Worldwide forest surveys reveal forty-three new species in Phytophthora major Clade 2 with fundamental implications for the evolution and biogeography of the genus and global plant biosecurity.

During 25 surveys of global Phytophthora diversity, conducted between 1998 and 2020, 43 new species were detected in natural ecosystems and, occasionally, in nurseries and outplantings in Europe, Southeast and East Asia and the Americas. Based on a multigene phylogeny of nine nuclear and four mitochondrial gene regions they were assigned to five of the six known subclades, 2a-c, e and f, of Phytophthora major Clade 2 and the new subclade 2g. The evolutionary history of the Clade appears to have involved the pre-Gondwanan divergence of three extant subclades, 2c, 2e and 2f, all having disjunct natural distributions on separate continents and comprising species with a soilborne and aquatic lifestyle and, in addition, a few partially aerial species in Clade 2c; and the post-Gondwanan evolution of subclades 2a and 2g in Southeast/East Asia and 2b in South America, respectively, from their common ancestor. Species in Clade 2g are soilborne whereas Clade 2b comprises both soil-inhabiting and aerial species. Clade 2a has evolved further towards an aerial lifestyle comprising only species which are predominantly or partially airborne. Based on high nuclear heterozygosity levels ca. 38 % of the taxa in Clades 2a and 2b could be some form of hybrid, and the hybridity may be favoured by an A1/A2 breeding system and an aerial life style. Circumstantial evidence suggests the now 93 described species and informally designated taxa in Clade 2 result from both allopatric non-adaptive and sympatric adaptive radiations. They represent most morphological and physiological characters, breeding systems, lifestyles and forms of host specialism found across the Phytophthora clades as a whole, demonstrating the strong biological cohesiveness of the genus. The finding of 43 previously unknown species from a single Phytophthora clade highlight a critical lack of information on the scale of the unknown pathogen threats to forests and natural ecosystems, underlining the risk of basing plant biosecurity protocols mainly on lists of named organisms. More surveys in natural ecosystems of yet unsurveyed regions in Africa, Asia, Central and South America are needed to unveil the full diversity of the clade and the factors driving diversity, speciation and adaptation in Phytophthora. Taxonomic novelties: New species: Phytophthora amamensis T. Jung, K. Kageyama, H. Masuya & S. Uematsu, Phytophthora angustata T. Jung, L. Garcia, B. Mendieta-Araica, & Y. Balci, Phytophthora balkanensis I. Milenkovic, Z. Tomic, T. Jung & M. Horta Jung, Phytophthora borneensis T. Jung, A. Durán, M. Tarigan & M. Horta Jung, Phytophthora calidophila T. Jung, Y. Balci, L. Garcia & B. Mendieta-Araica, Phytophthora catenulata T. Jung, T.-T. Chang, N.M. Chi & M. Horta Jung, Phytophthora celeris T. Jung, L. Oliveira, M. Tarigan & I. Milenkovic, Phytophthora curvata T. Jung, A. Hieno, H. Masuya & M. Horta Jung, Phytophthora distorta T. Jung, A. Durán, E. Sanfuentes von Stowasser & M. Horta Jung, Phytophthora excentrica T. Jung, S. Uematsu, K. Kageyama & C.M. Brasier, Phytophthora falcata T. Jung, K. Kageyama, S. Uematsu & M. Horta Jung, Phytophthora fansipanensis T. Jung, N.M. Chi, T. Corcobado & C.M. Brasier, Phytophthora frigidophila T. Jung, Y. Balci, K. Broders & I. Milenkovic, Phytophthora furcata T. Jung, N.M. Chi, I. Milenkovic & M. Horta Jung, Phytophthora inclinata N.M. Chi, T. Jung, M. Horta Jung & I. Milenkovic, Phytophthora indonesiensis T. Jung, M. Tarigan, L. Oliveira & I. Milenkovic, Phytophthora japonensis T. Jung, A. Hieno, H. Masuya & J.F. Webber, Phytophthora limosa T. Corcobado, T. Majek, M. Ferreira & T. Jung, Phytophthora macroglobulosa H.-C. Zeng, H.-H. Ho, F.-C. Zheng & T. Jung, Phytophthora montana T. Jung, Y. Balci, K. Broders & M. Horta Jung, Phytophthora multipapillata T. Jung, M. Tarigan, I. Milenkovic & M. Horta Jung, Phytophthora multiplex T. Jung, Y. Balci, K. Broders & M. Horta Jung, Phytophthora nimia T. Jung, H. Masuya, A. Hieno & C.M. Brasier, Phytophthora oblonga T. Jung, S. Uematsu, K. Kageyama & C.M. Brasier, Phytophthora obovoidea T. Jung, Y. Balci, L. Garcia & B. Mendieta-Araica, Phytophthora obturata T. Jung, N.M. Chi, I. Milenkovic & M. Horta Jung, Phytophthora penetrans T. Jung, Y. Balci, K. Broders & I. Milenkovic, Phytophthora platani T. Jung, A. Pérez-Sierra, S.O. Cacciola & M. Horta Jung, Phytophthora proliferata T. Jung, N.M. Chi, I. Milenkovic & M. Horta Jung, Phytophthora pseudocapensis T. Jung, T.-T. Chang, I. Milenkovic & M. Horta Jung, Phytophthora pseudocitrophthora T. Jung, S.O. Cacciola, J. Bakonyi & M. Horta Jung, Phytophthora pseudofrigida T. Jung, A. Durán, M. Tarigan & M. Horta Jung, Phytophthora pseudoccultans T. Jung, T.-T. Chang, I. Milenkovic & M. Horta Jung, Phytophthora pyriformis T. Jung, Y. Balci, K.D. Boders & M. Horta Jung, Phytophthora sumatera T. Jung, M. Tarigan, M. Junaid & A. Durán, Phytophthora transposita T. Jung, K. Kageyama, C.M. Brasier & H. Masuya, Phytophthora vacuola T. Jung, H. Masuya, K. Kageyama & J.F. Webber, Phytophthora valdiviana T. Jung, E. Sanfuentes von Stowasser, A. Durán & M. Horta Jung, Phytophthora variepedicellata T. Jung, Y. Balci, K. Broders & I. Milenkovic, Phytophthora vietnamensis T. Jung, N.M. Chi, I. Milenkovic & M. Horta Jung, Phytophthora ×australasiatica T. Jung, N.M. Chi, M. Tarigan & M. Horta Jung, Phytophthora ×lusitanica T. Jung, M. Horta Jung, C. Maia & I. Milenkovic, Phytophthora ×taiwanensis T. Jung, T.-T. Chang, H.-S. Fu & M. Horta Jung. Citation: Jung T, Milenkovic I, Balci Y, Janousek J, Kudlácek T, Nagy ZÁ, Baharuddin B, Bakonyi J, Broders KD, Cacciola SO, Chang T-T, Chi NM, Corcobado T, Cravador A, Dordevic B, Durán A, Ferreira M, Fu C-H, Garcia L, Hieno A, Ho H-H, Hong C, Junaid M, Kageyama K, Kuswinanti T, Maia C, Májek T, Masuya H, Magnano di San Lio G, Mendieta-Araica B, Nasri N, Oliveira LSS, Pane A, Pérez-Sierra A, Rosmana A, Sanfuentes von Stowasser E, Scanu B, Singh R, Stanivukovic Z, Tarigan M, Thu PQ, Tomic Z, Tomsovský M, Uematsu S, Webber JF, Zeng H-C, Zheng F-C, Brasier CM, Horta Jung M (2024). Worldwide forest surveys reveal forty-three new species in Phytophthora major Clade 2 with fundamental implications for the evolution and biogeography of the genus and global plant biosecurity. Studies in Mycology 107: 251-388. doi: 10.3114/sim.2024.107.04.

Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implications.

During extensive surveys of global Phytophthora diversity 14 new species detected in natural ecosystems in Chile, Indonesia, USA (Louisiana), Sweden, Ukraine and Vietnam were assigned to Phytophthora major Clade 10 based on a multigene phylogeny of nine nuclear and three mitochondrial gene regions. Clade 10 now comprises three subclades. Subclades 10a and 10b contain species with nonpapillate sporangia, a range of breeding systems and a mainly soil- and waterborne lifestyle. These include the previously described P. afrocarpa, P. gallica and P. intercalaris and eight of the new species: P. ludoviciana, P. procera, P. pseudogallica, P. scandinavica, P. subarctica, P. tenuimura, P. tonkinensis and P. ukrainensis. In contrast, all species in Subclade 10c have papillate sporangia and are self-fertile (or homothallic) with an aerial lifestyle including the known P. boehmeriae, P. gondwanensis, P. kernoviae and P. morindae and the new species P. celebensis, P. chilensis, P. javanensis, P. multiglobulosa, P. pseudochilensis and P. pseudokernoviae. All new Phytophthora species differed from each other and from related species by their unique combinations of morphological characters, breeding systems, cardinal temperatures and growth rates. The biogeography and evolutionary history of Clade 10 are discussed. We propose that the three subclades originated via the early divergence of pre-Gondwanan ancestors > 175 Mya into water- and soilborne and aerially dispersed lineages and subsequently underwent multiple allopatric and sympatric radiations during their global spread. Citation: Jung T, Milenkovic I, Corcobado T, et al. 2022. Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implications. Persoonia 49: 1-57. https://doi.org/10.3767/persoonia.2022.49.01.

