Alterations of lymphocyte count and platelet volume precede cerebrovascular lesions in stroke-prone spontaneously hypertensive rats.

Background: Cerebral small vessel disease (CSVD) is associated with future stroke. Although pathological alteration in small vessels of patients with CSVD can be detected by neuroimaging, diagnosis of CSVD is delayed because it is an asymptomatic disease. The stroke-prone spontaneously hypertensive rat (SHRSP) show similar pathological features to human CSVD and develop stroke-related symptoms with advancing age.Objective: We investigated the time course of haematological parameters in Wistar rats and SHRSP.Material and Methods: Blood cells were analysed using an automated haematological analyser.Results: SHRSP develop stroke-related symptoms including onset of neurological symptoms, decreased body weight and blood brain barrier leakage between 12 and 14 weeks of age. Lymphocyte counts were gradually decreased at 3 weeks before development of stoke-related symptoms and then were further decreased after the development of stroke-related symptoms. The both mean platelet volume and large platelet ratio gradually increased at 3 weeks before the development of stoke-related symptoms. However, although SHRSP showed more microcytic red cells than Wistar rats, the trajectories of change in erythrocyte-related parameters were similar between Wistar rats and SHRSP.Conclusion: Our pilot study suggests that alterations of lymphocyte count and platelet volume predictive indicators for asymptomatic CSVD and symptomatic stroke in SHRSP.

Bilateral Eyelid Edema in a Pediatric Patient With COVID-19: A Case Report and Literature Review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is primarily transmitted through the eyes, nose, or mouth. Ophthalmic complications, such as conjunctivitis and dacryoadenitis, have been reported in patients with coronavirus disease 19 (COVID-19). We report the case of an early adolescent girl who presented with bilateral urticarial rashes, eyelid edema, fever, and cough. She was diagnosed with acute dacryoadenitis with SARS-CoV-2 infection confirmed by a nasopharyngeal polymerase chain reaction and clinical investigations. The patient was treated with dexamethasone (3 mg daily) for three days, which resulted in the resolution of fever and urticarial rash, and improvement of eyelid edema. While bilateral upper eyelid edema and acute dacryoadenitis commonly occur in pediatric patients due to Epstein-Barr virus (EBV) infection and Kawasaki disease, they are rarely associated with other diseases. However, ocular symptoms have been reported in 11.4% of patients with COVID-19. In addition, eyelid edema and acute dacryoadenitis have also been reported after COVID-19 messenger RNA (mRNA) vaccination. The underlying mechanisms of these complications are not yet completely understood. Our case highlights the possibility of bilateral eyelid edema in children with COVID-19, which can occur in addition to other viral infections such as EBV.

The significance of nanofiber polyglycolic acid for promoting tissue repair in a rat subcutaneous implantation model.

Among various biomaterials, we focused on nanofiber-based polyglycolic acid (PGA) fabric and examined the dynamics of cells that migrate within the non-woven fabric after implantation. The efficacy of nano-PGA as a tissue reinforcement in the process of subcutaneous tissue repair was immunohistochemically investigated. Two types of clinically available PGA non-woven sheet (nano-PGA: fiber diameter = 2.0 µm, conventional PGA: fiber diameter = 14.2 µm) were used and subcutaneously implanted in rats. Samples were collected 3 days, and 1, 2, 3, and 4 weeks after the implantation to perform histological and immunohistochemical (CD68, CD163, α-SMA, Type I collagen, CD34, MCP-1, IL-6, TNF-α, TGF-ß, VEGF, IgG) examinations to assess the expression of molecules related to inflammation or tissue repair. Immunohistochemical analysis in nano-PGA revealed that the intensity and positive cells (CD68, MCP-1, IL-6, TNF-α) significantly increased which indicated an early inflammatory response. This was followed by phagocytosis of nano-PGA with foreign body giant cells and CD68+ macrophages. Finally, the number of proliferating cells (CD163, α-SMA, TGF-ß) and angiogenesis (CD34, VEGF) for tissue repair promoted the formation of collagen fibers (type I collagen). Unlike nano-PGA, implantation of conventional PGA sheet resulted in a prolonged inflammatory response and was characterized by the presence of discontinuous collagen fibers with many foreign body giant cells, which did not lead to tissue repair. Nano-PGA sheets demonstrated a better tissue compatibility compared with conventional PGA by inducing early polarization to M2 phenotype macrophages, which triggered subsequent angiogenesis and tissue repair in the subcutaneous tissue.

