Understanding the experiences of long-term maintenance of self-worth in persons with type 2 diabetes in Japan: a qualitative study.

OBJECTIVE: Persons with type 2 diabetes are often stigmatised for having what is considered a lifestyle-related disease. Accordingly, some blame themselves for their condition, resulting in feelings of low self-worth that ultimately impact their self-management behaviours. However, there are no studies examining why some do not blame themselves for their condition and manage to maintain their self-worth in relation to their illness. This study aimed to explore an understanding of how such persons experience the maintenance of self-worth in relation to their illness over the lifelong course of treatment. DESIGN: A cross-sectional qualitative study. Face-to-face semistructured interviews were conducted with a purposive sampling strategy. The data was analysed using a qualitative descriptive method that involved concurrent data collection and constant comparative analysis. SETTING: Two tertiary-level hospitals in Japan. PARTICIPANTS: Thirty-three outpatients with type 2 diabetes who currently had good glycaemic control but had previously had poor glycaemic control. RESULTS: Three themes explaining the maintenance of self-worth were identified: (1) Participants gained 'control' over their illness by living a 'normal life.' They found a way to eat preferred foods, dine out with family and friends, travel and work as usual; (2) Participants discovered the positive aspects of type 2 diabetes, as they felt 'healthier' from the treatment and felt a sense of security and gratitude for the care they received from healthcare professionals; (3) Participants discovered a new sense of self-worth by moving towards goals for type 2 diabetes treatment and experienced inner growth through positive lifestyle choices. CONCLUSIONS: The process of restoring and maintaining self-worth should be brought to the attention of healthcare professionals in diabetes care. These professionals could help patients discover positive self-representations through diabetes treatment (eg, a realisation that one does not lack self-control) and could aid in increasing patient engagement in diabetes self-management.

Histochemical examination on principal collagen fibers in periodontal ligaments of ascorbic acid-deficient ODS-od/od rats.

In this study, we aimed to clarify the role of ascorbic acid in collagen synthesis in periodontal ligaments using osteogenic disorder Shionogi (ODS)/ShiJcl-od/od rats lacking L-gulonolactone oxidase. These rats cannot synthesize ascorbic acid in vivo. Eight-week-old ODS/ShiJcl-od/od male rats were administered ascorbic acid solution at a concentration of 200 mg/dL (control group, n = 6) or ascorbic acid solution at concentration of 0.3 mg/dL (insufficient group, n = 12). Six rats of the insufficient group were then given with ascorbic acid solution at concentration of 200 mg/dL for additional 3 weeks (rescued group, n = 6), and then, their mandibles were histochemically examined. Consequently, the insufficient group specimens were seen to possess fewer collagen fibers, and silver impregnation revealed numerous fine, reticular fiber-like fibrils branching off from collagen in the periodontal ligaments. In control group, faint immunoreactivities for matrix metalloproteinase (MMP)2 and cathepsin H were seen in the periphery of blood vessels and throughout the ligament, respectively. In contrast, in the insufficient group, intense MMP2-immunoreactivity was observed to be associated with collagen fibrils in the periodontal ligaments, and cathepsin H-immunopositivity was seen in ligamentous cells. The rescued group showed abundant collagen fibers filling the periodontal ligament space. Under transmission electron microscopy, ligamentous fibroblasts incorporated collagen fibrils into tubular endosomes/lysosomes while simultaneously synthesizing collagen fibril bundles. Thus, ascorbic acid insufficiency affected the immunolocalization of cathepsin H and MMP2; however, ligamentous fibroblasts appear to possess the potential to synthesize collagen fibers when supplied with ascorbic acid.

The RNA Methyltransferase Complex of WTAP, METTL3, and METTL14 Regulates Mitotic Clonal Expansion in Adipogenesis.

Adipocyte differentiation is regulated by various mechanisms, of which mitotic clonal expansion (MCE) is a key step. Although this process is known to be regulated by cell cycle modulators, the precise mechanism remains unclear. N6-Methyladenosine (m6A) posttranscriptional RNA modification, whose methylation and demethylation are performed by respective enzyme molecules, has recently been suggested to be involved in the regulation of adipogenesis. Here, we show that an RNA N6-adenosine methyltransferase complex consisting of Wilms' tumor 1-associating protein (WTAP), methyltransferase like 3 (METTL3), and METTL14 positively controls adipogenesis by promoting cell cycle transition in MCE during adipogenesis. WTAP, coupled with METTL3 and METTL14, is increased and distributed in nucleus by the induction of adipogenesis dependently on RNA in vitro Knockdown of each of these three proteins leads to cell cycle arrest and impaired adipogenesis associated with suppression of cyclin A2 upregulation during MCE, whose knockdown also impairs adipogenesis. Consistent with this, Wtap heterozygous knockout mice are protected from diet-induced obesity with smaller size and number of adipocytes, leading to improved insulin sensitivity. These data provide a mechanism for adipogenesis through the WTAP-METTL3-METTL14 complex and a potential strategy for treatment of obesity and associated disorders.

