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Despite substantial evidence of the benefit of frequent self-monitoring of blood glucose (SMBG) in type 1 diabetes, certain insurers limit the number of test strips that they will provide. The large database of the T1D Exchange clinic registry provided an opportunity to evaluate the relationship between the number of SMBG measurements per day and HbA1c levels across a wide age range of children and adults. The analysis included 20,555 participants in the T1D Exchange clinic registry with type 1 diabetes ≥1 year and not using a continuous glucose monitor (11,641 younger than age 18 years and 8,914 18 years old or older). General linear models were used to assess the association between the number of SMBG measurements and HbA1c levels after adjusting for potential confounding variables. A higher number of SMBG measurements per day were associated with non-Hispanic white race, insurance coverage, higher household income, and use of an insulin pump for insulin delivery (P < 0.001 for each factor). After adjusting for these factors, a higher number of SMBG measurements per day was strongly associated with a lower HbA1c level (adjusted P < 0.001), with the association being present in all age-groups and in both insulin pump and injection users. There is a strong association between higher SMBG frequency and lower HbA1c levels. It is important for insurers to consider that reducing restrictions on the number of test strips provided per month may lead to improved glycemic control for some patients with type 1 diabetes.

Here human embryonic stem cell lines are derived by somatic cell nuclear transfer from cells of a newborn and from skin cells of an adult, a female with type 1 diabetes; the stem cells produced are pluripotent and can be differentiated into insulin-producing beta cells. Human adult somatic cells reprogrammed Previous research has shown that pluripotent stem-cell lines can be derived from human fetal and newborn fibroblasts (skin cells) via somatic cell nuclear transfer (SCNT), where the nucleus of a mature cell is transferred into an unfertilized, immature egg cell. Dieter Egli and colleagues now report the successful derivation of SCNT-derived embryonic stem-cell lines from adult somatic cells, including skin cells of an adult type 1 diabetic donor. Their study also systematically investigates the parameters affecting efficiency and developmental potential in their derivation, which may be important for improvement of the procedure for potential therapeutic applications. The transfer of somatic cell nuclei into oocytes can give rise to pluripotent stem cells that are consistently equivalent to embryonic stem cells 1 , 2 , 3 , holding promise for autologous cell replacement therapy 4 , 5 . Although methods to induce pluripotent stem cells from somatic cells by transcription factors 6 are widely used in basic research, numerous differences between induced pluripotent stem cells and embryonic stem cells have been reported 7 , 8 , 9 , 10 , 11 , potentially affecting their clinical use. Because of the therapeutic potential of diploid embryonic stem-cell lines derived from adult cells of diseased human subjects, we have systematically investigated the parameters affecting efficiency of blastocyst development and stem-cell derivation. Here we show that improvements to the oocyte activation protocol, including the use of both kinase and translation inhibitors, and cell culture in the presence of histone deacetylase inhibitors, promote development to the blastocyst stage. Developmental efficiency varied between oocyte donors, and was inversely related to the number of days of hormonal stimulation required for oocyte maturation, whereas the daily dose of gonadotropin or the total number of metaphase II oocytes retrieved did not affect developmental outcome. Because the use of concentrated Sendai virus for cell fusion induced an increase in intracellular calcium concentration, causing premature oocyte activation, we used diluted Sendai virus in calcium-free medium. Using this modified nuclear transfer protocol, we derived diploid pluripotent stem-cell lines from somatic cells of a newborn and, for the first time, an adult, a female with type 1 diabetes.