Surface modification of the cubic micro-cartilage by collagenase treatment and its efficacy in cartilage regeneration for ear tissue engineering.

BACKGROUND: In order to enhance cartilage regeneration, surface modification of the cubic micro-cartilage with the collagenase treatment was tested and its efficacy to tissue engineer ear cartilage was investigated. MATERIALS AND METHODS: Harvested cubic micro-cartilages were treated with collagenase with different digestion time (0, 15, 60, and 120 min). Histological, ultrastructural (SEM and TEM), and Western blot analyses were carried out. Subsequently, A total of 45 dogs were used to tissue engineer ear cartilage. Using collagenase-treated micro-cartilage, the ear cartilage regeneration with the prepared dilution (8, 12.5, 25, 50, 100%) of micro-cartilage block seeding was performed to determine the minimum amount of cartilage tissue required for ear tissue-engineering (n = 6 at each point in each group). At 10 weeks after surgery, samples were resected and subjected to histochemical and immune-histological evaluation for cartilage regeneration. RESULTS: In vitro study on micro-cartilage morphology and western blot analysis showed that collagenase digestion was optimal at 60 min for cartilage regeneration. In vivo evaluation on the reduced proportions of micro-cartilage block seeding onto implant scaffolds under 60-min collagenase digestion determined the minimum amount of cartilage tissue necessary to initiate a one-step ear cartilage regeneration in a canine autologous model, which was 12.5-25% of the original ear size. CONCLUSION: Tissue-engineering ear cartilage from limited volume of donor cartilage can possibly be achieved by the collagenase treatment on micro-cartilage to expand cartilage regeneration capacity, application of cytokine sustained-release system, and seeding on a suitable ear scaffold material.

A comparative study of sulphated polysaccharide effects on advanced glycation end-product uptake and scavenger receptor class A level in macrophages.

Advanced glycation end-products, especially toxic advanced glycation end-products derived from glyceraldehyde (advanced glycation end-product-2) and glycolaldehyde (advanced glycation end-product-3), are biologically reactive compounds associated with diabetic complications. We previously demonstrated that toxic advanced glycation end-products were internalised into macrophage-like RAW264.7 cells through scavenger receptor-1 class A (CD204). Toxic advanced glycation end-product uptake was inhibited by fucoidan, a sulphated polysaccharide and antagonistic ligand for scavenger receptors, suggesting that sulphated polysaccharides are emerging candidates for treatment of advanced glycation end-product-related diseases. In this study, we compared the effects of six types of sulphated and non-sulphated polysaccharides on toxic advanced glycation end-product uptake in RAW264.7 cells. Fucoidan, carrageenan and dextran sulphate attenuated toxic advanced glycation end-product uptake. Fucoidan and carrageenan inhibited advanced glycation end-product-2-induced upregulation of SR-A, while advanced glycation end-product-3-induced upregulation of scavenger receptor-1 class A was only suppressed by fucoidan. Dextran sulphate did not affect scavenger receptor-1 class A levels in toxic advanced glycation end-product-treated cells. Chondroitin sulphate, heparin and hyaluronic acid failed to attenuate toxic advanced glycation end-product uptake. Heparin and hyaluronic acid had no effect on scavenger receptor-1 class A levels, while chondroitin sulphate inhibited advanced glycation end-product-3-induced upregulation of scavenger receptor-1 class A. Taken together, fucoidan and carrageenan, but not the other sulphated polysaccharides examined, had inhibitory activities on toxic advanced glycation end-product uptake and toxic advanced glycation end-product-induced upregulation of scavenger receptor-1 class A, possibly because of structural differences among sulphated polysaccharides.

Immunohistochemical analysis of brain lesions using S100B and glial fibrillary acidic protein antibodies in arundic acid- (ONO-2506) treated stroke-prone spontaneously hypertensive rats.