Willingness of patients with diabetes to use an ICT-based self-management tool: a cross-sectional study.

OBJECTIVES: To examine the prevalence of the willingness of patients with diabetes to use a self-management tool based on information and communication technology (ICT) such as personal computers, smartphones, and mobile phones; and to examine the patient characteristics associated with that willingness. RESEARCH DESIGN AND METHODS: We conducted a cross-sectional interview survey of 312 adults with diabetes at a university hospital in an urban area in Japan. Participants were classified into 2 groups: those who were willing to use an ICT-based self-management tool and those who were unwilling. Multiple logistic regression analysis was used to identify factors associated with the willingness, including clinical and social factors, current use of ICT, self-management practices, self-efficacy, and diabetes-related emotional distress. RESULTS: The mean age of the 312 participants was 66.3 years (SD=11.5) and 198 (63%) were male. Most of the participants (93%) had type 2 diabetes. Although only 51 (16%) currently used ICT-based self-management tools, a total of 157 (50%) expressed the willingness to use such a tool. Factors associated with the willingness included: not having nephropathy (OR=2.02, 95% CI 1.14 to 3.58); outpatient visits once a month or more (vs less than once a month, OR=2.13, 95% CI 1.13 to 3.99); current use of personal computers and/or smartphones (OR=4.91, 95% CI 2.69 to 8.98); and having greater diabetes-related emotional distress (OR=1.10, 95% CI 1.01 to 1.20). CONCLUSIONS: Approximately half of the patients showed interest in using an ICT-based self-management tool. Willing patients may expect ICT-based self-management tools to complement outpatient visits and to make self-management easier. Starting with patients who display the willingness factors might optimize programs based on such tools.

Repeated bouts of fast eccentric contraction produce sciatic nerve damage in rats.

INTRODUCTION: We evaluated sciatic nerve impairment after eccentric contractions (ECs) in rat triceps surae. METHODS: Wistar rats were randomly assigned to different joint angular velocity: 180°/s (FAST), 30°/s (SLOW), or nontreated control (CNT). FAST and SLOW groups were subjected to multiple (1-4) bouts of 20 (5 reps, 4 sets) ECs. Nerve conduction velocity (NCV) and isometric tetanic ankle torque were measured 24 h after each ECs bout. We also assessed nerve morphology. RESULTS: After 4 ECs bouts, NCVs and isometric torque in the FAST group were significantly lower than those in the CNT (NCV: 42%, torque: 66%; P < 0.05). After 4 bouts, average nerve diameter was significantly smaller in the FAST group [2.39 ± 0.20 µm vs. 2.69 ± 0.20 µm (CNT) and 2.93 ± 0.24 µm (SLOW); P < 0.05] than that in other two groups. CONCLUSIONS: Chronic ECs with high angular velocity induce serious nerve damage. Muscle Nerve 54: 936-942, 2016.

[Thiazolidine, thiazolidinediones, TZD].

In addition to a good efficacy to lower blood glucose without hypoglycemia, thiazolidinediones(TZDs) have been proved to have the effects to increase plasma adiponectin, and actually decrease the cardiovascular events in several randomized clinical trials, while some adverse effects have also been demonstrated such as increase of heart failure and born fracture, and fear of bladder cancer. Since TZDs could intervene the pathogenesis of adipocytes' hypertrophy and inflammation in adipose tissue, atherosclerotic lesions and liver by modulating PPARγ of adipocytes and macrophages, TZDs are still considered at the special position among other diabetic drugs, and require further evidence for their efficacy and safety.

Morphological assessment of bone mineralization in tibial metaphyses of ascorbic acid-deficient ODS rats.

