Embryonic vitamin D deficiency programs hematopoietic stem cells to induce type 2 diabetes

Environmental factors may alter the fetal genome to cause metabolic diseases. It is unknown whether embryonic immune cell programming impacts the risk of type 2 diabetes in later life. We demonstrate that transplantation of fetal hematopoietic stem cells (HSCs) made vitamin D deficient in utero induce diabetes in vitamin D-sufficient mice. Vitamin D deficiency epigenetically suppresses Jarid2 expression and activates the Mef2/PGC1a pathway in HSCs, which persists in recipient bone marrow, resulting in adipose macrophage infiltration. These macrophages secrete miR106-5p, which promotes adipose insulin resistance by repressing PIK3 catalytic and regulatory subunits and down-regulating AKT signaling. Vitamin D-deficient monocytes from human cord blood have comparable Jarid2/Mef2/PGC1a expression changes and secrete miR-106b-5p, causing adipocyte insulin resistance. These findings suggest that vitamin D deficiency during development has epigenetic consequences impacting the systemic metabolic milieu.

Safety, tolerability, and effectiveness of the sodium-glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin in combination with standard chemotherapy for patients with advanced, inoperable pancreatic adenocarcinoma: a phase 1b observational study

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy. Thus, there is an urgent need for safe and effective novel therapies. PDAC's excessive reliance on glucose metabolism for its metabolic needs provides a target for metabolic therapy. Preclinical PDAC models have demonstrated that targeting the sodium-glucose co-transporter-2 (SGLT2) with dapagliflozin may be a novel strategy. Whether dapagliflozin is safe and efficacious in humans with PDAC is unclear.

METHODS

We performed a phase 1b observational study (ClinicalTrials.gov ID NCT04542291; registered 09/09/2020) to test the safety and tolerability of dapagliflozin (5 mg p.o./day × 2 weeks escalated to 10 mg p.o./day × 6 weeks) added to standard Gemcitabine and nab-Paclitaxel (GnP) chemotherapy in patients with locally advanced and/or metastatic PDAC. Markers of efficacy including Response Evaluation Criteria in Solid Tumors (RECIST 1.1) response, CT-based volumetric body composition measurements, and plasma chemistries for measuring metabolism and tumor burden were also analyzed.

RESULTS

Of 23 patients who were screened, 15 enrolled. One expired (due to complications from underlying disease), 2 dropped out (did not tolerate GnP chemotherapy) during the first 4 weeks, and 12 completed. There were no unexpected or serious adverse events with dapagliflozin. One patient was told to discontinue dapagliflozin after 6 weeks due to elevated ketones, although there were no clinical signs of ketoacidosis. Dapagliflozin compliance was 99.4%. Plasma glucagon increased significantly. Although abdominal muscle and fat volumes decreased; increased muscle-to-fat ratio correlated with better therapeutic response. After 8 weeks of treatment in the study, partial response (PR) to therapy was seen in 2 patients, stable disease (SD) in 9 patients, and progressive disease (PD) in 1 patient. After dapagliflozin discontinuation (and chemotherapy continuation), an additional 7 patients developed the progressive disease in the subsequent scans measured by increased lesion size as well as the development of new lesions. Quantitative imaging assessment was supported by plasma CA19-9 tumor marker measurements.

CONCLUSIONS

Dapagliflozin is well-tolerated and was associated with high compliance in patients with advanced, inoperable PDAC. Overall favorable changes in tumor response and plasma biomarkers suggest it may have efficacy against PDAC, warranting further investigation.

Clinical implications and guidelines for CKD in type 2 diabetes

BACKGROUND

Chronic kidney disease (CKD) is a complication of type 2 diabetes (T2D) with high morbidity and mortality. The prevalence of CKD in T2D is increasing due to rising numbers of persons with T2D. Multiple clinical trials have been conducted testing novel therapies to reduce the progression of CKD, cardiovascular morbidity, in particular hospitalization for heart failure, and mortality. Results of these clinical trials have informed guidelines for the management of CKD in T2D.

