A Polygenic Score for Type 2 Diabetes Improves Risk Stratification Beyond Current Clinical Screening Factors in an Ancestrally Diverse Sample.

A substantial proportion of the adult United States population with type 2 diabetes (T2D) are undiagnosed, calling into question the comprehensiveness of current screening practices, which primarily rely on age, family history, and body mass index (BMI). We hypothesized that a polygenic score (PGS) may serve as a complementary tool to identify high-risk individuals. The T2D polygenic score maintained predictive utility after adjusting for family history and combining genetics with family history led to even more improved disease risk prediction. We observed that the PGS was meaningfully related to age of onset with implications for screening practices: there was a linear and statistically significant relationship between the PGS and T2D onset (-1.3 years per standard deviation of the PGS). Evaluation of U.S. Preventive Task Force and a simplified version of American Diabetes Association screening guidelines showed that addition of a screening criterion for those above the 90th percentile of the PGS provided a small increase the sensitivity of the screening algorithm. Among T2D-negative individuals, the T2D PGS was associated with prediabetes, where each standard deviation increase of the PGS was associated with a 23% increase in the odds of prediabetes diagnosis. Additionally, each standard deviation increase in the PGS corresponded to a 43% increase in the odds of incident T2D at one-year follow-up. Using complications and forms of clinical intervention (i.e., lifestyle modification, metformin treatment, or insulin treatment) as proxies for advanced illness we also found statistically significant associations between the T2D PGS and insulin treatment and diabetic neuropathy. Importantly, we were able to replicate many findings in a Hispanic/Latino cohort from our database, highlighting the value of the T2D PGS as a clinical tool for individuals with ancestry other than European. In this group, the T2D PGS provided additional disease risk information beyond that offered by traditional screening methodologies. The T2D PGS also had predictive value for the age of onset and for prediabetes among T2D-negative Hispanic/Latino participants. These findings strengthen the notion that a T2D PGS could play a role in the clinical setting across multiple ancestries, potentially improving T2D screening practices, risk stratification, and disease management.

The Risk of Type 2 Diabetes Mellitus in a Russian Population Cohort According to Data from the HAPIEE Project.

The aim of this study is to investigate the 14-year risk of type 2 diabetes mellitus (T2DM) and develop a risk score for T2DM in the Siberian cohort. A random population sample (males/females, 45-69 years old) was examined at baseline in 2003-2005 (Health, Alcohol, and Psychosocial Factors in Eastern Europe (HAPIEE) project, n = 9360, Novosibirsk) and re-examined in 2006-2008 and 2015-2017. After excluding those with baseline T2DM, the final analysis included 7739 participants. The risk of incident T2DM during a 14-year follow-up was analysed using Cox regression. In age-adjusted models, male and female hazard ratios (HR) of incident T2DM were 5.02 (95% CI 3.62; 6.96) and 5.13 (95% CI 3.56; 7.37) for BMI ≥ 25 kg/m2; 4.38 (3.37; 5.69) and 4.70 (0.27; 6.75) for abdominal obesity (AO); 3.31 (2.65; 4.14) and 3.61 (3.06; 4.27) for fasting hyperglycaemia (FHG); 2.34 (1.58; 3.49) and 3.27 (2.50; 4.26) for high triglyceride (TG); 2.25 (1.74; 2.91) and 2.82 (2.27; 3.49) for hypertension (HT); and 1.57 (1.14; 2.16) and 1.69 (1.38; 2.07) for family history of diabetes mellitus (DM). In addition, secondary education, low physical activity (PA), and history of cardiovascular disease (CVD) were also significantly associated with T2DM in females. A simple T2DM risk calculator was generated based on non-laboratory parameters. A scale with the best quality included waist circumference >95 cm, HT history, and family history of T2DM (area under the curve (AUC) = 0.71). The proposed 10-year risk score of T2DM represents a simple, non-invasive, and reliable tool for identifying individuals at a high risk of future T2DM.

Placenta and appetite genes GDF15 and IGFBP7 are associated with hyperemesis gravidarum.

