Interleukin-12 (IL-12)-driven alloimmune responses in vitro and in vivo: requirement for beta1 subunit of the IL-12 receptor.

BACKGROUND: Interleukin-12 (IL-12) mediates its biologic activities via binding high-affinity receptors on T and natural killer cells. Although emphasis has been placed on the requirement for IL-12Rbeta2 in IL-12 bioactivity, the role of IL-12Rbeta1 is less well defined. The current study evaluated the effects of exogenous IL-12 on alloantigen-specific immune responses and determined the requirement for IL-12Rbeta1 in IL-12-mediated alloimmunity. METHODS: The mouse heterotopic cardiac transplant model was employed to evaluate the effects of IL-12 on alloantigen-specific immune responses in vivo. In addition, IFN-gamma production in mixed lymphocyte cultures (MLC) supplemented with IL-12 was measured to assess the effects of IL-12 on Th1 function in vitro. Mice deficient in IL-12Rbeta1 (IL-12Rbeta1-/-) were used to determine the requirement for this receptor component in IL-12-driven alloimmune responses. RESULTS: Addition of IL-12 to MLC consisting of wild-type splenocytes enhanced alloantigen-specific proliferative responses and Th1 development. In contrast, IL-12 did not alter these in vitro immune parameters in IL-12Rbeta1-/- MLC. Treatment of wild-type cardiac allograft recipients with IL-12 resulted in high concentrations of serum interferon-gamma (IFN-gamma) and a 10-fold increase in IFN-gamma production by recipient splenocytes after restimulation in vitro. However, this fulminate Th1 response did not accelerate allograft rejection. Importantly, IL-12 had no effect on serum IFN-gamma or in vivo priming of Thl in IL-12Rbeta1-/- recipients. Finally, administration of IL-12 to WT allograft recipients resulted in a bimodal alloantibody response: antibody production was suppressed at high doses of IL-12, and enhanced at lower doses. CONCLUSIONS: IL-12 markedly enhances alloantigen-specific immune function; however, these exaggerated Th1-driven responses do not culminate in accelerated allograft rejection. Further, these data indicate that IL-12Rbeta1 is essential for the enhancement of both in vitro and in vivo alloimmune responses by exogenous IL-12.     

Semen characteristics in pubertal boys. II. Semen quality in relation to bone age

Semen specimens from 134 pubertal boys were examined and compared to bone age. Normal figures for semen volume, liquefaction, sperm concentration, and morphology were observed between 15 0/12 and 16 0/12 years of bone age. The number of normally motile spermatozoa became standard at 17 0/12 years of bone age. Azoospermia was noted from 13 0/12 to 14 0/12 years of bone age, oligozoospermia from 14 0/12 to 15 0/12, asthenozoospermia from 16 0/12 to 17 0/12, and normospermia from 17 0/12 on.     

Loss of heterozygosity at 7q31.1 and 12p13-12 in advanced prostate cancer

BACKGROUND: Allelic losses on chromosome arms 2q, 3p, 5q, 6q, 7q, 8p, 9p, 10p, 10q, 11p, 11q, 12p, 13q, 16q, 17p, 17q, 18q, and 21q are reportedly associated with progression and/or initiation of prostate cancer. In the present study, we performed a polymerase chain reaction (PCR) analysis of polymorphic microsatellite loci on the human chromosomes 7 and 12p13-12 in prostate cancer tissue to investigate the extent of involvement of these regions, which may contain putative tumor suppressor genes. METHODS: Tissue samples were obtained at autopsy from 17 men who died of hormone-refractory prostate cancer at Chiba University, Japan, and affiliated hospitals between June of 1992 and June of 1995. DNA from normal tumor or metastatic tissue was used as the template for PCR amplification of a set of 16 polymorphic microsatellite loci on human chromosome 7 and 6 loci on the human chromosome region 12p13-12. RESULTS: The frequencies of cases with loss of heterozygosity (LOH) at 7q31.1 were 8% in primary tumor tissue and 11% in metastatic tissue. The frequencies of cases with LOH at 12p13-12 were 12% in primary tumor tissue and 25% in metastatic tumor tissue. CONCLUSIONS: In the present study, the frequencies of LOH at 7q31.1 were lower than in Western patients, suggesting that LOH in this region is not related to progression of prostate cancer in Japanese patients. The frequency of LOH at 12p13-12 was similar to that reported in Western countries, indicating that 12p13-12 may contain a tumor suppressor gene of prostate cancer.     