METHODS

The epidemiology of CKD in T2D and the process of guideline writing, including data gathering, grading and consensus development, were reviewed. Recent guidelines for the management of CKD in T2D that include recent renal outcome clinical trials are reported, along with supporting evidence.

RESULTS

All current guidelines recommend annual screening for CKD, control of blood pressure and glucose, although the target levels and background therapy recommendations vary. Renin-angiotensin system (RAS) inhibition is uniformly recommended. Sodium-glucose cotransporter-2 (SGLT2) inhibition with proven agents is recommended by all guidelines, with minor variations in suggested estimated glomerular filtration rate and albuminuria levels. Finerenone, the first nonsteroidal mineralocorticoid receptor antagonist with renal outcome data, is recommended by the most recent guideline available.

CONCLUSIONS

Current guidelines continue to recommend screening for CKD, blood pressure control using RAS inhibition as first-line therapy, and glucose control. SGLT2 inhibition and finerenone are recent additions to current guidelines to improve CKD outcomes in T2D, based on robust clinical trial data.

Immunity and Hypertension

Hypertension is the primary cause of cardiovascular mortality. Despite multiple existing treatments, only half of those with the disease achieve adequate control. Therefore, understanding the mechanisms causing hypertension is essential for the development of novel therapies. Many studies demonstrate that immune cell infiltration of the vessel wall, kidney and central nervous system, as well as their counterparts of oxidative stress, the renal renin-angiotensin system (RAS) and sympathetic tone play a critical role in the development of hypertension. Genetically modified mice lacking components of innate and/or adaptive immunity confirm the importance of chronic inflammation in hypertension and its complications. Depletion of immune cells improves endothelial function, decreases oxidative stress, reduces vascular tone and prevents renal interstitial infiltrates, sodium retention and kidney damage. Moreover, the ablation of microglia or central nervous system perivascular macrophages reduces RAS-induced inflammation and prevents sympathetic nervous system activation and hypertension. Therefore, understanding immune cell functioning and their interactions with tissues that regulate hypertensive responses may be the future of novel antihypertensive therapies.

Update on Biosimilar Insulins: A US Perspective

The development of biosimilar insulin products has slowly evolved with only two follow-on biologics currently available to patients in the US. Both Basaglar^® (insulin glargine) and Admelog^® (insulin lispro) have undergone extensive testing, and have gained significant use by patients in the US. Despite the availability of these follow-on products, the price of insulin has remained stubbornly high. New regulatory guidance under the Biologics Price Competition and Innovations Act that came into effect in March 2020 introduced an abbreviated pathway for the approval of biosimilar insulins and introduced the option to apply for interchangeability of the biosimilar insulin with the reference product. This abbreviated clinical testing may open the doors for numerous follow-on insulin products, with unknown supply-chain and fiscal ramifications. This review will highlight the development process of biosimilar insulin in the US and the recent regulatory changes that can aid this process. We will also discuss challenges for prescribers and patients who are navigating this ever-changing landscape. These new regulations for biosimilar insulins will have ramifications for patients, healthcare providers, and third-party payers, though the direction and scope of these changes is unclear.

Vitamin D3 supplementation decreases a unique circulating monocyte cholesterol pool in patients with type 2 diabetes

