Biology subjects

Johansson, A.

Publications and source records attributed to Johansson, A..

At least 19 recordsLinked to original sources

bioRxiv2026

A convergent metabolic-kinase signaling axis links Parkinson s disease and multiple system atrophy

Parkinsons disease (PD) and multiple system atrophy (MSA) are alpha-synucleinopathies with overlapping clinical phenotypes but distinct cellular pathological hallmarks. Whether these disorders share upstream molecular changes beyond alpha-synuclein aggregation remains unresolved. Here, we generated induced pluripotent stem cell (iPSC)-derived midbrain spheroids containing dopaminergic neurons from individuals with monogenic PD, idiopathic PD, MSA, and controls, and applied integrated proteomics, metabolomics, and phosphoproteomics to define disease-associated biochemical programs and their regulatory architecture. Despite their distinct etiologies, PD and MSA spheroids displayed highly concordant molecular remodeling, with cellular metabolism emerging as the dominant shared disturbance. Network analyses identified coordinated changes in central carbon metabolism, oxidative phosphorylation, branched-chain amino acid catabolism, pantothenate/CoA metabolism, and lipid remodeling, coupled to phosphorylation-driven rewiring of MAPK, mTOR, AMPK, PKA/PKC, and second-messenger kinase programs. Importantly, these metabolic and signaling axes were also prominent in postmortem substantia nigra from PD and MSA donors, supporting conservation between patient-derived models and postmortem brain tissue. Together, these data identify metabolic dysregulation as a unifying molecular feature across PD and MSA and suggesting phosphorylation-linked metabolic control nodes as candidate entry points for therapeutic intervention. HighlightsO_LIPD and MSA exhibit molecular programs that extend beyond alpha-synuclein pathology. C_LIO_LIProteomics identifies metabolism as the dominant shared disease axis across PD and MSA. C_LIO_LIMetabolomics resolves a coupled glucose-TCA-BCAA-CoA-lipid remodeling program in PD and MSA. C_LIO_LIPhosphorylation-centered kinase networks link signaling rewiring to metabolic bottlenecks. C_LIO_LIShared metabolic features are conserved between patient iPSC-derived midbrain spheroids and substantia nigra. C_LI Graphic abstract (generated using BioRender) O_FIG O_LINKSMALLFIG WIDTH=191 HEIGHT=200 SRC="FIGDIR/small/731777v1_ufig1.gif" ALT="Figure 1"> View larger version (77K): org.highwire.dtl.DTLVardef@1748e51org.highwire.dtl.DTLVardef@12b8f91org.highwire.dtl.DTLVardef@de8893org.highwire.dtl.DTLVardef@1d89ea1_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2026

Proteomic profiling reveals pleiotropic antimetabolite activity of triciribine in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) exhibits marked genetic and metabolic heterogeneity that limits the efficacy of targeted therapies. Antimetabolite strategies remain central to ALL treatment, yet the mechanisms underlying differential drug sensitivity are incompletely defined. Here, we investigated the activity of the purine analog triciribine (TCN) across diverse ALL cellular models. We find that TCN exerts potent cytotoxic effects in multiple ALL cell lines, exceeding those observed with canonical Akt inhibitors in our datasets. Phosphoproteomic analyses indicate that, at early time points, TCN does not primarily suppress Akt signaling but instead induces transient pathway activation accompanied by inhibition of cyclin-dependent kinases in both sensitive and resistant cells. The monophosphorylated metabolite TCN-P represents the predominant intracellular species and requires adenosine kinase (ADK) for activity, with ADK protein levels positively correlating with TCN sensitivity in both cell lines and primary patient samples. Using Proteome Integral Solubility Alteration profiling, we identify candidate protein interactions of TCN-P distributed across multiple cellular pathways, including nucleotide metabolism, DNA replication, and protein synthesis. These interactions are accompanied by impaired purine biosynthesis, DNA damage, translational stress, and cell-cycle arrest, as supported by time-course quantitative proteomics and immunoblot analyses. Together, these findings characterize triciribine as an antileukemic agent with pleiotropic antimetabolite activity in ALL and highlight ADK-dependent metabolism as a key determinant of therapeutic sensitivity, suggesting that ADK levels may serve as a predictive biomarker to stratify patients for triciribine-based precision treatment strategies.