Correlation Between Splenectomy and Portal Vein Complications in Living Donor Liver Transplantation.

OBJECTIVES: In adults undergoing living donor liver transplantation (LDLT), the transplanted livers are partial grafts, and the portal venous pressure is higher than that observed with whole liver grafts. In patients undergoing LDLT concomitant with splenomegaly, portal venous flow is often diverted to collateral vessels, leading to a high risk of portal vein thrombosis. In such cases, occlusion of the collateral veins is important; however, complete occlusion of all collaterals without blocking the blood flow through the splenic artery causes portal hypertension and liver failure. We aimed to examine the effect of performing a splenectomy concomitant with LDLT to reduce portal vein complications. METHODS: Between 1991 and 2017, we performed 170 LDLT operations, including 83 in adults. For this cohort study, adult cases were divided into 2 groups. Group I was those who underwent LDLT without splenectomy (n = 60); Group II was those who underwent LDLT with splenectomy for the reduction of portal hypertension (n = 23). We investigated the incident rates of complications, including blood loss, lethal portal vein thrombosis (intrahepatic thrombosis), acute rejection, and so on. We also investigated the survival rates in both groups. RESULTS: The incident rate of lethal portal vein thrombosis in Group II was significantly lower than that observed in Group I (4.4% vs 21.7%, respectively, P = .0363). There were no statistically significant differences observed between the groups with respect to blood loss, survival rates, and other such parameters. CONCLUSION: LDLT concomitant with splenectomy might effectively reduce the occurrence of portal vein complications in adults.

Effect of Middle Hepatic Vein Tributaries Preserving Technique Until Just Before Graft Retrieval on Donors' Surgical Outcomes in Living Donor Liver Transplantation.

BACKGROUND: The technique of preserving the major tributaries of the middle hepatic vein (MHV) (V5 and V8) until just before graft retrieval is beneficial to minimize congestion time of the graft. However, it remains unclear whether this technique exerts a burden on donors in terms of operative time, blood loss, and postoperative hepatic dysfunction. In this study we investigated adverse effects of the MHV tributaries preserving technique until immediately before graft retrieval on donors' surgical outcomes. METHODS: Data from 71 donors who underwent right hepatectomy without MHV for a liver transplantation at our hospital from January 2002 to August 2016 were retrospectively reviewed. Donors were divided into 3 groups as follows: group 1 (n = 12), no MHV tributary reconstruction; group 2 (n = 33), single MHV tributary reconstruction; group 3 (n = 26), 2 or 3 MHV tributaries reconstruction. Donor operation time, blood loss, proportion of the remnant liver, maximum postoperative total bilirubin, aspartate aminotransferase, alanine transaminase, minimum platelets, prothrombin time, albumin level, number of days in hospital from surgery to discharge, and surgical complications were compared. RESULTS: Compared with groups 2 and 3, group 1 exhibited shorter average operational time and less average blood loss, but the difference was not significant. Comparisons of all other factors indicated no significant differences. CONCLUSION: The technique of preserving the major tributaries of the MHV until just immediately before graft retrieval does not appear to impose an apparent burden on donors.

Effects of Subnormothermic Perfusion Before Transplantation for Liver Grafts from Donation After Cardiac Death: A Simplified Dripping Perfusion Method in Pigs.

