The retinal environment induces microglia-like properties in recruited myeloid cells.

BACKGROUND: Microglia are essential to the development of the CNS and its homeostasis. Our prior findings suggested a niche model to describe the behaviors of retinal microglia. Here, we ask whether new myeloid cells recruited to the retina are constrained to resemble endogenous microglia morphologically and functionally. METHODS: Use of CD11cDTR/GFP transgenic mouse allowed identification of two niches of retinal microglia distinguished by being GFPlo or GFPhi. We also used transgenic mice in which CX3CR1+ cells expressed YFP and were depletable following tamoxifen-induced expression of diphtheria toxin subunit A. We employed several ablation and injury stimulation protocols to examine the origin and fate of myeloid cells repopulating the retina. Analysis of retinal myeloid cells was done by microscopy, flow cytometry, and qRT-PCR. RESULTS: We found that the origin of new GFPhi and GFPlo myeloid cells in the retina of CD11cDTR/GFP mice, whether recruited or local, depended on the ablation and stimulation protocols. Regardless of origin, new GFPlo and GFPhi retinal myeloid cells were CD45medCD11b+Ly6G-Ly6CloIba1+F4/80+, similar to endogenous microglia. Following tamoxifen-induced diphtheria toxin ablation, myeloid cell repopulation differed in the retina compared to the brain and optic nerve. Stimulation of replacement GFPhi cells was substantially attenuated in repopulating retinas after tamoxifen-induced diphtheria toxin ablation compared to control or radiation-ablated mice. In radiation bone marrow chimeric mice, replacement GFPhi myeloid cells from the circulation were slow to repopulate the retina unless stimulated by an optic nerve crush injury. However, once stimulated, recruited GFPhi cells were found to concentrate on injured retinal ganglion cells and were morphologically similar to GFPhi cells in non-ablated control CD11cDTR/GFP mice. CONCLUSIONS: The results support the idea that GFPhi cells in the CD11cDTR/GFP mouse, whether recruited or from resident microglia, mark a unique niche of activated retinal myeloid cells. We conclude that the retinal environment has a potent influence on the function, morphology, and proliferative capacity of new myeloid cells regardless of their origin, compelling them to be equivalent to the endogenous microglia.

Retinal dendritic cell recruitment, but not function, was inhibited in MyD88 and TRIF deficient mice.

BACKGROUND: Immune system cells are known to affect loss of neurons due to injury or disease. Recruitment of immune cells following retinal/CNS injury has been shown to affect the health and survival of neurons in several models. We detected close, physical contact between dendritic cells and retinal ganglion cells following an optic nerve crush, and sought to understand the underlying mechanisms. METHODS: CD11c-DTR/GFP mice producing a chimeric protein of diphtheria toxin receptor (DTR) and GFP from a transgenic CD11c promoter were used in conjunction with mice deficient in MyD88 and/or TRIF. Retinal ganglion cell injury was induced by an optic nerve crush, and the resulting interactions of the GFPhi cells and retinal ganglion cells were examined. RESULTS: Recruitment of GFPhi dendritic cells to the retina was significantly compromised in MyD88 and TRIF knockout mice. GFPhi dendritic cells played a significant role in clearing fluorescent-labeled retinal ganglion cells post-injury in the CD11c-DTR/GFP mice. In the TRIF and MyD88 deficient mice, the resting level of GFPhi dendritic cells was lower, and their influx was reduced following the optic nerve crush injury. The reduction in GFPhi dendritic cell numbers led to their replacement in the uptake of fluorescent-labeled debris by GFPlo microglia/macrophages. Depletion of GFPhi dendritic cells by treatment with diphtheria toxin also led to their displacement by GFPlo microglia/macrophages, which then assumed close contact with the injured neurons. CONCLUSIONS: The contribution of recruited cells to the injury response was substantial, and regulated by MyD88 and TRIF. However, the presence of these adaptor proteins was not required for interaction with neurons, or the phagocytosis of debris. The data suggested a two-niche model in which resident microglia were maintained at a constant level post-optic nerve crush, while the injury-stimulated recruitment of dendritic cells and macrophages led to their transient appearance in numbers equivalent to or greater than the resident microglia.