cancer biology↗

bioRxiv2025

Distinct topologically associated domains underlie the regulatory logic in lymphatic endothelial cells contributing to proper cell differentiation

The activation and repression of genes is a fundamental part of proper embryonic development and functional tissue formation, ensuring that unique molecular codes are set up to orchestrate cell differentiation. Changes in chromatin organisation dictate accessibility to gene regulatory elements and control gene expression. Several molecular factors regulating lymphatic endothelial cell (LEC) specification and differentiation have been identified. However, it remains to be defined how chromatin is organised in lymphatic endothelium and how it orchestrates lymphatic vessel network formation. In this study, we combined Hi-C and ATAC-sequencing to characterise 3D chromatin architecture and accessibility in LECs and blood endothelial cells (BECs). We have identified cell type-specific topologically associated domains (TADs) in LECs and BECs. Specifically, our data revealed changes in the TAD boundaries and differentially segregating enhancers regions in lymphatic-associated loci, such as prox1a and tbx1. This multi-omic approach also defined the regulatory logic for nine genes whose expression is enriched in LECs. In vivo validation of their short- and long-range enhancers confirmed their LEC-confined activity. Leveraging these datasets, we reconstructed mafba tissue-specific regulatory networks and identified a genetic interaction with tfe3a in vivo necessary to limit ectopic vessel formation. Overall, our work provides a powerful resource of multi-omic datasets that can be used to systematically determine the regulatory networks governing LEC identity and genes linked to lymphatic disease.

developmental biology↗

bioRxiv2024

SOQ1 functions as a methionine sulfoxide reductase in the chloroplast lumen for regulation of photoprotective qH in Arabidopsis

Photosynthetic organisms must balance light absorption and energy dissipation to prevent photo-oxidative damage. Non-photochemical quenching (NPQ) dissipates excess light energy as heat, with the quenching component qH providing sustained photoprotection. However, the molecular mechanism underlying qH induction remains unclear. Our study focuses on the thylakoid membrane protein SUPPRESSOR OF QUENCHING 1 (SOQ1) and its inhibition of qH through interaction with LIPOCALIN IN THE PLASTID (LCNP) in Arabidopsis thaliana. Structural homology of SOQ1 lumenal domains with bacterial disulfide bond protein D suggested potential thiol-disulfide exchange activity. In vitro assays determined that both SOQ1 thioredoxin-like (Trx-like) and C-terminal (CTD) domains contain a redox-active cysteine pair and evidenced electron transfer from Trx-like to CTD. Importantly, we found that SOQ1 lumenal domains exhibit methionine sulfoxide reductase (Msr) activity converting oxidized methionine residues in LCNP back to methionine, which thereby inactivates LCNP and prevents qH formation. Mutational analyses identified cysteine residues in SOQ1-CTD and methionine residues in LCNP as critical for qH suppression, supporting their role in redox regulation. Additionally, we found that the redox state of SOQ1 in vivo is light-dependent, shifting from reduced to oxidized under stress conditions, indicating a dynamic regulation of its activity. We conclude that the Trx-like domain of SOQ1 provides reducing power to its CTD displaying Msr activity. SOQ1 is therefore an unusual example of a protein possessing both a disulfide reductase and Msr domain in tandem. Our findings elucidate the redox-regulation mechanism of qH involving SOQ1-mediated methionine reduction of LCNP, providing insights into the intricate control of photoprotective processes in chloroplasts and enhancing our understanding of plant resilience under environmental stress.

plant biology↗

bioRxiv2024

5-methylcytosine and 5-hydroxymethylcytosine are synergistic biomarkers for early detection of colorectal cancer

Early cancer detection has the potential to significantly improve treatment outcomes and survival rates. This study investigates the roles of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) as biomarkers for early-stage colorectal cancer (CRC) detection in cell-free DNA (cfDNA). Using whole genome sequencing, we analyzed cfDNA from 37 treatment-naive CRC patients and 32 healthy controls. Our findings indicate that combining measurements of 5mC and 5hmC significantly enhances diagnostic accuracy (AUC = 0.95) compared to traditional approaches that conflate these markers (modified C, AUC = 0.66). Notably, 71.7% of differentially methylated regions (DMRs) exhibiting an increase in 5hmC in stage I cfDNA also showed a corresponding decrease in 5mC in stage IV, suggesting that 5hmC can effectively track regions undergoing demethylation during tumor development. These results support the hypothesis that distinguishing between 5mC and 5hmC can improve the sensitivity of liquid biopsy tests for early cancer detection.

