T cells isolated from the pancreatic infiltrates of non-obese diabetic mice have been shown to recognize epitopes formed by the covalent cross-linking of proinsulin and secretory granule peptides. Formation of such hybrid insulin peptides (HIPs) was confirmed through mass spectrometry and responses to HIPs were observed among the islet-infiltrating T cells of pancreatic organ donors and in the peripheral blood of individuals with type 1 diabetes (T1D). However, questions remain about the prevalence of HIP-specific T cells in humans, the sequences they recognize, and their role in disease. We identified six novel HIPs that are recognized in the context of DRB1*04:01, discovered by utilizing a library of theoretical HIP sequences derived from insulin fragments covalently linked to one another or to fragments of secretory granule proteins or other islet-derived proteins. We demonstrate that T cells that recognize these HIPs are detectable in the peripheral blood of subjects with T1D and exhibit an effector memory phenotype. HIP-reactive T cell clones produced Th1-associated cytokines and proliferated in response to human islet preparations. These results support the relevance of HIPs in human disease, further establishing a novel post-translational modification that may contribute to the loss of peripheral tolerance in T1D.

Type 2 diabetes mellitus predicts outcome following acute myocardial infarction (AMI). Since underlying mechanics are incompletely understood, we investigated left ventricular (LV) and atrial (LA) pathophysiological changes and their prognostic implications using cardiovascular magnetic resonance (CMR). Consecutive patients (n=1147, n=265 diabetic; n=882 non-diabetic) underwent CMR 3 days after AMI. Analyses included LV ejection fraction (LVEF), global longitudinal, circumferential and radial strains (GLS, GCS and GRS), LA reservoir, conduit and booster pump strains, as well as infarct size, edema and microvascular obstruction. Predefined endpoints were major adverse cardiovascular events (MACE) within 12 months. Diabetic patients had impaired LA reservoir (19.8 vs. 21.2%, p<0.01) and conduit strains (7.6 vs. 9.0%, p<0.01) but not ventricular function or myocardial damage. They were at higher risk of MACE than non-diabetic patients (10.2% vs. 5.8%, p<0.01) with most MACE occurring in patients with LVEF≥35%. Whilst LVEF (p=0.045) and atrial reservoir strain (p=0.024) were independent predictors of MACE in non-diabetic patients, GLS was in diabetic patients (p=0.010). Considering patients with diabetes and LVEF≥35% (n=237), GLS and LA reservoir strain below median were significantly associated with MACE. In conclusion, in patients with diabetes, LA and LV longitudinal strain permit optimized risk assessment early after reperfused AMI with incremental prognostic value over and above LVEF.

Prevention of aberrant cutaneous wound repair and appropriate regeneration of an intact and functional integument require the coordinated timing of fibroblast and keratinocyte migration. Here, we identified a mechanism whereby opposing cell-specific motogenic functions of a multifunctional intracellular and extracellular protein, the receptor for hyaluronan-mediated motility (RHAMM), coordinates fibroblast and keratinocyte migration speed and ensures appropriate timing of excisional wound closure. We found that, unlike in WT mice, in Rhamm-null mice, keratinocyte migration initiates prematurely in the excisional wounds, resulting in wounds that have re-surfaced before the formation of normal granulation tissue, leading to a defective epidermal architecture. We also noted aberrant keratinocyte and fibroblast migration in the Rhamm-null mice, indicating that RHAMM suppresses keratinocyte motility but increases fibroblast motility. This cell context–dependent effect resulted from cell-specific regulation of extracellular signal-regulated kinase 1/2 (ERK1/2) activation and expression of a RHAMM target gene encoding matrix metalloprotease 9 (MMP-9). In fibroblasts, RHAMM promoted ERK1/2 activation and MMP-9 expression, whereas in keratinocytes, RHAMM suppressed these activities. In keratinocytes, loss of RHAMM function or expression promoted epidermal growth factor receptor–regulated MMP-9 expression via ERK1/2, which resulted in cleavage of the ectodomain of the RHAMM partner protein CD44 and thereby increased keratinocyte motility. These results identify RHAMM as a key factor that integrates the timing of wound repair by controlling cell migration.

