Biology subjects

Jansson, E.

Publications and source records attributed to Jansson, E..

6 recordsLinked to original sources

bioRxiv2026

Acute Sprint Exercise Transcriptome in Human Adipose Tissue: Associations with Growth Hormone

It was hypothesised that sprint exercise induces changes in adipose tissue (AT) gene expression related to lipolysis, and that growth hormone (GH) acts as a stimulus. Twelve healthy males and females perform 3x30-s all-out cycle sprints (SIT) and six unloaded cycling (CON). AT biopsies were performed pre and 2 hours post-exercise. Serum GH response was greater in SIT than CON, but no enrichment of differentially expressed genes (DEGs) related to lipolysis was found in AT. However, the GH-receptor was one of few DEGs in AT with interaction between SIT and CON and exercise-induced changes in expression of the pre-selected GH-related targets, CISH, PTEN and G0S2 were associated with exercise-induced increase in GH. This supports a GH-mediated effect of SIT on lipolysis. In a genome-wide analysis, exercise-induced changes in expression of ARHGAP24, TAF4B, ARID5B, MIR604 and MIR938, were associated with increase in GH. The function of these genes is not well understood, but some relationship to AT has earlier been demonstrated Sex influenced GH-response to exercise and expression of the GH-responsive gene CISH. Among the most downregulated genes were the core clock genes PER1, NR1D1 and CIART, which decreased in both SIT and CON. This underscores the necessity to control for diurnal variations and sex in future exercise studies on regulation of AT lipolysis.

physiology↗

bioRxiv2025

Genome-wide differentiation and SNP-based identification of northeastern Atlantic Sebastes species

Sustainable fisheries require reliable species identification and understanding of the underlying genetic hierarchies within the targeted species. Three Sebastes species are commonly found in the northeastern Atlantic: Sebastes mentella (beaked redfish), Sebastes norvegicus (golden redfish), and Sebastes viviparus (Norway redfish). These species are morphologically similar and have largely overlapping distribution ranges. Besides, three cryptic species for S. norvegicus and three depth-defined ecotypes for S. mentella have been suggested. Genetic knowledge and methods are needed to identify and monitor these species and to look at their geographic distribution. Here, a total of 99 specimens of S. mentella, S. viviparus as well as S. norvegicus A and B were sequenced in pools and aligned against a reference genome from a sister species, S. fasciatus (Acadian redfish). The measured divergence between all pairs, including the cryptic species pair S. norvegicus A and B, was high (mean FST = 0.33-0.61) and encompassing throughout genomes. Several shared megabase-scale regions of elevated divergence were observed, likely representing regions of reduced recombination. Moreover, 2914 fish collected across the northeastern Atlantic were analysed with a discriminatory SNP panel of high resolution (mean FST= 0.60-0.91), revealed few possible hybrids, and supported further sub-structuring within mentella and S. norvegicus B. The latter was split into two groups, one of which was the previously recognized giant morph and confirmed here for the first time in Norway. Sebastes mentella had two to three groups, likely representing previously identified depth-related ecotypes. Our study shows high genetic distinctiveness between acknowledged northeast-Atlantic Sebastes species, and between the cryptic species S. norvegicus A and B. Previously identified, fast-growing giant seems to be closely related to S. norvegicus B. Only few SNP markers are necessary for accurate species determination, facilitating further studies and widely applicable monitoring.

genetics↗

bioRxiv2024

Loss of chromogranin A and catestatin affect pancreatic islet homeostasis, endocrine function, and neurotransmitters

Chromogranin A (CgA), a neuroendocrine pro-hormone, undergoes proteolytic cleavage to yield bioactive peptides, notably catestatin (CST) and pancreastatin (PST), which exert opposing effects on metabolic and inflammatory processes. Using CgA and CST knockout (KO) mice, this study investigated their roles in pancreatic endocrine function, morphology, neurotransmitter dynamics, and systemic glucose homeostasis. CST deficiency induced insulin resistance, altered islet architecture, and heightened catecholamine levels, whereas CgA-KO mice lacking both CST and PST exhibited improved insulin sensitivity due to absence of PST. CST suppressed gluconeogenesis and enhanced glucagon regulation, while PST promoted insulin resistance and glucose production. Spatial mass spectrometry revealed altered neurotransmitter and polyamine profiles in pancreatic islets, implicating disrupted nerve-immune-islet interactions. CSTs modulation of catecholaminergic and inflammatory pathways positions it as a key regulator in the neuro-immune-endocrine axis. These findings highlight the therapeutic potential of targeting CgA-derived peptides, especially CST, for managing diabetes and metabolic-inflammatory diseases through precise peptide-based interventions.

