Modified aptamers enable quantitative sub-10-nm cellular DNA-PAINT imaging.

Although current implementations of super-resolution microscopy are technically approaching true molecular-scale resolution, this has not translated to imaging of biological specimens, because of the large size of conventional affinity reagents. Here we introduce slow off-rate modified aptamers (SOMAmers) as small and specific labeling reagents for use with DNA points accumulation in nanoscale topography (DNA-PAINT). To demonstrate the achievable resolution, specificity, and multiplexing capability of SOMAmers, we labeled and imaged both transmembrane and intracellular targets in fixed and live cells.

Selection of DNA aptamers with two modified bases.

The nucleobases comprising DNA and RNA aptamers provide considerably less chemical diversity than protein-based ligands, limiting their versatility. The introduction of novel functional groups at just one of the four bases in modified aptamers has recently led to dramatic improvement in the success rate of identifying nucleic acid ligands to protein targets. Here we explore the benefits of additional enhancement in physicochemical diversity by selecting modified DNA aptamers that contain amino-acid-like modifications on both pyrimidine bases. Using proprotein convertase subtilisin/kexin type 9 as a representative protein target, we identify specific pairwise combinations of modifications that result in higher affinity, metabolic stability, and inhibitory potency compared with aptamers with single modifications. Such doubly modified aptamers are also more likely to be encoded in shorter sequences and occupy nonoverlapping epitopes more frequently than aptamers with single modifications. These highly modified DNA aptamers have broad utility in research, diagnostic, and therapeutic applications.

Pulsed EPR characterization of HIV-1 protease conformational sampling and inhibitor-induced population shifts.

The conformational landscape of HIV-1 protease (PR) can be experimentally characterized by pulsed-EPR double electron-electron resonance (DEER). For this characterization, nitroxide spin labels are attached to an engineered cysteine residue in the flap region of HIV-1 PR. DEER distance measurements from spin-labels contained within each flap of the homodimer provide a detailed description of the conformational sampling of apo-enzyme as well as induced conformational shifts as a function of inhibitor binding. The distance distribution profiles are further interpreted in terms of a conformational ensemble scheme that consists of four unique states termed "curled/tucked", "closed", "semi-open" and "wide-open" conformations. Reported here are the DEER results for a drug-resistant variant clinical isolate sequence, V6, in the presence of FDA approved protease inhibitors (PIs) as well as a non-hydrolyzable substrate mimic, CaP2. Results are interpreted in the context of the current understanding of the relationship between conformational sampling, drug resistance, and kinetic efficiency of HIV-1PR as derived from previous DEER and kinetic data for a series of HIV-1PR constructs that contain drug-pressure selected mutations or natural polymorphisms. Specifically, these collective results support the notion that inhibitor-induced closure of the flaps correlates with inhibitor efficiency and drug resistance. This body of work also suggests DEER as a tool for studying conformational sampling in flexible enzymes as it relates to function.

Continuing Medical Education Improves Gastroenterologists' Compliance with Inflammatory Bowel Disease Quality Measures.

BACKGROUND: Low rates of compliance with quality measures for inflammatory bowel disease (IBD) have been reported for US gastroenterologists. AIMS: We assessed the influence of quality improvement (QI) education on compliance with physician quality reporting system (PQRS) measures for IBD and measures related to National Quality Strategy (NQS) priorities. METHODS: Forty community-based gastroenterologists participated in the QI study; 20 were assigned to educational intervention and control groups, respectively. At baseline, randomly selected charts of patients with moderate-to-severe ulcerative colitis were retrospectively reviewed for the gastroenterologists' performance of 8 PQRS IBD measures and 4 NQS-related measures. The intervention group participated in a series of accredited continuing medical education (CME) activities focusing on QI. Follow-up chart reviews were conducted 6 months after the CME activities. Independent t tests were conducted to compare between-group differences in baseline-to-follow-up rates of documented compliance with each measure. RESULTS: The analysis included 299 baseline charts and 300 follow-up charts. The intervention group had significantly greater magnitudes of improvement than the control group for the following measures: assessment of IBD type, location, and activity (+14 %, p = 0.009); influenza vaccination (+13 %, p = 0.025); pneumococcal vaccination (+20 %, p = 0.003); testing for latent tuberculosis before anti-TNF-α therapy (+10 %, p = 0.028); assessment of hepatitis B virus status before anti-TNF-α therapy (+9 %, p = 0.010); assessment of side effects (+17 %, p = 0.048), and counseling patients about cancer risks (+13 %, p = 0.013). CONCLUSIONS: QI-focused CME improves community-based gastroenterologists' compliance with IBD quality measures and measures aligned with NQS priorities.

