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Biomedical subjects

D Kempuraj

Publications and source records attributed to D Kempuraj.

At least 19 recordsLinked to original sources
PubMed2006

Inhibitory effect of quercetin on tryptase and interleukin-6 release, and histidine decarboxylase mRNA transcription by human mast cell-1 cell line.

Mast cells are involved in inflammatory processes and in allergic reactions where immunologic stimulation leads to degranulation and generation of numerous cytokines and inflammatory mediators. Mast cells have been proposed as an immune gate to the brain, as well as sensors of environmental and emotional stress, and are likely involved in neuropathologic processes such as multiple sclerosis. Among mast cell products, the protease tryptase could be associated with neurodegenerative processes through the activation of specific receptors (PARs) expressed in the brain, while interleukin (IL)-6 likely causes neurodegeneration and exacerbates dysfunction induced by other cytokines; or it could have a protective effect against demyelinisation. In this report we show that quercetin, a natural compound able to act as an inhibitor of mast cell secretion, causes a decrease in the release of tryptase and IL-6 and the down-regulation of histidine decarboxylase (HDC) mRNA from human mast cell (HMC)-1 cells. As quercetin dramatically inhibits mast cell tryptase and IL-6 release and HDC mRNA transcription by HMC-1 cell line, these results nominate quercetin as a therapeutical compound in association with other therapeutical molecules for neurological diseases mediated by mast cell degranulation.

Blotting, Northern↗
PubMed2006

Acute stress and intravesical corticotropin-releasing hormone induces mast cell dependent vascular endothelial growth factor release from mouse bladder explants.

PURPOSE: Corticotropin-releasing hormone is typically released from the hypothalamus but it has proinflammatory effects outside of the brain, possibly through the activation of mast cells. These cells express corticotropin-releasing hormone receptors with selective secretion of vascular endothelial growth factor, which may be involved in the pathogenesis of painful bladder syndrome/interstitial cystitis. This condition is characterized by bladder inflammation and worsened by stress. We investigated the effect of intravesical corticotropin-releasing hormone and acute restraint stress on vascular endothelial growth factor release from mouse bladder explants and the role of mast cells. MATERIALS AND METHODS: The bladder of C57BL/6 mast cell deficient (W/W(v)) and normal congenic (+/+) female mice (Jackson Laboratories, Bar Harbor, Maine) at ages 10 to 12 weeks was catheterized using anesthesia. After emptying urine 1) normal saline or corticotropin-releasing hormone was introduced for 45 minutes, urine was collected and the mice were allowed to recover for 4 hours before sacrifice or 2) the mice were stressed by placing them in a restrainer for 4 hours before sacrifice and urine was collected 2 hours after stress. The bladder was removed 4 hours after stress and processed for corticotropin-releasing hormone immunohistochemical staining. In other experiments the bladder was removed, minced into 1 mm(2) pieces and cultured with or without corticotropin-releasing hormone overnight. Urine and medium were frozen for histamine, interleukin-6, tumor necrosis factor-alpha and vascular endothelial growth factor assay. RESULTS: Corticotropin-releasing hormone (100 nM) or acute restraint stress (4 hours) increased histamine release in urine and vascular endothelial growth factor release in medium without increasing interleukin-6 or tumor necrosis factor-alpha in the bladder explants of C57BL/6 or +/+ but not W/W(v) mice. No vascular endothelial growth factor, interleukin-6 or tumor necrosis factor-alpha was detected in urine before or after stimulation. Corticotropin-releasing hormone immunoreactivity was present in control bladders but it increased dramatically in the bladder of stressed mice. CONCLUSIONS: Intravesical corticotropin-releasing hormone and acute restraint stress induced mast cell dependent vascular endothelial growth factor release from bladder explants. These findings suggest that stress, corticotropin-releasing hormone, mast cells and vascular endothelial growth factor might participate in the pathogenesis of painful bladder syndrome/interstitial cystitis, which is worsened by stress, and provide for new therapeutic targets.

Acute Disease↗
PubMed2005

A short-term diabetes induced changes of catecholamines and p38-MAPK in discrete areas of rat brain.