Local activation of dendritic cells alters the pathogenesis of autoimmune disease in the retina.

Interest in the identities, properties, functions, and origins of local APC in CNS tissues is growing. We recently reported that dendritic cells (DC) distinct from microglia were present in quiescent retina and rapidly responded to injured neurons. In this study, the disease-promoting and regulatory contributions of these APC in experimental autoimmune uveoretinitis (EAU) were examined. Local delivery of purified, exogenous DC or monocytes from bone marrow substantially increased the incidence and severity of EAU induced by adoptive transfer of activated, autoreactive CD4 or CD8 T cells that was limited to the manipulated eye. In vitro assays of APC activity of DC from quiescent retina showed that they promoted generation of Foxp3(+) T cells and inhibited activation of naive T cells by splenic DC and Ag. Conversely, in vitro assays of DC purified from injured retina demonstrated an enhanced ability to activate T cells and reduced induction of Foxp3(+) T cells. These findings were supported by the observation that in situ activation of DC before adoptive transfer of ß-galactosidase-specific T cells dramatically increased severity and incidence of EAU. Recruitment of T cells into retina by local delivery of Ag in vivo showed that quiescent retina promoted development of parenchymal Foxp3(+) T cells, but assays of preinjured retina did not. Together, these results demonstrated that local conditions in the retina determined APC function and affected the pathogenesis of EAU by both CD4 and CD8 T cells.

Peripheral induction of tolerance by retinal antigen expression.

The contribution of peripheral expression of tissue-specific CNS Ags to the generation of tolerance is uncertain. To study this question, we examined mice transgenic (Tg) for expression of beta-galactosidase (beta gal) on the retinal photoreceptor cell arrestin promoter, in conjunction with TCR Tg mice producing CD4(+) T cells specific for beta gal (beta galTCR). Several strategies were used to test the hypothesis that betagal expressed in the retina supported thymus-independent tolerance and regulatory T cell development. Retinal expression generated an immunoregulatory response that depressed development of immune responses to beta gal following systemic immunization with beta gal. This regulation was transferable to naive mice by CD3(+)4(+)25(+) T cells from naive retinal beta gal(+) donors. Experiments that removed the beta gal(+) retina by enucleation showed that subsequent development of a regulatory response was lost. Adoptive transfer of CD25(-) beta galTCR T cells into retinal beta gal Tg mice on the Rag(-/-) background led to regulatory activity that limited lymphopenia-induced proliferation of beta galTCR T cells in mice with retinal expression of beta gal and inhibited the ear-swelling assay for delayed type hypersensitivity. These results show that retinal expression of very small amounts of a tissue-specific Ag can generate tolerance that includes regulatory T cells.

SH3TC2, a protein mutant in Charcot-Marie-Tooth neuropathy, links peripheral nerve myelination to endosomal recycling.

Patients with Charcot-Marie-Tooth neuropathy and gene targeting in mice revealed an essential role for the SH3TC2 gene in peripheral nerve myelination. SH3TC2 expression is restricted to Schwann cells in the peripheral nervous system, and the gene product, SH3TC2, localizes to the perinuclear recycling compartment. Here, we show that SH3TC2 interacts with the small guanosine triphosphatase Rab11, which is known to regulate the recycling of internalized membranes and receptors back to the cell surface. Results of protein binding studies and transferrin receptor trafficking are in line with a role of SH3TC2 as a Rab11 effector molecule. Consistent with a function of Rab11 in Schwann cell myelination, SH3TC2 mutations that cause neuropathy disrupt the SH3TC2/Rab11 interaction, and forced expression of dominant negative Rab11 strongly impairs myelin formation in vitro. Our data indicate that the SH3TC2/Rab11 interaction is relevant for peripheral nerve pathophysiology and place endosomal recycling on the list of cellular mechanisms involved in Schwann cell myelination.

Dendritic cells are early responders to retinal injury.

