Biology subjects

Lange, T.

Publications and source records attributed to Lange, T..

14 recordsLinked to original sources

bioRxiv2026

Repeated UV-C exposure alters gibberellin homeostasis and inhibits growth in Arabidopsis thaliana

Ultraviolet-C (UV-C) radiation can be highly damaging to plants, yet its effects on gibberellin (GA) homeostasis are not well understood. In this study, we show that short daily UV-C pulse treatments (12 s, 1,200 J m-2) applied for seven days reduce plant height and delay flowering in Arabidopsis thaliana. Endogenous levels of the GA biosynthesis precursors GA12, GA53, GA15, and GA24, the bioactive GA4, and the GA catabolites GA34 and GA110 are all lower in UV-C treated plants than in untreated controls. These changes were accompanied by lower transcript levels of the GA biosynthesis genes KS, GA13ox1, GA20ox1, and GA3ox1, together with opposing changes in the expression of GA2ox genes. Exogenous GA4 restores growth in UV-C-treated plants, suggesting that reduced GA availability contributes to UV-C-induced growth inhibition. Consistent with this finding, the GA-signalling mutant gdella and the GA-biosynthesis mutants kao1 and kao2 show strongly reduced UV-C responses. Together, these findings highlight the importance of GA metabolism and signalling in the developmental response to repeated UV-C exposure, and suggest that exposure regimen influences the dynamics of UV-C-induced hormonal responses.

plant biology↗

bioRxiv2026

Exosome-mediated LNA anti-miR delivery achieves potent miR-21 inhibition and PTEN restoration in podocytes.

BackgroundPodocyte injury and loss are central drivers of chronic kidney disease (CKD) progression and are involved in the majority of glomerular diseases. Among the molecular pathways implicated in podocyte dysfunction, microRNA-21 (miR-21) is consistently upregulated during glomerular injury and suppresses protective target genes including PTEN. Although anti-miR-21 approaches have shown high efficacy in preclinical models for Alport Syndrome and diabetic nephropathy, clinical translation of free anti-miR-21 oligonucleotides remains challenging, potentially reflecting limited glomerular and podocyte target engagement. Here, we show that an exosome-mediated delivery of an LNA-miR-21 inhibitor results in a higher intracellular uptake, leading to functional miR-21 inhibition and PTEN restoration in podocytes. MethodsExosomes were isolated from immortalized murine podocytes SVI and were directly loaded with fluorescently-labeled LNA anti-miR-21 (LNA-21) and anti-miR-Ctrl. Exosome integrity was assessed by transmission electron microscopy, dynamic light scattering and Western blot analysis of CD9 and TSG101. Uptake efficiency and intracellular delivery were analyzed by confocal laser-scanning microscopy, time-series imaging (2-48 h) and (imaging) flow cytometry. Functional efficacy was evaluated by TaqMan RT-qPCR and PTEN protein expression in differentiated SVI podocytes, primary murine podocytes and puromycin aminonucleoside (PAN)-injured primary glomeruli. ResultsExosome number, morphology and marker expression remained unchanged after direct LNA-miR-21 loading. Time-series imaging demonstrated progressive intracellular accumulation of exosome-delivered LNA-21 cargo from 2 to 48 h, whereas free LNA-21 showed no detectable uptake. Flow cytometry and imaging flow cytometry confirmed an efficient (76.6%) intracellular delivery exclusively via exosomes. Exosome-mediated LNA-21 delivery induced a robust miR-21 suppression, resulting in an 99% reduction in immortalized podocytes, a 97% reduction in primary podocytes and a 97% reduction in PAN-injured glomeruli (all p < 0.05). In contrast, free LNA-21 did not achieve significant suppression in all investigated models. To evaluate the functional consequences of miR-21 inhibition, we examined PTEN expression, as PTEN is a known direct target of miR-21. Notably, restoration of PTEN protein expression was observed only following exosome-mediated LNA delivery which was confirmed by Western blot and immunofluorescence, suggesting efficient functional inhibition of miR-21 in podocytes. Transfection of scrambled controls confirmed sequence specificity throughout. ConclusionThese findings demonstrate that exosome-mediated LNA delivery overcomes the limited uptake of free inhibitor oligonucleotides in podocytes and enables functional inhibition of miR-21 across multiple experimental systems. These data provide mechanistic proof-of-principle for exosome-based miR inhibitor delivery as a potential strategy to improve podocyte-targeted therapies in CKD.