A combination of preductal aortic coarctation and type B dissection: Report of a case

(Received for publication on Sept. 12, 1996; accepted on May 12, 1997)     

中华眼镜蛇毒膜毒素对人类膀胱癌细胞EJ-m3作用的体外研究

目的 研究中华眼镜蛇毒膜毒素(MT-12)对人膀胱癌细胞株EJ-m3的作用,并探讨其作用机制.方法 以穿透人工基底膜能力为依据筛选具有体外高侵袭能力的膀胱癌细胞;采用四氮唑蓝(MTY)法检测MT-12不同浓度对EJ-m3细胞的生长抑制率;同时流式细胞仪检测不同浓度MT-12作用24h后细胞中趋化因子受体CXCR4的表达.结果 经过反复筛选获得膀胱癌细胞EJ的体外高侵袭力亚系,EJ-m3.MT-12可有效抑制FJ-m3细胞的生长,具有浓度依赖性特点.MT-12对EJ-m3作用72h的ICSO是0.66ug/mL;流式细胞仪检测结果 显示,在0.125～0.5ug/mL,MT-12组随着药物浓度的增加Cx-CR4的表达逐渐减弱(P=0.020).结论 MT-12可有效抑制膀胱癌细胞生长,其作用机制可能与CXCR4在膀胱癌细胞中高表达有关.MT-12有潜力成为新的抗膀胱癌药物.     

Inhibition of RANKL-induced osteoclast formation in mouse bone marrow cells by IL-12: involvement of IFN-gamma possibly induced from non-T cell population

IL-12 was shown to have the potential to inhibit osteoclast formation in mouse bone marrow cells treated with macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-kappaB ligand (RANKL). When bone marrow macrophages (BMM) were used as osteoclast precursors, IL-12 failed to inhibit M-CSF/RANKL-induced osteoclast formation from BMM. In coculture experiments using transwells, IL-12 did inhibit osteoclast formation from BMM cocultured with whole bone marrow cells. These results indicated that IL-12 indirectly affected M-CSF/RANKL-induced osteoclastogenesis in bone marrow cells and that the inhibition of IL-12 on osteoclast formation was caused by a humoral factor from bone marrow cells treated with IL-12. Experiments with anti-interferon (IFN)-gamma antibody and bone marrow cells from IFN-gamma receptor knockout mice revealed that IFN-gamma might be involved in the inhibition of osteoclast formation in this system. The expression of osteoprotegerin mRNA in bone marrow cells was not affected by treatment with IL-12. The inhibitory effect of IL-12 on osteoclast formation was also seen in the T cell-depleted bone marrow cells of normal mice and the whole bone marrow cells of athymic nude mice, while the inhibitory effect of IL-12 was partially suppressed in the B cell-depleted bone marrow cells. The inhibitory effect of IL-12 on M-CSF/RANKL-induced osteoclastogenesis was not accompanied with cell death, in contrast with our previous finding that the inhibitory effect of IL-12 on M-CSF/TNF-alpha-induced osteoclastogenesis is attributable to Fas and FasL-mediated apoptosis.     