Chemically modified DNA aptamers bind interleukin-6 with high affinity and inhibit signaling by blocking its interaction with interleukin-6 receptor.

Interleukin-6 (IL-6) is a pleiotropic cytokine that regulates immune and inflammatory responses, and its overproduction is a hallmark of inflammatory diseases. Inhibition of IL-6 signaling with the anti-IL-6 receptor antibody tocilizumab has provided some clinical benefit to patients; however, direct cytokine inhibition may be a more effective option. We used the systematic evolution of ligands by exponential enrichment (SELEX) process to discover slow off-rate modified aptamers (SOMAmers) with hydrophobic base modifications that inhibit IL-6 signaling in vitro. Two classes of IL-6 SOMAmers were isolated from modified DNA libraries containing 40 random positions and either 5-(N-benzylcarboxamide)-2'-deoxyuridine (Bn-dU) or 5-[N-(1-naphthylmethyl)carboxamide]-2'-deoxyuridine (Nap-dU) replacing dT. These modifications facilitate the high affinity binding interaction with IL-6 and provide resistance against degradation by serum endonucleases. Post-SELEX optimization of one Bn-dU and one Nap-dU SOMAmer led to improvements in IL-6 binding (10-fold) and inhibition activity (greater than 20-fold), resulting in lead SOMAmers with sub-nanomolar affinity (Kd = 0.2 nm) and potency (IC50 = 0.2 nm). Although similar in inhibition properties, the two SOMAmers have unique sequences and different ortholog specificities. Furthermore, these SOMAmers were stable in human serum in vitro for more than 48 h. Both SOMAmers prevented IL-6 signaling by blocking the interaction of IL-6 with its receptor and inhibited the proliferation of tumor cells in vitro as effectively as tocilizumab. This new class of IL-6 inhibitor may be an effective therapeutic alternative for patients suffering from inflammatory diseases.

Crystal structure of interleukin-6 in complex with a modified nucleic acid ligand.

IL-6 is a secreted cytokine that functions through binding two cell surface receptors, IL-6Rα and gp130. Because of its involvement in the progression of several chronic inflammatory diseases, IL-6 is a target of pharmacologic interest. We have recently identified a novel class of ligands called SOMAmers (S low Off-rate Modified Aptamers) that bind IL-6 and inhibit its biologic activity. SOMAmers exploit the chemical diversity of protein-like side chains assembled on flexible nucleic acid scaffolds, resulting in an expanded repertoire of intra- and intermolecular interactions not achievable with conventional aptamers. Here, we report the co-crystal structure of a high affinity SOMAmer (Kd = 0.20 nm) modified at the 5-position of deoxyuridine in a complex with IL-6. The SOMAmer, comprised of a G-quartet domain and a stem-loop domain, engages IL-6 in a clamp-like manner over an extended surface exhibiting close shape complementarity with the protein. The interface is characterized by substantial hydrophobic interactions overlapping the binding surfaces of the IL-6Rα and gp130 receptors. The G-quartet domain retains considerable binding activity as a disconnected autonomous fragment (Kd = 270 nm). A single substitution from our diversely modified nucleotide library leads to a 37-fold enhancement in binding affinity of the G-quartet fragment (Kd = 7.4 nm). The ability to probe ligand surfaces in this manner is a powerful tool in the development of new therapeutic reagents with improved pharmacologic properties. The SOMAmer·IL-6 structure also expands our understanding of the diverse structural motifs achievable with modified nucleic acid libraries and elucidates the nature with which these unique ligands interact with their protein targets.

Unique motifs and hydrophobic interactions shape the binding of modified DNA ligands to protein targets.

Selection of aptamers from nucleic acid libraries by in vitro evolution represents a powerful method of identifying high-affinity ligands for a broad range of molecular targets. Nevertheless, a sizeable fraction of proteins remain difficult targets due to inherently limited chemical diversity of nucleic acids. We have exploited synthetic nucleotide modifications that confer protein-like diversity on a nucleic acid scaffold, resulting in a new generation of binding reagents called SOMAmers (Slow Off-rate Modified Aptamers). Here we report a unique crystal structure of a SOMAmer bound to its target, platelet-derived growth factor B (PDGF-BB). The SOMAmer folds into a compact structure and exhibits a hydrophobic binding surface that mimics the interface between PDGF-BB and its receptor, contrasting sharply with mainly polar interactions seen in traditional protein-binding aptamers. The modified nucleotides circumvent the intrinsic diversity constraints of natural nucleic acids, thereby greatly expanding the structural vocabulary of nucleic acid ligands and considerably broadening the range of accessible protein targets.