The presence and activity of dendritic cells (DC) in retina is controversial, as these cells are difficult to identify in retina due to limited markers and sparse numbers. Transgenic mice that express green fluorescent protein (GFP) on the CD11c promoter to label DC allowed the visualization and quantification of retinal DC. Two retina injury models, the optic nerve crush (ONC) and light injury, were used to study their injury response. Many GFP(+) DC were tightly associated with retinal ganglion cell nerve fibers following ONC, while very few microglia (GFP(-)CD11b(+) cells) were found in close contact. The GFP(+) cells were greatly elevated in the outer plexiform layer following photic injury. All of the GFP(+) DC were CD11b(+), suggesting a myeloid origin. In addition, the GFP(+) DC upregulated expression of MHC class II after injury, while the GFP(-)CD11b(+) microglia did not. This study shows that DC were found in the retina and that they rapidly responded to neural injuries. We propose that they are a previously overlooked population, distinct from microglia, and may be important in the injury response.

Pioglitazone in addition to metformin improves erythrocyte deformability in patients with Type 2 diabetes mellitus.

The aim of the present study was to compare the effect of PIO (pioglitazone) or GLIM (glimepiride) on erythrocyte deformability in T2DM (Type 2 diabetes mellitus). The study covered 23 metformin-treated T2DM patients with an HbA1c (glycated haemoglobin) >6.5%. Patients were randomized to receive either PIO (15 mg, twice a day) or GLIM (1 mg, twice a day) in combination with metformin (850 mg, twice a day) for 6 months. Blood samples were taken for the measurement of fasting glucose, HbA1c, fasting insulin, intact proinsulin, adiponectin and Hct (haematocrit). In addition, the erythrocyte EI (elongation index) was measured using laser diffractoscopy. Both treatments significantly improved HbA1c levels (PIO, -0.9+/-1.1%; GLIM, -0.6+/-0.4%; both P<0.05) and resulted in comparable HbA1c levels after 6 months (PIO, 6.5+/-1.2%; GLIM, 6.2+/-0.4%) Treatment with PIO reduced fasting insulin levels (-8.7+/-15.8 milli-units/l; P=0.098), intact proinsulin levels (-11.8+/-9.5 pmol/l; P<0.05) and Hct (-1.3+/-2.3%; P=0.09), whereas adiponectin levels increased (8.2+/-4.9 microg/ml; P<0.05). No significant change in these parameters was observed during GLIM treatment. PIO improved the EI, resulting in a significant increase in EI at all physiological shear stress ranges (0.6-6.0 Pa; P<0.05). The improvement in EI correlated with the increase in adiponectin levels (r=0.74; P<0.001), and inversely with intact proinsulin levels (r=-0.47; P<0.05). This is the first study showing an improvement in EI during treatment with PIO, which was associated with an increase in adiponectin and a decrease in intact proinsulin levels, but independent of glycaemic control.

If the antibody fails--a mass western approach.

SUMMARY: Sucrose-phosphate synthase (SPS) has attracted the interest of plant scientists for decades. It is the key enzyme in sucrose metabolism and is under investigation in various plant species, e.g. spinach, tobacco, poplar, resurrection plants, maize, rice, kiwi and Arabidopsis thaliana. In A. thaliana, there are four distinct SPS isoforms. Their expression is thought to depend on environmental conditions and plant tissue. However, these data were derived from mRNA expression levels only. No data on SPS protein identification from crude extracts have been available until now. An antibody approach failed to distinguish the four isoforms. Therefore, we developed a method for SPS quantification and isoform-specific identification in A. thaliana complex protein samples. Samples were separated on SDS-PAGE, digested and directly applied to liquid chromatography/triple-stage quadrupole mass spectrometry (LC/TSQ-MS). In this approach, known as mass Western, samples were analysed in multi-reaction monitoring (MRM) mode, so that all four SPS isoforms could be measured in one experiment. In addition to the relative quantification, stable isotope-labelled internal peptide standards allowed absolute quantification of SPS proteins. Protein extracts from various plant tissues, samples harvested during the day or the night, and cold-stressed plants were analysed. The stress-specific SPS5a isoform showed increased concentrations in cold-stressed leaf material.

Investigation of the vascular and pleiotropic effects of atorvastatin and pioglitazone in a population at high cardiovascular risk.