BACKGROUND: Liver transplantation from donors after cardiac death (DCD) provides a solution to the donor shortage. However, DCD liver grafts are associated with a high incidence of primary graft nonfunction. We investigated the effectiveness of subnormothermic porcine liver perfusion, before transplantation from DCD, on graft viability. METHODS: Landrace pigs (25-30 kg) were randomly allocated to 3 groups (5 per group): heart-beating (HB) graft, transplanted after a 4-hour period of cold storage (CS); DCD graft, retrieved 20 minutes after apnea-induced cardiac arrest (respiratory withdrawal) and transplanted after a 4-hour period of CS; and subnormothermic ex vivo liver perfusion (SELP) graft, retrieved in the same manner as the DCD graft but perfused with a subnormothermic oxygenated Krebs-Henseleit buffer (21-25°C, 10-15 cm H2O) for 30 minutes in a simplified dripping manner, without a machine perfusion system, after the 4-hour period of CS, and subsequently transplanted. RESULTS: Although all animals in the HB group survived for >7 days, all animals in the DCD group died within 12 hours after transplantation. In the SELP group, 2 recipients survived for >7 days and another 2 recipients were killed on day 5. The survival rate was significantly better for SELP than for DCD grafts (P = .0016). The values of tumor necrosis factor α were not significantly different between the SELP and HB groups. Preserved structure of the parenchyma was observed in the SELP group on histologic examination. CONCLUSIONS: A simplified subnormothermic perfusion before liver transplantation is expected to improve graft viability and survival.

Multidisciplinary treatment for a patient with traumatically intruded permanent canine and premolar.

When selecting treatment for traumatically intruded teeth, various factors should be evaluated including the degree of intrusion, pulp vitality, patient's age and maturity of the tooth. Treatment options consist of surgical repositioning, orthodontic extrusion and spontaneous re-eruption. This study describes a case of a 22-year-old male with traumatically intruded maxillary canine and first premolar that was treated comprehensively by an orthodontist, endodontist and prosthodontist two months after injury.

The effect of IL-17 on the production of proinflammatory cytokines and matrix metalloproteinase-1 by human periodontal ligament fibroblasts.

OBJECTIVES: To investigate the effects of IL-17 on IL-6, IL-1ß, and matrix metalloproteinase (MMP-1) production, and to compare the MMP-1 production between the individual and combined effects of IL-1ß and IL-6 in human periodontal ligament fibroblasts (HPDLF). MATERIALS AND METHODS: Human periodontal ligament fibroblasts were cultured with IL-17 for 0.5, 1, 4, 24, 48, and 72 h, and were cultured with IL-1ß, IL-6/sIL-6R, or a combination of IL-1ß and IL-6/sIL-6R for 24 h. To measure the mRNA levels of IL-6, IL-1ß, and MMP-1, total RNA was extracted from the cultured HPDLF, and a real-time PCR analysis was performed. The protein levels of IL-6, IL-1ß, and MMP-1 in supernatants were measured using enzyme-linked immunosorbent assays (ELISAs). RESULTS: IL-17 significantly increased the expression of IL-6 and MMP-1 mRNA and protein, while IL-17 transiently increased the expression of IL-1ß mRNA. The combination of IL-1ß and IL-6/sIL-6R induced significantly higher levels of MMP-1 protein than IL-1ß alone. CONCLUSIONS: IL-17 upregulated the production of IL-6 and MMP-1 sequentially in HPDLF. IL-6/sIL-6R may enhance the effects of IL-1ß on MMP-1 production. The present results suggest that IL-17 induces MMP-1 production not only directly, but also indirectly by promoting IL-6 production, thus resulting in the degradation of collagens in the PDL.

CD103-CD11b+ dendritic cells regulate the sensitivity of CD4 T-cell responses to bacterial flagellin.

Toll-like receptor 5 (TLR5) has been widely studied in an inflammatory context, but the effect of TLR5 on the adaptive response to bacterial flagellin has received considerably less attention. Here, we demonstrate that TLR5 expression by dendritic cells (DCs) allows a 1,000-fold enhancement of T-cell sensitivity to flagellin, and this enhancement did not require the expression of NLRC4 or Myd88. The effect of TLR5 on CD4 T-cell sensitivity was independent of the adjuvant effect of flagellin and TLR5 ligation did not alter the sensitivity of ovalbumin (OVA)-specific T cells to OVA. In the spleen, the exquisite T-cell sensitivity to flagellin was regulated by CD4-CD8α- DCs and was blocked by a monoclonal antibody to TLR5. In the mesenteric lymph nodes, flagellin-specific T-cell activation was regulated by a population of CD103-CD11b+ DCs. Thus, TLR5 expression by mucosal and systemic DC subsets controls the sensitivity of the adaptive immune response to flagellated pathogens.

Adhesion of Streptococci to various orthodontic composite resins.