Stroke-prone spontaneously hypertensive rats (SHRSP) used as a model of essential hypertension cause a high incidence of brain stroke on the course of hypertension. Incidences and sizes of brain lesions are known to relate to the astrocyte activities. Therefore, relation between brain damage and the expression profile of the astrocytes was investigated with morphometric and immunohistochemical analyses using astrocyte marker antibodies of S100B and glial fibrillary acidic protein (GFAP) with or without arundic acid administration, a suppressor on the activation of astrocytes. Arundic acid extended the average life span of SHRSP. An increase in brain tissue weight was inhibited concomitant with a lower rate of gliosis/hemosiderin deposit/scarring in brain lesions. S100B- or GFAP-positive dot and filamentous structures were decreased in arundic acid-treated SHRSP, and this effect was most pronounced in the cerebral cortex, white matter, and pons, and less so in the hippocampus, diencephalon, midbrain, and cerebellum. Blood pressure decreased after administration of arundic acid in the high-dose group (100 mg/kg/day arundic acid), but not in the low-dose group (30 mg/kg/day). These data indicate that arundic acid can prevent hypertension-induced stroke, and may inhibit the enlargement of the stroke lesion by preventing the inflammatory changes caused by overproduction of the S100B protein in the astrocytes.

Risk factors for in-hospital mortality during infective endocarditis in patients with congenital heart disease.

Despite developments in preventative and medical therapy, infective endocarditis (IE) carries a high rate of mortality. Risk factors for mortality are unknown in pediatric and adult patients with congenital heart disease (CHD). We determined the risk factors for in-hospital mortality in pediatric and adult patients with CHD. A retrospective observational cohort study was conducted from January 1997 to December 2001 in Japan. Of the 239 patients for whom complete data were available, 216 patients with CHD were identified. Outcomes were alive or deceased. The proposed modified Duke's criteria identified 137 patients, aged 1 month to 62 years with a median of 12 years, with IE. In-hospital mortality was 10%. Four risk factors were independently associated with mortality by stepwise logistic regression analysis: (1) vegetation size > or =20 mm (odds ratio 40.6, 95% confidence interval 2.42 to 681); (2) age <1 year (odds ratio 19.5, 95% confidence interval 1.74 to 219); (3) presence of heart failure (odds ratio 7.16, 95% confidence ratio 1.34 to 38.4); and (4) Staphylococcus aureus as a causative organism (odds ratio 5.68, 95% confidence interval 1.16 to 27.9). Surgical intervention emerged as a predictive factor for lower in-hospital mortality (odds ratio 0.045, 95% confidence interval 0.003 to 0.70) by stepwise logistic regression analysis. In conclusion, surgical intervention, which decreases the risk of in-hospital mortality, should always be considered.

Acetylsalicylic acid provides cerebrovascular protection from oxidant damage in salt-loaded stroke-prone rats.

Inflammatory processes may play a pivotal role in the pathogenesis of cerebrovascular injury in salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP). Recent reports revealed that acetylsalicylic acid (aspirin) has anti-oxidative properties and elicits nitric oxide release by a direct activation of the endothelial NO synthase. The present study was designed to determine whether low-dose aspirin might prevent cerebrovascular injury in salt-loaded SHRSP by protecting oxidative damage. Nine-week-old SHRSP were fed a 0.4% NaCl or a 4% NaCl diet with or without treatment by naproxen (20 mg/kg/day), salicylic acid (5 mg/kg/day), or aspirin (5 mg/kg/day) for 5 weeks. Blood pressure, blood brain barrier impairment, mortality, and the parameters of cerebrovascular inflammation and damage were compared among them. High salt intake in SHRSP significantly increased blood brain barrier impairment and early mortality, which were suppressed by treatment with aspirin independent of changes in blood pressure. Salt loading significantly increased superoxide production in basilar arteries of SHRSP, which were significantly suppressed by treatment with aspirin. Salt loading also significantly decreased NOS activity in the basilar arteries of SHRSP, which were significantly improved by treatment with aspirin. At 5 weeks after salt loading, macrophage accumulation and matrix metalloproteinase-9 activity at the stroke-negative area in cerebral cortex of SHRSP were significantly reduced by treatment with aspirin. These results suggest that low-dose aspirin may exert protective effects against cerebrovascular inflammation and damage by salt loading through down-regulation of superoxide production and induction of nitric oxide synthesis.