Multisite Quality Improvement Initiative to Identify and Address Racial Disparities and Deficiencies in Delivering Equitable, Patient-Centered Care for Multiple Myeloma-Exploring the Differences between Academic and Community Oncology Centers.

Treatment of multiple myeloma (MM) is complex; however, with equal access to care, clinical outcomes for Black patients match those in other patient groups. To reveal and begin to address clinical practice barriers to equitable, patient-centered MM care, this quality improvement (QI) initiative assessed patient electronic medical records (EMRs) and surveyed patients and providers at two large hospital systems and four community-based practices. For the educational intervention, providers participated in feedback-focused grand rounds sessions to reflect on system barriers and develop action plans to improve MM care. EMR reviews revealed infrequent documentation of cytogenetics and disease staging at community-based practices compared to large hospital systems. In surveys, providers from each care setting reported different challenges in MM care. Notably, the goals of treatment for patients and providers aligned at community clinics while providers and patients from large hospital systems had discordant perspectives. However, providers in community settings underreported race-associated barriers to care and identified different factors impacting treatment decision-making than Black patients. Relative to pre-session responses, providers were more likely to report high confidence after the educational sessions in aligning treatment decisions with guidelines and clinical evidence and shared decision-making (SDM). This QI study identified discordant perceptions among providers at large hospital systems and community-based practices in providing quality MM care. Provider education yielded increased confidence in and commitment to patient-centered care.

What Can State Medical Boards Do to Effectively Address Serious Ethical Violations?

State Medical Boards (SMBs) can take severe disciplinary actions (e.g., license revocation or suspension) against physicians who commit egregious wrongdoing in order to protect the public. However, there is noteworthy variability in the extent to which SMBs impose severe disciplinary action. In this manuscript, we present and synthesize a subset of 11 recommendations based on findings from our team's larger consensus-building project that identified a list of 56 policies and legal provisions SMBs can use to better protect patients from egregious wrongdoing by physicians.

Sequential proteolysis and high-field FTICR MS to determine disulfide connectivity and 4-maleimide TEMPO spin-label location in L126C GM2 activator protein.

The GM2 activator protein (GM2AP) is an 18 kDa nonenzymatic accessory protein involved in the degradation of neuronal gangliosides. Genetic mutations of GM2AP can disrupt ganglioside catabolism and lead to deadly lysosomal storage disorders. Crystallography of wild-type GM2AP reveals 4 disulfide bonds and multiple conformations of a flexible loop region that is thought to be involved in lipid binding. To extend the crystallography results, a cysteine construct (L126C) was expressed and modified with 4-maleimide TEMPO for electron paramagnetic resonance (EPR) studies. However, because a ninth cysteine has been added by site-directed mutagenesis and the protein was expressed in E. coli in the form of inclusion bodies, the protein could misfold during expression. To verify correct protein folding and labeling, a sequential multiple-protease digestion, nano-liquid chromatograph (LC) electrospray ionization 14.5 T Fourier transform ion cyclotron resonance mass spectrometry assay was developed. High-magnetic field and robust automatic gain control results in subppm mass accuracy for location of the spin-labeled cysteine and verification of proper connectivity of the four disulfide bonds. The sequential multiple protease digestion strategy and ultrahigh mass accuracy provided by FTICR MS allow for rapid and unequivocal assignment of relevant peptides and provide a simple pipeline for analyzing other GM2AP constructs.

A practical guide to rodent islet isolation and assessment.

Pancreatic islets of Langerhans secrete hormones that are vital to the regulation of blood glucose and are, therefore, a key focus of diabetes research. Purifying viable and functional islets from the pancreas for study is an intricate process. This review highlights the key elements involved with mouse and rat islet isolation, including choices of collagenase, the collagenase digestion process, purification of islets using a density gradient, and islet culture conditions. In addition, this paper reviews commonly used techniques for assessing islet viability and function, including visual assessment, fluorescent markers of cell death, glucose-stimulated insulin secretion, and intracellular calcium measurements. A detailed protocol is also included that describes a common method for rodent islet isolation that our laboratory uses to obtain viable and functional mouse islets for in vitro study of islet function, beta-cell physiology, and in vivo rodent islet transplantation. The purpose of this review is to serve as a resource and foundation for successfully procuring and purifying high-quality islets for research purposes.