Accumulating evidence suggests that brown adipose tissue (BAT) is a potential therapeutic target for managing obesity and related diseases. PGAM family member 5, mitochondrial serine/threonine protein phosphatase (PGAM5), is a protein phosphatase that resides in the mitochondria and regulates many biological processes, including cell death, mitophagy, and immune responses. Because BAT is a mitochondria-rich tissue, we have hypothesized that PGAM5 has a physiological function in BAT. We previously reported that PGAM5-knockout (KO) mice are resistant to severe metabolic stress. Importantly, lipid accumulation is suppressed in PGAM5-KO BAT, even under unstressed conditions, raising the possibility that PGAM5 deficiency stimulates lipid consumption. However, the mechanism underlying this observation is undetermined. Here, using an array of biochemical approaches, including quantitative RT-PCR, immunoblotting, and oxygen consumption assays, we show that PGAM5 negatively regulates energy expenditure in brown adipocytes. We found that PGAM5-KO brown adipocytes have an enhanced oxygen consumption rate and increased expression of uncoupling protein 1 (UCP1), a protein that increases energy consumption in the mitochondria. Mechanistically, we found that PGAM5 phosphatase activity and intramembrane cleavage are required for suppression of UCP1 activity. Furthermore, utilizing a genome-wide siRNA screen in HeLa cells to search for regulators of PGAM5 cleavage, we identified a set of candidate genes, including phosphatidylserine decarboxylase (PISD), which catalyzes the formation of phosphatidylethanolamine at the mitochondrial membrane. Taken together, these results indicate that PGAM5 suppresses mitochondrial energy expenditure by down-regulating UCP1 expression in brown adipocytes and that its phosphatase activity and intramembrane cleavage are required for UCP1 suppression.

SUMOylation is a posttranslational modification (PTM) at a lysine residue and is crucial for the proper functions of many proteins, particularly of transcription factors, in various biological processes. Zinc finger homeobox 3 (ZFHX3), also known as AT motif-binding factor 1 (ATBF1), is a large transcription factor that is active in multiple pathological processes, including atrial fibrillation and carcinogenesis, and in circadian regulation and development. We have previously demonstrated that ZFHX3 is SUMOylated at three or more lysine residues. Here, we investigated which enzymes regulate ZFHX3 SUMOylation and whether SUMOylation modulates ZFHX3 stability and function. We found that SUMO1, SUMO2, and SUMO3 each are conjugated to ZFHX3. Multiple lysine residues in ZFHX3 were SUMOylated, but Lys-2806 was the major SUMOylation site, and we also found that it is highly conserved among ZFHX3 orthologs from different animal species. Using molecular analyses, we identified the enzymes that mediate ZFHX3 SUMOylation; these included SUMO1-activating enzyme subunit 1 (SAE1), an E1-activating enzyme; SUMO-conjugating enzyme UBC9 (UBC9), an E2-conjugating enzyme; and protein inhibitor of activated STAT2 (PIAS2), an E3 ligase. Multiple analyses established that both SUMO-specific peptidase 1 (SENP1) and SENP2 deSUMOylate ZFHX3. SUMOylation at Lys-2806 enhanced ZFHX3 stability by interfering with its ubiquitination and proteasomal degradation. Functionally, Lys-2806 SUMOylation enabled ZFHX3-mediated cell proliferation and xenograft tumor growth of the MDA-MB-231 breast cancer cell line. These findings reveal the enzymes involved in, and the functional consequences of, ZFHX3 SUMOylation, insights that may help shed light on ZFHX3's roles in various cellular and pathophysiological processes.

Optic atrophy 1 (OPA1) is a dynamin protein that mediates mitochondrial fusion at the inner membrane. OPA1 is also necessary for maintaining the cristae and thus essential for supporting cellular energetics. OPA1 exists as membrane-anchored long form (L-OPA1) and short form (S-OPA1) that lacks the transmembrane region and is generated by cleavage of L-OPA1. Mitochondrial dysfunction and cellular stresses activate the inner membrane–associated zinc metallopeptidase OMA1 that cleaves L-OPA1, causing S-OPA1 accumulation. The prevailing notion has been that L-OPA1 is the functional form, whereas S-OPA1 is an inactive cleavage product in mammals, and that stress-induced OPA1 cleavage causes mitochondrial fragmentation and sensitizes cells to death. However, S-OPA1 contains all functional domains of dynamin proteins, suggesting that it has a physiological role. Indeed, we recently demonstrated that S-OPA1 can maintain cristae and energetics through its GTPase activity, despite lacking fusion activity. Here, applying oxidant insult that induces OPA1 cleavage, we show that cells unable to generate S-OPA1 are more sensitive to this stress under obligatory respiratory conditions, leading to necrotic death. These findings indicate that L-OPA1 and S-OPA1 differ in maintaining mitochondrial function. Mechanistically, we found that cells that exclusively express L-OPA1 generate more superoxide and are more sensitive to Ca2+-induced mitochondrial permeability transition, suggesting that S-OPA1, and not L-OPA1, protects against cellular stress. Importantly, silencing of OMA1 expression increased oxidant-induced cell death, indicating that stress-induced OPA1 cleavage supports cell survival. Our findings suggest that S-OPA1 generation by OPA1 cleavage is a survival mechanism in stressed cells.

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.