BACKGROUND: This investigation aimed to determine quantitatively the adhesion of Streptococcus mutans and Streptococcus sobrinus to orthodontic composite resins that were tested simultaneously using radio-markers. METHODS: Seven orthodontic composite resins were classified into seven groups: BeautyOrtho Bond (GI), Blugloo (GII), Enlight (GIII), Grengloo (GIV), Kurasper F (GV), Transbond CC (GVI) and Turbo Bond II (GVII). Thirty 4 x 4 x 1 mm blocks of each orthodontic composite resin were made (a total of 210 blocks). Both Streptococcus species were cultivated independently. For the quantitative analysis, radioactive markers were used to codify the bacteria ((3) H for Streptococcus mutans and (14) C for Streptococcus sobrinus). The blocks were submerged in a solution with microorganisms previously radiolabelled for 2 hours at 37 °C in constant movement. The blocks were placed in a combustion system to quantify the Streptococcus adhering to the surface of the materials by capturing the residues and measuring the radiation. RESULTS: Significant differences in bacterial adhesion were found among the groups. The lowest significant scores for both microorganisms were observed in GIII. CONCLUSIONS: The orthodontic composite resin evaluated in GIII exhibited the lowest adhesion of Streptococcus mutans and Streptococcus sobrinus, which may reduce enamel demineralization and the risk of white spot lesion formation.

Adherence of Streptococcus mutans to orthodontic band cements.

BACKGROUND: The aim of this study was to quantitatively determine the adherence of Streptococcus mutans to orthodontic band cements. METHODS: Two hundred and ten blocks of seven different band cements for orthodontic prescription were made using a Teflon mould (4 × 4 × 1 mm). The obtained blocks were slightly polished and cleansed ultrasonically. Certified S. mutans ATCC 25175 were cultured with conventional methods for growth in Petri dishes and trypticase soy broth. Quantitative analysis was carried out with radioactive markers to codify the bacteria ((3) H). Subsequently, a combustion system was used to capture the residues, the radioactivity of the samples was measured, and the values recorded in disintegrations per minute (dpm). One-way analysis of variance (ANOVA) with a Scheffé test for multiple comparisons was realized with a significance level of ≤0.05. RESULTS: Significant differences were found among different band cement materials (p < 0.001). Two band cement materials showed statistically lower values than the others (Transbond Plus Band Cem and Ketac Cem). In contrast, GC Fuji Ortho Band presented the highest adherence of S. mutans. CONCLUSIONS: Among the cements evaluated, Transbond Plus Band Cem and Ketac Cem showed lower adherence of S. mutans.

Microsomal prostaglandin E synthase-1 is involved in multiple steps of colon carcinogenesis.

Accumulating evidence indicates that cyclooxygenase (COX)-2-derived prostaglandin (PG) E(2) is involved in the development of various tumors, including colorectal cancer. However, the precise contribution of microsomal PGE synthase (mPGES)-1, a terminal enzyme that acts downstream of COX-2 in the PGE(2)-biosynthetic pathway, to multiple processes of tumor development is not yet fully understood. Here, we show the pro-tumorigenic role of mPGES-1 in chemical carcinogen-induced colon carcinogenesis and intrasplenic tumor transplantation models. Genetic deletion of mPGES-1 significantly reduced both the total number and size of colorectal polyps at 18 weeks after azoxymethane administration with reduced nuclear translocation of ß-catenin, altered expression profiles of chemokines/cytokines and increased production of antitumorigenic PGs, prostaglandin D(2) and prostacyclin in tumor tissues. At an early stage (6 weeks), mPGES-1 deficiency significantly reduced the number of aberrant crypt foci, while its transgenic overexpression increased the number. Furthermore, the growth of intrasplenically transplanted tumor cells was suppressed in mPGES-1 knockout (KO) mice. Co-culture of tumor cells with bone marrow-derived macrophages (BM-MΦs) isolated from wild-type (WT) mice resulted in the induction of mPGES-1 in BM-MΦs and increased the growth of tumor cells in vitro, whereas mPGES-1-null BM-MΦs failed to facilitate tumor growth. The adoptive transfer of WT BM-MΦs into mPGES-1 KO mice restored the growth of transplanted tumor cells, indicating that mPGES-1 in MΦs is important for the growth of adjacent tumor cells. Taken together, our findings suggest that the inhibition of mPGES-1 is an alternative therapeutic target for colorectal and possibly other cancers.