We investigated the effect of atorvastatin monotherapy and combined treatment with atorvastatin and pioglitazone on intima-media thickness, vascular function and the cardiovascular risk profile. In all, 148 patients (76 male, 72 female; aged 61.4+/-6.5 years; body mass index [BMI] 29.2+/-4.1 kg/m2; mean +/- SD) with increased cardiovascular (CV) risk factors were randomised. Intima-media thickness (IMT), the augmentation index (Aix@75), the microvascular response to acetylcholine (LDF), lipid status, and plasma levels of intact proinsulin, adiponectin, interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), sCD40L, P-selectin, tissue plasminogen activator (t-PA) and blood lipids were monitored over six months. Atorvastatin treatment, alone and in combination with pioglitazone, revealed a significant regression in IMT (0.923+/-0.013 to 0.874+/-0.012 mm and 0.921+/-0.015 to 0.882+/-0.015 mm; mean +/- SEM; p<0.05 respectively) and Aix@75 (27.3+/-1.2 to 25.9+/-1.4; and 25.6+/-1.4 to 24.8+/-1.7%; p<0.05). The endothelial response to acetylcholine as measured by laser Doppler fluximetry (LDF) improved during combined treatment (373+/-57 to 576+/-153 AU; p<0.05). Addition of pioglitazone to atorva-statin resulted in significant further effects on high-sensitivity C-reactive protein (hsCRP), t-PA, P-selectin, adiponectin, triglycerides and high-density lipoprotein (HDL) cholesterol (p<0.05 respectively). Atorvastatin significantly improved IMT and vascular elasticity. Co-administration of pioglitazone provided additional effects on endothelial function, lipid profile and laboratory markers of inflammation.

Evidence for extrathymic generation of regulatory T cells specific for a retinal antigen.

BACKGROUND: Thymic expression of a photoreceptor cell antigen, interphotoreceptor retinoid-binding protein, is known to generate regulatory T cells (T(reg)) that prevent spontaneous autoimmune disease of the retina. However, the contribution of other endogenous, tissue-specific antigens (Ags) expressed in the retina to the generation of T(reg) is uncertain. METHODS: Transgenic mice that express beta-galactosidase (beta-gal) in photoreceptor cells, together with beta-gal-specific T cell receptor transgenic mice, were used to study the induction of T(reg) in vivo. RESULTS: Transgenic expression of beta-gal on the arrestin promoter led to a spontaneous immunoregulatory response that inhibited the development of immune responses to beta-gal. The regulation was transferred by CD3+4+25+ T(reg). Several strategies were then used to show that beta-gal expressed in the retina supported spontaneous, thymus-independent T(reg) development. The endogenous T(reg) also differed from the T(reg) induced by Ag inoculation into the anterior chamber of the eye. CONCLUSION: These results demonstrate that retinal expression of very small amounts of a tissue-specific Ag can generate T(reg) in the periphery.

Determinants governing the potency of STAT3 activation via the individual STAT3-recruiting motifs of gp130.

In recent years, the elucidation of the structures of many signalling molecules has allowed new insights into the molecular mechanisms that govern signal transduction events. In the field of cytokine signalling, the solved structures of cytokine/receptor complexes and of key components involved in signal transduction such as STAT factors or the tyrosine phosphatase SHP2 have broadened our understanding of the molecular basis of the signalling events and provided key information for the rational design of therapeutic approaches to modulate or block cytokine signal transduction. Unfortunately, no structural data on the intracellular parts of cytokine receptors are available. The exact molecular mechanism underlying one of the first steps in signal transduction, namely the recruitment of signalling components to the cytoplasmic parts of cytokine receptors, remains elusive. Here we investigated possible mechanisms underlying the different potency of the STAT3-activating motifs of gp130 after IL-6 stimulation. Our data indicate that the extent of STAT3 activation by the different receptor motifs is not influenced by structural features such as contacts between the two gp130 chains. In addition, the proximity of the negatively regulating motif around tyrosine Y759 to the different STAT3-recruiting motifs does not seem to be responsible for their differential capacity to activate STAT3. However, the potency of a specific motif to activate STAT3 directly reflects the affinity for the binding of STAT3 to this motif.