Cross-sectional studies indicate consistent associations between low 25(OH)D concentration and increased risk of cardiovascular disease (CVD), but results of randomized control trials (RCTs) are mixed. However, the majority of the RCTs do not focus on type 2 diabetics, potentially obscuring the effects of vitamin D in this population. In vitro 1,25(OH)₂D₃ downregulates macrophage cholesterol deposition, but the in vivo effects are unknown. To explore potential mechanisms of the effects of vitamin D on CVD risk in patients with type 2 diabetes, we isolated monocytes in a subset of 26 patients from our RCT of diabetics with baseline serum 25(OH)D <25ng/mL randomized to vitamin D₃ 4000 IU/day or placebo for 4 months. Upon enrollment, the mean 25(OH)D level was 17ng/mL, which increased to 36ng/mL after vitamin D and remained unchanged in the placebo group. Before randomization, groups demonstrated similar mean hemoglobin A1c and plasma lipids levels, none of which was significantly altered by vitamin D supplementation. Moreover, assessment of oxidized LDL uptake in monocytes cultured in the patient's own serum before vs. after treatment resulted in >50% reduction in the vitamin D group with no change in the placebo group. This was mediated through suppression of endoplasmic reticulum stress and scavenger receptor CD36 protein expression. The reduction in monocyte cholesterol uptake was reflected in a 19% decrease in total monocyte cholesterol content. Interestingly, cross-sectional analysis of circulating monocytes from vitamin D-deficient vs. sufficient diabetic patients revealed 8-fold higher cholesteryl ester content, confirming the capacity of these monocytes to uptake and carry cholesterol in the circulation. This study identifies a unique circulating cholesterol pool within monocytes that is modulated by vitamin D and has the potential to contribute to CVD in type 2 diabetes.

Deletion of JNK2 prevents vitamin-D-deficiency-induced hypertension and atherosclerosis in mice

The c-Jun N-terminal kinase 2 (JNK2) signaling pathway contributes to inflammation and plays a key role in the development of obesity-induced insulin resistance and cardiovascular disease. Macrophages are key cells implicated in these metabolic abnormalities. Active vitamin D downregulates macrophage JNK activation, suppressing oxidized LDL cholesterol uptake and foam cell formation and promoting an anti-inflammatory phenotype. To determine whether deletion of JNK2 prevents high blood pressure and atherosclerosis known to be induced by vitamin D deficiency in mice, we generated mice with knockout of JNK2 in a background susceptible to diet-induced atherosclerosis (LDLR^-/-). JNK2^-/- LDLR^-/- and LDLR^-/- control mice were fed vitamin D-deficient chow for 8 weeks followed by vitamin D-deficient high fat diet (HFD) for 10 weeks and assessed before and after HFD. There was no difference in fasting glucose, cholesterol, triglycerides, or free fatty acid levels. However, JNK2^-/- mice, despite vitamin D-deficient diet, had 20-30mmHg lower systolic (SBP) and diastolic (DBP) blood pressure before HFD compared to control mice fed vitamin D-deficient diets, with persistent SBP differences after HFD. Moreover, deletion of JNK2 reduced HFD-induced atherosclerosis by 30% in the proximal aorta when compared to control mice fed vitamin D-deficient diets. We have previously shown that peritoneal macrophages obtained from LDLR^-/- mice fed vitamin D-deficient HFD diets have higher foam cell formation compared to those from mice on vitamin D-sufficient HFD. The increased total cellular cholesterol and modified cholesterol uptake in macrophages from mice on vitamin D-deficient HFD were blunted by deletion of JNK2. These data suggest that JNK2 signaling activation is necessary for the atherosclerosis and hypertension induced by vitamin D deficiency.

[A cross-sectional survey of receiving no methadone maintenance treatment in HIV infected injecting drug users in Dehong Dai and Jingpo autonomous prefecture, Yunnan province]