Mitochondrial DNA mutations transmitted maternally within the oocyte cytoplasm often cause life-threatening disorders. Here we explore the use of nuclear genome transfer between unfertilized oocytes of two donors to prevent the transmission of mitochondrial mutations. Nuclear genome transfer did not reduce developmental efficiency to the blastocyst stage, and genome integrity was maintained provided that spontaneous oocyte activation was avoided through the transfer of incompletely assembled spindle–chromosome complexes. Mitochondrial DNA transferred with the nuclear genome was initially detected at levels below 1%, decreasing in blastocysts and stem-cell lines to undetectable levels, and remained undetectable after passaging for more than one year, clonal expansion, differentiation into neurons, cardiomyocytes or β-cells, and after cellular reprogramming. Stem cells and differentiated cells had mitochondrial respiratory chain enzyme activities and oxygen consumption rates indistinguishable from controls. These results demonstrate the potential of nuclear genome transfer to prevent the transmission of mitochondrial disorders in humans. Nuclear genome transfer using unfertilized donor oocytes is performed and shown to be effective in preventing the transmission of mitochondrial DNA mutations; the swapped oocytes can develop to the blastocyst stage, and produce parthenogenetic embryonic stem-cell lines that show normal karyotypes and only mitochondrial DNA from the donor oocyte. Mitochondrial gene replacement Mutations in mitochondrial DNA (mtDNA) cause various human diseases. Their inheritance is through the mother because all zygotic mitochondria derive from the oocyte. Shoukhrat Mitalipov and colleagues previously reported proof-of-concept replacement of mtDNA through chromosome spindle transfer in macaque oocytes, and here they extend the technology to human oocytes. They also report on the health of a 3-year-old macaque born from an mtDNA-replaced oocyte. This work suggests that replacement therapy for mtDNA disorders could become a reality. Dieter Egli and colleagues took a different approach: they performed nuclear genome transfer between unfertilized human oocytes from two different donors. The resulting oocytes retained the ability to develop to the blastocyst stage and to produce embryonic stem cell lines with normal karyotypes. This technique has the potential to prevent the transmission of mtDNA mutations without causing manipulation-induced karyotypic abnormalities.

Type 1 diabetes (T1D) is the result of an autoimmune destruction of pancreatic β cells. The cellular and molecular defects that cause the disease remain unknown. Pluripotent cells generated from patients with T1D would be useful for disease modeling. We show here that induced pluripotent stem (iPS) cells can be generated from patients with T1D by reprogramming their adult fibroblasts with three transcription factors (OCT4, SOX2, KLF4). T1D-specific iPS cells, termed DiPS cells, have the hallmarks of pluripotency and can be differentiated into insulin-producing cells. These results are a step toward using DiPS cells in T1D disease modeling, as well as for cell replacement therapy.

Hypoglycemia is a major concern in type 2 diabetes (T2DM), but little is known about its likelihood compared across common therapies. We compared the likelihood of hypoglycemia among metformin-treated patients with T2DM randomized to the addition of one of 4 common therapies. Randomized, controlled trial of 5,047 participants with T2DM of <10 years' duration, hemoglobin A1c (HbA1c) 6.8-8.5% (50.8-69.4 mmol/mol). Randomization to addition of glargine U100, glimepiride, liraglutide, or sitagliptin over 5.0 ± 1.3 (mean ± SD) years. HbA1c was measured quarterly; if a level >7.5% (>58.5 mmol/mol) was confirmed, rescue glargine and/or aspart insulin was added. We conducted a per-protocol analysis of 4,830, who attended at least one post-baseline visit and took at least one dose of assigned study medication. We assessed severe hypoglycemia events reported throughout the entire study. At quarterly visits, all participants were asked about hypoglycemic symptoms within the last 30 days, and those in the glargine and glimepiride groups were asked for any measured glucose <70 mg/dL (3.9 mmol/L) within this time period. While participants were taking their assigned medications, severe hypoglycemia occurred in 10 (0.8%), 16 (1.3%), 6 (0.5%), and 4 (0.3%), (p<0.05) and hypoglycemic symptoms in 659 (54.2%), 833 (68.3%), 375 (32.4%), and 361 (29.1%) of participants following randomization to glargine, glimepiride, liraglutide, and sitagliptin, respectively (p<0.001). In metformin-treated patients with T2DM who add a second medication, hypoglycemia is most likely with addition of glimepiride, less with glargine, and least likely with liraglutide and sitagliptin. ClinicalTrials.gov Identifier: NCT01794143.