Toll-like receptor 4 (TLR4), but not TLR3 or TLR9, knock-out mice have neuroprotective effects against focal cerebral ischemia.

Toll-like receptors (TLRs) are signaling receptors in the innate immune system that is a specific immunologic response to systemic bacterial infection. We investigated whether cerebral ischemia induced by the middle cerebral artery occlusion (MCAO) for 2 h differed in mice that lack a functional TLR3, TLR4, or TLR9 signaling pathway. TLR4, but not TLR3 or TLR9, knock-out (KO) mice had significantly smaller infarct area and volume at 24 h after ischemia-reperfusion (I/R) compared with wild-type mice. In addition, TLR4 KO mice improved in neurological deficits after I/R compared with wild-type mice. Moreover, we investigated the expression of TLR4 in the ischemic brain with immunohistochemistry. The number of TLR4-positive cells gradually increased from 1 h after MCAO to 22 h after I/R. We also examined the localization of TLR4 in the ischemic area. TLR4 was localized with CD11b-positive microglial cells in the ischemic striatum and the number of CD11b-positive microglial cells was smaller in TLR4 KO mice than in wild-type mice. In addition, we investigated the translocation of NF-κB among TLR3, 4, and 9 KO mice after I/R injury using western blotting. NF-κB's p65 subunit was decreased in TLR4 KO mice compared to wild-type mice, but not TLR3 or 9 KO mice. These data suggest that TLR4 knockout, but not TLR3 or TLR9 knockout, may play a neuroprotective role in ischemic brain injury induced by MCAO in mice.

Microsomal prostaglandin E synthase-1 contributes to ischaemic excitotoxicity through prostaglandin E2 EP3 receptors.

BACKGROUND AND PURPOSE: Although microsomal prostaglandin E synthase (mPGES)-1 is known to contribute to stroke injury, the underlying mechanisms remain poorly understood. This study examines the hypothesis that EP(3) receptors contribute to stroke injury as downstream effectors of mPGES-1 neurotoxicity through Rho kinase activation. EXPERIMENTAL APPROACH: We used a glutamate-induced excitotoxicity model in cultured rat and mouse hippocampal slices and a mouse middle cerebral artery occlusion-reperfusion model. Effects of an EP(3) receptor antagonist on neuronal damage in mPGES-1 knockout (KO) mice was compared with that in wild-type (WT) mice. KEY RESULTS: In cultures of rat hippocampal slices, the mRNAs of EP(1-4) receptors were constitutively expressed and only the EP(3) receptor antagonist ONO-AE3-240 attenuated and only the EP(3) receptor agonist ONO-AE-248 augmented glutamate-induced excitotoxicity in CA1 neurons. Hippocampal slices from mPGES-1 KO mice showed less excitotoxicity than those from WT mice and the EP(3) receptor antagonist did not attenuate the excitotoxicity. In transient focal ischaemia models, injection (i.p.) of an EP(3) antagonist reduced infarction, oedema and neurological dysfunction in WT mice, but not in mPGES-1 KO mice, which showed less injury than WT mice. EP(3) receptor agonist-induced augmentation of excitotoxicity in vitro was ameliorated by the Rho kinase inhibitor Y-27632 and Pertussis toxin. The Rho kinase inhibitor HA-1077 also ameliorated stroke injury in vivo. CONCLUSION AND IMPLICATIONS: Activity of mPGES-1 exacerbated stroke injury through EP(3) receptors and activation of Rho kinase and/or G(i). Thus, mPGES-1 and EP(3) receptors may be valuable therapeutic targets for treatment of human stroke.

Microsomal prostaglandin E synthase-1 and cyclooxygenase-2 are both required for ischaemic excitotoxicity.