Clinical Implication of CXCL12 Expression in Gastric Cancer

PURPOSE: Recent research has revealed that tumor cells expressing chemokine receptors have a crucial impact on patient survival. However, there is no information regarding chemokine expression in gastro-intestinal cancer. This study immunohistochemically investigated CXCL12 expression in gastric cancer and evaluated its association with clinical factors, including patient prognosis. METHOD: A total of 185 gastric cancer patients receiving curative gastrectomy were assessed. CXCL12 expression was evaluated by immunohistochemical analysis. Tumors with CXCL12-positive cancer cells were regarded as CXCL12 positive, and according to the degree of CXCL12 expression, patients were divided into three groups (weak, 31 cases; moderate, 27 cases; strong, 20 cases). Correlations between CXCL12 expression and clinical factors in gastric cancer were then determined. RESULTS: CXCL12 was found in the cellular membrane of cancer cells. Seventy-four of 185 patients were classified into the CXCL12-positive group. Patients were divided into three groups according to the positivity of CXCL12 expression. Significant associations between CXCL12 and lymph node metastases (p < 0.05), depth of invasion (p < 0.01), lymphatic invasion (p < 0.01), tumor diameter (p < 0.05), and clinical stage (p < 0.01) were seen. Univariate analysis revealed that the CXCL12-positive group had significantly poorer surgical outcome than the CXCL12-negative group (p < 0.01). Multivariate analysis revealed CXCL12 to be an independent prognostic factor in gastric cancer (p = 0.02). CONCLUSION: Cancerous CXCL12 positivity was determined to be an independent prognostic factor in gastric cancer, with CXCL12-positive gastric cancer showing more-aggressive behavior. Autocrine CXCL12 secretion from tumor cells may activate CXCR-4 on the tumor cells, which may be related to of the viability of distant metastases.     

Association between metformin and vitamin B12 deficiency in patients with type 2 diabetes

Diabetes mellitus (DM) is still one of the most common diseases worldwide, and its prevalence is still increasing globally. According to the American and European recommendations, metformin is considered a first-line oral hypo-glycemic drug for controlling type 2 DM (T2DM) patients. Metformin is the ninth most often prescribed drug in the world, and at least 120 million diabetic people are estimated to receive the drug. In the last 20 years, there has been increasing evidence of vitamin B12 deficiency among metformin-treated diabetic patients. Many studies have reported that vitamin B12 deficiency is related to the ma-labsorption of vitamin B12 among metformin-treated T2DM patients. Vitamin B12 deficiency may have a very bad complication for the T2DM patient. In this review, we will focus on the effect of metformin on the absorption of vitamin B12 and on its proposed mechanisms in hindering vitamin B12 absorption. In addition, the review will describe the clinical outcomes of vitamin B12 deficiency in metformin-treated T2DM.     

IL-12 cDNA direct injection: antimetastatic effect from a single injection in a murine hepatic metastases model

BACKGROUND: Interleukin 12 (IL-12) gene therapy is an effective antitumor agent in local and metastatic murine tumor models. We sought to evaluate the antimetastatic effect of IL-12 cDNA in a liver metastases model. MATERIALS AND METHODS: A liver metastases model was induced by creating a "primary" splenic tumor through inoculation of 1 x 10(5) TS/A adenocarcinoma cells directly into the inferior pole of the spleen in female BALB/c mice. On day 4, 50 microg of IL-12 cDNA or control plasmid DNA was injected into splenic tumor, followed by splenectomy on day 8. Mice were sacrificed on day 25 to assess liver tumor burden. IL-12 mRNA and mIL-12 and IFN-gamma protein levels were assessed after IL-12 injection. Peripheral blood CD4+, CD8+, and NK cells were quantified on day 14 using FACS. To determine the significance of site of cytokine DNA injection, IL-12 cDNA was injected on day 4 into splenic tumor or into the non-involved spleen after isolation of the inferior and superior portions of the spleen, respectively, with surgical clips. Splenectomy was performed on day 8 and sacrifice was performed on day 25. RESULTS: IL-12 mRNA was detected in the liver 8 h after injection, with a peak at 24 h. After splenic injection, protein levels of IL-12 and IFN-gamma were detectable in the liver and spleen 24 h after treatment. IL-12 and IFN-gamma were not detectable in control animals. In the peripheral blood, there was a marked increase in NK cells (13% of total lymphocytes versus 4%, control) and in the CD4+/CD8+ ratio (5.5 versus 1.9). At day 25, there was a marked antimetastatic effect after IL-12 injection into either splenic tumor [liver:body weight, 6.2 versus 10.9 (control), P = 0.007] or non-involved spleen (6.8 g versus 10.7 g, P = 0.005). There was no difference in the antimetastatic effect between animals injected into splenic tumor or non-involved spleen (P = 0.3). CONCLUSION: Injection with a single dose of IL-12 cDNA into splenic tumor or non-involved spleen resulted in a profound antimetastatic effect. Splenic IL-12 injection results in mRNA expression in the liver, protein expression in the liver and spleen, and a marked increase in NK cells and the CD4+/CD8+ ratio in peripheral blood.     

