Biology subjects

Pauly, D.

Publications and source records attributed to Pauly, D..

7 recordsLinked to original sources

bioRxiv2026

Chronicle of a Death Foretold: The Ecological Collapse of Sakumo Lagoon, Ghana

Sakumo Lagoon, a small (1 km2) semi-open coastal lagoon in Ghana, lies between the cities of Accra and Tema. The lagoon and its surrounding wetland were designated a Ramsar Site in 1992, mainly because it served as a refuge for 66 local and migratory bird species. Its ecology, and the biology of its major fish species, notably the blackchin tilapia (Sarotherodon melanotheron) were thoroughly studied in 1971, when the lagoon was a diverse, mainly brackish ecosystem supporting a traditionally and well-managed fishery. In 2016-2017, another study found the lagoon mostly covered by floating vegetation and plastic waste. Finally, in 2024, a visual survey established that the floating vegetation had been almost completely replaced by terrestrial plants, with only a few square meters of garbage-strewn water in front of a culvert connecting the lagoon to the open sea. Several lagoons along the coast of Ghana have been similarly lost to urban sprawl and its various forms of pollution, but Sakumo Lagoon is a Ramsar Site, and its imminent disappearance should not remain undocumented.

ecology↗

bioRxiv2026

Early Vertebrates Were Not Slow: Rapid Life Histories in Devonian Agnathans

Life history strategies such as rapid growth and high population turnover rates observed in vertebrates have been thought to have emerged relatively late in evolution. However, very little direct evidence exists at the species level for early vertebrates. In this study, a large fossil collection of over 450 specimens of Protaspis spp, heterostracan agnathans from the Cottonwood Canyon Formation at Beartooth Butte, Wyoming, from the Early Devonian, was analyzed. Morphological observations, analysis of bone plate completeness, and length-frequency analyses using ELEFAN--commonly used in recent fish studies--were applied to reconstruct growth rates, cohort structure, and ontogenetic processes. Protaspis specimens exhibited a continuous growth series from juvenile to adult stages, and a clear cohort structure was identified from the length-frequency distributions. The ELEFAN analysis suggested a life-history characterized by rapid growth and a short life span, and these features remained consistent in subset analyses restricted by species or locality, confirming the robustness of the estimates. Furthermore, the integration of the dermal bone plates progressed during the late stages of ontogeny, revealing that the rapid growth during the juvenile stage preceded the completion of this defensive structure. Comparisons of their growth parameters with those of extant fishes show that Protaspis does not align with slow-growing, long-lived "living fossil" taxa, but instead clusters with small-bodied, fast-growing species. These findings suggest that life-history strategies involving rapid growth and high population turnover were already established in early jawless vertebrates, much earlier than previously assumed.

paleontology↗

bioRxiv2025

Maturation-dependent complement production and C3 processing in human retinal pigment epithelium cells

Induced pluripotent stem cell-derived retinal pigment epithelial (iPSC-RPE) cells, closely resembling healthy RPE, offer valuable insights for retinal disease modelling. This study evaluates immature and mature phenotypes of iPSC-RPE and ARPE-19 cells, comparing RPE characteristics, cell-associated complement profiles, and TGF-{beta}1-mediated stress responses across transcript expression, secretion, and protein levels. Statistical analyses were performed using independent means t-test and Wilcoxon rank-sum test. Mature iPSC-RPE cells exhibited characteristic RPE-morphology, with elevated secretion of complement components (C3, FH/FHL-1, FI), unique FB secretion, and apical complement localisation. Intracellular C3 processing revealed cleavage products different from known blood-derived C3 fragments and showed maturation-dependent differences; only mature iPSC-RPE cells secreted active C3 forms (C3(H2O), C3a) and exhibited the intact C3 {beta}-chain. Mature ARPE-19 and iPSC-RPE cells demonstrated resistance to TGF-{beta}1 treatment, which reduced complement secretion without affecting C3a release. In conclusion, ARPE-19 and iPSC-RPE cells demonstrated local production of complement components and maturation-dependent intracellular processing of C3 into active forms. These findings highlight the impact of RPE maturation on local C3 activation, providing a basis for future studies on C3 functionality in the RPE and its potential pathological effects. Impact statementCell state-dependent local processing of complement C3 in retinal pigment epithelium cells generates active C3 forms that may evade anti-C3 therapies, influencing age-related macular degeneration and treatment outcomes. Funding statementThis project has received funding from the PRO RETINA, Amberg, Germany, under grant agreement number "Pro-Re/Projekt/Schikora - Pauly.05-2022", and Deutsche Forschungsgemeinschaft (DFG), under grant agreement number "498244102 (MA 6139/5-1)". Open access funding provided by the Open Access Publishing Fund of University Marburg. Funding sources were not involved in study design, data collection and interpretation, or the decision to submit the work for publication. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=149 SRC="FIGDIR/small/636432v1_ufig1.gif" ALT="Figure 1"> View larger version (67K): org.highwire.dtl.DTLVardef@6c63b3org.highwire.dtl.DTLVardef@58010org.highwire.dtl.DTLVardef@11ab625org.highwire.dtl.DTLVardef@ac4924_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2021

Proteomic phenotyping of stimulated Mueller cells uncovers profound pro-inflammatory signaling and antigen-presenting capacity