The tyrosine 974 within the LIF-R-chain of the gp130/LIF-R heteromeric receptor complex mediates negative regulation of LIF signalling.

Signalling of interleukin (IL)-6 and interleukin-11 through gp130 homodimeric receptor complexes has been analysed with respect to initiation and termination of signalling in great detail. Gp130 contains a crucial motif around tyrosine Y759, which mediates negative regulation through the feedback inhibitor SOCS3 and the protein tyrosine phosphatase SHP2. Signalling of leukaemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF), cardiotrophin-1 (CT-1), CT-1-like factor (CLC) or oncostatin M (OSM) through gp130/LIF-R is believed to be similar due to the presence of the common signal transducer gp130 within the receptor complexes utilized, but the difference in the composition of gp130/gp130-homodimers and gp130/LIF-R-heterodimers is likely to be reflected in different signalling. Here, we analysed the contribution of the LIF-R within the gp130/LIF-R complex to negative regulation mediated by SHP2 and SOCS3. We show that SHP2 contributes to the negative regulation of signalling through gp130/LIF-R complexes. The inhibitory tyrosine motifs within the cytoplasmic parts of gp130 and the LIF-R act independently. Whereas SHP2 and SOCS3 bind directly to the inhibitory motif of gp130, only SHP2 was found to bind to the corresponding inhibitory sequence of the LIF-R. This observation was further corroborated by experiments indicating that mainly gp130 contributes to the inhibition of signalling by SOCS3.

The role of the inhibitors of interleukin-6 signal transduction SHP2 and SOCS3 for desensitization of interleukin-6 signalling.

The immediate early response of cells treated with IL-6 (interleukin-6) is the activation of the signal transducer and activator of transcription (STAT)3. The Src homology domain 2 (SH2)-containing protein tyrosine phosphatase SHP2 and the feedback inhibitor SOCS3 (suppressor of cytokine signalling) are potent inhibitors of IL-6 signal transduction. Impaired function of SOCS3 or SHP2 leads to enhanced and prolonged IL-6 signalling. The inhibitory function of both proteins depends on their recruitment to the tyrosine motif 759 within glycoprotein gp130. In contrast to inactivation, desensitization of signal transduction is regarded as impaired responsiveness due to prestimulation. Usually, after activation the sensing receptor becomes inactivated by modifications such as phosphorylation, internalization or degradation. We designed an experimental approach which allows discrimination between desensitization and inactivation of IL-6 signal transduction. We observed that pre-stimulation with IL-6 renders cells less sensitive to further stimulation with IL-6. After several hours, the cells become sensitive again. We show that not only signal transduction through previously activated receptors is affected by desensitization but signalling through receptors which were not targeted by the first stimulation was also attenuated ( trans -desensitization). Interestingly, in contrast to inhibition, desensitization does not depend on the presence of functional SHP2. Furthermore, cells lacking SOCS3 show constitutive STAT3 activation which is not affected by pre-stimulation with IL-6. All these observations suggest that desensitization and inhibition of signalling are mechanistically distinct.

[Conversion to tapentadol PR improves analgesia and quality of life in patients with severe and chronic pain despite using tramadol > 300 mg/d]. / Konsekutive Umstellung auf Tapentadol PR verbessert Analgesie und Lebensqualität bei Patienten mit starken und chronischen Schmerzen unter Tramadol > 300 mg/d.