Osteogenic disorder shionogi (ODS) rats carry a hereditary defect in ascorbic acid synthesis, mimicking human scurvy when fed with an ascorbic acid-deficient (aa-def) diet. As aa-def ODS rats were shown to feature disordered bone formation, we have examined the bone mineralization in this rat model. A fibrous tissue layer surrounding the trabeculae of tibial metaphyses was found in aa-def ODS rats, and this layer showed intense alkaline phosphatase activity and proliferating cell nuclear antigen-immunopositivity. Many osteoblasts detached from the bone surfaces and were characterized by round-shaped rough endoplasmic reticulum (rER), suggesting accumulation of malformed collagen inside the rER. Accordingly, fine, fragile fibrillar collagenous structures without evident striation were found in aa-def bones, which may result from misassembling of the triple helices of collagenous α-chains. Despite a marked reduction in bone formation, ascorbic acid deprivation seemed to have no effect on mineralization: while reduced in number, normal matrix vesicles and mineralized nodules could be seen in aa-def bones. Fine needle-like mineral crystals extended from these mineralized nodules, and were apparently bound to collagenous fibrillar structures. In summary, collagen mineralization seems unaffected by ascorbic acid deficiency in spite of the fine, fragile collagenous fibrils identified in the bones of our animal model.

Adiponectin enhances insulin sensitivity by increasing hepatic IRS-2 expression via a macrophage-derived IL-6-dependent pathway.

Insulin resistance is often associated with impeded insulin signaling due either to decreased concentrations or functional modifications of crucial signaling molecules including insulin receptor substrates (IRS) in the liver. Many actions of adiponectin, a well-recognized antidiabetic adipokine, are currently attributed to the activation of two critical molecules downstream of AdipoR1 and R2: AMP-activated kinase (AMPK) and peroxisome proliferator-activated receptor α (PPARα). However, the direct effects of adiponectin on insulin signaling molecules remain poorly understood. We show here that adiponectin upregulates IRS-2 through activation of signal transducer and activator of transcription-3 (STAT3). Surprisingly, this activation is associated with IL-6 production from macrophages induced by adiponectin through NFκB activation independent of its authentic receptors, AdipoR1 and AdipoR2. These data have unraveled an insulin-sensitizing action initiated by adiponectin leading to upregulation of hepatic IRS-2 via an IL-6 dependent pathway through a still unidentified adiponectin receptor.

Mechanism of HSV infection through soluble adapter-mediated virus bridging to the EGF receptor.

Herpes simplex virus entry into cells requires the binding of envelope glycoprotein D (gD) to an entry receptor. Depending on the cell, entry occurs by different mechanisms, including fusion at the cell surface or endocytosis. Here we examined the entry mechanism through a non-HSV receptor mediated by a soluble bi-specific adapter protein composed of recognition elements for gD and the EGF receptor (EGFR). Virus entered into endosomes using either EGF or an EGFR-specific single chain antibody (scFv) for receptor recognition. Infection was less efficient with the EGF adapter which could be attributed to its weaker binding to a viral gD. Infection mediated by the scFv adapter was pH sensitive, indicating that gD-EGFR bridging alone was insufficient for capsid release from endosomes. We also show that the scFv adapter enhanced infection of EGFR-expressing tumor tissue in vivo. Our results indicate that adapters may retarget HSV infection without drastically changing the entry mechanism.

Blockade of class IB phosphoinositide-3 kinase ameliorates obesity-induced inflammation and insulin resistance.

Obesity and insulin resistance, the key features of metabolic syndrome, are closely associated with a state of chronic, low-grade inflammation characterized by abnormal macrophage infiltration into adipose tissues. Although it has been reported that chemokines promote leukocyte migration by activating class IB phosphoinositide-3 kinase (PI3Kγ) in inflammatory states, little is known about the role of PI3Kγ in obesity-induced macrophage infiltration into tissues, systemic inflammation, and the development of insulin resistance. In the present study, we used murine models of both diet-induced and genetically induced obesity to examine the role of PI3Kγ in the accumulation of tissue macrophages and the development of obesity-induced insulin resistance. Mice lacking p110γ (Pik3cg(-/-)), the catalytic subunit of PI3Kγ, exhibited improved systemic insulin sensitivity with enhanced insulin signaling in the tissues of obese animals. In adipose tissues and livers of obese Pik3cg(-/-) mice, the numbers of infiltrated proinflammatory macrophages were markedly reduced, leading to suppression of inflammatory reactions in these tissues. Furthermore, bone marrow-specific deletion and pharmacological blockade of PI3Kγ also ameliorated obesity-induced macrophage infiltration and insulin resistance. These data suggest that PI3Kγ plays a crucial role in the development of both obesity-induced inflammation and systemic insulin resistance and that PI3Kγ can be a therapeutic target for type 2 diabetes.