Flux entre modalités de traitement de l’IRCT

This chapter provides indicators to describe the outcome of prevalent and incident patients in the various modalities of treatment.Among the 36 849 patients on dialysis at 31/10/2010, 79% were already on RRT at 31/12/2009. Respectively 91%, 85% and 93% of the patients on HD in-center, HD self-care unit and peritoneal dialysis were in the same modality of treatment the year before. Among the 29 758 patients with a functioning graft at 31/12/2010, 98% were already on RRT at 31/12/2009, 95% of them with a functioning graft.72%, 72% and 74% of the patients with in-center HD, outcenter HD and self-care unit were in the same modality of treatment at 31/12/2011. But 37% of the patients on PD at 31/12/2010 were not on PD at 31/12/2011.In 2011, new patients represented 89% of the entries in peritoneal dialysis. Renal transplantation represented 10% of the outcomes of the HD patients in self-care unit or at home.     

ADAM12-S stimulates bone growth in transgenic mice by modulating chondrocyte proliferation and maturation.

ADAM12-S transgenic mice exhibit a pronounced increase in the length of bones, such as femur, tibia, and vertebrae. The effect of ADAM12-S on longitudinal bone growth involves the modulation of chondrocyte proliferation and maturation, likely through proteolytic activities and altered cell-extracellular matrix interactions in the growth plate. INTRODUCTION: The disintegrin and metalloprotease ADAM12 is expressed in both osteoblasts and osteoclasts, suggesting a regulatory role of ADAM12 in bone. However, thus far, no in vivo function of ADAM12 in the skeleton has been reported. MATERIALS AND METHODS: Transgenic mice expressing the secreted form of human ADAM12, ADAM12-S, or a truncated metalloprotease-deficient form of ADAM12-S in the circulation were used to study the effects of ADAM12 on the skeleton. In addition, murine chondrocyte cultures were used to study the effect of ADAM12-S on cell-extracellular matrix interactions. RESULTS: ADAM12-S transgenic mice exhibit increased longitudinal bone growth. The increased bone length is progressive and age dependent, with a maximum increase of 17% seen in the femur from 6-month-old transgenic mice. The effect is gene dose dependent, being more pronounced in mice expressing higher levels of the transgene than in a lower-expressing line. Histological analysis revealed no alterations in the growth plate organization, but mean growth plate width was increased. Both the cellular incorporation of bromodeoxyuridine and the width of the collagen type X-positive hypertrophic zone were increased in the growth plate of ADAM12-S transgenic mice. Importantly, mice expressing a truncated form of ADAM12-S that lacked the pro- and metalloprotease domains showed no alterations in bone length, suggesting that protease activity is required for the ADAM12-S effect. In vitro studies showed that ADAM12-S inhibits chondrocyte adhesion to fibronectin and collagen type II. CONCLUSIONS: ADAM12-S stimulates bone growth in mice by modulating chondrocyte proliferation and maturation through mechanisms probably involving both metalloprotease and adhesion activities.     

钙黏蛋白12在结肠癌细胞株与结肠直肠癌组织中的表达及其影响

目的：研究钙黏蛋白12（cadherin-12,CDH-12）在结肠癌细胞株与结肠直肠癌组织中的表达及其对结肠癌细胞株增殖、侵袭、迁移的影响。方法：应用实时PCR和Western印迹法在7株结肠癌细胞株中筛选CDH-12高表达细胞株;shRNA瞬转干扰高表达细胞株SW1116,Western印迹法验证干扰效果;CCK-8检测癌细胞增殖活性变化;transwell实验验证癌细胞迁移、侵袭能力的变化;组织芯片免疫组织化学技术检测CDH-12在结肠直肠癌组织中的表达。结果：实时PCR和Western印迹结果显示CDH-12在细胞株中表达,SW1116和LoVo两个细胞株高表达CDH-12,在成功下调SW1116细胞中CDH-12表达之后,SW1116结肠癌细胞株的增殖、迁移、侵袭能力较对照组明显下降;免疫组化染色结果显示,CDH-12在结肠直肠癌组织中的表达明显高于癌旁正常组织中的表达。结论：CDH-12在结肠直肠癌组织中的表达明显高于癌旁正常组织,证实了CDH-12为癌基因的可能性;下调CDH-12在结肠癌细胞株SW1116的表达可明显抑制细胞的增殖、迁移、侵袭能力,显示其在肿瘤细胞生长和转移中的重要作用。     