STUDY OBJECTIVE: This subgroup analysis of a non-interventional study involving general practitioners and internists investigated the administration of tapentadol PR (prolonged release) in patients with widely-utilized tramadol pretreatment in routine clinical practice in Germany. METHODS: Data of all patients in the study cohort who had tramadol as the only opioid in their previous therapy were included in the analysis (n = 685); among them especially the 99 patients with tramadol dosages exceeding 300 mg/d were focused. Data collection during the 3-month observation period included previous and concomitant analgesic treatment, tapentadol PR dosage, pain intensity, sleep and quality of life parameters, and tolerability of tapentadol PR. RESULTS: Back pain was the most common cause of pain (n = 86/99), other pain diagnoses were (partly additionally) recorded in 68 cases. A mixed type of pain dominated. The previous tramadol therapy was usually combined with non-opioids (n = 74), co-analgesics (n = 44) and analgesic rescue medication (n = 35). Tapentadol PR therapy reduced the mean initial pain intensity of 7.3 ± 1.5 to 3.1 ± 1.8 points (NRS-11, 11-point pain scale, n = 96) at the end of observation, using an average dosage of 218.7 mg/d. Tapentadol PR was finally applied as the sole analgesic in 32/95 patients. 69/96 patients achieved a clinically meaningful pain relief of at least 50 %, while 63 patients gained a pain reduction of ≥ 4 NRS-points. 89/95 patients reached or exceeded their additional individual treatment goal. This was accompanied by a significant decrease in pain-related impairments of daily activities and an improvement in quality of life with an overall good tolerability of tapentadol PR. Treatment with tapentadol PR was assessed positively by physicians and patients. CONCLUSIONS: Data analysis shows a clinically relevant benefit in patients unsuccessfully pretreated with tramadol by consecutive conversion to the potent analgesic tapentadol PR.

Immunoproteasome deficiency protects in the retina after optic nerve crush.

The immunoproteasome is upregulated by disease, oxidative stress, and inflammatory cytokines, suggesting an expanded role for the immunoproteasome in stress signaling that goes beyond its canonical role in generating peptides for antigen presentation. The signaling pathways that are regulated by the immunoproteasome remain elusive. However, previous studies suggest a role for the immunoproteasome in the regulation of PTEN and NF-κB signaling. One well-known pathway upstream of NF-κB and downstream of PTEN is the Akt signaling pathway, which is responsible for mediating cellular survival and is modulated after optic nerve crush (ONC). This study investigated the role of retinal immunoproteasome after injury induced by ONC, focusing on the Akt cell survival pathway. Retinas or retinal pigment epithelial (RPE) cells from wild type (WT) and knockout (KO) mice lacking either one (LMP2) or two (LMP7 and MECL-1) catalytic subunits of the immunoproteasome were utilized in this study. We show that mRNA and protein levels of the immunoproteasome subunits are significantly upregulated in WT retinas following ONC. Mice lacking the immunoproteasome subunits show either a delayed or dampened apoptotic response as well as altered Akt signaling, compared to WT mice after ONC. Treatment of the RPE cells with insulin growth factor-1 (IGF-1) to stimulate Akt signaling confirmed that the immunoproteasome modulates this pathway, and most likely modulates parallel pathways as well. This study links the inducible expression of the immunoproteasome following retinal injury to Akt signaling, which is important in many disease pathways.

Palladium-catalyzed cross-coupling reactions between dihydropyranylindium reagents and aryl halides. synthesis of C-aryl glycals.

[reaction: see text] Palladium(0)-catalyzed cross-coupling reactions between tris(dihydropyranyl)indium 1 and aryl halides 2 have been investigated. Aryl iodides and electron-deficient aryl bromides couple efficiently with the in situ-generated indium reagents in the presence of 1-5 mol % Cl(2)Pd(PPh(3))(2) to produce substituted dihydropyrans 3 with minimal (<10%) dimer (4) formation. Organoindium reagents derived from D-glucal also undergo cross couplings with aryl iodides to produce C-aryl glycals.

PIOfix-study: effects of pioglitazone/metformin fixed combination in comparison with a combination of metformin with glimepiride on diabetic dyslipidemia.