cell biology↗

bioRxiv2026

A single UV-C pulse modulates Gibberellin homeostasis and Plant Development in Arabidopsis

Under natural growth conditions, plants are not usually exposed to the high-energy ultraviolet C range (UV-C, 100-280 nm) of the solar spectrum, as this is absorbed by the ozone layer. However, low doses of UV-C radiation can trigger stress responses in plants. Nevertheless, it is not yet fully understood how UV-C light affects plant development at the hormonal level. Here we show that a single one-min UV-C light pulse (20 W/m2) alters gibberellin (GA) homeostasis in Arabidopsis in two phases: initially, the level of GA12 - a key precursor of the final part of gibberellin biosynthesis - is reduced. Consistent with this, the transcript levels of the CPS, KS and KAO2 genes, which encode enzymes involved in the initial parts of gibberellin biosynthesis, decrease. The level of the plant hormone GA4 also decreases initially, probably due to the reduced GA12 precursor levels. However, in a second phase, the endogenous GA4 levels rise in UV-C treated plants relative to control plants. This increase leads to an early onset of flowering, as well as increased growth and fertility, in UV-C-treated Arabidopsis plants. The GA signalling mutant gdella does not exibit wild-type phenotypic responses to UV-C treatment, indicating that GA signalling is essential for the UV-C response. To further narrow down the responsible steps in the GA-signalling pathway, we tested the kao1 and kao2 mutants, which are both impaired in early gibberellin biosynthesis. Neither mutant displays phenotypic responses to the UV-C treatment, indicating that both genes are required for mediating the UV-C response. In contrast, the quintuple 2-oxidase mutant C19--2oxqM exhibits responses to UV-C treatment similar to the wild-type, suggesting that the five catabolic 2-oxidases that act on C19-GAs play a negligible role in regulation GA-hormone levels for growth and development in this case. HighlightUV-C pulse triggers biphasic gibberellin dynamics, delaying early development but ultimately enhancing growth and fertility in Arabidopsis thaliana.

plant biology↗

bioRxiv2026

Spermatogonial stem cells and their differentiation roadmap throughout marmoset development

Sperm transfer genetic information from one generation to the next. These cells originate from gonocytes, which are specified during early embryonal development. To date however, there is limited information on the transcriptional gatekeepers governing the key events leading to sperm production: transition of gonocytes out of pluripotency around the time of birth, formation of the spermatogonial compartment prior to puberty, and initiation of germ cell differentiation at the time of puberty. We address this knowledge gap by employing the marmoset monkey (Callithrix jacchus) as a model for human postnatal testicular development. We analysed the transcriptional profiles of [~]48,000 neonatal, pre-pubertal, pubertal, and adult testicular cells and correlated these with histomorphometric measurements. We uncovered a transcriptional state linking gonocytes and spermatogonia characterized by CITED2 expression. Moreover, we propose NANOS2 and DPPA4 as regulators of spermatogonial plasticity from pre-puberty onwards and identify molecular gatekeepers of male germ cell differentiation.

developmental biology↗

bioRxiv2025

Glomage: A multimodal platform for high-content morphological and RNA profiling of glomeruli in zebrafish and mouse models

