Correction to: Defined serum- and xeno-free cryopreservation of mesenchymal stem cells.

In the original article, Fig. 1A was by mistakenly duplicated. The corrected image is provided in this correction article.

Bowman-Birk inhibitor concentrate suppresses experimental autoimmune neuritis via shifting macrophages from M1 to M2 subtype.

BACKGROUND: In the present study, we investigated the immuno-regulatory and therapeutic effects of Bowman-Birk inhibitor concentrate (BBIC) on experimental autoimmune neuritis (EAN), an animal model of Guillain-Barré syndrome (GBS) in human. METHODS: EAN in Lewis rats induced by inoculation with peripheral nerve myelin P0 protein peptide 180-199 (P0 peptide) was treated with BBIC at two different therapeutic regimens. RESULTS: Our data indicated that the administration of BBIC daily orally effectively inhibited and ameliorated the clinical and pathological signs of EAN. The suppression of EAN was associated with an insufficiency of autoreactive T cells, as reflected by inhibited P0 peptide-specific mononuclear cell proliferation and decreased in CD4 and CD8T cells infiltrating into the peripheral nervous system (PNS). BBIC might mediate its therapeutic effects by shifting macrophages from M1 to M2 subtype as evidenced by increasing Arg-1, CD206 and IL-10 and inhibiting IFN-γ, TNF-α, IL-12, iNOS and CD40 expressions on macrophages as well as enhancing anti-inflammatory cytokines IL-4 and IL-10 and decreasing inflammatory cytokines, IFN-γ, TNF-α and IL-17 in the PNS. CONCLUSION: Our results suggest that BBIC may have therapeutic potential in human GBS and other autoimmune diseases in the future.

Defined serum- and xeno-free cryopreservation of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have vast potential in cell therapy, and are experimentally used in the clinic. Therefore, it is critical to find a serum- and xeno-free cryopreservation method. The aim of this study was to compare two serum- and xeno-free cryoprotectants for MSCs. Adipose tissue MSCs (Ad-MSCs) and bone marrow MSCs (BM-MSCs) were cryopreserved in two cryoprotectants: the defined serum- and xeno-free STEM-CELLBANKER™ (CB) and 10 % dimethyl sulfoxide (DMSO) in a xeno-free serum replacement cell culture medium and compared to non-cryopreserved MSCs. MSCs cryopreserved in CB or DMSO had similar morphology and surface marker expression compared to their respective non-cryopreserved MSC. Ad-MSCs and BM-MSC in both cryoprotectant media exhibited reduced mean fluorescence intensity (MFI) for CD105, BM-MSCs for CD73 and Ad-MSC increased MFI for HLA class I compared to non-cryopreserved MSCs. Population doubling time of CB cryopreserved and non-cryopreserved Ad-MSCs was similar (38.1 ± 13.6 and 36.8 ± 12.1 h), but somewhat higher when cryopreserved in DMSO (42.2 ± 10.8 h). BM-MSCs had higher population doubling time (CB 47.7 ± 11.4 and DMSO 62.3 ± 32.9 h respectively, p < 0.05) compared to Ad-MSCs. The viability of Ad-MSCs was significantly higher after cryopreservation in CB compared to DMSO (90.4 ± 4.5 % vs. 79.9 ± 3.8 % respectively). Ad-MSCs and BM-MSCs retained their mesodermal differentiation potential when cryopreserved in both cryoprotectants. The characteristics of Ad-MSCs post-thawing are better preserved by CB than by DMSO in serum- and xeno-free medium. Furthermore, Ad-MSCs and BM-MSCs are differently affected by the cryoprotectants, which may have implications for cell therapy.

mTor is a signaling hub in cell survival: a mass-spectrometry-based proteomics investigation.

mTor plays a central role in controlling protein homeostasis and cell survival. Recently, we have demonstrated that perturbations of mTor signaling are implicated in Alzheimer's disease (AD) and that mTor complex 1 (mTorC1) is involved in the formation of toxic phospho-tau. Therefore, we employed mass-spectrometry-based proteomics to identify specific protein expression changes in relation with cell survival in human neuroblastoma SH-SY5Y cells expressing genetically modified mTor. Cell death in SH-SY5Y cells was induced by moderate serum deprivation. Using flow cytometry we observed that up-regulated mTor complex 2 (mTorC2) increases the number of viable cells. By using a combination approach of proteomic and enrichment analysis we have identified several proteins (Thioredoxin-dependent peroxide reductase, Peroxiredoxin-5, Cofilin 1 (non-muscle), Annexin A5, Mortalin, and 14-3-3 protein zeta/delta) involved in mitochondrial integrity, apoptotosis, and pro-survival functions (caspase inhibitor activity and anti-apoptosis) that were significantly altered by mTor activity modulation. The major findings of this study are the implication of mTorC2 but not mTorC1 in cell viability modulation by activating the pro-survival machinery. Taken together, these results suggest that up-regulated mTorC2 might be playing an important role in promoting cell survival by suppressing the mitochondria-caspase-apoptotic pathway in vitro.