Effects of scavenger receptors-1 class A stimulation on macrophage morphology and highly modified advanced glycation end product-protein phagocytosis.

Advanced glycation end-products (AGEs), which comprise non-enzymatically glycosylated proteins, lipids, and nucleic acid amino groups, play an important role in several diseases and aging processes including angiopathy, renal failure, diabetic complications, and neurodegenerative diseases. Among AGE-associated phenotypes, toxic AGEs, glyceraldehyde-derived AGE-2, and glycolaldehyde-derived AGE-3 are involved in the pathogenesis of diabetic complications. In addition, macrophages are reported to remove extracellular AGEs from tissues via scavenger receptors, leading to the progression of atherosclerosis. In the present study, we found that AGE-2 and AGE-3 enhanced their own endocytic uptake by RAW264.7 mouse macrophage-like cells in a concentration-dependent manner. Furthermore, we demonstrated, for the first time, the morphology of phagocytic macrophages and the endocytosis of AGE particles. The toxic AGEs induced the expression of a scavenger receptor, CD204/scavenger receptors-1 class A (SR-A). Notably, an antibody against CD204 significantly prevented toxic AGE uptake. Moreover, an SR-A antagonistic ligand, fucoidan, also attenuated the AGE-2- and AGE-3-evoked uptake in a concentration-dependent manner. These results indicated that SR-A stimulation, at least in part, plays a role in AGE uptake.

Interleukin-18 Amplifies Macrophage Polarization and Morphological Alteration, Leading to Excessive Angiogenesis.

M2 macrophage (Mφ) promotes pathologic angiogenesis through a release of pro-angiogenic mediators or the direct cell-cell interaction with endothelium in the micromilieu of several chronic inflammatory diseases, including rheumatoid arthritis and cancer, where interleukin (IL)-18 also contributes to excessive angiogenesis. However, the detailed mechanism remains unclear. The aim of this study is to investigate the mechanism by which M2 Mφs in the micromilieu containing IL-18 induce excessive angiogenesis in the in vitro experimental model using mouse Mφ-like cell line, RAW264.7 cells, and mouse endothelial cell line, b.End5 cells. We discovered that IL-18 acts synergistically with IL-10 to amplify the production of Mφ-derived mediators like osteopontin (OPN) and thrombin, yielding thrombin-cleaved form of OPN generation, which acts through integrins α4/α9, thereby augmenting M2 polarization of Mφ with characteristics of increasing surface CD163 expression in association with morphological alteration. Furthermore, the results of visualizing temporal behavior and morphological alteration of Mφs during angiogenesis demonstrated that M2-like Mφs induced excessive angiogenesis through the direct cell-cell interaction with endothelial cells, possibly mediated by CD163.

Involvement of thromboxane A2 receptor in the cerebrovascular damage of salt-loaded, stroke-prone rats.

BACKGROUND: Inflammatory processes may play a pivotal role in the pathogenesis of cerebrovascular injury in salt-loaded, stroke-prone, spontaneously hypertensive rats (SHRSP). Thromboxane A2 (TP) receptor stimulation by 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) is involved in the process of vascular inflammation. OBJECTIVE: In the present study, we examined the involvement of TP receptor in the development of cerebrovascular damage in salt-loaded SHRSP. METHODS: Nine-week-old SHRSP were fed a 0.4% NaCl or a 4% NaCl diet with or without ONO-8809 treatment (a TP receptor antagonist) for 5 weeks. Blood pressure, mortality, and the parameters of cerebrovascular inflammation and damage were compared between the groups. Moreover, we examined the effect of 8-iso-PGF2alpha infusion on cerebrovascular injury of SHRSP. RESULTS: High salt intake in SHRSP significantly increased blood-brain barrier impairment and early mortality, which were suppressed by ONO-8809 treatment independent of changes in blood pressure. Salt loading also significantly increased superoxide production in basilar arteries of SHRSP, which was suppressed by ONO-8809 treatment. Macrophage accumulation and matrix metalloproteinase-9 (MMP-9) activity in the stroke-negative area in the contralateral cerebral cortex to the stroke lesion of salt-loaded SHRSP and 8-iso-PGF2alpha-treated SHRSP were significantly reduced by ONO-8809 treatment. The ONO-8809 treatment prevented thinning of the vessel layer in cerebral arterioles of salt-loaded SHRSP and 8-iso-PGF2alpha-treated SHRSP. CONCLUSIONS: These results suggest that TP receptor stimulation by 8-iso-PGF2alpha may involve salt loading-induced stroke through activation of cerebrovascular inflammation and damage.