Structure analysis of membrane-reconstituted subunit c-ring of E. coli H+-ATP synthase by solid-state NMR.

The subunit c-ring of H(+)-ATP synthase (F(o) c-ring) plays an essential role in the proton translocation across a membrane driven by the electrochemical potential. To understand its structure and function, we have carried out solid-state NMR analysis under magic-angle sample spinning. The uniformly [(13)C, (15)N]-labeled F(o) c from E. coli (EF(o) c) was reconstituted into lipid membranes as oligomers. Its high resolution two- and three-dimensional spectra were obtained, and the (13)C and (15)N signals were assigned. The obtained chemical shifts suggested that EF(o) c takes on a hairpin-type helix-loop-helix structure in membranes as in an organic solution. The results on the magnetization transfer between the EF(o) c and deuterated lipids indicated that Ile55, Ala62, Gly69 and F76 were lined up on the outer surface of the oligomer. This is in good agreement with the cross-linking results previously reported by Fillingame and his colleagues. This agreement reveals that the reconstituted EF(o) c oligomer takes on a ring structure similar to the intact one in vivo. On the other hand, analysis of the (13)C nuclei distance of [3-(13)C]Ala24 and [4-(13)C]Asp61 in the F(o) c-ring did not agree with the model structures proposed for the EF(o) c-decamer and dodecamer. Interestingly, the carboxyl group of the essential Asp61 in the membrane-embedded EF(o) c-ring turned out to be protonated as COOH even at neutral pH. The hydrophobic surface of the EF(o) c-ring carries relatively short side chains in its central region, which may allow soft and smooth interactions with the hydrocarbon chains of lipids in the liquid-crystalline state.

Warfarin administration disrupts the assembly of mineralized nodules in the osteoid.

This study aimed to elucidate the ultrastructural role of Gla proteins in bone mineralization by means of a warfarin-administration model. Thirty-six 4-week-old male F344 rats received warfarin (warfarin group) or distilled water (control group), and were fixed after 4, 8 and 12 weeks with an aldehyde solution. Tibiae and femora were employed for histochemical analyses of alkaline phosphatase, osteocalcin and tartrate-resistant acid phosphatase, and for bone histomorphometry and electron microscopy. After 4, 8 and 12 weeks, there were no marked histochemical and histomorphometrical differences between control and warfarin groups. However, osteocalcin immunoreactivity was markedly reduced in the warfarin-administered bone. Mineralized nodules and globular assembly of crystalline particles were seen in the control osteoid. Alternatively, warfarin administration resulted in crystalline particles being dispersed throughout the osteoid without forming mineralized nodules. Immunoelectron microscopy unveiled lower osteocalcin content in the warfarin-administered osteoid, which featured scattered crystalline particles, whereas osteocalcin was abundant on the normally mineralized nodules in the control osteoid. In summary, Gla proteins appear to play a pivotal role in the assembly of mineralized nodules.

Characteristic morphology and distribution of bone marrow derived cells in the cornea.

Enhanced green fluorescence protein (eGFP)-labeled bone marrow (BM) cells were transplanted into syngeneic C57BL/6 (wild-type) mice to investigate the distribution pattern, immunohistochemical characteristics, three-dimensional structure, and ultrastructure of the BM-derived cells in the mouse cornea using a fluorescence microscope, a confocal laser scanning microscope, and a transmission electron microscope. This study provided direct evidence that two morphologically distinct types of BM-derived cells were distributed in the mouse cornea. The majority of the GFP+ cells showed a flattened polygonal form with obtuse angles and these cells were distributed in the corneal stroma. The other type was the GFP+ cells demonstrating slim cell bodies with long and extremely thin dendrites and which were distributed in the corneal epithelium. The immunohistochemical characteristics and ultrastructure of BM-derived cells suggest that most of these cells have a macrophage lineage, whereas some cells in the corneal stroma do not. Interestingly, the direct intimate contact between GFP-labeled BM derived cells and non-GFP-labeled resident cells within the corneal stroma were also clearly visualized at the fine structural level. These data provide new and more detailed insight into the nature of BM-derived cells in the cornea.

Vitamin K2, a gamma-carboxylating factor of gla-proteins, normalizes the bone crystal nucleation impaired by Mg-insufficiency.