Defined serum-free media for in vitro expansion of adipose-derived mesenchymal stem cells.

BACKGROUND: There is a growing interest in mesenchymal stem cells (MSCs) because they are regarded as good candidates for cell therapy. Adipose tissue represents an easily accessible source to derive mesenchymal stem cells (Ad-MSCs) non-invasively in large numbers. The aim of this study was to evaluate a defined serum-free medium for in vitro expansion of MSCs as a prerequisite for their clinical use. METHODS: Adipose tissue was isolated from healthy donors. Cells were isolated and expanded for five passages in serum-free medium (Mesencult-XF) and Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum (DMEM-FBS). MSC morphology, marker expression, viability, population doubling time and differentiation potential toward osteogenic and adipogenic lineages were evaluated. Bone marrow MSCs were included as controls. RESULTS: Ad-MSCs cultured in Mesencult-XF had shorter population doubling time (33.3 ± 13.7 h) compared with those cultured in DMEM-FBS (54.3 ± 41.0 h, P < 0.05). Ad-MSCs cultured in Mesencult-XF displayed a stable morphology and surface marker expression and a higher differentiation potential in comparison to Ad-MSCs cultured in DMEM-FBS. CONCLUSIONS: The defined serum-free and xeno-free Mesencult-XF media appear to be a good choice for Ad-MSCs, but it is not as good in supporting culture of bone marrow MSCs when the cells are to be used for clinical purposes.

Inhibition of microsomal prostaglandin E synthase-1 by aminothiazoles decreases prostaglandin E2 synthesis in vitro and ameliorates experimental periodontitis in vivo.

The potent inflammatory mediator prostaglandin E2 (PGE2) is implicated in the pathogenesis of several chronic inflammatory conditions, including periodontitis. The inducible enzyme microsomal prostaglandin E synthase-1 (mPGES-1), catalyzing the terminal step of PGE2 biosynthesis, is an attractive target for selective PGE2 inhibition. To identify mPGES-1 inhibitors, we investigated the effect of aminothiazoles on inflammation-induced PGE2 synthesis in vitro, using human gingival fibroblasts stimulated with the cytokine IL-1ß and a cell-free mPGES-1 activity assay, as well as on inflammation-induced bone resorption in vivo, using ligature-induced experimental periodontitis in Sprague-Dawley rats. Aminothiazoles 4-([4-(2-naphthyl)-1,3-thiazol-2-yl]amino)phenol (TH-848) and 4-(3-fluoro-4-methoxyphenyl)-N-(4-phenoxyphenyl)-1,3-thiazol-2-amine (TH-644) reduced IL-1ß-induced PGE2 production in fibroblasts (IC50 1.1 and 1.5 µM, respectively) as well as recombinant mPGES-1 activity, without affecting activity or expression of the upstream enzyme cyclooxygenase-2. In ligature-induced experimental periodontitis, alveolar bone loss, assessed by X-ray imaging, was reduced by 46% by local treatment with TH-848, compared to vehicle, without any systemic effects on PGE2, 6-keto PGF1α, LTB4 or cytokine levels. In summary, these results demonstrate that the aminothiazoles represent novel mPGES-1 inhibitors for inhibition of PGE2 production and reduction of bone resorption in experimental periodontitis, and may be used as potential anti-inflammatory drugs for treatment of chronic inflammatory diseases, including periodontitis.

Attenuated EAN in TNF-α deficient mice is associated with an altered balance of M1/M2 macrophages.

