine environment of endometrial cells, but not that of recipient animals. The results emphasize the role of both endometrial cell types for ectopic implantation.     

Pig islet xenografts are resistant to autoimmune destruction by non-obese diabetic recipients after anti-CD4 treatment

Abstract: In addition to providing a large source of donor tissue, xenogeneic islet transplantation might avoid recurrent autoimmunity in patients with type 1 diabetes. To examine this possibility further, xenogeneic pig islets were transplanted into recipient mice in the presence or absence of autoimmunity. Spontaneously, non-obese diabetic (NOD) recipients rejected isografts rapidly whether or not the recipients were depleted of CD4+ T-cells. Young NOD mice made diabetic with streptozotocin accepted islet isografts without immunosuppression, indicating that destructive autoimmunity did not develop in these recipients. Pig xenografts were rejected equally quickly in the two types of NOD recipients in the absence of immunosuppression and survived for up to 9 weeks in both types of NOD recipients after CD4 depletion. BALB/c mice often accepted pig xenografts indefinitely after anti-CD4 antibody treatment. These results suggest that pig islets are resistant to recurrent autoimmunity when CD4+ T-cells are depleted. The difficulty in obtaining indefinite islet xenograft survival in NOD recipients occurs independently from the development of destructive autoimmunity.     

Experimental photodynamic therapy for malignant pleural mesothelioma with pegylated mTHPC

BACKGROUND AND OBJECTIVES: Experimental assessment of photodynamic therapy (PDT) for malignant pleural mesothelioma using a polyethylene glycol conjugate of meta-tetrahydroxyphenylchlorin (PEG-mTHPC). STUDY DESIGN/MATERIALS AND METHODS: (a) PDT was tested on H-meso-1 xenografts (652 nm laser light; fluence 10 J/cm(2); 0.93, 9.3, or 27.8 mg/kg of PEG-mTHPC; drug-light intervals 3-8 days). (b) Intraoperative PDT with similar treatment conditions was performed in the chest cavity of minipigs (n = 18) following extrapleural pneumonectomy (EPP) using an optical integrating balloon device combined with in situ light dosimetry. RESULTS: (a) PDT using PEG-mTHPC resulted in larger extent of tumor necrosis than in untreated tumors (P < or = 0.01) without causing damage to normal tissue. (b) Intraoperative PDT following EPP was well tolerated in 17 of 18 animals. Mean fluence and fluence rates measured at four sites of the chest cavity ranged from 10.2 +/- 0.2 to 13.2 +/- 2.3 J/cm(2) and 5.5 +/- 1.2 to 7.9 +/- 1.7 mW/cm(2) (mean +/- SD). Histology 3 months after light delivery revealed no PDT related tissue injury in all but one animal. CONCLUSIONS: PEG-mTHPC mediated PDT showed selective destruction of mesothelioma xenografts without causing damage to intrathoracic organs in pigs at similar treatment conditions. The light delivery system afforded regular light distribution to different parts of the chest cavity.