白细胞介素-12基因修饰对树突状细胞表面分子表达及细胞因子分泌的影响

目的 观察白细胞介素(IL)-12基因修饰对树突状细胞(DC)表面分子及细胞因子分泌的影响.方法 采用重组逆转录病毒介导IL-12基因修饰人外周血单个核细胞(PBMC)来源的Dc;ELISA法检测各组DCs和各组T细胞上清中IL-12、IL-10、IFN-γ因子的分泌水平;流式细胞仪(FACS)分析各组DC表面CD83、CD86的表达;MTT法检测DC刺激同源T淋巴细胞增殖的能力;统计学分析比较各组间的差异.结果 IL-12基因修饰使得DC高表达CD83和CD86分子,分泌高水平IL-12及IFN-γ,但对IL-10因子的分泌无明显影响,刺激同源T淋巴细胞增殖明显,诱导激活的T细胞上清中IFN-γ水平显著增高、IL-10分泌水平显著降低.结论 经IL-12基因修饰后的DC表型成熟,分泌IL-12及IFN-γ的能力增强,对IL-10因子的分泌无影响,能抑制T细胞分泌IL-10因子,优化抗原提呈的微环境.     

The effects of recombinant human bone morphogenetic protein-2, recombinant human bone morphogenetic protein-12, and adenoviral bone morphogenetic protein-12 on matrix synthesis in human annulus fibrosis and nucleus pulposus cells

BACKGROUND CONTEXT: Bone morphogenetic proteins (BMPs) are potential therapeutic factors for degenerative discs, and BMP-12 does not have the osteogenic potential of BMP-2, making it better suited for intradiscal injection. However, no reports have compared the actions of BMP-2 and -12 on human annulus fibrosus (AF) and nucleus pulposus (NP) cells nor evaluated adenoviral-mediated gene therapy in human AF cells. PURPOSE: To evaluate and compare the effects of recombinant human (rh) BMP-2, rhBMP-12, and adenoviral BMP-12 (Ad-BMP-12) on nucleus pulposus and annulus fibrosis cell matrix protein synthesis. STUDY DESIGN: In vitro study using rhBMP-2 and -12 and adenoviral BMP-12 with human intervertebral disc (IVD) cells. METHODS: Human NP and AF IVD cells were isolated, maintained in monolayer, and incubated with BMP-2 or -12 for 2 days. AF and NP cells were transduced with Ad-BMP-12, pellets formed, and incubated for 6 days. Growth factor-treated cells were labelled with either 35-S or 3H-proline to assay matrix protein synthesis. RESULTS: rhBMP-2 increased NP proteoglycan, collagen, and noncollagen protein synthesis to 355%, 388%, and 234% of control. RhBMP-12 increased the same NP matrix proteins' synthesis to 140%, 143%, and 160% of control. Effects on AF matrix protein synthesis were minimal. Ad-BMP-12 significantly increased matrix protein synthesis and DNA content of AF and NP cells in pellet culture. NP synthesis of all matrix proteins and AF synthesis of proteoglycans was increased when the data were normalized to pellet DNA. AF synthesis of noncollagen protein and collagen was not modulated by Ad-BMP-12 if the data are normalized to pellet DNA content. CONCLUSIONS: Both rhBMP-2 and -12 increase human NP cell matrix protein synthesis while having minimal effects on AF cells. However, Ad-BMP-12 did increase matrix protein synthesis in both NP and AF cells, making it a potential therapy for enhancing matrix production in the IVD. These responses plus the proliferative action of Ad-BMP-12 seen in the current studies, and the lack of an osteogenic action noted in other studies justifies future studies to determine if gene therapy with BMP-12 could provide protective and/or reparative actions in degenerating discs.     