Assessing Patient and Provider Perceptions of Factors Associated with Patient Engagement in Asthma Care.

RATIONALE: National quality improvement initiatives emphasize building partnerships between patients and providers by promoting patient engagement through communication, shared decision-making, and self-care skills. Efforts to promote patient engagement are especially important for people with asthma. To cultivate effective partnerships in asthma care, patients and providers may benefit from understanding each other's values and perceptions regarding treatment goals, shared decision-making, as well as barriers to optimal care and outcomes. OBJECTIVES: We conducted a survey study to assess and compare asthma patient and provider perceptions of factors that are associated with effective partnerships and patient engagement. METHODS: Surveys were administered to adult patients with poorly controlled asthma (n = 328) and their physicians (n = 40) before they participated in collaborative learning sessions held in 40 allergy and immunology practices across the United States. The surveys included items for both groups to report their asthma-related treatment goals and perceptions about information needs and knowledge, shared decision-making, and barriers to medication adherence. RESULTS: Providers rated their knowledge about different aspects of their patients' health status (on a scale from 1 = poor knowledge to 5 = excellent knowledge). The lowest percentages of ratings 4 and 5 were for knowledge about patients' financial status (29%), adherence (42%), lifestyle (46%), and workplace situation (46%). The highest percentages of ratings 4 and 5 were for knowledge about patients' exacerbation history (75%), smoking status (76%), hospitalization history (79%), and comorbidities (79%). The percentages of patients and providers, respectively, who indicated the following treatment goals as important differed significantly: preventing exacerbations (62% and 83%; P = 0.01), preventing emergency department visits (44% and 76%; P < 0.01), and improving ability to perform daily activities (69% and 48%; P < 0.01). However, there were no significant differences in percentages of provider-reported goals and goals that providers estimated their patients would indicate as important. Disconnects were also observed for perceived barriers to asthma medication adherence. CONCLUSIONS: The observed disconnects in patient and provider perceptions may inform strategies for cultivating effective partnerships and patient engagement to improve care quality and outcomes for people with asthma.

Impact of Quality Improvement Educational Interventions on Documented Adherence to Quality Measures for Adults with Crohn's Disease.

BACKGROUND: In recent years, leading organizations in inflammatory bowel disease (IBD) have developed quality measures for the care of adults with Crohn's disease or ulcerative colitis. We used chart audits to assess the impact of quality improvement educational activities on documented adherence to Physician Quality Reporting System measures for IBD. METHODS: Twenty community-based gastroenterologists were recruited to participate in baseline chart audits (n = 200), a series of 4 accredited educational activities with feedback, and follow-up chart audits (n = 200). Trained abstractors reviewed randomly selected charts of adults with moderate or severe Crohn's disease. The charts were retrospectively abstracted for physicians' documented performance of the 2013 Physician Quality Reporting System IBD quality measures. We compared the physicians' baseline and posteducation rates of documented adherence with 10 of these measures. In a secondary analysis, we compared preeducation with posteducation difference scores of low-performing physicians, those whose baseline documentation rates were in the lowest quartile, and the rest of the cohort. RESULTS: At baseline, documentation of mean provider-level adherence to the 10 quality measures ranged from 3% to 98% (grand mean = 35.8%). In the overall analysis, baseline and posteducation rates of documented adherence did not differ significantly for any of the measures. However, for 4 measures, preeducation to posteducation difference scores were significantly greater among low performers than physicians in the highest 3 quartiles. CONCLUSIONS: The results of this preliminary pragmatic study indicate that quality improvement education affords the potential to improve adherence to Physician Quality Reporting System quality measures for IBD among low-performing gastroenterologists.

Practical synthesis of cytidine-5-carboxamide-modified nucleotide reagents.