The role of tumor necrosis factor (TNF)-α and its receptors in neuroautoimmune and neuroinflammatory diseases has been controversial. On the basis of our previous studies, we hereby aimed to further clarify TNF-α's mechanism of action and to explore the potential role of TNF-α receptor (TNFR)1 as a therapeutic target in experimental autoimmune neuritis (EAN). EAN was induced by immunization with P0 peptide 180-199 in TNF-α knockout (KO) mice and anti-TNFR1 antibodies were used to treat EAN. Particularly, the effects of TNF-α deficiency and TNFR1 blockade on macrophage functions were investigated. The onset of EAN in TNF-α KO mice was markedly later than that in wild type (WT) mice. From day 14 post immunization, the clinical signs of TNF-α KO mice were significantly milder than those of their WT counterparts. Further, we showed that the clinical severity of WT mice treated with anti-TNFR1 antibodies was less severe than that of the control WT mice receiving PBS. Nevertheless, no difference with regard to the clinical signs of EAN or inflammatory infiltration in cauda equina was seen between TNF-α KO and WT mice with EAN after blockade of TNFR1. Although TNF-α deficiency did not alter the proliferation of lymphocytes in response to either antigenic or mitogenic stimuli, it down-regulated the production of interleukin (IL)-12 and nitric oxide (NO), and enhanced the production of IL-10 in macrophages. Increased ratio of regulatory T cells (Tregs) and reduced production of interferon (IFN)-γ in cauda equina infiltrating cells, and elevated levels of IgG2b antibodies against P0 peptide 180-199 in sera were found in TNF-α KO mice with EAN. In conclusion, TNF-α deficiency attenuates EAN via altering the M1/M2 balance of macrophages.

Apolipoprotein E isoform-specific effects on cytokine and nitric oxide production from mouse Schwann cells after inflammatory stimulation.

Previously, we reported that apolipoprotein E (apoE) deficiency increased the susceptibility to experimental autoimmune neuritis (EAN), an inflammatory autoimmune disorder of the peripheral nervous system (PNS) and an animal model for human Guillain-Barré syndrome (GBS) by affecting the antigen-presenting function of Schwann cells (SCs) via influence upon IL-6 production. To further elucidate the role of apoE in inflammation of the PNS, here we studied the effect of different isoforms of apoE on SCs in response to inflammatory stimulation. SCs from apoE2, E3 and E4 transgenic (Tg) and wild type (WT) mice were cultured, and their responses to stimulation by lipopolysaccharide (LPS) plus interferon (IFN)-γ were compared. Upon stimulation, the morphology of cultured SCs changed. Pronounced production of interleukin (IL)-6 and IL-10 within SCs, and of IL-6 and nitric oxide (NO) in the supernatants were found in an isoform-dependent manner (apoE3>apoE2≈apoE4). Further results indicated that both nuclear factor (NF) κB and Akt signaling pathways were involved in the process by the same isoform-dependent pattern. However, the expression of co-stimulatory molecules as showing the antigen-presenting capacity of SCs was not significantly different among these groups. In conclusion, SCs respond to inflammatory insults accompanied by increased productions of IL-6, IL-10 and NO in an apoE-isoform-dependent manner. SCs from apoE2 and apoE4 Tg mice seem to bear some dysfunction in producing cytokines (IL-6 and IL-10) and NO as compared with their apoE3 counterparts, probably resulting from their insufficiency to suppress the activation of NFκB and Akt pathways. Our findings may help to understand the role of different isoforms of apoE in inflammatory disorders of the PNS.

Clinical-grade, large-scale, feeder-free expansion of highly active human natural killer cells for adoptive immunotherapy using an automated bioreactor.

BACKGROUND AIMS: Natural killer (NK) cell-based adoptive immunotherapy is a promising approach for the treatment of cancer. Ex vivo expansion and activation of NK cells under good manufacturing practice (GMP) conditions are crucial for facilitating large clinical trials. The goal of this study was to optimize a large-scale, feeder-free, closed system for efficient NK cell expansion. METHODS: Peripheral blood mononuclear cells (PBMCs) from healthy donors and myeloma patients were cultured for 21 days using flasks, cell culture bags and bioreactors. Final products from different expansions were evaluated comparatively for phenotype and functionality. RESULTS: Significant NK cell expansions were obtained in all systems. The bioreactor yielded a final product rich in NK cells (mean 38%) ensuring that a clinically relevant cell dose was reached (mean 9.8 x 109 NK cells). Moreover, we observed that NK cells expanded in the bioreactor displayed significantly higher cytotoxic capacity. It was possible to attribute this partially to a higher expression level of NKp44 compared with NK cells expanded in flasks. CONCLUSIONS: These results demonstrate that large amounts of highly active NK cells for adoptive immunotherapy can be produced in a closed, automated, large-scale bioreactor under feeder-free current GMP conditions, facilitating clinical trials for the use of these cells.