Chronic diabetes is associated with the alteration of second messengers and CNS disorders. We have recently identified that protein kinases (CaMKII and PKC-alpha) and brain neurotransmitters are altered during diabetes as well as in hyperglycemic and acidotic conditions. In this study, we investigated the effects of acute diabetes on the levels of dopamine (DA), norepinephrine (NE), epinephrine (E) and p38-Mitogen-Activated Protein Kinase (p38-MAPK) in striatum (ST), hippocampus (HC), hypothalamus (HT), midbrain (MB), pons medulla (PM), cerebellum (CB) and cerebral cortex (CCX). Alloxan (45 mg/kg) diabetic untreated rats that showed hyperglycemia (>260 mg%), revealed significant increases of DA level in ST (1.5 fold), HC (2.2 fold) and PM (2.0 fold) and the E level also found to be increased significantly in HT (2.4 fold), whereas the NE level was decreased in CB (0.5 fold), after 7 days of diabetes. Immunoblotting study of p38-MAPK expression under identical conditions showed significant alterations in ST, HC, HT and PM (p<0.05) correlated with the changes of catecholamines (DA and E). On the other hand, the above changes were reversed in insulin-treated diabetic rats maintained under normal glucose level (80 -110 mg %). These results suggest that p38-MAPK may regulate the rate of either the synthesis or release of DA and E in corresponding brain areas, but not NE, under these conditions.

Animals↗
PubMed2003

IL-10 subfamily members: IL-19, IL-20, IL-22, IL-24 and IL-26.

It has been reported that the CD4+ T cell is a very important source of interleukin 10 (IL-10), while CD8+ cells produce low amounts. IL-10 exerts several immune stimulating, as well as inhibitory effects. There are at least five novel human IL-10 family-related molecules: IL-19, IL-20, IL-22, IL-24, and IL-26. Activated T cells produce IL-19, IL-22 and IL-26, while IL-24 is produced by activated monocytes and T-cells. IL-20 induces cheratin proliferation and Stat-3 signal transduction pathway, while IL-22 induces acute-phase production by hepatocytes and neonatal lethality with skin abnormalities reminiscent of psoriasic lesions in humans. In addition, IL-22 mediates inflammation and binds class II cytokine receptor heterodimers IL-22 RA1/CRF2-4. This cytokine is also involved in immuno-regulatory responses. IL-26 (AK155) is a novel cytokine generated by memory cells and is involved in the transformed phenotype of human T cells after infection by herpes virus. All these new IL-10 subfamily member cytokines are strongly involved in immune regulation and inflammatory responses.

Animals↗
PubMed2002

Intravesical sodium hyaluronate inhibits the rat urinary mast cell mediator increase triggered by acute immobilization stress.