Hyperemesis gravidarum (HG), severe nausea and vomiting of pregnancy, occurs in 0.3-2% of pregnancies and is associated with maternal and fetal morbidity. The cause of HG remains unknown, but familial aggregation and results of twin studies suggest that understanding the genetic contribution is essential for comprehending the disease etiology. Here, we conduct a genome-wide association study (GWAS) for binary (HG) and ordinal (severity of nausea and vomiting) phenotypes of pregnancy complications. Two loci, chr19p13.11 and chr4q12, are genome-wide significant (p < 5 × 10-8) in both association scans and are replicated in an independent cohort. The genes implicated at these two loci are GDF15 and IGFBP7 respectively, both known to be involved in placentation, appetite, and cachexia. While proving the casual roles of GDF15 and IGFBP7 in nausea and vomiting of pregnancy requires further study, this GWAS provides insights into the genetic risk factors contributing to the disease.

Extracellular matrix presentation modulates vascular smooth muscle cell mechanotransduction.

The development of atherosclerosis involves phenotypic changes among vascular smooth muscle cells (VSMCs) that correlate with stiffening and remodeling of the extracellular matrix (ECM). VSMCs are highly sensitive to the composition and mechanical state of the surrounding ECM, and ECM remodeling during atherosclerosis likely contributes to pathology. We hypothesized that ECM mechanics and biochemistry are interdependent in their regulation of VSMC behavior and investigated the effect of ligand presentation on certain stiffness-mediated processes. Our findings demonstrate that substrate stiffening is not a unidirectional stimulus-instead, the influence of mechanics on cell behavior is highly conditioned on ligand biochemistry. This "stiffness-by-ligand" effect was evident for VSMC adhesion, spreading, cytoskeletal polymerization, and focal adhesion assembly, where VSMCs cultured on fibronectin (Fn)-modified substrates showed an augmented response to increasing stiffness, whereas cells on laminin (Ln) substrates showed a dampened response. By contrast, cells on Fn substrates showed a decrease in myosin light chain (MLC) phosphorylation and elongation with increasing stiffness, whereas Ln supported an increase in MLC phosphorylation and no change in cell shape with increasing stiffness. Taken together, these findings show that identical cell populations exhibit opposing responses to substrate stiffening depending on ECM presentation. Our results also suggest that the shift in VSMC phenotype in a developing atherosclerotic lesion is jointly regulated by stromal mechanics and biochemistry. This study highlights the complex influence of the blood vessel wall microenvironment on VSMC phenotype and provides insight into how cells may integrate ECM biochemistry and mechanics during normal and pathological tissue function.

Thermo-responsive poly(N-isopropylacrylamide) grafted onto microtextured poly(dimethylsiloxane) for aligned cell sheet engineering.

Poly(N-isopropylacrylamide) (PNIPAAm)-grafted poly(dimethylsiloxane) (PDMS) offers an inexpensive, biocompatible, oxygen permeable, and easily microtextured thermo-responsive substrate for producing cell sheets. This study introduces a method of grafting PNIPAAm onto microtextured PDMS that is suitable for generating aligned vascular smooth muscle cell (VSMC) sheets. We examined a wide range of processing parameters in order to identify the conditions that led to acceptable sheet growth and detachment behavior. Substrates grafted under these conditions produced confluent cell sheets that fully detached in less than 10 min after lowering the culture temperature from 37 °C to 20 °C. The grafted layer thickness was determined to be 496±8 nm by atomic force microscopy. Surface characterization by Fourier transform infrared spectroscopy showed a relative grafting yield of 0.488±0.10, defined as the ratio of the PNIPAAm 1647 cm(-1) to the PDMS 2962 cm(-1) absorbance peaks. The water contact angle of the substrates was shown to change from 89.6° to 101.0° at 20 °C and 37 °C, respectively. We also found that cell behavior on PNIPAAm-grafted PDMS was not directly related to surface wettability or relative grafting densities.

Cell-cell interactions mediate the response of vascular smooth muscle cells to substrate stiffness.