The immunopathogenesis of type 1 diabetes mellitus is associated with T-cell autoimmunity. To be fully active, immune T cells need a co-stimulatory signal in addition to the main antigen-driven signal. Abatacept modulates co-stimulation and prevents full T-cell activation. We evaluated the effect of abatacept in recent-onset type 1 diabetes. In this multicentre, double-blind, randomised controlled trial, patients aged 6–45 years recently diagnosed with type 1 diabetes were randomly assigned (2:1) to receive abatacept (10 mg/kg, maximum 1000 mg per dose) or placebo infusions intravenously on days 1, 14, 28, and monthly for a total of 27 infusions over 2 years. Computer-generated permuted block randomisation was used, with a block size of 3 and stratified by participating site. Neither patients nor research personnel were aware of treatment assignments. The primary outcome was baseline-adjusted geometric mean 2-h area-under-the-curve (AUC) serum C-peptide concentration after a mixed-meal tolerance test at 2 years' follow-up. Analysis was by intention to treat for all patients for whom data were available. This trial is registered at ClinicalTrials.gov, NCT00505375. 112 patients were assigned to treatment groups (77 abatacept, 35 placebo). Adjusted C-peptide AUC was 59% (95% CI 6·1–112) higher at 2 years with abatacept (n=73, 0·378 nmol/L) than with placebo (n=30, 0·238 nmol/L; p=0·0029). The difference between groups was present throughout the trial, with an estimated 9·6 months' delay (95% CI 3·47–15·6) in C-peptide reduction with abatacept. There were few infusion-related adverse events (36 reactions occurred in 17 [22%] patients on abatacept and 11 reactions in six [17%] on placebo). There was no increase in infections (32 [42%] patients on abatacept vs 15 [43%] on placebo) or neutropenia (seven [9%] vs five [14%]). Co-stimulation modulation with abatacept slowed reduction in β-cell function over 2 years. The beneficial effect suggests that T-cell activation still occurs around the time of clinical diagnosis of type 1 diabetes. Yet, despite continued administration of abatacept over 24 months, the decrease in β-cell function with abatacept was parallel to that with placebo after 6 months of treatment, causing us to speculate that T-cell activation lessens with time. Further observation will establish whether the beneficial effect continues after cessation of abatacept infusions. US National Institutes of Health.

The hypothalamus is the central regulator of systemic energy homeostasis, and its dysfunction can result in extreme body weight alterations. Insights into the complex cellular physiology of this region are critical to the understanding of obesity pathogenesis; however, human hypothalamic cells are largely inaccessible for direct study. Here, we developed a protocol for efficient generation of hypothalamic neurons from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) obtained from patients with monogenetic forms of obesity. Combined early activation of sonic hedgehog signaling followed by timed NOTCH inhibition in human ESCs/iPSCs resulted in efficient conversion into hypothalamic NKX2.1+ precursors. Application of a NOTCH inhibitor and brain-derived neurotrophic factor (BDNF) further directed the cells into arcuate nucleus hypothalamic-like neurons that express hypothalamic neuron markers proopiomelanocortin (POMC), neuropeptide Y (NPY), agouti-related peptide (AGRP), somatostatin, and dopamine. These hypothalamic-like neurons accounted for over 90% of differentiated cells and exhibited transcriptional profiles defined by a hypothalamic-specific gene expression signature that lacked pituitary markers. Importantly, these cells displayed hypothalamic neuron characteristics, including production and secretion of neuropeptides and increased p-AKT and p-STAT3 in response to insulin and leptin. Our results suggest that these hypothalamic-like neurons have potential for further investigation of the neurophysiology of body weight regulation and evaluation of therapeutic targets for obesity.