1 May 2007 , Number 8

Corruption and Misuse of Public Office,
Colin Nicholls Qc, Tim Daniel, Martin Polaine and John Hatchard, Oxford University Press.

Bio-Synthesis is USA based Custom Peptide Synthesis Company. In organic chemistry, peptide synthesis is the production of peptides. Peptides are chemically synthesized by the condensation reaction of the carboxyl group of amino acid.

AS ARTISTES and musicians try to manage the situation brought on by COVID-19’s stranglehold on the world and its economy, in the interim, many have resorted to hosting live-stream events. But that only succeeds to a point. Performers retain their...

By the month of May in any given year, the many and varied events and competitions staged by the Jamaica Cultural Development Commission (JCDC) islandwide would have been in high gear. Each year the JCDC rolls out its much-anticipated menu board...

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.

As Braves manager Brian Snitker evaluates who might serve as his closer, A.J. Minter has made it clear he wants to be the guy who is consistently called upon to handle high-leverage threats that develop in late innings.

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.

The European Medicines Agency (EMA) has embraced a new model of drug testing and marketing called “adaptive pathways”, allowing new drugs for “unmet medical needs” to be launched on the market faster, on the basis of fewer data. While industry claims this is necessary, an analysis on thebmj.com looks at the assumptions underlying the new pathway,...

The BMJ has published a series of articles, taking an in-depth look at health in South Asia. In this collection, authors from India, Pakistan, Nepal, Bangladesh, Sri Lanka, and Afghanistan collaborate to identify evidence-based solutions to shape health policy and interventions, and drive innovations and research in the region. In this podcast,...

Pharma companies say that money spent on promotion is essential to educate doctors about the best drugs - but when a medical student asked Joseph Ross, associate professor of medicine and public health at Yale, if those companies are promoting the right drugs for that message to be true, the answer wasn't available. Ross and Tyler Greenaway, his...

The problem we had publishing our feed has been fixed, and normal service has resumed. Thank you for subscribing to the podcast, if you have thoughts you'd like to express, we'd love to hear them. https://www.bmj.com/podcasts

In 2001, Gottfried Hirnschall joined the WHO to work on the global response to HIV/AIDs, 18 years later he just retired as the director of WHO’s department for HIV and Hepatitis. The intervening period, almost half the time we’ve been aware of the disease the fight against the infection has been characterised by scientific breakthroughs, and...

Reverse innovation may sound like some attempt to return to the dark ages - but it has a specific meaning, especially when it comes to med-tech. It’s about where we look for innovation - and overturning our preconceived ideas of where new ideas come from. Mark Skopec, and Matthew Harris - both from Imperial College London are two of the authors...

If you read the Christmas BMJ in the last few weeks, you might have noticed a lot around art and health - the way in which engagement in arts can help in prevention and treatment, but can also affect those more nebulous things which really matter to patients - loneliness, self expression, being connected to the wider community. That obviously...

This edition of talk evidence was recorded before the big increase in covid-19 infections in the UK, and then delayed by some self isolation. We'll be back with more evidence on the pandemic very soon. As always Duncan Jarvies is joined by Helen Macdonald (resting GP and editor at The BMJ) and Carl Heneghan (active GP, director of Oxford...

Christophe Bonny
Jan 1, 2001; 50:77-82
Islet Studies

Eve Van Cauter
Mar 1, 1992; 41:368-377
Original Article

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.

Incretin hormone dysregulation contributes to reduced insulin secretion and hyperglycemia in patients with type 2 diabetes mellitus (T2DM). Resistance to glucose-dependent insulinotropic polypeptide (GIP) action may occur through desensitization or downregulation of β-cell GIP receptors (GIP-R). Studies in rodents and cell lines show GIP-R expression can be regulated through peroxisome proliferator–activated receptor (PPAR) response elements (PPREs). Whether this occurs in humans is unknown. To test this, we conducted a randomized, double-blind, placebo-controlled trial of pioglitazone therapy on GIP-mediated insulin secretion and adipocyte GIP-R expression in subjects with well-controlled T2DM. Insulin sensitivity improved, but the insulinotropic effect of infused GIP was unchanged following 12 weeks of pioglitazone treatment. In parallel, we observed increased GIP-R mRNA expression in subcutaneous abdominal adipocytes from subjects treated with pioglitazone. Treatment of cultured human adipocytes with troglitazone increased PPAR binding to GIP-R PPREs. These results show PPAR agonists regulate GIP-R expression through PPREs in human adipocytes, but suggest this mechanism is not important for regulation of the insulinotropic effect of GIP in subjects with T2DM. Because GIP has antilipolytic and lipogenic effects in adipocytes, the increased GIP-R expression may mediate accretion of fat in patients with T2DM treated with PPAR agonists.