Objective: To understand the current status of receiving no methadone maintenance treatment (MMT) and influencing factors in HIV infected injecting drug users (IDUs) in Dehong Dai and Jingpo autonomous prefectures, Yunnan province. Methods: Data of survival of IDUs with AIDS in Dehong were collected from " Chinese National Comprehensive HIV/AIDS and Care Information System" in December, 2014. Results: There were 987 IDUs who should receive MMT, the majority of them were males (94.6%, 934/987), aged 35-44 years (53.0%, 523/987) and farmers (77.2%, 762/987). Among the 987 IDUs, 60.2% (592/987) received no MMT. Multivariate logistic regression analysis showed that being female (OR=2.66, 95%CI: 1.21-5.87), in Jingpo ethnic group (OR=3.05, 95% CI: 1.97-4.71) were the major risk factors for receiving no MMT; not being farmers (OR=0.46, 95%CI: 0.31-0.70), in Dai ethnic group (OR=0.53, 95%CI: 0.36-0.79), diagnosed HIV infection history ≥10 years (OR=0.60, 95%CI: 0.45-0.81) were the major protective factors for receiving no MMT. The reasons for receiving no MMT included long distance journey (289, 48.8%), fear of exposure (124, 20.9%), poor daily medication compliance (59, 10.0%), fear of side effects (47, 7.9%), others (73, 12.3%). Conclusions: The proportion of receiving no MMT in IDUs with AIDS in Dehong was high. Being female and farmer, in Jingpo ethnic group, low educational level, short diagnosed HIV infection history were influencing factors for receiving no MMT. The effective intervention measures should be taken to further improve MMT coverage according to the different characteristics of the patients.

Predictive factors for open conversion of laparoscopic adrenalectomy: a 13-year review of 456 cases

BACKGROUND AND PURPOSE

Laparoscopic adrenalectomy has largely replaced open adrenalectomy for the treatment of adrenal tumor. However, certain cases still require conversion to open procedures. Identifying the risk of conversion remains difficult. This study identified risk factors that may predict conversion from a laparoscopic to an open procedure.

PATIENTS AND METHODS

From January 1993 to September 2006, a total of 456 laparoscopic adrenalectomies were performed at two urologic centers. A retrospective analysis of parameters, including tumor size, patient age, American Society of Anesthesiology classification, body mass index (BMI), sex, laparoscopic approach, previous abdominal surgery, laterality, type of tumor, laparoscopist experience, and surgeon, was performed. Multivariate logistic regression was used to identify those variables predicting conversion.

RESULTS

A total of 25 (5.5%) laparoscopic adrenalectomies required conversion. Significant predictors of conversion according to univariate analysis were tumor size > or =5 cm, BMI > or =24 kg/m(2), and pheochromocytoma. Multivariate analysis showed that the significant independent predictive factors for conversion were tumor size > or =5 cm (8.884 greater odds ratio [OR] of conversion; 95% confidence interval 3.543, 22.277; P < 0.001), BMI > or = 24 kg/m(2) (OR 3.632; 95% confidence interval 1.367, 9.648; P = 0.010), and pheochromocytoma (OR 3.068; 95% confidence interval 1.175, 8.007; P = 0.022).

CONCLUSIONS

Knowledge of tumor size, BMI, and tumor type can help in counseling patients undergoing laparoscopic adrenalectomy with regard to the probability of conversion. The size of the tumor was found to be the most important predictor.

High frequency of level II-V lymph node involvement in RET/PTC positive papillary thyroid carcinoma

AIMS

To investigate the frequency and clinical significance of RET rearrangement in Chinese patients with papillary thyroid carcinoma (PTC) and discuss the role of RET rearrangement in therapeutic decision-making after the performance of level VI lymph node dissection and the 2002 AJCC staging system.

METHODS

RET/PTC-1 and RET/PTC-3 were detected in 126 PTCs using reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing.

RESULTS

RET rearrangement was detected in 18 cases of PTC. The patient group aged < 20 years had the highest frequency (3/6) of RET rearrangement among the age groups (< 20 years, 20-40 years and > or = 40 years; P=0.03). RET/PTC-1 positive patients were more likely to suffer from Hashimoto's thyroiditis simultaneously (P=0.02) while RET/PTC-3 positive patients had a higher frequency of extrathyroidal extension (P<0.01) and advanced T classification (P<0.01). RET rearrangement (OR=8.70, 95% CI 1.69-44.81), male (OR=3.88, 95% CI 1.41-10.69), age (OR=0.96, 95% CI 0.93-0.99), multifocality (OR=3.54, 95% CI 1.33-9.41) and advanced T classification (OR=7.32, 95% CI 2.91-18.40) were all identified as risk factors of level II-V lymph node involvement in the multivariate analysis.