BACKGROUND AND PURPOSE: Although both microsomal prostaglandin E synthase (mPGES)-1 and cyclooxygenase (COX)-2 are critical factors in stroke injury, but the interactions between these enzymes in the ischaemic brain is still obscure. This study examines the hypothesis that mPGES-1 activity is required for COX-2 to cause neuronal damage in ischaemic injury. EXPERIMENTAL APPROACH: We used a glutamate-induced excitotoxicity model in cultures of rat or mouse hippocampal slices and a mouse middle cerebral artery occlusion-reperfusion model in vivo. The effect of a COX-2 inhibitor on neuronal damage in mPGES-1 knockout (KO) mice was compared with that in wild-type (WT) mice. KEY RESULTS: In rat hippocampal slices, glutamate-induced excitotoxicity, as well as prostaglandin (PG) E(2) production and PGES activation, was significantly attenuated by either MK-886 or NS-398, inhibitors of mPGES-1 and COX-2 respectively; however, co-application of these inhibitors had neither an additive nor a synergistic effect. The protective effect of NS-398 on the excitotoxicity observed in WT slices was completely abolished in mPGES-1 KO slices, which showed less excitotoxicity than WT slices. In the transient focal ischaemia model, mPGES-1 and COX-2 were co-localized in the infarct region of the cortex. Injection of NS-398 reduced not only ischaemic PGE(2) production, but also ischaemic injuries in WT mice, but not in mPGES-1 KO mice, which showed less dysfunction than WT mice. CONCLUSION AND IMPLICATIONS: Microsomal prostaglandin E synthase-1 and COX-2 are co-induced by excess glutamate in ischaemic brain. These enzymes are co-localized and act together to exacerbate stroke injury, by excessive PGE(2) production.

Genetic deletion of mPGES-1 accelerates intestinal tumorigenesis in APC(Min/+) mice.

The induced synthesis of bioactive prostanoids downstream of cyclooxygenase-2 (COX-2) and prostaglandin H(2) (PGH(2)) exerts a critical event in colorectal carcinogenesis. Here we demonstrate that APC(Min/+) mice with genetic deletion of microsomal prostaglandin E synthase-1 (mPGES-1), which catalyses the terminal conversion of PGH(2) into PGE(2), surprisingly develop more and generally larger intestinal tumors than do mPGES-1 wild type littermates (mean number of tumors/intestine 80 vs. 38, p<0.0005, mean tumor diameter 1.64 vs. 1.12 mm, p<0.0005). No deviation regarding the expression of other PGE(2) related enzymes (COX-1, COX-2, mPGES-2, cPGES, and 15-PGDH) or receptors (EP1-4) was obvious among the mPGES-1 deficient mice. PGE(2) levels were suppressed in tumors of mPGES-1 deficient animals, but the concentrations of other PGH(2) derived prostanoids were generally enhanced, being most prominent for TxA(2) and PGD(2). Thus, we hypothesise that a redirected synthesis towards other lipid mediators might (over)compensate for loss of mPGES-1/PGE(2) during intestinal tumorigenesis. Nevertheless, our results question the suitability for mPGES-1 targeting therapy in the treatment or prevention of colorectal cancer.

Change in maximum occlusal force in association with maxillofacial growth.

OBJECTIVE: To clarify the correlation between variations in maximum occlusal force and the maxillofacial skeletal pattern in subjects with malocclusion using a compact device. DESIGN: Three hundred and fifty patients (150 males 200 females) with malocclusion were included. The male and female subjects were divided into five groups each based on chronological age. The maximum occlusal force was measured with a simplified occlusal force meter. The maxillofacial skeletal pattern was analyzed with lateral cephalograms. On the basis of these data, we studied the correlation between the maximum occlusal force and the maxillofacial skeletal pattern in each age group. RESULTS: The maximum occlusal force tended to increase with age, with a tendency to be greater in male than in female subjects. In the male subjects, up to their 20s, the maximum occlusal force continued to increase, while in the female subjects its increase almost terminated in the later teens. In some of the age groups, the maximum occlusal force showed a negative correlation with the mandibular plane angle. CONCLUSIONS: Maximum occlusal force tended to increase with age. There was a gender difference in the maximum occlusal force at all age groups, values being larger in the males. In the males, the maximum occlusal force continued to increase until their 20s, while in the females, this increase almost terminated at the age of 17.

Inorganic polyphosphate: a possible stimulant of bone formation.

Inorganic polyphosphates [Poly(P)] are often distributed in osteoblasts. We undertook the present study to verify the hypothesis that Poly(P) stimulates osteoblasts and facilitates bone formation. The osteoblast-like cell line MC 3T3-E1 was cultured with Poly(P), and gene expression and potential mineralization were evaluated by reverse-transcription polymerase chain-reaction. Alkaline phosphatase activity, von Kossa staining, and resorption pit formation analyses were also determined. The potential role of Poly(P) in bone formation was assessed in a rat alveolar bone regeneration model. Poly(P) induced osteopontin, osteocalcin, collagen 1alpha, and osteoprotegerin expression and increased alkaline phosphatase activity in MC 3T3-E1 cells. Dentin slice pit formation decreased with mouse osteoblast and bone marrow macrophage co-cultivation in the presence of Poly(P). Promotion of alveolar bone regeneration was observed locally in Poly(P)-treated rats. These findings suggest that Poly(P) plays a role in osteoblastic differentiation, activation, and bone mineralization. Thus, local poly(P) delivery may have a therapeutic benefit in periodontal disease.