The vessel wall experiences progressive stiffening with age and the development of cardiovascular disease, which alters the micromechanical environment experienced by resident vascular smooth muscle cells (VSMCs). In vitro studies have shown that VSMCs are sensitive to substrate stiffness, but the exact molecular mechanisms of their response to stiffness remains unknown. Studies have also shown that cell-cell interactions can affect mechanotransduction at the cell-substrate interface. Using flexible substrates, we show that the expression of proteins associated with cell-matrix adhesion and cytoskeletal tension is regulated by substrate stiffness, and that an increase in cell density selectively attenuates some of these effects. We also show that cell-cell interactions exert a strong effect on cell morphology in a substrate-stiffness dependent manner. Collectively, the data suggest that as VSMCs form cell-cell contacts, substrate stiffness becomes a less potent regulator of focal adhesion signaling. This study provides insight into the mechanisms by which VSMCs respond to the mechanical environment of the blood vessel wall, and point to cell-cell interactions as critical mediators of VSMC response to vascular injury.

The effect of stromal components on the modulation of the phenotype of human bronchial epithelial cells in 3D culture.

The stroma plays an important role in the development and progression of human diseases. Pulmonary diseases such as asthma, fibrosis and cancer are thought to be the result of altered communications between the epithelial and stromal tissue compartments. In order to study these epithelial-mesenchymal interactions, we developed a three dimensional (3D) in vitro model of the human airway that mimics bronchial morphology and function. This model consists of a type-I collagen matrix, normal human fetal lung fibroblasts (IMR-90) or primary human adult lung cancer-associated fibroblasts (LuCAFs), and a surface epithelium of normal human bronchial epithelial cells (HBECs). When cultured at an air-liquid interface (ALI), the epithelial component generated a well-differentiated pseudo-stratified bronchial epithelium that contained basal, ciliated, and non-ciliated (secretory) epithelial cells. IMR-90 and LuCAFs differentially altered the phenotype of HBECs in distinct ways. While IMR-90 permitted HBECs to form a typical respiratory surface epithelium, LuCAFs promoted HBECs to invade the collagen gel forming both epithelial nodules and cysts, suggesting that LuCAFs may alter the HBEC phenotype by modifying biomechanical signals conveyed through the extracellular matrix (ECM). Furthermore, LuCAFs secreted soluble factors that induced HBECs to express genes associated with immune responses, apoptosis, mitosis, cell survival, differentiation and cancer.

beta-Actin-derived peptides isolated from acidic extract of rat spleen suppress tumor cell growth.

Twenty-two fragments of beta-actin and beta-actin-related protein were isolated from the acidic extracts of rat spleen tissue. beta-Actin fragments (75-90), (78-89), and (78-88), 0.01-1 microM, decreased live cell number of L929 murine tumor fibroblasts by 80-90%, with maximal cytotoxic effect of 30-40%. The fragments of (78-90) segment and the fragment of beta-actin-related protein (69-77) were less active (inhibitory effect up to 55%, cytotoxic-up to 25%).

Stimulation of fibroblast proliferation by neokyotorphin requires Ca influx and activation of PKA, CaMK II and MAPK/ERK.

Neokyotorphin [TSKYR, hemoglobin alpha-chain fragment (137-141)] has previously been shown to enhance fibroblast proliferation, its effect depending on cell density and serum level. Here we show the dependence of the effect of neokyotorphin on cell type and its correlation with the effect of protein kinase A (PKA) activator 8-Br-cAMP, but not the PKC activator 4beta-phorbol 12-myristate, 13-acetate (PMA). In L929 fibroblasts, the proliferative effect of neokyotorphin was suppressed by the Ca2+ L-type channel inhibitors verapamil or nifedipine, the intracellular Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester, kinase inhibitors H-89 (PKA), KN-62 (Ca2+/calmodulin-dependent kinase II) and PD98059 (mitogen-activated protein kinase). The proliferative effect of 8-Br-cAMP was also suppressed by KN-62 and PD98059. PKC suppression (downregulation with PMA or inhibition with bisindolylmaleimide XI) did not affect neokyotorphin action. The results obtained point to a cAMP-like action for neokyotorphin.

Antitumor effect of valorphin in vitro and in vivo: combined action with cytostatic drugs.