Glutamic acid decarboxylase (GAD) is a major target of the autoimmune response that occurs in type 1 diabetes mellitus. In animal models of autoimmunity, treatment with a target antigen can modulate aggressive autoimmunity. We aimed to assess whether immunisation with GAD formulated with aluminum hydroxide (GAD-alum) would preserve insulin production in recent-onset type 1 diabetes. Patients aged 3–45 years who had been diagnosed with type 1 diabetes for less than 100 days were enrolled from 15 sites in the USA and Canada, and randomly assigned to receive one of three treatments: three injections of 20 μg GAD-alum, two injections of 20 μg GAD-alum and one of alum, or 3 injections of alum. Injections were given subcutaneously at baseline, 4 weeks later, and 8 weeks after the second injection. The randomisation sequence was computer generated at the TrialNet coordinating centre. Patients and study personnel were masked to treatment assignment. The primary outcome was the baseline-adjusted geometric mean area under the curve (AUC) of serum C-peptide during the first 2 h of a 4-h mixed meal tolerance test at 1 year. Secondary outcomes included changes in glycated haemoglobin A 1c (HbA 1c) and insulin dose, and safety. Analysis included all randomised patients with known measurements. This trial is registered with ClinicalTrials.gov, number NCT00529399. 145 patients were enrolled and treated with GAD-alum (n=48), GAD-alum plus alum (n=49), or alum (n=48). At 1 year, the 2-h AUC of C-peptide, adjusted for age, sex, and baseline C-peptide value, was 0·412 nmol/L (95% CI 0·349–0·478) in the GAD-alum group, 0·382 nmol/L (0·322–0·446) in the GAD-alum plus alum group, and 0·413 nmol/L (0·351–0·477) in the alum group. The ratio of the population mean of the adjusted geometric mean 2-h AUC of C-peptide was 0·998 (95% CI 0·779–1·22; p=0·98) for GAD-alum versus alum, and 0·926 (0·720–1·13; p=0·50) for GAD-alum plus alum versus alum. HbA 1c, insulin use, and the occurrence and severity of adverse events did not differ between groups. Antigen-based immunotherapy therapy with two or three doses of subcutaneous GAD-alum across 4–12 weeks does not alter the course of loss of insulin secretion during 1 year in patients with recently diagnosed type 1 diabetes. Although antigen-based therapy is a highly desirable treatment and is effective in animal models, translation to human autoimmune disease remains a challenge. US National Institutes of Health.

Mutations in HNF1A cause Maturity Onset Diabetes of the Young (HNF1A-MODY). To understand mechanisms of β-cell dysfunction, we generated stem cell-derived pancreatic endocrine cells with hypomorphic mutations in HNF1 A. HNF1A- deficient β-cells display impaired basal and glucose stimulated-insulin secretion, reduced intracellular calcium levels in association with a reduction in CACNA1A expression, and accumulation of abnormal insulin granules in association with SYT13 down-regulation. Knockout of CACNA1A and SYT13 reproduce the relevant phenotypes. In HNF1A deficient β-cells, glibenclamide, a sulfonylurea drug used in the treatment of HNF1A-MODY patients, increases intracellular calcium, and restores insulin secretion. While insulin secretion defects are constitutive in β-cells null for HNF1A , β-cells heterozygous for hypomorphic HNF1A (R200Q) mutations lose the ability to secrete insulin gradually; this phenotype is prevented by correction of the mutation. Our studies illuminate the molecular basis for the efficacy of treatment of HNF1A-MODY with sulfonylureas, and suggest promise for the use of cell therapies. hPSCs model of Maturity Onset Diabetes of the Young caused by mutations in the transcription factor HNF1A (HNF1A-MODY), regulates the expression of genes required for the formation of dense-core insulin granules and calcium-dependent insulin secretion, demonstrating a basis to treat HNF1A-MODY patients with sulfonylureas.

Limitations in cell proliferation are important for normal function of differentiated tissues and essential for the safety of cell replacement products made from pluripotent stem cells, which have unlimited proliferative potential. To evaluate whether these limitations can be established pharmacologically, we exposed pancreatic progenitors differentiating from human pluripotent stem cells to small molecules that interfere with cell cycle progression either by inducing G 1 arrest or by impairing S phase entry or S phase completion and determined growth potential, differentiation, and function of insulin-producing endocrine cells. We found that the combination of G 1 arrest with a compromised ability to complete DNA replication promoted the differentiation of pancreatic progenitor cells toward insulin-producing cells and could substitute for endocrine differentiation factors. Reduced replication fork speed during differentiation improved the stability of insulin expression, and the resulting cells protected mice from diabetes without the formation of cystic growths. The proliferative potential of grafts was proportional to the reduction of replication fork speed during pancreatic differentiation. Therefore, a compromised ability to enter and complete S phase is a functionally important property of pancreatic endocrine differentiation, can be achieved by reducing replication fork speed, and is an important determinant of cell-intrinsic limitations of growth.