It has been reported that the Mg-insufficient bone is fragile upon mechanical loading, despite its high bone mineral density, while vitamin K2 (MK-4: menatetrenone) improved the mechanical strength of Mg-insufficient bone. Therefore, we aimed to elucidate the ultrastructural properties of bone in rats with dietary Mg insufficiency with and without MK-4 supplementation. Morphological examinations including histochemistry, transmission electron microscopy, electron probe microanalysis (EPMA) and X-ray diffraction were conducted on the femora and tibiae of 4-week-old Wistar male rats fed with 1) a normal diet (control group, 0.09% Mg), 2) a Mg-insufficient diet (low Mg group, 0.006% Mg), or 3) a Mg-insufficient diet supplemented with MK-4 (MK-4 group, 0.006% Mg, 0.03% MK-4). MK-4 appeared to inhibit the osteoclastic bone resorption that is stimulated by Mg insufficiency. EPMA analysis, however, revealed an increased concentration of Ca paralleling Mg reduction in the low Mg group. Assessment by X-ray diffraction revealed an abundance of a particular synthetic form of hydroxyapatite in the low Mg group, while control bones featured a variety of mineralized crystals. In addition, Mg-deficient bones featured larger mineral crystals, i.e., crystal overgrowth. This crystalline aberration in Mg-insufficient bones induced collagen fibrils to mineralize easily, even in the absence of mineralized nodules, which therefore led to an early collapse of the fibrils. MK-4 prevented premature collagen mineralization by normalizing the association of collagen fibrils with mineralized nodules. Thus, MK-4 appears to rescue the impaired collagen mineralization caused by Mg insufficiency by promoting a re-association of the process of collagen mineralization with mineralized nodules.

Fluid mechanical matching of H+-ATP synthase subunit c-ring with lipid membranes revealed by 2H solid-state NMR.

The F(1)F(o)-ATP synthase utilizes the transmembrane H(+) gradient for the synthesis of ATP. F(o) subunit c-ring plays a key role in transporting H(+) through F(o) in the membrane. We investigated the interactions of Escherichia coli subunit c with dimyristoylphosphatidylcholine (DMPC-d(54)) at lipid/protein ratios of 50:1 and 20:1 by means of (2)H-solid-state NMR. In the liquid-crystalline state of DMPC, the (2)H-NMR moment values and the order parameter (S(CD)) profile were little affected by the presence of subunit c, suggesting that the bilayer thickness in the liquid-crystalline state is matched to the transmembrane hydrophobic surface of subunit c. On the other hand, hydrophobic mismatch of subunit c with the lipid bilayer was observed in the gel state of DMPC. Moreover, the viscoelasticity represented by a square-law function of the (2)H-NMR relaxation was also little influenced by subunit c in the fluid phase, in contrast with flexible nonionic detergents or rigid additives. Thus, the hydrophobic matching of the lipid bilayer to subunit c involves at least two factors, the hydrophobic length and the fluid mechanical property. These findings may be important for the torque generation in the rotary catalytic mechanism of the F(1)F(o)-ATPse molecular motor.

Influence of bone osteocalcin levels on bone loss induced by ovariectomy in rats.

To investigate the role of osteocalcin (OC) in bones, bone parameters in warfarin (WF)-treated rats after ovariectomy (OVX) were compared with those in intact rats. Rats were divided into an intact group and WF-treated group. Warfarin was orally given to rats for 16 weeks, and then OVX was performed and rats in the WF-treated groups continued receiving WF. Twelve weeks after OVX, bone properties were observed. The diaphysial bone OC level in the WF group was 10%-14% of the normal level at the preoperative point and 12 weeks after surgery. On comparison of the intact and WF groups before surgery, no significant differences were noted in bone mass parameters or mechanical properties, but 12 weeks after surgery, the diaphysial bone mineral content (BMC), bone area, and cortical thickness (Cth) were significantly higher in the WF-sham group than in the intact-sham group. Ovariectomy significantly decreased the diaphysial BMC, bone mineral density (BMD), Cth, and maximum load, and increased the endosteal perimeter in the WF group. In the intact group, no such OVX-induced changes were noted, and the metaphysial bone area and the endosteal and periosteal perimeters were increased by OVX. The CO(3)/PO(4) ratio in the femur measured by Fourier-transform infrared imaging using reflection preparations was higher in the WF-sham group than the intact-sham group, and higher in the intact-OVX group than the intact-sham group, but no significant difference was noted between the WF-sham and WF-OVX groups. It has been reported that CO(3)(-) is contained in new bone and decreases with mineral maturation. These data suggest that long-term reduction in bone OC levels may induce the formation of immature bone, which is easily resorbed with changes in bone metabolism such as OVX, and that OC may be one of the factors affecting bone turnover.