丙泊酚对布比卡因诱导的PC12细胞毒性、活性氧和过氧化氢酶的影响

目的探讨丙泊酚对布比卡因诱导的PC12细胞毒性的保护作用及活性氧(ROS)和过氧化氢酶(CAT)在其中的作用。方法培养的PC12细胞分成四组:正常对照组(C组);丙泊酚组(P组),在细胞培养基中加入2mmol/L丙泊酚;布比卡因组(B组),在细胞培养基中加入0.09mmol/L布比卡因;丙泊酚加布比卡因组(PB组),在细胞培养基中同时加入2mmol/L丙泊酚和0.09mmol/L布比卡因;每组6孔。培养6h和24h后,用倒置相差显微镜观察细胞形态、MTT比色微量分析细胞活性,测定上清液乳酸脱氢酶(LDH)活性和细胞内CAT、ROS活性。结果与C组相比,B组PC12细胞活性和细胞内CAT活性显著降低(P<0.01),LDH活性和细胞内ROS活性显著增加(P<0.01);P组PC12细胞活性及其它指标无显著变化;与B组相比,PB组PC12细胞活性和细胞内CAT活性显著增加(P<0.05),LDH活性和细胞内ROS活性显著降低(P<0.01)。结论布比卡因对PC12细胞具有毒性作用,可能与降低细胞内CAT活性、增加ROS活性有关;丙泊酚通过保护细胞内CAT活性和清除ROS而减轻布比卡因诱导的PC12细胞毒性。     

The effect of vitamin B12 supplement on post-thaw motility,viability and DNA damage of human sperm

Sperm cryopreservation may lead to adverse effects on sperm structure and function. Cyanocobalamin (vitamin B12) has antioxidant potential and can protect DNA from free radical-induced damages. Recent studies have shown that vitamin B12 preserves glutathione that leads to modulate oxidative stress responses. Also, vitamin B12 might act directly as a scavenger of ROS. The aim of this study was to investigate the effects of vitamin B12 supplementation on human sperm parameters during the cryopreservation process. Thirty semen samples were obtained from normozoospermic men. Using cryopreservation medium supplemented with different concentrations of vitamin B12 (0, 0.5, 1, 2, 2.5 mg/ml), the semen samples were cryopreserved. After thawing, all samples were evaluated for motility and viability. Based on results, 2 mg/ml was considered as the optimal concentration of vitamin B12 for evaluating sperm DNA fragmentation. The results showed that 1 and 2 mg/ml vitamin B12 significantly increased post-thawing motility and viability compared with the 0 mg/ml vitamin B12 (p < .05). Also, by supplementing with 2 mg/ml vitamin B12, DNA fragmentation decreased when compared to the control. The present study showed that cryopreservation medium supplemented with vitamin B12 at 2 mg/ml could improve sperm quality after freeze–thaw process.     

大鼠诱发肝癌模型中脾内转染IL-2和IL-12基因激活NK细胞

目的研究大鼠诱发肝癌模型中脾内直接注射携带白介素2（IL-2）和（或）白介素12（IL-12）基因的逆转录病毒包装细胞株对血IL-2和IL-12,以及NK细胞活性的影响.方法大鼠随即分为生理盐水对照组、空载体对照组、IL-12基因治疗组、IL-2基因治疗组及IL-2/IL-12联合基因治疗组.构建携带IL-2和（或）IL-12基因的逆转录病毒载体.口服二乙基亚硝胺诱癌后,含IL-2和（或）IL-12基因的包装细胞转染脾细胞.比较大鼠血IL-2和IL-12浓度、NK细胞活性、病理变化和毒性反应.结果IL基因治疗后血IL-2和IL-12明显增加.联合基因组同时表达IL-2和IL-12,总水平高于单基因治疗组.病理示治疗后肝癌组织中淋巴细胞浸润明显增多.IL治疗组NK细胞活性较对照组显著增高（P＜0.01）.联合基因组较IL单基因增高（P＜0.05）.治疗后3 d血清IL达高峰,以后逐步下降.结论脾内直接注射携带IL-2和（或）IL-12基因的逆转录包装细胞株可明显增强NK细胞活性,IL联合基因治疗优于IL单基因.     