Chronic kidney disease affects over 800 million people worldwide, but therapeutic options remain limited. The glomerulus, with its highly specialized podocytes, forms the functional core of blood filtration. However, studying this complex three-dimensional kidney compartment is difficult, which has slowed progress in identifying drugs. Zebrafish larvae are a powerful model for kidney research and drug discovery, but histological staining of individual larvae is time-consuming, and scalable methods for glomerular analysis have been lacking. Here, we establish a high-throughput workflow for isolating, staining, imaging, as well as extracting RNA from hundreds of zebrafish glomeruli simultaneously. The workflow preserves the three-dimensional architecture, enables quantitative assessment of podocyte numbers, and was validated in a podocyte-specific injury model. Moreover, we adapted the protocol for mouse glomeruli, allowing reliable detection of the age-related loss of podocytes. Glomage provides a systematic, cross-species platform for glomerular analysis, opening new opportunities for kidney research and drug discovery.

cell biology↗

bioRxiv2025

Regulation of the transcriptome, miRNAs, and alternative splicing in a FSGS zebrafish injury model

BackgroundFocal Segmental Glomerulosclerosis (FSGS) is a severe kidney disorder with complex and not yet fully understood pathogenesis. Alternative splicing (AS) - the generation of distinct protein isoforms from the same gene - might play a critical role by the regulation of gene functions and disease development. MethodsTo investigate the role of AS in FSGS, we used a zebrafish model, which mimics key human FSGS features, including foot process effacement, matrix accumulation, podocyte detachment and parietal epithelial cell activation. We performed total RNA sequencing of isolated zebrafish glomeruli and whole larvae, followed by integrative bioinformatic analysis to identify AS events and regulatory miRNAs. ResultsOur data revealed a downregulation of essential podocyte genes (nphs1, nphs2, podxl, wt1) and an inhibition of pathways associated with nephron development and cytoskeletal organization. We also observed increased expression of the transcription factor stat3 and disease-associated miRNAs such as miR-21 and miR-193. AS analysis identified approximately [~]7,000 splicing events, primarily exon skipping ([~]80%), affecting genes such as nphs1, magi2, and ptpro. A total of 136 and 612 alternatively spliced genes were found at 5 and 6 days post-fertilization (dpf), respectively. Isoform switch analysis uncovered 70 genes affected by AS in FSGS, including epb41l5 (linked to podocyte adhesion), fgfr1a (fibroblast growth signaling), and members of the SRSF splicing factor family (e.g., srsf3a). ConclusionsThese findings emphasize the importance of transcriptional and post-transcriptional regulation, including AS, in FSGS pathogenesis. Furthermore, they support the zebrafish model as a valuable system for identifying novel mechanisms and potential therapeutic targets for kidney diseases.

cell biology↗

bioRxiv2024

A Novel C. elegans Model for Tau spreading Reveals Genes Critical for Endolysosomal Integrity and Seeded Tau Aggregation

The spreading of Tau pathology is closely associated with the progression of neurodegeneration and cognitive decline in Alzheimers disease and other tauopathies. A key event in this process is the rupture of endolysosomal vesicles following the intercellular transfer of Tau aggregates, releasing the transferred Tau species into the cytosol where they can promote the aggregation of endogenous Tau. However, understanding of the cellular pathways involved in this process remains limited. In this study, we investigated cellular pathways that prevent endolysosomal vesicle rupture. We established a new C. elegans model of Tau spreading by introducing an mCherry-labelled, disease-associated aggregation-prone fragment of human Tau (F3{Delta}K281::mCh) into the six touch receptor neurons. F3{Delta}K281::mCh transgenic animals exhibited significant neurotoxicity and mechanosensory deficits due to the accumulation of this Tau fragment. In addition, its intercellular transmission compromised the endolysosomal system in receiving hypodermal cells. Using this model, we conducted an unbiased genome-wide RNAi screen and identified 59 genes critical for maintaining endolysosomal integrity. GO-term analysis revealed an enrichment of genes related to the ESCRT complex, the ubiquitin-proteasome system, mRNA splicing, and fatty acid metabolism. Silencing of selected conserved genes exacerbated seeded Tau aggregation in a human induced pluripotent stem cell (hiPSC)-derived cortical neuron model and triggered endolysosomal rupture in HEK293T cells, confirming the crucial role of endolysosomal damage in seeded Tau aggregation. Overall, this study discovered novel cellular pathways that safeguard endolysosomal integrity. These findings may guide the development of therapeutics that improve endolysosomal integrity to halt the progression of Tau pathology.

cell biology↗

bioRxiv2024

Efficient delivery of small RNAs to podocytes in vitro by direct exosome transfection.