PURPOSE: Mast cell activation and stress have been suggested as factors in the pathogenesis of interstitial cystitis, a painful disorder of the bladder that is diagnosed more frequently in women and characterized by increased urgency and frequency with absent infection. Intravesical sodium hyaluronate has been used to treat interstitial cystitis due to its possible replenishment of bladder glycosaminoglycans. We investigated the effect of sodium hyaluronate on the activation of bladder mast cell and release of proinflammatory mediators in the urine induced by acute immobilization stress in rats. MATERIALS AND METHODS: Using anesthesia a catheter was inserted in the bladder of 170 gm. female Sprague-Dawley rats. After emptying post-void residual urine a solution of normal saline, 0.08% or 0.4% sodium hyaluronate was introduced for 30 minutes. Each rat was allowed to recover from anesthesia and stressed for 30 minutes by confining it in a clear acrylic plastic immobilizer, while urine was continuously collected. Urinary histamine, rat mast cell protease-I and interleukin (IL)-6 were then determined. At the end of the experiments each rat was sacrificed by CO2 asphyxiation, and the bladder was removed and fixed with 4% paraformaldehyde. Frozen sections were stained with acidified toluidine blue, and the mast cell number and degree of activation were determined by granule extrusion and reduced cellular staining. RESULTS: Mean bladder mast cell activation plus or minus standard deviation in 6 control rats was 30.4% +/- 3.7% but it increased to 76.2% +/- 6.1% in 6 stressed animals (p = 0.0001). Intravesical administration of 0.4% sodium hyaluronate for 30 minutes in 6 rats before stress reduced mean bladder mast cell activation by 69.7% to 23.1% +/- 6.1% compared with stressed controls (p = 0.0003). However, compared to itself before stress there was no significant difference, indicating complete inhibition in 6 rats. Intravesical 0.08% sodium hyaluronate had a weaker inhibitory effect in 6 rats, decreasing mean degranulation by 22.5% to 59.1% +/- 7.6% (p = 0.02). In 6 rats stress increased the total mean amount of urinary rat mast cell protease-I by 271% from 0.14 +/- 0.09 to 0.52 +/- 0.17 ng. (p = 0.008). Pretreatment with 0.4% sodium hyaluronate reduced mean rat mast cell protease-I 80.8% compared with stressed controls (p = 0.008) and prevented any increase in response to stress in the same group of 8 rats with a mean pre-stress and post-stress level of 0.09 +/- 0.04 and 0.1 +/- 0.04 ng., respectively (p = 0.8). Acute stress increased mean urinary histamine in 6 rats 40.2% from 137.3 +/- 29.7 before to 193.7 +/- 7.6 ng./ml. after stress (p = 0.004). Pretreatment with 0.4% sodium hyaluronate reduced mean histamine 7.1% compared with stressed controls but completely prevented any increase in the same group of 8 rats, in which it was 174.5 +/- 23.1 before and remained 179.4 +/- 9.9 ng./ml. after stress (p = 0.75). Acute stress in 7 rats also increased the mean amount of IL-6 released in the urine by 31.5% from 775.9 +/- 69.2 to 1,021.1 +/- 93.3 pg./ml. (p = 0.007). Pretreatment with 0.4% sodium hyaluronate in 9 rats reduced mean IL-6 17% compared with stressed controls but again prevented any increase from baseline, since the value was 898.6 +/- 299.3 before and 824.4 +/- 196.4 pg./ml. after stress (p = 0.03). CONCLUSIONS: Immobilization stress induces bladder mast cell activation and the secretion of proinflammatory mediators, which are inhibited by sodium hyaluronate. Intravesical sodium hyaluronate may be a useful therapeutic option for interstitial cystitis, especially in patients with bladder mastocytosis who have symptom exacerbation with stress.

Administration, Intravesical↗
PubMed2001

Mast cell involvement in interstitial cystitis: a review of human and experimental evidence.

Interstitial cystitis (IC) is a heterogeneous syndrome of unknown etiology. Altered bladder glycosaminoglycans lining and bladder mastocytosis have been documented in IC. The objective of this article is to critically examine the published data on bladder mastocytosis in clinical, experimental, and animal studies, with particular emphasis on morphologic evidence of mast cell increase and activation. The literature on bladder mastocytosis and mast cell activation in IC is critically reviewed with particular reference to staining methodology, tryptase immunoreactivity, and electron microscopy. Data from humans and animal models of IC are included. Mastocytosis in IC is best documented by tryptase immunocytochemical staining. Standard surgical stains such as Giemsa and toluidine blue routinely underestimate the degree of mastocytosis. Mast cells are 6- to 8-fold higher in the detrusor compared with controls in "classic IC," and 2- to 3-fold higher in "nonulcerative" IC. Detrusor mastocytosis occurs in both classic and nonulcer IC. Mucosal mast cell increase is present in nonulcerative IC. Mast cell activation without typical exocytosis occurs in the mucosa and submucosa. Activation of mast cells, irrespective of bladder location or degree of mastocytosis, is significant. Mast cell-derived vasoactive and proinflammatory molecules may contribute to the pathogenesis of IC.

Animals↗
PubMed2000

Chondroitin sulphate inhibits connective tissue mast cells.