Voluntary exercise induces neurogenesis in the hypothalamus and ependymal lining of the third ventricle.

In the adult hypothalamus and ependymal lining of the third ventricle, tanycytes function as multipotential progenitor cells that enable continuous neurogenesis, suggesting that tanycytes may be able to mediate the restoration of homeostatic function after stroke. Voluntary wheel running has been shown to alter neurochemistry and neuronal function and to increase neurogenesis in rodents. In the present study, we found that voluntary exercise improved the survival rate and energy balance of stroke-prone spontaneously hypertensive rats (SHRSP/Kpo). We also investigated the effect of exercise on the proliferation and differentiation of hypothalamic cells using immunoreactivity for tanycytes and neural markers. The proliferation of elongated cells, which may be the tanycytes, was enhanced in exercising SHRSP compared to sedentary rats before and after stroke. In addition, the proliferation of cells was correlated with the induction of fibroblast growth factor-2 in the subependymal cells of the third ventricle and in the cerebrospinal fluid. Some of the newborn cells of exercising SHRSP showed differentiation into mature neurons after stroke. Our results suggest that voluntary exercise correlates with hypothalamic neurogenesis, leading to recovery of homeostatic functions in the adult brain after stroke.

Genotypes at chromosome 22q12-13 are associated with HIV-1-exposed but uninfected status in Italians.

OBJECTIVE: Despite multiple and repeated exposures to HIV-1, some individuals possess no detectable HIV genome and show T-cell memory responses to the viral antigens. HIV-1-reactive mucosal IgA detected in such uninfected individuals suggests their possible immune resistance against HIV. We tested if the above HIV-1-exposed but uninfected status was associated with genetic markers other than a homozygous deletion of the CCR5 gene. METHODS: Based on our mapping in chromosome 15 of a gene controlling the production of neutralizing antibodies in a mouse retrovirus infection, we genotyped 42 HIV-1-exposed but uninfected Italians at polymorphic loci in the syntenic segment of human chromosome 22, and compared them with 49 HIV-1-infected and 47 uninfected healthy control individuals by a closed testing procedure. RESULTS: A significant association was found between chromosome 22q12-13 genotypes and a putative dominant locus conferring anti-HIV-1 immune responses in the exposed but uninfected individuals. Distributions of linkage disequilibrium across chromosome 22 also differed between the exposed but uninfected and two other phenotypic groups. CONCLUSIONS: The data indicated the presence of a new genetic factor associated with the HIV-1-exposed but uninfected status.

Histamine inhibits high mobility group box 1-induced adhesion molecule expression on human monocytes.

Cell-cell interaction through binding of adhesion molecules on monocytes to their ligands on T-cells plays roles in cytokine production and lymphocyte proliferation. High mobility group box 1 (HMGB1), an abundant and conserved nuclear protein, acts in the extracellular environment as a primary pro-inflammatory signal. HMGB1 induces expression of intercellular adhesion molecule (ICAM), B7.1, B7.2 and CD40 on monocytes, resulting in production of interferon (IFN)-γ and tumor necrosis factor (TNF)-α production and lymphocyte proliferation in human peripheral blood mononuclear cells (PBMCs). Histamine inhibits pro-inflammatory cytokine production via histamine H2-receptors; however, it is not known whether histamine inhibits HMGB1 activity. This study was designed to study the inhibitory effect of histamine on HMGB1 activity. We examined the effect of histamine on HMGB1-induced expression of ICAM-1, B7.1, B7.2 and CD40 on monocytes, production of IFN-γ and TNF-α and lymphocyte proliferation in PBMCs. Histamine inhibited HMGB1 activity in a concentration-dependent manner. The effects of histamine were partially ablated by the H2-receptor antagonist, famotidine, and mimicked by the H2/H4-receptor agonists, dimaprit and 4-methylhistamine. Histamine induced cyclic adenosine monophosphate (cAMP) production in the presence and absence of HMGB1. The effects of histamine were reversed by the protein kinase A (PKA) inhibitor, H89, and mimicked by the membrane-permeable cAMP analog, dibutyryl cAMP (dbcAMP), and the adenylate cyclase activator, forskolin. These results together indicated that histamine inhibited HMGB1 activity.