The action of the cytostatic drugs (epirubicin and vincristine) in combination with the endogenous antiproliferative beta-hemoglobin fragment (33-39), valorphin, was studied in tumor (L929 and A549) cell cultures, primary culture of murine bone marrow cells and in murine model of breast carcinoma in vivo. Simultaneous application of 1 microM valorphin and 1 microM epirubicin, in vitro, did not result in an additive suppressive effect on cell culture growth. Additive effects were achieved with alternating applications of the peptide and the drugs, namely, 0.5 microM (but not 1 microM) epirubicin added 24 h prior to 1 microM valorphin; 1 microM valorphin added 48 h prior to 0.1 microM epirubicin, or 0.1 microM vincristine, or 0.05 microM vincristine, which resulted in 100% cell death in the both series with vincristine and up to 78% cell biomass reduction in the experiments with epirubicin. In the in vivo model (female BLRB mice with subcutaneously inoculated syngeneic mammary carcinoma), simultaneous treatment with 25 mg/m(2) epirubicin and 1 mg/kg valorphin resulted in 42% of tumor growth inhibition, as compared with the negative control group and 22% inhibition as compared with the epirubcin-treated group (at 20th day of treatment). Survival was significantly improved (69% compared to 39% in the group treated with epirubicin only) at day 26 after the treatment beginning.

What to synthesize? From Emil Fischer to peptidomics.

The driving forces, incentives and strategic targets of peptide synthesis have undergone considerable evolution during the centenary following the pioneer work of Emil Fischer. In those days peptide synthesis was considered as a way of confirming the polypeptide theory of protein structure. The scientific community also expected (naively) that the synthesis would eventually lead to the creation of artificial living organisms. Only in the 1950s, when the first exact amino acid sequences were established did peptide chemistry obtain firmer ground and clearly defined targets. The total synthesis of peptide hormones and antibiotics became possible, providing valuable material for elucidating structure-functional relationships and the mechanisms of biological action. In the following years the number of peptides isolated from various biological sources grew with impressive speed and peptides became known as the most abundant, ubiquitous group of low molecular bioregulators. The design and synthesis of novel peptide based pharmaceuticals became an important area of peptide chemistry. At present we are facing the challenge of analysing the structures and bioactivities of total sets of peptides, i.e. peptidoms, present in concrete tissues or groups of cells. The results obtained along these lines at the IBCH RAS Institute of Bioorganic Chemistry are briefly considered in the review.

Proliferative activity of neokyotorphin-related hemoglobin fragments in cell cultures.

alpha-Hemoglobin fragments alpha-(133-141), alpha-(134-141), alpha-(135-141), alpha-(137-141), alpha-(134-140), alpha-(133-138), alpha-(134-140) and alpha-(137-138) stimulate L929 tumor cell proliferation, alpha-(134-141) being the most active. alpha-(134-141) stimulates proliferation of M3 melanoma cells, murine embryonic fibroblasts, primary cultures of red bone marrow and spleen cells. In L929 cells the effect of alpha-(134-141) is cell density independent; in M3 cells alpha-(137-141) and alpha-(134-141) are most active at density 10,000 cells/well (96 well plate) independently on FBS content.

Family of hemorphins: co-relations between amino acid sequences and effects in cell cultures.

Hemorphins, i.e. endogenous fragments of beta-globin chain segment (32-41) LVVYPWTQRY(F) suppress the growth of transformed murine fibroblasts L929 cell culture, the effect is due to cytotoxicity and inhibition of cell proliferation. The contribution of cytotoxicity depends on the presence of Leu(32): VV-hemorphins, except VV-hemorphin-4, exhibit cytotoxicity significantly higher than respective LVV-hemorphins. Decrease of cell number induced by hemorphins depend on the extent of N- and C-terminal degradation of hemorphins: VV-hemorphins in most cases are more active than LVV-, V-hemorphins, and hemorphins. In the group of VV-hemorphins the activity of VV-hemorphin-5 (valorphin) is significantly higher than of VV-hemorphin-7, VV-hemorphin-6, and VV-hemorphin-4, meaning that the presence of C-terminal Gln is important for suppressing of cell number. The amino acid sequence VVYPWTQ corresponding to valorphin was identified as important for manifestation of the both cytotoxic and antiproliferative effects.