Kainic acid-induced microglial activation is attenuated in aged interleukin-18 deficient mice.

BACKGROUND: Previously, we found that interleukin (IL)-18 deficiency aggravates kainic acid (KA)-induced hippocampal neurodegeneration in young C57BL/6 mice due to an over-compensation by IL-12. Additionally, IL-18 participates in fundamental inflammatory processes that increase during aging. In the present study, we were interested in the role of IL-18 in KA-induced neurodegeneration in aged female C57BL/6 mice. METHODS: Fifteen aged female IL-18 knockout (KO) and 15 age-matched wild-type (WT) mice (18 to 19 months old) were treated with KA at a dose of 25 mg/kg body weight intranasally. Seizure activities and behavioral changes were rated using a 6-point scoring system and open-field test, respectively. Seven days after KA treatment, degenerating neurons were detected by Nissl's method and Fluoro-Jade B staining; and microglial activation was analyzed by immunohistochemistry and flow cytometry. RESULTS: Aged female IL-18 KO and WT mice showed similar responses to treatment with KA as demonstrated by comparable seizure activities, behavioral changes and neuronal cell death. However, aged female IL-18 KO mice failed to exhibit the strong microglial activation shown in WT mice. Interestingly, even though the number of activated microglia was less in KA-treated IL-18 KO mice than in KA-treated WT mice, the proportion of microglia that expressed the cytokines tumor necrosis factor (TNF)-alpha, IL-6 and IL-10 was higher in KA-treated IL-18 KO mice. CONCLUSION: Deficiency of IL-18 attenuates microglial activation after KA-induced excitotoxicity in aged brain, while the net effects of IL-18 deficiency are balanced by the enhancement of other cytokines, such as TNF-alpha, IL-6 and IL-10.

TNF-alpha receptor 1 deficiency reduces antigen-presenting capacity of Schwann cells and ameliorates experimental autoimmune neuritis in mice.

Tumor necrosis factor-alpha (TNF-alpha) is a pleiotropic pro-inflammatory cytokine with potentially neurodestructive effects and plays a pivotal role in autoimmune demyelinating disease. To address the role of TNF-alpha in the pathogenesis of experimental autoimmune neuritis (EAN), the current study investigated the antigen-presenting capacity of Schwann cells (SCs) in EAN induced by P0 protein peptide 106-125 in TNF-alpha receptor 1 deficient (TNFR1(-/-)) mice. The antigen-presenting capacity of SCs was assessed by the expression of MHC class II (MHCII), CD40, CD80 and CD86 molecules on activated SCs as well as by induction of T cell proliferation in co-cultures of P0 protein peptide 106-125 specific T cells with activated SCs. In addition, the expression of inducible nitric oxide synthase (iNOS) was measured in activated SCs by flow cytometry. TNFR1(-/-) EAN mice developed significantly delayed and reduced clinical signs of EAN compared to wild type EAN mice. In parallel, the expression of MHCII, CD80 and iNOS on SCs were decreased in TNFR1(-/-) mice compared to wild type mice. Likewise, proliferation of P0 protein peptide 106-125 specific T cells simulated by activated SCs of TNFR1(-/-) EAN mice was lower than that of wild type EAN mice. Our data suggest that TNF-alpha may exert pro-inflammatory effects in EAN via TNFR1 by up-regulating the antigen-presenting function and iNOS production of SCs.

The expression of TNF-alpha receptors 1 and 2 on peripheral blood mononuclear cells in chronic inflammatory demyelinating polyneuropathy.

The proportion of peripheral blood mononuclear cells (PBMCs) expressing TNF-alpha and its receptors (TNFR1, TNFR2) and the serum concentrations of its soluble forms were analyzed by FACS and ELISA in the patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and in controls. Elevated levels of TNFR2 were observed on blood T cells in CIDP and idiopathic polyneuropathy. Low levels of TNFR1 were detected on monocytes in the subgroup of patients with CIDP examined after treatment with intravenous immunoglobulin. However, the proliferative activity of PBMCs in CIDP was not influenced by soluble recombinant TNFR1. Our limited data suggested the exact role of TNF-alpha and its receptors need to study further in CIDP, as well as in idiopathic neuropathies.

TNF-alpha receptor 1 deficiency enhances kainic acid-induced hippocampal injury in mice.