Podocytes are a crucial component of the glomerular filtration barrier and changes in their 3D structure contribute to over 80% of chronic kidney disease (CKD) cases. Exosomal small RNAs play a key role in cell-cell communication in CKD and may serve as nanocarriers for delivering small RNAs into podocytes. However, the uptake of exosomal cargo by podocytes remains poorly understood. This study explores the use of isolated exosomes, directly transfected with fluorescently labeled small RNAs, for tracking and delivering small RNAs to cultured podocytes. Exosomes were isolated from immortalized murine podocytes and transfected with Cy3-labeled siRNA and miRNA controls using the ExoFect siRNA/miRNA Transfection Kit. We characterized the transfected exosomes via transmission electron microscopy (TEM) and Western blot for exosomal markers CD9 and TSG101. Subsequently, we co-cultured these exosomes with podocytes and used confocal laser-scanning microscopy (cLSM) and structured illumination microscopy (SIM) to visualize cargo uptake. The isolated exosomes were also transfected with pre-miR-21 and filamin A (FlnA)-siRNAs before being co-cultured with podocytes. We confirmed the efficiency of transfection and knockdown using RT-qPCR, Western blotting, and immunofluorescence staining. TEM revealed that the exosomes maintained a consistent shape and size of approximately 20 nm post-transfection and exhibited a stable expression of CD9 and TSG101. Our imaging showed that podocytes take up Cy3-labeled exosomal miRNAs and siRNAs, utilizing various mechanisms, including encapsulation within vesicular structures, endocytosis and free distribution within the cells. Transfection of exosomes with FlnA-siRNAs resulted in a significant 2.8-fold reduction of FlnA expression in co-cultured podocytes, while pre-miR-21-transfected exosomes led to a remarkable 338-fold increase in mature miR-21 levels. These findings demonstrate that direct exosome transfection with fluorescently labeled small RNAs is an effective tool for exosomal cargo tracking in podocytes. This study is the first to show that directly transfected exosomes can deliver small RNAs to podocytes in vitro, suggesting their potential as RNA carriers for therapeutic strategies in more complex settings.

cell biology↗

bioRxiv2024

BMP4 regulates asymmetric Pkd2 distribution in mouse nodal immotile cilia and ciliary mechanosensing required for left-right determination

BackgroundMouse nodal immotile cilia mechanically sense the bending direction for left-right (L-R) determination and activate the left-side-specific signaling cascade, leading to increased Nodal activity. Asymmetric distribution of Pkd2, a crucial channel for L-R determination, on immotile cilia has been reported recently. However, the causal relationship between the asymmetric Pkd2 distribution and direction-dependent flow sensing is not well understood. Furthermore, the underlying molecular mechanism directing this asymmetric Pkd2 distribution remains unclear. ResultsThe effects of several recombinant proteins and inhibitors on the Pkd2 distribution were analyzed using super-resolution microscopy. Notably, bone morphogenetic protein 4 (BMP4) affected the Pkd2 distribution. Additionally, three-dimensional manipulation of nodal immotile cilia using optical tweezers revealed that excess BMP4 caused defects in the mechanosensing ability of the cilia. ConclusionsExperimental data together with model calculations suggest that BMP4 regulates the asymmetric distribution of Pkd2 in nodal immotile cilia, thereby affecting the ability of these cilia to sense the bending direction for L-R determination. This study, for the first time, provides insight into the relationship between the asymmetric protein distribution in cilia and their function.