28 January 2016

Private-sector commitments and government policies, a loss of support for biofuels, and health concerns over the consumption of palm oil and beef, are factors that may help to restrict the further expansion of agricultural land into forest areas.

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.

The signal peptide of preproinsulin is a major source for HLA class I autoantigen epitopes implicated in CD8 T cell (CTL)–mediated β-cell destruction in type 1 diabetes (T1D). Among them, the 10-mer epitope located at the C-terminal end of the signal peptide was found to be the most prevalent in patients with recent-onset T1D. While the combined action of signal peptide peptidase and endoplasmic reticulum (ER) aminopeptidase 1 (ERAP1) is required for processing of the signal peptide, the mechanisms controlling signal peptide trimming and the contribution of the T1D inflammatory milieu on these mechanisms are unknown. Here, we show in human β-cells that ER stress regulates ERAP1 gene expression at posttranscriptional level via the IRE1α/miR-17-5p axis and demonstrate that inhibition of the IRE1α activity impairs processing of preproinsulin signal peptide antigen and its recognition by specific autoreactive CTLs during inflammation. These results underscore the impact of ER stress in the increased visibility of β-cells to the immune system and position the IRE1α/miR-17 pathway as a central component in β-cell destruction processes and as a potential target for the treatment of autoimmune T1D.

Members Event

Event participants

Rory Stewart, Member of Parliament for Penrith and The Border (2010-19); Secretary of State for International Development (2019)

Chair: Daniel Bruce, Chief Executive, Transparency International UK

Award winners were honored at the second annual awards ceremony in Washington, DC, on May 18, 2010.

Winners of the 2nd annual E Pluribus Unum Prizes awarded to exceptional immigrant integration initiatives by MPI's National Center on Immigrant Integration Policy are the Illinois New Americans Integration Initiative; the Latino Community Credit Union in Durham, NC; Tacoma Community House in Tacoma, WA; and Upwardly Global in San Francisco, CA. McDonald's Corp. of Oak Brook, IL, received the sole honorable mention. The Prizes seek to reward exemplary efforts that uphold and update the ideal of "out of many, one" and inspire others to take on the important work of helping immigrants and their children join the mainstream of U.S. society as well as build stronger ties between immigrants and the native-born. Award winners were honored at the second annual awards ceremony in Washington, DC, on May 18, 2010. Watch highlights of the ceremony here.

Amid aging populations and the growth of chronic diseases, the demand for skilled health-care professionals is on the rise in the United States, Canada, and Mexico. This report explores the policy implications, benefits, and challenges of harmonizing nursing qualifications in the region, suggesting that a more collaborative approach could result in greater supply and quality of nurses.

A webinar releasing a report examining deportations to Central America and reception and reintegration services in El Salvador, Guatemala, and Honduras.

For a growing population of migrants deported from Mexico and the United States to Central America, the conditions upon return typically are worse than when they left, setting up a revolving-door cycle of migration, deportation, and remigration. This report provides a detailed profile of reception and reintegration services offered in El Salvador, Guatemala, and Honduras to deported migrants, examining their challenges and opportunities for improvement. 

A webinar releasing a report examining deportations to Central America and reception and reintegration services in El Salvador, Guatemala, and Honduras.

OBJECTIVE

To assess the impact of a telemedicine visit using the platform Diabetic compared with a face-to-face visit on clinical outcomes, patients’ health-related quality of life (HRQoL), and physicians’ satisfaction in patients with type 1 diabetes.

OBJECTIVE

Glucosamine is a widely used supplement typically taken for osteoarthritis and joint pain. Emerging evidence suggests potential links of glucosamine with glucose metabolism, inflammation, and cardiometabolic risk. We prospectively analyzed the association of habitual glucosamine use with risk of type 2 diabetes (T2D) and assessed whether genetic susceptibility and inflammation status might modify the association.

A South Carolina man had extra trouble convincing his wife that his $250,000 lottery win was legitimate due to her memories of a past prank.

A San Francisco rapper is attempting to break a Guinness World Record with a live-streamed performance featuring 33 hours, 30 minutes and 30 seconds of freestyle rapping.

Ralph A. DeFronzo
Oct 1, 2013; 36:3169-3176
Emerging Technologies and Therapeutics

Michaela Diamant
Oct 1, 2014; 37:2763-2773
Emerging Technologies and Therapeutics

Tina Vilsbøll
Jun 1, 2007; 30:1608-1610
BR Emerging Treatments and Technologies

David M Nathan
Feb 1, 1992; 15:270-276
Short Report

Despite worrying economic projections, business leaders in Latin America remain optimistic about post-pandemic economy.

Alan J. Garber
May 1, 2011; 34:S279-S284
Diabetes Treatments