OBJECTIVE: Dyslipidemia in patients with type 2 diabetes is characterized by elevated triglyceride levels, decreased high-density lipoprotein (HDL) cholesterol, and a predominance of small dense low-density lipoprotein (LDL) particles. Also, patients suffer from ß-cell dysfunction, chronic systemic inflammation, increased hormonal visceral adipose tissue activity, and an increased risk of cardiovascular events. The aim of our study was to investigate the effect of a fixed pioglitazone + metformin (PM) combination (vs. glimepiride + metformin [GM]) on diabetic dyslipidemia. RESEARCH DESIGN AND METHODS: A total of 288 type 2 diabetes patients completed this double-blind parallel study (187 men, 101 women; age [mean ± SD], 59 ± 10 years; body mass index, 32.6 ± 5.1 kg/m(2); hemoglobin A1c [HbA1c], 7.3 ± 0.8%). They were randomized to PM or GM for 6 months. Observation parameters at baseline and end point included HDL, LDL, triglycerides, fasting insulin, fasting glucose, total adiponectin, intact proinsulin, and high-sensitivity C-reactive peptide (hsCRP). RESULTS: HDL increased in the PM group by 0.08 ± 0.25 mmol/L (GM, -0.01 ± 0.2.8 mmol/L; P < 0.001 vs. PM), whereas LDL increased in both groups (GM, 0.25 ± 0.90 mmol/L; PM, 0.29 ± 0.66 mmol/L; difference not significant between groups). Improvements were seen for triglycerides (PM, -0.47 ± 1.30; GM, -0.19 ± 1.39 mmol/L), HbA1c (PM, -0.8 ± 0.9%; GM, -1.0 ± 0.9%), and glucose (PM, -1.2 ± 2.1; GM, -1.2 ± 2.2 mmol/L). Decreases in fasting insulin (PM, -5.2 ± 11.9; GM, -0.1 ± 9.8 µU/mL; P < 0.001 between groups), hsCRP (PM, -0.9 ± 1.9; GM, 0.0 ± 1.8 mg/L; P < 0.001), and fasting intact proinsulin (PM, -5.5 ± 11.1; GM, -0.1 ± 10.0 pmol/L; P < 0.001) and an increase in adiponectin (PM, +6.8 ± 6.4 mg/L; GM, +0.7 ± 2.7 mg/L; P < 0.001) were seen in the PM arm, only. CONCLUSIONS: With comparable glycemic control, the fixed PM combination was more efficacious on HDL cholesterol improvement than the GM combination. Additional positive effects were observed for biomarkers of lipid metabolism, ß-cell function, activity of the visceral adipose tissue, and chronic systemic inflammation.

The fixed combination of pioglitazone and metformin improves biomarkers of platelet function and chronic inflammation in type 2 diabetes patients: results from the PIOfix study.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is characterized by a proinflammatory and procoagulant condition. This study investigates the impact of a pioglitazone plus metformin therapy on biomarkers of inflammation and platelet activation in comparison to a treatment with glimepiride plus metformin. METHODS: The study was designed as a multicenter, randomized, double-blinded two-arm trial. Patients with T2DM and dyslipidemia under metformin monotherapy with hemoglobin A1c value between 6.5% and 9.0% were eligible for trial participation. Blood was drawn at baseline and after 24 weeks of treatment from patients of five centers. Markers of inflammation and thrombocyte function (soluble CD40 ligand, thromboxane, vWillebrand factor, adhesion molecules, clotting reaction) were evaluated subsequently in a central laboratory. RESULTS: A total of 46 patients were included in the final analyses. Mean (± standard deviation) age was 58.5 ± 9.0 years (13 women, 33 men; disease duration 6.3 ± 5.0 years; body mass index 32.0 ± 4.8 kg/m(2)). A total of 25 patients were treated with pioglitazone plus metformin, and 21 patients were in the glimepiride arm. There was a significant decline of E-selectin (-3.7 ± 4.8 ng/ml, p < .001 versus baseline), vWillebrand factor (-19.5 ± 32.0%, p < .05), and high-sensitivity C-reactive protein concentrations (-1.08 ± 0.91 mg/liter, p < .05) in the metformin + pioglitazone arm only (metformin + glimepiride, -0.5 ± 3.4 ng/ml, +1.4 ± 33.2%, + 0.08 ± 0.72 mg/liter, respectively, all not significant). Also, all other surrogate markers for platelet function and inflammation showed slight improvements in the metformin + pioglitazone arm but not in the metformin + glimepiride arm. CONCLUSIONS: The fixed metformin + pioglitazone combination treatment showed an overall improvement of laboratory surrogate markers, indicating improvement of platelet function and of chronic systemic inflammation, which was not seen with metformin + glimepiride.

Limitations of the HOMA-B score for assessment of beta-cell functionality in interventional trials-results from the PIOglim study.