cancer biology↗

bioRxiv2024

Temporally discordant chromatin accessibility and DNA demethylation define short and long-term enhancer regulation during cell fate specification

Epigenetic mechanisms govern the transcriptional activity of lineage-specifying enhancers; but recent work challenges the dogma that joint chromatin accessibility and DNA demethylation are prerequisites for transcription. To understand this paradox, we established a highly-resolved timeline of DNA demethylation, chromatin accessibility, and transcription factor occupancy during neural progenitor cell differentiation. We show thousands of enhancers undergo rapid, transient accessibility changes associated with distinct periods of transcription factor expression. However, most DNA methylation changes are unidirectional and delayed relative to chromatin dynamics, creating transiently discordant epigenetic states. Genome-wide detection of 5-hydroxymethylcytosine further revealed active demethylation begins ahead of chromatin and transcription factor activity, while enhancer hypomethylation persists long after these activities have dissipated. We demonstrate that these timepoint specific methylation states predict past, present and future chromatin accessibility using machine learning models. Thus, chromatin and DNA methylation collaborate on different timescales to mediate short and long-term enhancer regulation during cell fate specification.

genomics↗

bioRxiv2024

Neonatal microbiota colonization drives maturation of primary and secondary goblet cell mediated protection in the pre-weaning colon

In the distal colon, mucus secreting goblet cells primarily confer protection from luminal microorganisms via generation of a sterile inner mucus layer barrier structure. Bacteria-sensing sentinel goblet cells provide a secondary defensive mechanism that orchestrates mucus secretion in response to microbes that breach the mucus barrier. Previous reports have identified mucus barrier deficiencies in adult germ-free mice, thus implicating a fundamental role for the microbiota in programming mucus barrier generation. In this study, we have investigated the natural neonatal development of the mucus barrier and sentinel goblet cell-dependent secretory responses upon postnatal colonization. Combined in vivo and ex vivo analyses of pre- and post-weaning colonic mucus barrier and sentinel goblet cell maturation demonstrated a sequential microbiota-dependent development of these primary and secondary goblet cell-intrinsic protective functions, with dynamic changes in mucus processing dependent on innate immune signalling via MyD88, and development of functional sentinel goblet cells dependent on the NADPH/Dual oxidase family member Duox2. Our findings therefore identify new mechanisms of microbiota-goblet cell regulatory interaction and highlight the critical importance of the pre-weaning period for the normal development of colonic barrier function.

immunology↗

bioRxiv2023

Medicago truncatula SOBIR1 controls specificity in the Rhizobium-legume symbiosis

Medicago truncatula Nod Factor Perception (MtNFP) is a lysin-domain Receptor-Like Kinase (LysM-RLK) that plays a key role in the Rhizobium-legume symbiosis, and is involved in plant immunity. MtNFP also has an inactive kinase domain, suggesting that the protein is involved in different receptor complexes. Using the MtNFP pseudo-kinase domain as a bait in a Yeast two Hybrid screen, we identified M. truncatula SUPPRESSOR OF BIR1 (MtSOBIR1) as a new interactor of MtNFP. We showed that an interaction between the two RLKs can occur in planta and that the kinase domain of MtSOBIR1 is active and can transphosphorylate the pseudo-kinase domain of MtNFP. Like in other plants, our data suggest a positive role of MtSOBIR1 in immunity; MtSOBIR1 could functionally complement an Atsobir1 mutant for defence activation, and a Mtsobir1 mutant was defective in pathogen-induced defence gene expression. We also showed that MtSOBIR1 has a symbiotic role with Mtsobir1 mutants showing a strong symbiotic phenotype in a plant genotype- and rhizobial strain-specific manner. The symbiotic role was apparent both at an early stage of rhizobial infection and in nodules. Together, these data suggest that, like MtNFP, MtSOBIR1 has a dual role, and can control immunity in both pathogenic and beneficial situations, with positive or negative roles, respectively.