Chemically-modified derivatives of cytidine, bearing a 5-(N-substituted-carboxamide) functional group, are new reagents for use in aptamer discovery via the SELEX process (Systematic Evolution of Ligands by EXponential enrichment). Herein, we disclose a practical synthesis of 5-(N-benzylcarboxamide)-2'-deoxycytidine, and the corresponding 5-(N-1-naphthylmethylcarboxamide)- and 5-(N-3-phenylpropylcarboxamide)-2'-deoxycytidine analogs, as both the suitably-protected 3'-O-cyanoethylphosphoramidite reagents (CEP; gram scale) and the 5'-O-triphosphate reagents (TPP; milligram-scale). The key step in the syntheses is a mild, palladium(0)-catalyzed carboxyamidation of an unprotected 5-iodo-cytidine. Use of the CEP reagents for solid-phase oligonucleotide synthesis was demonstrated and incorporation of the TPP reagents by KOD polymerase in a primer extension assay confirmed the utility of these reagents for SELEX. Finally, the carboxyamidation reaction was also used to prepare the nuclease-resistant sugar-variants: 5-(N-benzylcarboxamide)-2'-O-methyl-cytidine and 5-(N-3-phenylpropylcarboxamide)-2'-deoxy-2'-fluoro-cytidine.

Influence of Continuing Medical Education on Rheumatologists' Performance on National Quality Measures for Rheumatoid Arthritis.

INTRODUCTION: In recent years researchers have reported deficits in the quality of care provided to patients with rheumatoid arthritis (RA), including low rates of performance on quality measures. We sought to determine the influence of a quality improvement (QI) continuing education program on rheumatologists' performance on national quality measures for RA, along with other measures aligned with National Quality Strategy priorities. Performance was assessed through baseline and post-education chart audits. METHODS: Twenty community-based rheumatologists across the United States were recruited to participate in the QI education program and chart audits. Charts were retrospectively audited before (n = 160 charts) and after (n = 160 charts) the rheumatologists participated in a series of accredited QI-focused educational activities that included private audit feedback, small-group webinars, and online- and mobile-accessible print and video activities. The charts were audited for patient demographics and the rheumatologists' documented performance on the 6 quality measures for RA included in the Physician Quality Reporting System (PQRS). In addition, charts were abstracted for documentation of patient counseling about medication benefits/risks and adherence, lifestyle modifications, and quality of life; assessment of RA medication side effects; and assessment of RA medication adherence. RESULTS: Mean rates of documented performance on 4 of the 6 PQRS measures for RA were significantly higher in the post-education versus baseline charts (absolute increases ranged from 9 to 24% of patient charts). In addition, after the intervention, significantly higher mean rates were observed for patient counseling about medications and quality of life, and for assessments of medication side effects and adherence (absolute increases ranged from 9 to 40% of patient charts). CONCLUSION: This pragmatic study provides preliminary evidence for the positive influence of QI-focused education in helping rheumatologists improve performance on national quality measures for RA.

The novel anti-inflammatory agent lisofylline prevents autoimmune diabetic recurrence after islet transplantation.

BACKGROUND: Pancreatic islet transplantation has become a promising treatment for type 1 diabetes. However, autoimmune reactivity destroys engrafted islets in type 1 diabetic recipients. The authors' previous studies demonstrated that a novel anti-inflammatory agent, lisofylline (LSF), suppressed autoimmune reactivity and protected nonobese diabetic (NOD) mice from diabetes. In this study, the authors investigated the potential of LSF in preventing autoimmune diabetes recurrence after islet transplantation. METHODS: Spontaneously diabetic NOD mice received NOD severe combined immunodeficiency islet transplants and were treated with daily LSF injections at 50 mg/kg for 3 weeks. Blood glucose levels were monitored. Serum cytokine levels were measured at 1 and 3 weeks after engraftment. Nephrectomy of the islet-implanted kidney was performed in LSF-treated recipients. Histology of islet grafts was assessed at the end of the study. The effect of LSF on beta-cell function was studied in vitro. RESULTS: Without immunosuppressants and insulin, the LSF-treated recipient mice maintained euglycemia significantly longer than the saline-treated recipients (mean, >65 days in the LSF-treated group vs. 6 days in saline controls; P=0.0004). Serum levels of interferon-gamma were markedly reduced in LSF-treated recipients at 1 and 3 weeks posttransplant. Diabetes recurred in the LSF-treated recipients after removing the islet-implanted kidneys. Immunohistochemistry showed retention of insulin-positive cells in the grafts of the LSF-treated recipients. LSF preserved beta-cell insulin secretory function in the presence of inflammatory cytokines in vitro. CONCLUSIONS: This study demonstrates that autoimmune diabetes recurrence after islet transplantation could be prevented by treatment with LSF. LSF and its analogues may have the potential to prevent islet autoimmune destruction in clinical transplantation.

Effects of PRE and POST therapy drug-pressure selected mutations on HIV-1 protease conformational sampling.

