Karolinska Institutet

About: Karolinska Institutet is a education organization based out in Stockholm, Sweden. It is known for research contribution in the topics: Population & Cancer. The organization has 46212 authors who have published 121142 publications receiving 6008130 citations.

The Hyperglycemia and Adverse Pregnancy Outcome Study: Associations of GDM and obesity with pregnancy outcomes

Abstract: OBJECTIVE To determine associations of gestational diabetes mellitus (GDM) and obesity with adverse pregnancy outcomes in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study. RESEARCH DESIGN AND METHODS Participants underwent a 75-g oral glucose tolerance test (OGTT) between 24 and 32 weeks. GDM was diagnosed post hoc using International Association of Diabetes and Pregnancy Study Groups criteria. Neonatal anthropometrics and cord serum C-peptide were measured. Adverse pregnancy outcomes included birth weight, newborn percent body fat, and cord C-peptide >90th percentiles, primary cesarean delivery, preeclampsia, and shoulder dystocia/birth injury. BMI was determined at the OGTT. Multiple logistic regression was used to examine associations of GDM and obesity with outcomes. RESULTS Mean maternal BMI was 27.7, 13.7% were obese (BMI ≥33.0 kg/m 2 ), and GDM was diagnosed in 16.1%. Relative to non-GDM and nonobese women, odds ratio for birth weight >90th percentile for GDM alone was 2.19 (1.93, 2.47), for obesity alone 1.73 (1.50, 2.00), and for both GDM and obesity 3.62 (3.04, 4.32). Results for primary cesarean delivery and preeclampsia and for cord C-peptide and newborn percent body fat >90th percentiles were similar. Odds for birth weight >90th percentile were progressively greater with both higher OGTT glucose and higher maternal BMI. There was a 339-g difference in birth weight for babies of obese GDM women, compared with babies of normal/underweight women (64.2% of all women) with normal glucose based on a composite OGTT measure of fasting plasma glucose and 1- and 2-h plasma glucose values (61.8% of all women). CONCLUSIONS Both maternal GDM and obesity are independently associated with adverse pregnancy outcomes. Their combination has a greater impact than either one alone.

Cells release subpopulations of exosomes with distinct molecular and biological properties

Abstract: Cells release nano-sized membrane vesicles that are involved in intercellular communication by transferring biological information between cells. It is generally accepted that cells release at least three types of extracellular vesicles (EVs): apoptotic bodies, microvesicles and exosomes. While a wide range of putative biological functions have been attributed to exosomes, they are assumed to represent a homogenous population of EVs. We hypothesized the existence of subpopulations of exosomes with defined molecular compositions and biological properties. Density gradient centrifugation of isolated exosomes revealed the presence of two distinct subpopulations, differing in biophysical properties and their proteomic and RNA repertoires. Interestingly, the subpopulations mediated differential effects on the gene expression programmes in recipient cells. In conclusion, we demonstrate that cells release distinct exosome subpopulations with unique compositions that elicit differential effects on recipient cells. Further dissection of exosome heterogeneity will advance our understanding of exosomal biology in health and disease and accelerate the development of exosome-based diagnostics and therapeutics.

Lgr6 Marks Stem Cells in the Hair Follicle That Generate All Cell Lineages of the Skin

Abstract: Mammalian epidermis consists of three self-renewing compartments: the hair follicle, the sebaceous gland, and the interfollicular epidermis. We generated knock-in alleles of murine Lgr6, a close relative of the Lgr5 stem cell gene. Lgr6 was expressed in the earliest embryonic hair placodes. In adult hair follicles, Lgr6+ cells resided in a previously uncharacterized region directly above the follicle bulge. They expressed none of the known bulge stem cell markers. Prenatal Lgr6+ cells established the hair follicle, sebaceous gland, and interfollicular epidermis. Postnatally, Lgr6+ cells generated sebaceous gland and interfollicular epidermis, whereas contribution to hair lineages gradually diminished with age. Adult Lgr6+ cells executed long-term wound repair, including the formation of new hair follicles. We conclude that Lgr6 marks the most primitive epidermal stem cell.

Topogenic signals in integral membrane proteins.

Abstract: Integral membrane proteins are characterized by long apolar segments that cross the lipid bilayer. Polar domains flanking these apolar segments have a more balanced amino acid composition, typical for soluble proteins. We show that the apolar segments from three different kinds of membrane-assembly signals do not differ significantly in amino acid content, but that the inside/outside location of the polar domains correlates strongly with their content of arginyl and lysyl residues, not only for bacterial inner-membrane proteins, but also for eukaryotic.proteins from the endoplasmic reticulum, the plasma membrane, the inner mitochondrial membrane, and the chloroplast thylakoid membrane. A positive-inside rule thus seems to apply universally to all integral membrane proteins, with apolar regions targeting for membrane integration and charged residues providing the topological information.