plant biology↗

bioRxiv2022

Genomic characterization of Francisella tularensis and other diverse Francisella species from complex samples

Francisella tularensis, the bacterium that causes the zoonosis tularemia, and its genetic near neighbor species, can be difficult or impossible to cultivate from complex samples. Thus, there is a lack of genomic information for these species that has, among other things, limited the development of robust detection assays for F. tularensis that are both specific and sensitive. The objective of this study was to develop and validate approaches to capture, enrich, sequence, and analyze Francisella DNA present in DNA extracts generated from complex samples. RNA capture probes were designed based upon the known pan genome of F. tularensis and other diverse species in the family Francisellaceae. Probes that targeted genomic regions also present in non-Francisellaceae species were excluded, and probes specific to particular Francisella species or phylogenetic clades were identified. The capture-enrichment system was then applied to diverse, complex DNA extracts containing low-level Francisella DNA, including human clinical tularemia samples, environmental samples (i.e., animal tissue and air filters), and whole ticks/tick cell lines, which was followed by sequencing of the enriched samples. Analysis of the resulting data facilitated rigorous and unambiguous confirmation of the detection of F. tularensis or other Francisella species in complex samples, identification of mixtures of different Francisella species in the same sample, analysis of gene content (e.g., known virulence and antimicrobial resistance loci), and high-resolution whole genome-based genotyping. The benefits of this capture-enrichment system include: even very low target DNA can be amplified; it is culture-independent, reducing exposure for research and/or clinical personnel and allowing genomic information to be obtained from samples that do not yield isolates; and the resulting comprehensive data not only provide robust means to confirm the presence of a target species in a sample, but also can provide data useful for source attribution, which is important from a genomic epidemiology perspective.

genomics↗

bioRxiv2021

Uncovering the Genetic Architecture of Broad Antisocial Behavior through a Genome-Wide Association Study Meta-analysis.

Despite the substantial heritability of antisocial behavior (ASB), specific genetic variants robustly associated with the trait have not been identified. The present study by the Broad Antisocial Behavior Consortium (BroadABC) meta-analyzed data from 28 discovery samples (N = 85,359) and five independent replication samples (N = 8,058) with genotypic data and broad measures of ASB. We identified the first significant genetic associations with broad ASB, involving common intronic variants in the forkhead box protein P2 (FOXP2) gene (lead SNP rs12536335, P = 6.32 x 10-10). Furthermore, we observed intronic variation in Foxp2 and one of its targets (Cntnap2) distinguishing a mouse model of pathological aggression (BALB/cJ strain) from controls (BALB/cByJ strain). The SNP-based heritability of ASB was 8.4% (s.e.= 1.2%). Polygenic-risk-score (PRS) analyses in independent samples revealed that the genetic risk for ASB was associated with several antisocial outcomes across the lifespan, including diagnosis of conduct disorder, official criminal convictions, and trajectories of antisocial development. We found substantial genetic correlations of ASB with mental health (depression rg{square}={square}0.63, insomnia rg = 0.47), physical health (overweight rg = 0.19, waist-to-hip ratio rg = 0.32), smoking (rg{square}={square}0.54), cognitive ability (intelligence rg= -0.40), educational attainment (years of schooling rg = -0.46) and reproductive traits (age at first birth rg={square}- 0.58, fathers age at death rg= -0.54). Our findings provide a starting point towards identifying critical biosocial risk mechanisms for the development of ASB.

genetics↗

bioRxiv2021

Heterogeneity of Staphylococcus epidermidis in prosthetic joint infections: Time to reevaluate microbiological criteria?