1. Mast cells derive from the bone marrow and are responsible for the development of allergic and possibly inflammatory reactions. Mast cells are stimulated by immunoglobulin E (IgE) and specific antigen, but also by a number of neuropeptides such as neurotensin (NT), somatostatin or substance P (SP), to secrete numerous pro-inflammatory molecules that include histamine, cytokines and proteolytic enzymes. 2. Chondroitin sulphate, a major constituent of connective tissues and of mast cell secretory granules, had a dose-dependent inhibitory effect on rat peritoneal mast cell release of histamine induced by the mast cell secretagogue compound 48/80 (48/80). This inhibition was stronger than that of the clinically available mast cell 'stabilizer' disodium cromoglycate (cromolyn). Inhibition by chondroitin sulphate increased with the length of preincubation and persisted after the drug was washed off, while the effect of cromolyn was limited by rapid tachyphylaxis. 3. Immunologic stimulation of histamine secretion from rat connective tissue mast cells (CTMC) was also inhibited, but this effect was weaker in umbilical cord-derived human mast cells and was absent in rat basophilic leukemia (RBL) cells which are considered homologous to mucosal mast cells (MMC). Oligo- and monosaccharides were not as effective as the polysaccharides. 4. Inhibition, documented by light and electron microscopy, involved a decrease of intracellular calcium ion levels shown by confocal microscopy and image analysis. Autoradiography at the ultrastructural level showed that chondroitin sulphate was mostly associated with plasma and perigranular membranes. 5. Chondroitin sulphate appears to be a potent mast cell inhibitor of allergic and nonimmune stimulation with potential clinical implications.

Animals↗
PubMed2000

Regulation of chymase production in human mast cell progenitors.

BACKGROUND: Although mature tryptase-positive mast cells (MCs) and tryptase and chymase double-positive MCs are recognized using in situ staining and are preferentially distributed in different tissues, recent findings suggest that tryptase-positive MCs can give rise to tryptase and chymase double-positive MCs. OBJECTIVE: We investigated the regulation of chymase production in developing MCs. METHODS: Human cord blood or peripheral blood cells were cultured in the presence of stem cell factor and IL-6 with or without IL-4 in methylcellulose or liquid medium. Intracellular chymase and tryptase were determined with immunocytochemistry, flow cytometry, and ELISA. Chymase messenger RNA expression was examined with 3 different methods, such as Northern blotting. RESULTS: Flow cytometric analysis always showed a unimodal histogram of chymase-positive, as well as tryptase-positive, cells in the presence of various cytokines, even when chymase was not detected in some MCs with immunocytochemistry. The chymase protein expression increased by culture duration and was enhanced by cytokines, such as a high concentration of stem cell factor or IL-4. Chymase messenger RNA was expressed higher in immature MCs than mature chymase protein-rich MCs. We generated macroscopic MC colonies in methylcellulose by culturing CD34(+) cells for 10 weeks and measured cellular chymase, tryptase, and histamine. The chymase/histamine ratio widely varied (0.07-1.01) depending on MC colony, even under the same culture conditions, including IL-4, whereas the tryptase/histamine ratio was relatively constant (1.02-1.89). CONCLUSION: All human MCs in culture are capable of producing chymase, and the production is clonally regulated at their progenitors by cytokine-independent mechanisms, as well as being totally controlled by cytokine-dependent mechanisms accompanied by maturation.

Cells, Cultured↗
PubMed1999

Characterization of mast cell-committed progenitors present in human umbilical cord blood.

Human mast cells are derived from CD34(+) hematopoietic cells present in cord blood, bone marrow, and peripheral blood. However, little is known about the properties of the CD34(+) cells. We demonstrated here that mast cell progenitors that have distinct phenotypes from other hematopoietic cell types are present in cord blood by culturing single, sorted CD34(+) cells in 96-well plates or unsorted cells in methylcellulose. The CD34(+) mast cell-committed progenitors often expressed CD38 and often lacked HLA-DR, whereas CD34(+) erythroid progenitors often expressed both CD38 and HLA-DR and CD34(+) granulocyte-macrophage progenitors often had CD33 and sometimes expressed CD38. We then cultured single cord blood-derived CD34(+)CD38(+) cells under conditions optimal for mast cells and three types of myeloid cells, ie, basophils, eosinophils, and macrophages. Of 1,200 CD34(+)CD38(+) cells, we were able to detect 13 pure mast cell colonies and 52 pure colonies consisting of either one of these three myeloid cell types. We found 17 colonies consisting of two of the three myeloid cell types, whereas only one colony consisted of mast cells and another cell type. These results indicate that human mast cells develop from progenitors that have unique phenotypes and that committed mast cell progenitors develop from multipotent hematopoietic cells through a pathway distinct from myeloid lineages including basophils, which have many similarities to mast cells.

ADP-ribosyl Cyclase↗
PubMed1998

Carnoy's fixative reduces the number of chymase-positive cells in immunocytochemical staining of cord-blood-derived human cultured mast cells.