In vivo diagnostic imaging using micro-CT: sequential and comparative evaluation of rodent models for hepatic/brain ischemia and stroke.

BACKGROUND: There is an increasing need for animal disease models for pathophysiological research and efficient drug screening. However, one of the technical barriers to the effective use of the models is the difficulty of non-invasive and sequential monitoring of the same animals. Micro-CT is a powerful tool for serial diagnostic imaging of animal models. However, soft tissue contrast resolution, particularly in the brain, is insufficient for detailed analysis, unlike the current applications of CT in the clinical arena. We address the soft tissue contrast resolution issue in this report. METHODOLOGY: We performed contrast-enhanced CT (CECT) on mouse models of experimental cerebral infarction and hepatic ischemia. Pathological changes in each lesion were quantified for two weeks by measuring the lesion volume or the ratio of high attenuation area (%HAA), indicative of increased vascular permeability. We also compared brain images of stroke rats and ischemic mice acquired with micro-CT to those acquired with 11.7-T micro-MRI. Histopathological analysis was performed to confirm the diagnosis by CECT. PRINCIPAL FINDINGS: In the models of cerebral infarction, vascular permeability was increased from three days through one week after surgical initiation, which was also confirmed by Evans blue dye leakage. Measurement of volume and %HAA of the liver lesions demonstrated differences in the recovery process between mice with distinct genetic backgrounds. Comparison of CT and MR images acquired from the same stroke rats or ischemic mice indicated that accuracy of volumetric measurement, as well as spatial and contrast resolutions of CT images, was comparable to that obtained with MRI. The imaging results were also consistent with the histological data. CONCLUSIONS: This study demonstrates that the CECT scanning method is useful in rodents for both quantitative and qualitative evaluations of pathologic lesions in tissues/organs including the brain, and is also suitable for longitudinal observation of the same animals.

Ipomoea batatas and Agarics blazei ameliorate diabetic disorders with therapeutic antioxidant potential in streptozotocin-induced diabetic rats.

Ipomoea batatas, Agaricus blazei and Smallanthus sonchifolius are known to favorably influence diabetes mellitus. To clarify their antidiabetic efficacy and hypoglycemic mechanisms, we treated streptozotocin-induced diabetic rats with daily oral feeding of powdered Ipomoea batatas (5 g kg(-1) d(-1)), Agaricus blazei (1 g kg(-1) d(-1)) or Smallanthus sonchifolius (4 g kg(-1) d(-1)) for 2 months. Treatments with Ipomoea batatas or Agaricus blazei, but not Smallanthus sonchifolius, significantly suppressed the increases of fasting plasma glucose and hemoglobin A1c levels, and restored body weight loss during diabetes. Serum insulin levels after oral glucose administration tests increased along the treatments of Ipomoea batatas or Agaricus blazei. Moreover, Ipomoea batatas and Agaricus blazei reduced superoxide production from leukocytes and vascular homogenates, serum 8-oxo-2'-deoxyguanosine, and vascular nitrotyrosine formation of diabetic rats to comparable levels of normal control animals. Stress- and inflammation-related p38 mitogen-activated protein kinase activity and tumor necrosis factor-α production of diabetic rats were significantly depressed by Ipomoea batatas administration. Histological examination also exhibited improvement of pancreatic ß-cells mass after treatments with Ipomoea batatas or Agaricus blazei. These results suggest that hypoglycemic effects of Ipomoea batatas or Agaricus blazei result from their suppression of oxidative stress and proinflammatory cytokine production followed by improvement of pancreatic ß-cells mass.

Gene expression in the adrenal glands of three spontaneously hypertensive rat substrains.