The exact role of TNF-alpha in excitotoxic neurodegeneration of the brain is unclear. To address this issue, the kainic acid (KA)-induced hippocampal injury model, a well-characterized model of human neurodegenerative diseases, was used in TNF-alpha receptor 1 (TNFR1)-knockout (TNFR1-/-) mice in the present study. After nasal application of a single dose of 40 mg of KA per kilogram body weight, TNFR1-/- mice showed significantly more severe seizures than the wild-type mice. In addition, obvious neurodegeneration, enhanced microglia activation, and astrogliosis in the hippocampus, as well as increased locomotor activity, were found in TNFR1-/- mice compared with the wild-type controls 8 days after KA delivery. Moreover, CC chemokine receptor 3 expression on activated microglia was increased 3 days after KA treatment in TNFR1-/- mice, as measured by flow cytometry. These data suggest that TNF-alpha may play a protective role through TNFR1 signaling.

Autologous antitumor activity by NK cells expanded from myeloma patients using GMP-compliant components.

Multiple myeloma (MM) is an incurable plasma cell malignancy with poor outcome. The most promising therapeutic options currently available are combinations of transplantation, targeted pharmacotherapy, and immunotherapy. Cell-based immunotherapy after hematopoietic stem-cell transplantation has been attempted, but with limited efficacy. Natural killer (NK) cells are interesting candidates for new means of immunotherapy; however, their potential clinical use in MM has not been extensively studied. Here, we explored the possibility of expanding NK cells from the peripheral blood of 7 newly diagnosed, untreated MM patients, using good manufacturing practice (GMP)-compliant components. After 20 days of culture, the number of NK cells from these patients had expanded on average 1600-fold. Moreover, expanded NK cells showed significant cytotoxicity against primary autologous MM cells, yet retained their tolerance against nonmalignant cells. Based on these findings, we propose that autologous NK cells expanded ex vivo deserve further attention as a possible new treatment modality for MM.

Regulation of prostaglandin E synthases: effects of siRNA-mediated inhibition of microsomal prostaglandin E synthase-1.

Prostaglandin E2 (PGE2) is a key mediator involved in several inflammatory conditions. In this study, we investigated the expression and regulation of the terminal PGE2 synthesizing enzyme prostaglandin E synthases (mPGES-1, mPGES-2 and cPGES) in gingival fibroblasts stimulated with pro-inflammatory cytokines. We used siRNA knockdown of mPGES-1 to elucidate the impact of mPGES-1 inhibition on mPGES-2 and cPGES expression, as well as on PGE2 production. The cytokines TNFalpha and IL-1beta increased protein expression and activity of mPGES-1, accompanied by increased COX-2 expression and PGE2 production. The isoenzymes mPGES-2 and cPGES, constitutively expressed at mRNA and protein levels, were unaffected by the pro-inflammatory cytokines. We show for the first time that treatment with mPGES-1 siRNA down-regulated the cytokine-induced mPGES-1 protein expression and activity. Interestingly, mPGES-1 siRNA did not affect the cytokine-stimulated PGE2 production, whereas PGF(2alpha) levels were enhanced. Neither mPGES-2 nor cPGES expression was affected by siRNA silencing of mPGES-1. Dexamethasone and MK-886 both inhibited the cytokine-induced mPGES-1 expression while mPGES-2 and cPGES expression remained unaffected. In conclusion, mPGES-1 siRNA down-regulates mPGES-1 expression, and neither mPGES-2 nor cPGES substituted for mPGES-1 in a knockdown setting in gingival fibroblasts. Moreover, mPGES-1 siRNA did not affect PGE2 levels, whereas PGF(2alpha) increased, suggesting a compensatory pathway of PGE2 synthesis when mPGES-1 is knocked down.

Aggravation of experimental autoimmune neuritis in TNF-alpha receptor 1 deficient mice.

The role of tumor necrosis factor (TNF)-alpha and its receptors in the pathogenesis of experimental autoimmune neuritis (EAN) induced by P0 peptide 180-199 in TNFR1 (p55) deficient (TNFR1-/-) mice was investigated. Compared to wild type EAN mice, TNFR1-/- EAN mice developed significantly more severe clinical signs, in parallel with enhanced numbers of inflammatory infiltrating cells in peripheral nerves and splenic P0-reactive T cell proliferation, as well as increased obviously MHC class II and CCR3 expression on the macrophages in the cauda equina. Our data indicated that TNF-alpha might have anti-inflammatory effect preventing the development of EAN in this mouse model.

IL-18 deficiency aggravates kainic acid-induced hippocampal neurodegeneration in C57BL/6 mice due to an overcompensation by IL-12.