KleinJan et al. (Allergy 1996;51:614-20) reported that Carnoy's fixative reduced the number of chymase-positive mast cells in the nasal mucosa. Therefore, in the present study, we investigated whether Carnoy's fixative reduces the number of chymase-positive cells from cord-blood-derived human cultured mast cells when compared with other types of fixatives. Human mast cells were obtained by culturing cord-blood-derived CD34-positive cells in the presence of stem cell factor and interleukin-6. Staining procedures of the cells in fixation with Carnoy's fixative and with other fixatives gave no differences among the number of tryptase-positive cells, whereas fixation with Carnoy's fixative for 15 min gave a significant decrease in the number of chymase-positive cells compared with acetone for 10 min. The number of chymase-positive cells decreased in a time-dependent manner under fixation with Carnoy's fixative, indicating that Carnoy's fixative had a negative effect on the number of chymase-positive cells from cord-blood-derived human cultured mast cells.

Acetic Acid↗
PubMedDate not supplied

Inhibitory effect of retinoic acid on proliferation, maturation and tryptase level in human leukemic mast cells (HMC-1).

Mast cells play important role in allergic inflammation by releasing histamine, tryptase and several inflammatory cytokines. Human leukemic mast cells (HMC-1) have been used to study mast cell mediator and their role in inflammatory mechanisms. HMC-1 contain and release several inflammatory mediators, of which the proteolytic enzyme tryptase is most characteristic. Retinoids, including retinoic acid, are naturally occurring and synthetic derivatives of vitamin A. All-trans-retinoic (ATRA) acid had been previously reported to inhibit cell proliferation, differentiation and apoptosis. In the present study, we investigated the effect of ATRA on the proliferation and secretion of tryptase in HMC-1. HMC-1 were treated with ATRA at 10(-4M), 10(-5M) or 10(-6M) for 3, 4 or 5 days in culture. Control HMC-1 were treated with equal amount of culture medium only. ATRA decreased the number of HMC-1 as compared to the control group. The same treatment for 3, 4 or 5 days also decreased intracellular tryptase levels. These results indicate that ATRA significantly inhibits both proliferation and growth as shown by the decreased intracellular tryptase levels in HMC-1. ATRA may be a useful agent in the treatment of mast cell proliferative disorders.

Cell Differentiation↗
PubMedDate not supplied

T lymphocyte subsets and immunoglobulins in intracranial tumor patients before and after treatment, and based on histological type of tumors.

It has been reported that nervous system and peripheral immune system communicate with each other and the peripheral immune status is depressed in some intracranial tumor (ICT) patients pre operatively. Little is known about the immune status of intracranial tumor patients during the post operative survival period. We thus investigated total T cells (CD 11+), helper/inducer (CD4+) T cells, suppressor/cytotoxic (CD8+) T cells, B cells (CD19+) and serum immunoglobulins in peripheral blood in certain ICT patients before and after treatment, and based on the histological type of the tumors. Post treatment analysis were conducted 30 days after surgical removal of tumor tissue in benign brain tumor patients and 30 days after chemo therapy (CT)/radiotherapy (RT) following surgical removal of tumor tissue in malignant brain tumor patients. Decreased CD11+, CD4+ and increased CD8+ T cell counts were observed in both benign and malignant tumor cases before treatment compared with control subjects. After treatment, CD4+ T cell count increased and CD8+ T cell count decreased than their pre treatment levels. Serum IgA and IgG levels were decreased in both benign and malignant brain tumor patients before treatment than in control subjects. Serum IgM level has been increased in both benign and malignant tumor patients before and after treatment than in control subjects. Anaplastic malignant astrocytoma, medulloblastoma and glioblastoma multiforme patients showed higher IgM level than astrocytoma, meningioma and ependymoma patients. In conclusions, the depressed host cellular immunity in benign and malignant tumor patients before treatment may be due to the changes in CD4+ and CD8+ counts in addition to tumour specific immunosuppressive factors. Treatment procedures such as surgery, CT and RT may play certain role in the post operative depressed immunosuppression in malignant tumor patients. Humoral immune mechanism (CD19+) in the ICT patients was less markedly affected.

Adjuvants, Immunologic↗