immunology↗

bioRxiv2023

GABA, glucose and insulin orchestrate CD4+ T cells effector functions

Metabolic programs of immune cells are closely linked to their effector functions. Physiological molecules including glucose, insulin and {gamma}-aminobutyric acid (GABA) provide environmental cues and guidance, although how they coordinate to regulate the cells is still being unraveled. Here, we demonstrate that GABA-mediated reduction of metabolic activity and release of inflammatory molecules, including IFN{gamma} and IL-10, was abolished in human CD4+ T cells when the glucose concentration was elevated above normal levels. Insulin enhanced the GABAA receptors-mediated currents and Ca2+ influx. GABA decreased, whereas insulin sustained glycolysis but in a SGLT (Na+-glucose transporter)-dependent manner. In high glucose (16.7 mM), the SGLTs antagonist phlorizin alone or together with GABA restored the inhibition of IFN{gamma} and IL-10 release. This study exposes concerted effects of GABA, glucose and insulin on CD4+ T cells metabolic activity and release of inflammatory molecules, and identifies a role for SGLTs in CD4+ T cells function.

physiology↗

bioRxiv2022

Global, regional, and cryptic population structure in a high gene-flow transatlantic fish

1Lumpfish (Cyclopterus lumpus) is a transatlantic marine fish displaying large population sizes and a high potential for dispersal and gene-flow. These features are expected to result in weak population structure. Here, we investigated population genetic structure of lumpfish throughout its natural distribution in the North Atlantic using two approaches: I) 4393 genome wide SNPs and 95 individuals from 10 locations, and II) 139 discriminatory SNPs and 1,669 individuals from 40 locations. Both approaches identified extensive population genetic structuring with a major split between the East and West Atlantic and a distinct Baltic Sea population, as well as further differentiation of lumpfish from the English Channel, Iceland, and Greenland. The targeted discriminatory loci displayed [~]2-5 times higher divergence than the genome wide approach, revealing further evidence of local population substructures. Lumpfish from Isfjorden in Svalbard were highly distinct but resembled most fish from Greenland. The Kattegat area in the Baltic transition zone, formed a previously undescribed distinct genetic group. Also, further subdivision was detected within North America, Iceland, West Greenland, Barents Sea, and Norway. Although lumpfish have considerable potential for dispersal and gene-flow, the observed high levels of population structuring throughout the Atlantic suggests that this species displays natal homing and potentially local populations with adaptive differences. This fine-scale population structure calls for consideration when defining management units for lumpfish fishing stocks and in decisions related to sourcing and moving lumpfish for farming and cleaner fish use.

evolutionary biology↗

bioRxiv2021

Biological Insights Knowledge Graph: an integrated knowledge graph to support drug development

The use of knowledge graphs as a data source for machine learning methods to solve complex problems in life sciences has rapidly become popular in recent years. Our Biological Insights Knowledge Graph (BIKG) combines relevant data for drug development from public as well as internal data sources to provide insights for a range of tasks: from identifying new targets to repurposing existing drugs. Besides the common requirements to organisational knowledge graphs such as being able to capture the domain precisely and give the users the ability to search and query the data, the focus on handling multiple use cases and supporting use case-specific machine learning models presents additional challenges: the data models must also be streamlined for the performance of downstream tasks; graph content must be easily customisable for different use cases; different projections of the graph content are required to support a wider range of different consumption modes. In this paper we describe our main design choices in implementation of the BIKG graph and discuss different aspects of its life cycle: from graph construction to exploitation.

systems biology↗