Infrared analysis of bones in magnesium-deficient rats treated with vitamin K2.

In this study, we compared the effects of vitamin K(2) menatetrenone on bone mechanical properties in rats fed a low-magnesium (Mg) diet. In addition, the mechanism of bone quality was examined using Fourier transform infrared imaging (FTIRI). Thirty 4-week-old male Wistar rats were divided into three groups: intact, low-Mg-control, and low-Mg-MK-4 groups. Rats in the low-Mg groups were given a diet containing 6 mg/100 g Mg (intact, 90 mg/100 g). After an 8-week-treatment, the cortical bone mineral content (CtBMC), outer perimeter, and endo perimeter of the femoral diaphysis in the low-Mg-control group were significantly higher, while the maximum load (ML) and elastic modulus (EM) were 81% and 50% of those in the intact group, respectively (respectively, P < 0.05). In the low-Mg-MK-4 group, ML and EM were significantly higher than in the low-Mg-control group (P < 0.05), with no differences in CtBMC. The mineral/matrix ratios for the periosteal and central regions in the low-Mg-control group were 162% and 120% of those in the intact group (both, P < 0.05), respectively. MK-4 significantly inhibited these increases (P < 0.05). We found that the mineral/matrix ratios for the periosteal region of the femoral diaphysis were negatively correlated with EM, suggesting that an increase in the mineral/matrix ratio may be involved in the reduction of EM and that MK-4 may improve EM by improving the mineral/matrix ratio.

Signal assignment and secondary structure analysis of a uniformly [13C, 15N]-labeled membrane protein, H +-ATP synthase subunit c, by magic-angle spinning solid-state NMR.

Signal assignment and secondary structural analysis of uniformly [13C, 15N] labeled H+-ATP synthase subunit c from E. coli (79 residues) in the solid state were carried out by two- and three-dimensional solid-state NMR under magic-angle spinning. The protein took on a unique structure even in the solid state from the 13C linewidths of about 1.7 ppm. On the basis of several inter- and intra-residue 13C-13C and 13C-15N chemical shift correlations, 78% of Calpha, 72% of Cbeta, 62% of C' and 61% of NH signals were assigned, which provided the secondary structure information for 84% of the 79 residues. Here, inter-residue correlations involving Gly, Ala, Pro and side-chains and a higher resolution in the 3D spectrum were significantly useful for the sequence specific assignment. On top of this, the 13C-13C correlation spectra of subunit c was analyzed by reproducing experimental cross peaks quantitatively with chemical shift prediction and signal-intensity calculation based on the structure. It revealed that the subunit c in the solid state could be specified by alpha-helices with a loop structure in the middle (at sequence 41-45) as in the case of the solution structure in spite of additional extended conformations at 76-79 at the C-terminus.

Overexpression of monocyte chemoattractant protein-1 in adipose tissues causes macrophage recruitment and insulin resistance.

Adipose tissue expression and circulating concentrations of monocyte chemoattractant protein-1 (MCP-1) correlate positively with adiposity. To ascertain the roles of MCP-1 overexpression in adipose, we generated transgenic mice by utilizing the adipocyte P2 (aP2) promoter (aP2-MCP-1 mice). These mice had higher plasma MCP-1 concentrations and increased macrophage accumulation in adipose tissues, as confirmed by immunochemical, flow cytometric, and gene expression analyses. Tumor necrosis factor-alpha and interleukin-6 mRNA levels in white adipose tissue and plasma non-esterified fatty acid levels were increased in transgenic mice. aP2-MCP-1 mice showed insulin resistance, suggesting that inflammatory changes in adipose tissues may be involved in the development of insulin resistance. Insulin resistance in aP2-MCP-1 mice was confirmed by hyperinsulinemic euglycemic clamp studies showing that transgenic mice had lower rates of glucose disappearance and higher endogenous glucose production than wild-type mice. Consistent with this, insulin-induced phosphorylations of Akt were significantly decreased in both skeletal muscles and livers of aP2-MCP-1 mice. MCP-1 pretreatment of isolated skeletal muscle blunted insulin-stimulated glucose uptake, which was partially restored by treatment with the MEK inhibitor U0126, suggesting that circulating MCP-1 may contribute to insulin resistance in aP2-MCP-1 mice. We concluded that both paracrine and endocrine effects of MCP-1 may contribute to the development of insulin resistance in aP2-MCP-1 mice.