TLR engagement prevents transplantation tolerance.

In many experimental models, heart, pancreas and kidney allografts are accepted long-term following costimulation-targeting therapies, whereas skin, lung and intestine resist the induction of tolerance under the same regimens. We noted that a common feature of the resistant organs is their constant exposure to commensal microbes and hypothesized that these microorganisms may stimulate Toll-like receptors (TLRs), promote alloresponses and prevent tolerance induction. This hypothesis prompts the predictions that TLR engagement at the time of transplantation should avert tolerance to heart allografts in animals treated with costimulation-targeting therapies, whereas inhibition of TLR signaling should promote tolerance to skin allografts under the same conditions. Indeed, engagement of a single TLR was sufficient to prevent anti-CD154-mediated long-term cardiac allograft acceptance and correlated with abolished intragraft recruitment of CD4+/FoxP3+ regulatory T cells and the development of linked-suppression. Conversely, a lack of donor and recipient MyD88-dependent signaling led to successful skin allograft acceptance in anti-CD154-treated animals. Thus, the status of TLR signaling contributes to the resistance versus susceptibility of organs to transplantation tolerance.

MyD88-dependent pathways mediate resistance to Cryptosporidium parvum infection in mice.

Cryptosporidium spp. cause diarrheal disease worldwide. Innate immune responses mediating resistance to this parasite are not completely understood. To determine whether MyD88-dependent pathways play a role in resistance to Cryptosporidium parvum, we compared the course of infection in MyD88(-/-) mice to that in their wild-type (WT) littermate controls. Three- to 4-week-old mice were infected with C. parvum, and infection was monitored by quantifying fecal oocyst shedding. Twelve days postinfection, the histology of the intestines was examined to quantify intestinal parasite burden and to determine if there were any pathological changes. Fecal oocyst shedding and intestinal parasite burden were significantly greater in MyD88(-/-) mice than in littermate controls. Nonetheless, both WT and MyD88(-/-) mice cleared the infection within 3 weeks. These results indicate that MyD88-dependent pathways are involved in mediating initial resistance to C. parvum. Since gamma interferon (IFN-gamma) is known to mediate resistance to C. parvum, we also studied infection in MyD88(-/-) mice and WT controls in which this cytokine was temporarily neutralized. Fecal oocyst shedding, as well as intestinal parasite burden, intestinal inflammation, and mortality, was significantly greater in MyD88(-/-) mice in which IFN-gamma was neutralized than in IFN-gamma-neutralized WT mice or in MyD88(-/-) mice in which this cytokine was active. These results suggest that MyD88 and IFN-gamma had an additive effect in conferring protection from C. parvum infection. While this study confirms the importance of IFN-gamma in conferring resistance to infection with C. parvum, it suggests that MyD88-mediated pathways also play a role in innate immunity to this parasite.

Regulation of IL-1-induced gingival collagenase gene expression by activator protein-1 (c-Fos/c-Jun).

Matrix metalloproteinase-1 is probably involved in the progression of periodontal disease. The aim of this study was to investigate whether IL-1beta stimulates the expression of the activator protein 1 (AP-1) transcription factor and, consequently, if the AP-1 transcription factor participates in the regulation of collagenase gene expression in human gingival fibroblast cells. In this study, we demonstrate that the concentration of the protein components of AP-1 transcription factor, c-Fos and c-Jun, is enhanced by IL-1beta both at mRNA and protein levels, utilizing Northern blot analysis, electrophoretic mobility gel shift assay and Western blot analysis. The IL-1beta stimulated the collagenase-CAT and AP-1-CAT activities in a dose dependent manner with respect to the amount of DNA used in transfections. Further, overexpression of c-Fos and c-Jun proteins revealed a dose-dependent transcriptional activation of the collagenase promoter. These findings, coupled with the existence of AP-1 consensus DNA binding sites on the collagenase gene promoter, show that regulation of collagenase gene expression by IL-1beta involves the transcription factor AP-1 in gingival fibroblasts.