developmental biology↗

bioRxiv2022

GAS2 encodes a 2-oxoglutarate dependent dioxygenase involved in ABA catabolism

Liu et al.1 recently reported the characterization of Arabidopsis thaliana GAS2 (Gain of Function in ABA-modulated Seed Germination 2), which was described as an enzyme that catalyzes the stereospecific hydration of GA12 to produce GA12 16, 17-dihydro-16-ol (DHGA12). However, as previously reported2, we did not find conversion of [17-14C]-labeled or [1-,7-,12-,18-14C4]-labeled GA12 by GAS2. Furthermore, the authors1 state the isolation of endogenous DHGA12 from dry Arabidopsis seeds, which we cannot confirm by our attempts to isolate this compound from 0.5 g dry Arabidopsis Col-0 seeds (data not shown). Instead, we present here data showing that the recombinant GAS2 enzyme is able to catabolize abscisic acid (ABA) to phaseic acid (PA) and further to a second product, putative 8-carboxy-ABA (Fig. 1a). O_FIG O_LINKSMALLFIG WIDTH=141 HEIGHT=200 SRC="FIGDIR/small/516706v1_fig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@18fe917org.highwire.dtl.DTLVardef@11006a1org.highwire.dtl.DTLVardef@1235c94org.highwire.dtl.DTLVardef@930b98_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFig. 1.C_FLOATNO GAS2 is an ABA catabolizing oxidase. (a) The proposed ABA catabolic pathway catalyzed by GAS2. (b) Metabolism of d6-ABA incubated with 70 l cell-lysate of recombinant ATGA2ox1 and cofactors (negative control, upper lane). Metabolism of d6-ABA incubated with different volumes of cell-lysates containing recombinant GAS2 and cofactors as described in Methods. Chromatograms of characteristic single ions are shown in the first row for ABA (194 Da), in the middle row for PA (125 DA), and in the right row for compound A (194 Da). Products that were identified on the basis of their mass spectra of the methyl ester derivatives are labelled in red. (c) Top lane: Representative mass spectra of the d6-ABA substrate (KRI = 2087), and of its incubation products, PA (KRI = 2141) and compound A (KRI = 2197), by recombinant GAS2 enzyme. Bottom lane: Mass spectra of unlabeled PA substrate (KRI = 2146), and of the incubation product, compound A (KRI = 2201), by recombinant GAS2 enzyme. C_FIG

plant biology↗

bioRxiv2022

Integrated workflow of down-scaled Smart-seq2 and absolute quantitative, single-cell digital PCR validates lack of representability of low-abundant transcripts

Single-cell RNA sequencing (scRNA-seq) can unmask transcriptional heterogeneity facilitating the detection of rare subpopulations at unprecedented resolution. In response to challenges related to coverage and quantity of transcriptome analysis, the lack of unbiased and absolutely quantitative validation methods hampers further improvements. Digital PCR (dPCR) represents such a method as we could show that the inherent partitioning enhances molecular detections by increasing effective mRNA concentrations. We developed a scRT-ddPCR method and validated it using two breast cancer cell lines, MCF7 and BT-474, and bulk methods. ErbB2, a low-abundant transcript in MCF7 cells, suffers from dropouts in scRNA-seq and thus calculated fold changes are biased. Using our scRT-ddPCR, we could improve the detection of ErbB2 and based on the absolute counts obtained we could validate the scRNA-seq fold change. We think this workflow is a valuable addition to the single-cell transcriptomic research toolbox and could even become a new standard in fold change validation because of its reliability, ease of use and increased sensitivity.

molecular biology↗

bioRxiv2021

The distinct role of ALDH1A1 and ALDH1A3 in the regulation of prostate cancer metastases