Prosthetic joint infection (PJI) is a feared complication after arthroplasty with Staphylococcus epidermidis as a major pathogen. One diagnostic criteria for PJI diagnosis is the finding of phenotypically identical organisms based on common laboratory tests in two or more periprosthetic microbial cultures. Because of phenotypical variation within a genetic clone, and clonal variation within a phenotype, the criteria may be ambiguous. Here, we investigate the extent of diversity among coagulase-negative staphylococci in PJI and characterize in detail S. epidermidis isolates from these infections. We performed a retrospective cohort study of 62 consecutive patients with PJI caused by coagulase-negative staphylococci (CoNS) from two hospitals in Northern Sweden. From 16 of the patients, two to nine S. epidermidis isolates were available for whole-genome analyses. Hospital-adapted multidrug-resistant genetic clones of S. epidermidis were identified in 40/62 (65%) of the PJIs using a combination of analysis by pulsed-field gel electrophoresis and multiple-locus sequence typing. Whole genome sequencing showed presence of multiple sequence types (STs) in seven (7/16, 44%) PJIs. Among isolates of the same ST, within-patient phenotypical variation in antibiotic susceptibility and/or whole-genome antibiotic resistance gene content was frequent (11/16, 69%). These results highlight the ambiguity of using phenotypical characterization of S. epidermidis as diagnostic criteria in PJI. The results call for larger systematic studies to determine the frequency of CoNS diversity in PJIs, the implications of such diversity for microbiological diagnostics, and for the therapeutic outcome in patients.

microbiology↗

bioRxiv2020

CRISPRi screens reveal genes modulating yeast growth in lignocellulose hydrolysate

BackgroundBakers yeast is a widely used eukaryotic cell factory, producing a diverse range of compounds including biofuels and fine chemicals. The use of lignocellulose as feedstock offers the opportunity to run these processes in an environmentally sustainable way. However, the required hydrolysis pretreatment of lignocellulosic material releases toxic compounds that hamper yeast growth and consequently productivity. ResultsHere, we employ CRISPR interference in S. cerevisiae to identify genes modulating fermentative growth in plant hydrolysate and in presence of lignocellulosic toxins. We find that at least one third of hydrolysate-associated gene functions are explained by effects of known toxic compounds, such as the decreased growth of YAP1 or HAA1, or increased growth of DOT6 knock-down strains in hydrolysate. ConclusionOur study confirms previously known genetic elements and uncovers new targets towards designing more robust yeast strains for the utilization of lignocellulose hydrolysate as sustainable feedstock, and, more broadly, paves the way for applying CRISPRi screens to improve industrial fermentation processes.

microbiology↗

bioRxiv2020

Gene dosage screens in yeast reveal core signalling pathways controlling heat adaptation

Heat stress causes proteins to unfold and lose their function, jeopardizing essential cellular processes. To protect against heat and proteotoxic stress, cells mount a dedicated stress-protective programme, the so-called heat shock response (HSR). Our understanding of the mechanisms that regulate the HSR and their contributions to heat resistance and growth is incomplete. Here we employ CRISPRi/a to down- or upregulate protein kinases and transcription factors in S. cerevisiae. We measure gene functions by quantifying perturbation effects on HSR activity, thermotolerance, and cellular fitness at 23, 30 and 38{degrees}C. The integration of these phenotypes allowed us to identify core signalling pathways of heat adaptation and reveal novel functions for the high osmolarity glycerol, unfolded protein response and protein kinase A pathways in adjusting both thermotolerance and chaperone expression. We further provide evidence for unknown cross-talk of the HSR with the cell cycle-dependent kinase Cdc28, the primary regulator of cell cycle progression. Finally, we show that CRISPRi efficiency is temperature-dependent and that different phenotypes vary in their sensitivity to knock-down. In summary, our study quantifies regulatory gene functions in different aspects of heat adaptation and advances our understanding of how eukaryotic cells counteract proteotoxic and other heat-caused damage.

genetics↗

bioRxiv2020

Malignant Schwann cell precursors mediate intratumoral plasticity in human neuroblastoma

Neuroblastoma is a heterogeneous embryonal malignancy and the most deadly tumor of childhood, although a minor subset may show spontaneous differentiation. It arises from the multipotent neural crest lineage during development. Some of this multipotency is retained in neuroblastoma, which can give rise to both adrenergic and mesenchymal tumor cells. The mechanisms enabling such dual fates are unknown, but likely help neuroblastoma to evade existing therapies. To understand neuroblastoma plasticity, we analyzed patient tumors using single-cell transcriptomics. In addition to the heterogeneous adrenergic and mesenchymal populations, we identify a subpopulation of malignant cells resembling Schwann cell precursors (SCPs). This SCP-like population connects the adrenergic and mesenchymal compartments through transitions structurally reminiscent of the SCP cell-fate decision fork that occurs during normal development. While the directionality of such transitions in neuroblastoma remains to be established, this finding expands the potential reservoirs of malignant cells, and suggests intratumoral plasticity mechanisms relevant for therapeutic resistance and relapse.