CONCLUSIONS

The frequency of RET rearrangement in Chinese patients is low and age related. RET/PTC-1 and RET/PTC-3 are associated with different clinical pathological characteristics but not with lymph node involvement. The RET/PTC positive patients should receive more attention to lateral neck in the management of PTC.

Genetic dissection of ethanol tolerance in the budding yeast Saccharomyces cerevisiae

Uncovering genetic control of variation in ethanol tolerance in natural populations of yeast Saccharomyces cerevisiae is essential for understanding the evolution of fermentation, the dominant lifestyle of the species, and for improving efficiency of selection for strains with high ethanol tolerance, a character of great economic value for the brewing and biofuel industries. To date, as many as 251 genes have been predicted to be involved in influencing this character. Candidacy of these genes was determined from a tested phenotypic effect following gene knockout, from an induced change in gene function under an ethanol stress condition, or by mutagenesis. This article represents the first genomics approach for dissecting genetic variation in ethanol tolerance between two yeast strains with a highly divergent trait phenotype. We developed a simple but reliable experimental protocol for scoring the phenotype and a set of STR/SNP markers evenly covering the whole genome. We created a mapping population comprising 319 segregants from crossing the parental strains. On the basis of the data sets, we find that the tolerance trait has a high heritability and that additive genetic variance dominates genetic variation of the trait. Segregation at five QTL detected has explained approximately 50% of phenotypic variation; in particular, the major QTL mapped on yeast chromosome 9 has accounted for a quarter of the phenotypic variation. We integrated the QTL analysis with the predicted candidacy of ethanol resistance genes and found that only a few of these candidates fall in the QTL regions.

Constructing genetic linkage maps under a tetrasomic model

An international consortium has launched the whole-genome sequencing of potato, the fourth most important food crop in the world. Construction of genetic linkage maps is an inevitable step for taking advantage of the genome projects for the development of novel cultivars in the autotetraploid crop species. However, linkage analysis in autopolyploids, the kernel of linkage map construction, is theoretically challenging and methodologically unavailable in the current literature. We present here a theoretical analysis and a statistical method for tetrasomic linkage analysis with dominant and/or codominant molecular markers. The analysis reveals some essential properties of the tetrasomic model. The method accounts properly for double reduction and incomplete information of marker phenotype in regard to the corresponding phenotype in estimating the coefficients of double reduction and recombination frequency and in testing their significance by using the marker phenotype data. Computer simulation was developed to validate the analysis and the method and a case study with 201 AFLP and SSR markers scored on 228 full-sib individuals of autotetraploid potato is used to illustrate the utility of the method in map construction in autotetraploid species.

Modeling population genetic data in autotetraploid species

Allozyme and PCR-based molecular markers have been widely used to investigate genetic diversity and population genetic structure in autotetraploid species. However, an empirical but inaccurate approach was often used to infer marker genotype from the pattern and intensity of gel bands. Obviously, this introduces serious errors in prediction of the marker genotypes and severely biases the data analysis. This article developed a theoretical model to characterize genetic segregation of alleles at genetic marker loci in autotetraploid populations and a novel likelihood-based method to estimate the model parameters. The model properly accounts for segregation complexities due to multiple alleles and double reduction at autotetrasomic loci in natural populations, and the method takes appropriate account of incomplete marker phenotype information with respect to genotype due to multiple-dosage allele segregation at marker loci in tetraploids. The theoretical analyses were validated by making use of a computer simulation study and their utility is demonstrated by analyzing microsatellite marker data collected from two populations of sycamore maple (Acer pseudoplatanus L.), an economically important autotetraploid tree species. Numerical analyses based on simulation data indicate that the model parameters can be adequately estimated and double reduction is detected with good power using reasonable sample size.