Conformational sampling of pre- and post-therapy subtype B HIV-1 protease sequences derived from a pediatric subject infected via maternal transmission with HIV-1 were characterized by double electron-electron resonance spectroscopy. The conformational ensemble of the PRE construct resembles native-like inhibitor bound states. In contrast, the POST construct, which contains accumulated drug-pressure selected mutations, has a predominantly semi-open conformational ensemble, with increased populations of open-like states. The single point mutant L63P, which is contained in PRE and POST, has decreased dynamics, particularly in the flap region, and also displays a closed-like conformation of inhibitor-bound states. These findings support our hypothesis that secondary mutations accumulate in HIV-1 protease to shift conformational sampling to stabilize open-like conformations, while maintaining the predominant semi-open conformation for activity.

Circulating levels of IL-1B+IL-6 cause ER stress and dysfunction in islets from prediabetic male mice.

Elevated levels of circulating proinflammatory cytokines are associated with obesity and increased risk of type 2 diabetes, but the mechanism is unknown. We tested whether proinflammatory cytokines IL-1B+IL-6 at low picogram per milliliter concentrations (consistent with serum levels) could directly trigger pancreatic islet dysfunction. Overnight exposure to IL-1B+IL-6 in islets isolated from normal mice and humans disrupted glucose-stimulated intracellular calcium responses; cytokine-induced effects were more severe among islets from prediabetic db/db mice that otherwise showed no signs of dysfunction. IL-1B+IL-6 exposure reduced endoplasmic reticulum (ER) calcium storage, activated ER stress responses (Nos2, Bip, Atf4, and Ddit3 [CHOP]), impaired glucose-stimulated insulin secretion, and increased cell death only in islets from prediabetic db/db mice. Furthermore, we found increased serum levels of IL-1B and IL-6 in diabetes-prone mice at an age before hyperglycemia was exhibited, suggesting that low-grade systemic inflammation develops early in the disease process. In addition, we implanted normal outbred and inbred mice with subcutaneous osmotic mini-pumps containing IL-1B+IL-6 to mimic the serum increases found in prediabetic db/db mice. Both IL-1B and IL-6 were elevated in serum from cytokine-pump mice, but glucose tolerance and blood glucose levels did not differ from controls. However, when compared with controls, isolated islets from cytokine-pump mice showed deficiencies in calcium handling and insulin secretion that were similar to observations with islets exposed to cytokines in vitro. These findings provide proof of principle that low-grade systemic inflammation is present early in the development of type 2 diabetes and can trigger ER stress-mediated islet dysfunction that can lead to islet failure.

Valsartan protects pancreatic islets and adipose tissue from the inflammatory and metabolic consequences of a high-fat diet in mice.

Obesity, hypertension, cardiovascular disease, and inflammation are closely associated with the rising incidence of diabetes mellitus. One pharmacological target that may have significant potential to lower the risk of obesity-related diseases is the angiotensin type 1 receptor (AT1R). We examined the hypothesis that the AT1R blocker valsartan reduces the metabolic consequences and inflammatory effects of a high-fat (Western) diet in mice. C57BL/6J mice were treated by oral gavage with 10 mg/kg per day of valsartan or vehicle and placed on either a standard chow or Western diet for 12 weeks. Western diet-fed mice given valsartan had improved glucose tolerance, reduced fasting blood glucose levels, and reduced serum insulin levels compared with mice fed a Western diet alone. Valsartan treatment also blocked Western diet-induced increases in serum levels of the proinflammatory cytokines interferon-gamma and monocyte chemotactic protein 1. In the pancreatic islets, valsartan enhanced mitochondrial function and prevented Western diet-induced decreases in glucose-stimulated insulin secretion. In adipose tissue, valsartan reduced Western diet-induced macrophage infiltration and expression of macrophage-derived monocyte chemotactic protein 1. In isolated adipocytes, valsartan treatment blocked or attenuated Western diet-induced changes in expression of several key inflammatory signals: interleukin 12p40, interleukin 12p35, tumor necrosis factor-alpha, interferon-gamma, adiponectin, platelet 12-lipoxygenase, collagen 6, inducible NO synthase, and AT1R. Our findings indicate that AT1R blockade with valsartan attenuated several deleterious effects of the Western diet at the systemic and local levels in islets and adipose tissue. This study suggests that AT1R blockers provide additional therapeutic benefits in the metabolic syndrome and other obesity-related disorders beyond lowering blood pressure.