BACKGROUND: Drugs with unspecific stimulating effects on beta-cell secretion increase the homeostasis model assessment (HOMA)-B score, indicating improved beta-cell "function." We investigated whether the beta-cell protection provided by adding pioglitazone (PIO) to glimepiride (GLIM) in comparison to up-titrating the GLIM dose alone is reflected by appropriate changes in several measures of beta-cell function, including HOMA-B score. METHODS: This double-blind, parallel prospective 6-month study was performed with 82 patients (47 men, 35 women; age, 61 +/- 9 years; duration of disease, 5.3 +/- 4.4 years; body mass index, 32.6 +/- 6.0 kg/m(2); hemoglobin A1c [HbA1c], 7.3 +/- 0.7%) with GLIM monotherapy (1-3 mg). They were randomized to receive a GLIM + PIO combination with up-titration (2 mg + 30 mg/4 mg + 30 mg/4 mg + 4 mg) or to remain on GLIM (up-titration 4/5/6 mg). Observation parameters determined at baseline and end point included HOMA-B, HOMA-IR, HbA1c, glucose, insulin, and intact proinsulin. RESULTS: There was a slight increase in the HOMA-B score in the GLIM group but not in the GLIM + PIO arm (baseline/end point: for GLIM, 71 +/- 48/88 +/- 64; for PIO + GLIM, 74 +/- 56/69 +/- 52). Improvements in the other observation parameters were predominantly detected in the PIO + GLIM group (HbA1c, 7.20 +/- 0.61%/6.36 +/- 0.90%; HOMA-IR, 7.0 +/- 4.5/4.1 +/- 2.1; intact proinsulin, 12.4 +/- 10.3/7.6 +/- 4.8 pmol/L [all P < 0.05 vs. baseline]) compared with the GLIM group (HbA1c, 7.45 +/- 0.69%/7.15 +/- 0.97% [P < 0.05]; HOMA-IR, 7.4 +/- 4.5/7.5 +/- 4.3 [not significant]; intact proinsulin, 17.3 +/- 21.6/16.3 +/- 15.5 pmol/L [not significant]). CONCLUSIONS: The PIO + GLIM combination led to overall improvement of laboratory biomarkers for beta-cell function, except for HOMA-B. Glimepiride up-titration had no such effects but increased the HOMA-B score. HOMA-B seems to provide misleading results when used as a diagnostic tool in patients treated with sulfonylurea drugs. A corrective term for consideration of proinsulin in the HOMA-B equation may address this limitation.

Leuprorelin acetate every-3-months depot versus cyclophosphamide, methotrexate, and fluorouracil as adjuvant treatment in premenopausal patients with node-positive breast cancer: the TABLE study.

PURPOSE: Ovarian suppression with luteinizing hormone-releasing hormone (LHRH) agonists is an effective adjuvant treatment for premenopausal women with estrogen receptor (ER) -positive breast cancer. Whereas monthly LHRH agonist therapy has been well established, the value of every-3-months (3-monthly) formulations is unclear. PATIENTS AND METHODS: This randomized phase III trial was performed to compare the 3-monthly depot LHRH agonist leuprorelin acetate (LAD-3M; n = 299) and chemotherapy with cyclophosphamide, methotrexate, and fluorouracil (CMF; n = 300) in pre- or perimenopausal patients with ER-positive, node-positive breast cancer. RESULTS: With a median follow-up of 5.8 years, recurrence-free survival was similar for patients treated with LAD-3M or CMF (hazard ratio [HR], 1.19; 95% CI, 0.94 to 1.51; P = .15). There was no substantial heterogeneity in the relative treatment effect among subgroups defined by age, progesterone receptor (PR) status, nodal status, hormone levels, or menstrual recovery after treatment. Exploratory overall survival analysis favored LAD-3M (HR, 1.50; 95% CI, 1.13 to 1.99; P = .005). Chemotherapy-related adverse effects such as nausea, vomiting, and alopecia were more common with CMF, whereas symptoms of estrogen suppression such as hot flushes and sweating were initially more pronounced with LAD-3M. CONCLUSION: The 3-monthly depot LHRH-agonist leuprorelin acetate is an effective adjuvant treatment in premenopausal patients with hormone receptor-positive, node-positive breast cancer that is not inferior to CMF.