Theoretical basis for genetic linkage analysis in autotetraploid species

Linkage analysis in autotetraploid species has been an historical challenge in quantitative genetics theory and is a stumbling block that urgently needs to be removed in the rapidly emerging genome research on this species, such as cultivated potato. This article presents theory of a full model of tetrasomic linkage and develops a statistical framework for the linkage analysis. The model considers both double reduction and recombination, the most essential features of tetrasomic inheritance with linked loci, whereas the statistical method takes appropriate account of the major complexities in analyzing both dominant and codominant molecular marker data during map reconstruction in tetraploid species. These complexities include the problems arising from multiple dosage of allelic inheritance, the null allele, allelic segregation distortion, mixed bivalent and quadrivalent pairing in meiosis, and incomplete information of marker phenotype data. The theoretical analysis established the relationship between the coefficients of double reduction at linked loci, which is essential in the present tetrasomic linkage analysis and in assessing the impact of double reduction on the evolution of tetraploid populations. The statistical method, based on the combination of theoretical analysis and a computer-based algorithm, provided analytical tools for predicting the maximum-likelihood estimates of the model parameters. A simulation study showed the feasibility of a practical implementation of the method, detailed the procedure of the analysis, validated the power and reliability in the parameter estimation, and compared the present method with those proposed in the current literature.

Factors governing selective formation of specific disulfides in synthetic variants of alpha-conotoxin

alpha-Conotoxin GI is a snail toxin protein consisting of 13 amino acids cross-linked by 2 intramolecular disulfide bridges. This toxin is an antagonist of acetylcholine receptors. The native sequence has been synthesized, along with nine additional variants in which non-cysteine residues are replaced by alanine or the cysteine positions are altered. Each reduced peptide has been oxidized by reaction with oxygen or glutathione both in a folding buffer and in 6 M guanidine hydrochloride. Purified products of oxidation have been characterized with respect to molecular weights and the positions of disulfides. The four cysteines in conotoxin can form two intramolecular disulfides in three different combinations. Relative yields of each of the three isomers have been determined, thereby permitting evaluation of the roles of non-cysteine residues and cysteine placements in the folding of conotoxin. Cysteine positions dominate factors directing formation of the nativelike isomer in a manner that may be predicted from equilibrium constants for loop formation in model peptides containing two cysteines. Alanine substitutions at several positions which are conserved in naturally occurring conotoxins affect the discrimination between the two most favored disulfide arrangements. Substitutions at three nonconserved positions have no structural effect on isomer yields. It therefore is possible to vary these latter three positions in a manner which might help to generate a functional binding surface which is complementary to receptors in the specific prey of a particular species of snail, without affecting the toxin's folding.

Dependence of formation of small disulfide loops in two-cysteine peptides on the number and types of intervening amino acids

Microscopic disulfide-exchange rate constants have been measured for the formation and opening of small disulfide loops in reactions between glutathione and peptides containing 2 cysteines. Twelve cysteine-Xm-cysteine peptides have been studied, where X is an amino acid and m is the number of amino acids between the cysteines. Homopolymers of alanine for m equaling 0-5 are evaluated, as well as X1 and X2 series employing glycine, valine, or proline. Equilibrium constants Kc for loop closing are only slightly dependent on the nature of X. Loops with even values of m generally are favored relative to loops with odd values. Kc increases in the rank order X1, X3, X0, X5, X4, and X2. Formation of a disulfide between sequentially adjacent cysteines therefore is not especially difficult. The dependence of Kc on the odd-even nature of m is compared with similar patterns observed both in statistics of disulfide formation in naturally occurring proteins and in theoretical studies of peptide cyclization. The relative equilibrium populations of intramolecular disulfides in peptides containing cysteine-cysteine-cysteine and cysteine-serine-cysteine-serine-cysteine clusters are consistent with predictions based on the values of Kc in the two-cysteine peptides.