骶髂关节不同固定方式对骶部影响的生物力学研究

背景:长节段固定治疗腰椎退变性侧凸取得了良好的矫形效果.目前对于骶髂关节不同固定方式对骶部影响的生物力学研究尚少..目的:研究骶髂关节不同固定方式对S1螺钉应力分布的影响,为腰椎退变性手术方式的选择提供依据.方法:抽取6具成人新鲜尸体按照三种不同固定方式分成T12-S1组(T12-S1固定)、T12-S2组(T12-S...     

Matrix metalloproteinase-12 (MMP-12) in osteoclasts: new lesson on the involvement of MMPs in bone resorption

Osteoclasts require matrix metalloproteinase (MMP) activity and cathepsin K to resorb bone, but the critical MMP has not been identified. Osteoclasts express MMP-9 and MMP-14, which do not appear limiting for resorption, and the expression of additional MMPs is not clear. MMP-12, also called metalloelastase, is reported only in a few cells, including tissue macrophages and hypertrophic chondrocytes. MMP-12 is critical for invasion and destruction in pathologies such as aneurysm and emphysema. In the present study, we demonstrate that osteoclasts express MMP-12, although only in some situations. Northern blots show that highly purified rabbit osteoclasts in culture express MMP-12 at the same level as macrophages, whereas in situ hybridizations performed on rabbit bone do not show any MMP-12 expression in osteoclasts whatever the bone type. In contrast, in situ hybridizations performed on mouse bone show MMP-12 expression in osteoclasts in calvariae and long bones. We also demonstrate that recombinant MMP-12 cleaves the putative functional domains of osteopontin and bone sialoprotein, two bone matrix proteins that strongly influence osteoclast activities, such as attachment, spreading and resorption. Furthermore, we investigated the role of MMP-12 in bone resorption and osteoclast recruitment by comparing MMP-12 knockout and wild-type mice in specialized culture models known to depend on MMP activity, as well as in the ovariectomy model, and we did not find any indication for a limiting role of MMP-12 in these processes. In conclusion, we found that osteoclasts are able to express MMP-12, but MMP-12 did not appear critical for osteoclast recruitment or resorption. The fact that none of the MMPs identified so far in osteoclasts appears limiting for resorption, gives strength to the hypothesis that the critical MMP for bone solubilization is produced by non-osteoclastic cells.     

Evidence from a large U.K. family collection that genes influencing age of onset of type 2 diabetes map to chromosome 12p and to the MODY3/NIDDM2 locus on 12q24

Additional information on genetic susceptibility effects relevant to type 2 diabetes pathogenesis can be extracted from existing genome scans by extending examination to related phenotypes such as age at disease onset. In this study, we report the reanalysis of data from 573 U.K. sibships ascertained for multiplex type 2 diabetes, using age at onset (assessed by the proxy measure of age at diagnosis) as the phenotype of interest. Genome-wide evidence for linkage to age at diagnosis was evaluated using both variance components and Haseman-Elston (HECOM) regression approaches, with extensive simulations to derive empirical significance values. There was broad agreement across analyses with six regions of interest (logarithm of odds [LOD] >/==" BORDER="0">1.18) identified on chromosomes 1qter, 4p15-4q12, 5p15, 12p13-12q13, 12q24, and 14q12-14q21. The strongest empirically "suggestive" evidence for linkage comes from regions on chromosome 12. The first region (12p13-12q13), peaking at D12S310 (variance components LOD [LOD(VC)] = 2.08, empirical pointwise P = 0.0007; HECOM LOD [LOD(HECOM)] = 2.58, P = 0.0010) seems to be novel. The second (12q24) peaking between D12S324 and D12S1659 (LOD(VC) = 1.87, P = 0.0016; LOD(HECOM) = 1.93, P = 0.0027) overlaps a region showing substantial prior evidence for diabetes linkage. These data provide additional evidence that genes mapping to these chromosomal regions are involved in the susceptibility to, and/or development of, type 2 diabetes.