The role of interleukin-18 (IL-18) in excitotoxic neurodegeneration is largely unknown. To address this issue, we used kainic acid (KA)-induced hippocampal neurodegeneration in IL-18 knockout (KO) mice. One day after KA administration, clinical symptoms and histopathological changes did not differ between IL-18 KO mice and wild-type mice. However, 7 days after KA application the hippocampal neurodegeneration was markedly severe in IL-18 KO mice as demonstrated by increased locomotion and prominent histopathological changes including neuronal cell loss, microglia activation and astrogliosis. Surprisingly, when wild-type mice received recombinant mouse IL-18 (rmIL-18) in advance, after KA treatment both the clinical and pathological signs were dose-dependently aggravated compared to mice without rmIL-18 pre-treatment. To clarify the mechanism behind this, we assessed the expression of the IL-18 associated cytokines IL-12, IL-1beta, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) in the hippocampus by immunohistochemistry and flow cytometry. IL-12 and IFN-gamma expression was strongly increased in IL-18 KO mice when compared to wild-type mice 7 days after KA treatment in agreement with increased microglia activation. These results suggest that the role of IL-18 in excitotoxic injury in IL-18 deficient mice may be overcompensated by increased IL-12 secretion.

IL-18 deficiency inhibits both Th1 and Th2 cytokine production but not the clinical symptoms in experimental autoimmune neuritis.

IL-18 deficient (IL-18-/-) mice were used to investigate the role of IL-18 in the pathogenesis of experimental autoimmune neuritis (EAN) which was induced by immunization of the mice with P0 protein peptide 180-199. The clinical course was not different between IL-18-/- and wild-type mice. The splenic mononuclear cell (MNC) proliferation was also similar in both animal groups. However, the percentages of IFN-gamma, IL-10 and IL-12 positive cells were decreased among infiltrating MNC of cauda equine in IL-18-/- mice. This indicates that IL-18 deficiency inhibits the production of both Th1 and Th2 cytokines in the target organ of mice with EAN.

Cell expression of MMP-1 and TIMP-1 in co-cultures of human gingival fibroblasts and monocytes: the involvement of ICAM-1.

Matrix metalloproteinase-1 (MMP-1) plays an important role in the degradation of collagen in inflammatory diseases. The aim of this study was to investigate the cellular expression of MMP-1 and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), in gingival fibroblasts co-cultured with monocytes and the possible mediating role of intercellular adhesion molecule-1 (ICAM-1). In co-cultures, the expression of MMP-1 and TIMP-1 increased in fibroblasts, but not in monocytes, although the number of MMP-1+ and TIMP-1+ adhered monocytes increased. Moreover, ICAM-1 expression in both fibroblasts and adhered monocytes increased. In the presence of an anti-ICAM-1 antibody, the expression of MMP-1 in fibroblasts decreased whereas the number of TIMP-1+ adhered monocytes increased. The p38 MAPK inhibitor SB203580 reduced MMP-1 expression in fibroblasts, as well as ICAM-1 expression in both fibroblasts and adhered monocytes. The results suggest that co-culture with monocytes enhances cellular expression of MMP-1 and TIMP-1 in gingival fibroblasts, and that the increased MMP-1 expression, in contrast to TIMP-1, is partly mediated by the adhesion molecule ICAM-1 and the p38 MAPK signal pathway.

Increased microglial activation and astrogliosis after intranasal administration of kainic acid in C57BL/6 mice.

Glutamate excitotoxicity plays a key role in inducing neuronal cell death in many neurological diseases. In mice, intranasal administration of kainic acid (KA), an analogue of the excitotoxin glutamate, results in hippocampal cell death and provides a well-characterized model for studies of human neurodegenerative diseases. In this study, we describe neurodegeneration and gliosis following intranasal administration of KA in C57BL/6 mice. By using Nissl's staining, neurodegeneration was found in area CA3 of hippocampus, and neuronal apoptosis was demonstrated by enhanced FAS(CD95/APO-1) expression detected by immunohistochemistry and Western blotting. Astrogliosis was exhibited by increased glial fibrillary acidic protein (GFAP) expression in the hippocampus and cortex. We also studied the profile of molecular expression on microglia in C57BL/6 mice. One and 3 days after KA administration, CD45, F4/80, CD86, MHCII, iNOS but not CD40 expression was enhanced or induced on microglia. In summary, KA administration results in an early microglial activation and a prolonged astrogliosis in C57BL/6 mice.