Cancer stem cells (CSC) are characterized by high self-renewal capacity, tumor-initiating potential, and therapy resistance. Aldehyde dehydrogenase (ALDH)+ cell population serves as an indicator of prostate CSCs with increased therapy resistance, enhanced DNA double-strand break repair, and activated epithelial-mesenchymal transition (EMT) and migration. Numerous ALDH genes contribute to ALDH enzymatic activity; however, only some of them showed clinical relevance. We found that ALDH1A1 and ALDH1A3 genes functionally regulate CSC properties and radiation sensitivity of PCa. We revealed a negative correlation between ALDH1A1 and ALDH1A3 expression in publicly available prostate cancer (PCa) datasets and demonstrated that ALDH1A1 and ALDH1A3 have opposing predictive value for biochemical recurrence-free survival. Our data suggest an association of ALDH1A1 with the metastatic burden, elucidating the role of ALDH genes in the metastatic spread and homing to the bone, which can be, at least partially, attributed to regulating the transforming growth factor beta 1 (TGFB1) and matrix metalloproteinases (MMPs). ALDH genes play a diverse role in PCa development under AR and {beta}-catenin-dependent regulation, with ALDH1A1 becoming dominant in later stages of tumor development when PCa cells gain androgen independence. Taken together, our results indicate that ALDH1A1 and ALDH1A3 modulate PCa radiosensitivity, regulate CSCs phenotype, and spread of PCa cells to the bone, therefore having clinical implication for identifying patients at high risk for progression to metastatic disease.

cancer biology↗

bioRxiv2021

Evaluation of endogenous miRNA reference genes across different zebrafish strains, developmental stages and kidney disease models

The majority of kidney diseases arise from the loss of podocytes and from morphological changes of their highly complex foot process architecture, which inevitably leads to a reduced kidney filtration and total loss of kidney function. It could have been shown that microRNAs (miRs) play a pivotal role in the pathogenesis of podocyte-associated kidney diseases. Due to their fully functioning pronephric kidney, larval zebrafish have become a popular vertebrate model, to study kidney diseases in vivo. Unfortunately, there is no consensus about a proper normalization strategy of RT-qPCR-based miRNA expression data in zebrafish. In this study we analyzed 9 preselected candidates dre-miR-92a-3p, dre-miR-206-3p, dre-miR-99-1, dre-miR-92b-3p, dre-miR-363-3p, dre-let-7e, dre-miR-454a, dre-miR-30c-5p, dre-miR-126a-5p for their capability as endogenous reference genes in zebrafish experiments. Expression levels of potential candidates were measured in 3 different zebrafish strains, different developmental stages, and in different kidney disease models by RT-qPCR. Expression values were analyzed with NormFinder, BestKeeper, GeNorm, and DeltaCt and were tested for inter-group differences. All candidates show an abundant expression throughout all samples and relatively high stability. The most stable candidate without significant inter-group differences was dre-miR-92b-3p making it a suitable endogenous reference gene for RT-qPCR-based miR expression zebrafish studies.

molecular biology↗

bioRxiv2021

Association of stress-related limbic activity and baseline interleukin-6 plasma levels in healthy adults

Several studies suggest a link between acute changes in inflammatory parameters due to an endotoxin or (psychological) stressor and the brains stress response. The extent to which basal circulating levels of inflammatory markers are associated with the brains stress response has been hardly investigated so far. In the present study, baseline plasma levels of the cytokine interleukin (IL)-6 were obtained and linked to neural markers of psychosocial stress using a modified version of the Montreal Imaging Stress Task in a sample of N=65 healthy subjects (N=39 female). Of three a-priori defined regions of interest - the amygdala, anterior insula, and anterior cingulate cortex - baseline IL-6 was significantly and negatively associated with stress-related neural activation in the right amygdala and left anterior insula. Our results suggest that baseline cytokines might be related to differences in the neural stress response and that this relationship could be inverse to that previously reported for induced acute changes in inflammation markers.

neuroscience↗