cancer biology↗

bioRxiv2020

Genomic evaluation of circulating proteins for drug target characterisation and precision medicine

Circulating proteins are vital in human health and disease and are frequently used as biomarkers for clinical decision-making or as targets for pharmacological intervention. By mapping and replicating protein quantitative trait loci (pQTL) for 90 cardiovascular proteins in over 30,000 individuals, we identified 467 pQTLs for 85 proteins. The pQTLs were used in combination with other sources of information to evaluate known drug targets, and suggest new target candidates or repositioning opportunities, underpinned by a) causality assessment using Mendelian randomization, b) pathway mapping using trans-pQTL gene assignments, and c) protein-centric polygenic risk scores enabling matching of plausible target mechanisms to sub-groups of individuals enabling precision medicine.

genetics↗

bioRxiv2019

Loss of Y in leukocytes, dysregulation of autosomal immune genes and disease risks

Mosaic loss of chromosome Y (LOY) in leukocytes has been associated with many diseases, yet it remains unclear whether this form of clonal mosaicism exerts a direct physiological effect. Here we perform single-cell and bulk RNA sequencing in leukocytes, observing considerable variation in the rate of LOY across individuals, cell types and disease state. Cells with LOY demonstrated a profound degree of transcriptional dysregulation impacting [~]500 autosomal genes. These genes are preferentially involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y challenging the view of it as a "genetic wasteland". Furthermore, they support the hypothesis that altered immune function in leukocytes is a mechanism directly linking LOY to disease.

immunology↗

bioRxiv2018

Using synthetic semiochemicals to train canines to detect bark beetle-infested trees

In this proof of concept study, we report the off season training of two detection dogs on a series of synthetic semiochemicals associated with Ips typographus pest bark beetle infestations of spruce trees. Scent detection training allowed dogs to discriminate between physiologically-relevant infestation (target) odours, quantified by GC-MS using extracted ion chromatogram to be bio-active at levels of < 10-4 ng /15 min or lower, and natural non-target odours that might be encountered in the forest. Detection dogs trained to recognize four different synthetic pheromone compounds in the winter time, well before beetle flight, were able to detect natural infested spruce trees unknown to humans the following summer. The trained detection dogs were able to detect an infested spruce tree from the first hour of bark beetle attack until several weeks after the attack. Trained detection dogs appear to be more efficient than humans in detecting early bark beetle infestations because the canines ability to cover a greater area and by olfaction detect infestations from a far greater distance than can humans. Infested spruce trees could be detected by trained detection dogs out to more than 100 m.\n\nKey MessageO_LIDetection dogs were rapidly trained to locate release of synthetic bark beetle pheromone components\nC_LIO_LISynthetics allowed dog training off-season both in laboratory and field\nC_LIO_LIDogs trained on synthetics detected naturally target pest insect attacked trees at a distance of more than 100 m.\nC_LIO_LIThe method allows rapid removal of single, first attacked trees before offspring emergence, thus curbing local pest increase and lowering spread of attacks in the landscap\nC_LI

ecology↗

bioRxiv2017

Genome-wide association study of body fat distribution identifies novel loci and sex-specific effects

Body mass and body fat composition are of clinical interest due to their links to cardiovascular- and metabolic diseases. Fat stored in the trunk has been suggested as more pathogenic compared to fat stored in other compartments of the body. In this study, we performed genome-wide association studies (GWAS) for the proportion of body fat distributed to the arms, legs and trunk estimated from segmental bio-electrical impedance analysis (sBIA) for 362,499 individuals from the UK Biobank. A total of 97 loci, were identified to be associated with body fat distribution, 40 of which have not previously been associated with an anthropometric trait. A high degree of sex-heterogeneity was observed and associations were primarily observed in females, particularly for distribution of fat to the legs or trunk. Our findings also implicate that body fat distribution in females involves mesenchyme derived tissues and cell types, female endocrine tissues a well as several enzymatically active members of the ADAMTS family of metalloproteinases, which are involved in extracellular matrix maintenance and remodeling.

genetics↗