We examined gene expression profiles in rat adrenal glands using genome-wide microarray technology. Gene expression levels were determined in four rat strains, including one normotensive strain [Wistar-Kyoto (WKY)] and three substrains derived from WKY rats: spontaneously hypertensive rats (SHR), stroke-prone SHR (SHRSP) and malignant SHRSP (M-SHRSP). This study represents the first attempt at using microarrays to compare gene expression profiles in SHR, SHRSP and M-SHRSP adrenal glands, employing WKY as controls. Expression measurements were made in these four rat strains at 6 and 9 weeks of age; 6 weeks of age covers the pre-hypertensive period in SHR and SHRSP, and 9 weeks of age is the period of rapidly rising blood pressure (BP). Since the aim of this study was to identify candidate genes involved in the genesis of hypertension in the SHR substrains, we identified genes that were consistently different in their expression, isolating 87 up-regulated genes showing a more than 4-fold increase and 128 down-regulated genes showing a less than 1/4-fold decrease in at least two different experiments. We classified all these up- or down-regulated genes by their expression profiles, and searched for candidate genes. At 6 weeks of age, several BP-regulating genes including sparc/osteonectin (Spock2), kynureninase (Kynu), regulator of G-protein signaling 2 (Rgs2) and gap junction protein α1 (Gja1) were identified as up-regulated, and urotensin 2 (Uts2), cytoplasmic epoxide hydrolase 2 (Ephx2), apelin (Apln), insulin-like growth factor 1 receptor (Igf1r) and angiotensin II receptor-associated protein (Agtrap) were identified as down-regulated. The Kynu and Ephx2 genes have previously been reported by other groups to be responsible for hypertension in SHR; however, our present approach identified at least seven new candidate genes.

Antagonism of IL-4 signaling by a phosphodiesterase-4 inhibitor, rolipram, in human T cells.

BACKGROUND: Phosphodiesterase (PDE4) inhibitors prevent breakdown of cAMP and affect the increase in cellular levels of cAMP, which is known to regulate immune cell functions. Because IL-4 plays a causal role in the pathogenesis of allergic disorders, we were interested to study the modulatory mechanisms of a PDE4 inhibitor, rolipram, in IL-4-mediated signaling in T cells. METHODS: Human peripheral T cells were stimulated with IL-4 in combination with rolipram, and RT-PCR was performed using primers specific for IL-5. To monitor activation of transcription factors, immunostaining was employed. RESULTS: Rolipram or a cAMP-analogue, 8-Br-cAMP, significantly downregulated IL-4-induced expression of IL-5 mRNA. The rolipram-induced inhibition of IL-5 mRNA was mediated by activation of protein kinase A (PKA), because rolipram-downregulated mRNA expression of IL-5 was restored by PKA inhibitors. Immunostaining revealed that rolipram interfered with IL-4-induced nuclear translocation of activator protein (AP)-1 components. CONCLUSIONS: This is the first demonstration of suppression of IL-4 signaling by PDE4 inhibitors via prevention of nuclear translocation of AP-1.

Peptide-induced immune protection of CD8+ T cell-deficient mice against Friend retrovirus-induced disease.

CD8+ CTLs and virus-neutralizing antibodies have been associated with spontaneous and vaccine-induced immune control of retroviral infections. We previously showed that a single immunization with an env gene-encoded CD4+ T cell epitope protected mice against fatal Friend retrovirus infection. Here, we analyzed immune cell components required for the peptide-induced anti-retroviral protection. Mice lacking CD8+ T cells were nevertheless protected against Friend virus infection, while mice lacking B cells were not. Virus-producing cells both in the spleen and bone marrow decreased rapidly in their number and became undetectable by 4 weeks after infection in the majority of the peptide-immunized animals even in the absence of CD8+ T cells. In the vaccinated animals the production and class switching of virus-neutralizing and anti-leukemia cell antibodies were facilitated; however, virus-induced erythroid cell expansion was suppressed before neutralizing antibodies became detectable in the serum. Further, the numbers of virus-producing cells in the spleen and bone marrow in the early stage of the infection were smaller in the peptide-immunized than in unimmunized control mice in the absence of B cells. Thus, peptide immunization facilitates both early cellular and late humoral immune responses that lead to the effective control of the retrovirus-induced disease, but CD8+ T cells are not crucial for the elimination of virus-infected cells in the peptide-primed animals.