Muller cells are the main macroglial cells of the retina exerting a wealth of functions to maintain retinal homoeostasis. Upon pathological changes in the retina, they become gliotic with both protective and detrimental consequences. Accumulating data also provide evidence for a pivotal role of Muller cells in the pathogenesis of diabetic retinopathy (DR). While microglial cells, the resident immune cells of the retina are considered as main players in inflammatory processes associated with DR, the implication of activated Muller cells in chronic retinal inflammation remains to be elucidated. In order to assess the signaling capacity of Muller cells and their role in retinal inflammation, we performed in-depth proteomic analysis of Muller cell proteomes and secretomes after stimulation with INF{gamma}, TNF, IL-4, IL-6, IL-10, VEGF, TGF{beta}1, TGF{beta}2 and TGF{beta}3. We used both, primary porcine Muller cells and the human Muller cell line MIO-M1 for our hypothesis generating approach. Our results point towards an intense signaling capacity of Muller cells, which reacted in a highly discriminating manner upon treatment with different cytokines. Stimulation of Muller cells resulted in a primarily pro-inflammatory phenotype with secretion of cytokines and components of the complement system. Furthermore, we observed evidence for mitochondrial dysfunction, implying oxidative stress after treatment with the various cytokines. Finally, both MIO-M1 cells and primary porcine Muller cells showed several characteristics of atypical antigen-presenting cells, as they are capable of inducing MHC class I and MHC class II with co-stimulatory molecules. In line with this, they express proteins associated with formation and maturation of phagosomes. Thus, our findings underline the importance of Muller cell signaling in the inflamed retina, indicating an active role in chronic retinal inflammation underlying the pathogenesis of diabetic retinopathy.

immunology↗

bioRxiv2020

Low cost conservation: Fishing gear threats to marine species

Understanding conflicts between objectives of fisheries and conservation is the key to finding win-win situations for marine biodiversity and fishers. Many marine species are threatened by harmful interactions with fisheries, but the threats they face are associated with the fishing gear used. Here, we undertake a novel analysis of marine species and their gear-specific threats to evaluate conservation-fisheries trade-offs to identify areas with high competing goals. Our analysis suggests that gillnet and longline fisheries pose the greatest risk to marine species yet deliver relatively low profits, emphasizing the inefficiencies of these gears. We find that the majority of the high seas has low economic fisheries benefits with over 25% of the high seas categorized as areas of conservation prioritisation over fisheries.

ecology↗

bioRxiv2019

Oxidative stress in retinal pigment epithelial cells increased endogenous complement-dependent inflammatory and angiogenic responses - independent from exogenous complement sources

Oxidative stress-induced damage of the retinal pigment epithelium (RPE) together with chronic inflammation has been suggested as major contributors to retinal diseases. Here, we examine the effects of oxidative stress and endogenous complement components on the RPE and its pro-inflammatory and -angiogenic responses.\n\nThe RPE cell line, ARPE-19, treated with H2O2 reduced cell-cell contacts, increased marker for epithelial-mesenchymal transition but showed less cell death. Stressed ARPE-19 cells increased the expression of complement receptors CR3 and C5aR1. CR3 was co-localized with cell-derived complement protein C3, which was observed in its activated form in ARPE-19 cells. C3 as well as its regulators CFH and properdin accumulated in ARPE-19 cells after oxidative stress independent from external complement sources. This cell-associated complement accumulation promoted nlrp3 and foxp3 expression and subsequent increased secretion of pro-inflammatory and pro-angiogenic factors. The complement-associated ARPE-19 reaction to oxidative stress, independent from external complement source, was increased by the PARP-inhibitor olaparib.\n\nOur results indicated that RPE cell-derived complement proteins and receptors are involved in RPE cell homeostasis following oxidative stress and should be considered as targets for treatment developments for retinal degeneration.\n\nO_FIG O_LINKSMALLFIG WIDTH=160 HEIGHT=200 SRC=\"FIGDIR/small/722470v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (79K):\norg.highwire.dtl.DTLVardef@9b5cddorg.highwire.dtl.DTLVardef@1edd562org.highwire.dtl.DTLVardef@15415eborg.highwire.dtl.DTLVardef@16b0a72_HPS_FORMAT_FIGEXP M_FIG GRAPHICAL ABSTRACT C_FIG We show a functional link between oxidative stress, complement receptors, endogenous complement proteins, pro-angiogenic and -inflammatory responses in ARPE-19 cells. These effects are independent from extracellularly added complement proteins or receptor ligands. We suggest an oxidative stress-associated autocrine mechanism of complement receptor regulation in ARPE-19 cells in connection with upregulated intracellular proteases.\n\nHIGHLIGHTSO_LIOxidative stress accumulates complement proteins and receptors in RPE cells\nC_LIO_LIOxidative stress activates the RPE inflammasome without external complement proteins\nC_LIO_LIOxidative stress increases foxp3 expression and IL-8/VEGF secretion in RPE cells\nC_LIO_LIOlaparib enhances pro-inflammatory response of RPE\nC_LI

cell biology↗

bioRxiv2018

Cell type-specific complement expression from healthy and diseased retinae

Retinal degeneration is associated with complement system activation, but retinal sources of complement are unknown. Here, we describe the human and murine complement transcriptomes of Muller cells, microglia/macrophages, vascular cells, neurons and retinal pigment epithelium (RPE) in health and disease. All cell populations expressed c1s, c3, cfb, cfp, cfh and cfi. Murine Muller cells contributed the highest amount of complement activators (c1s, c3, cfb). RPE mainly expressed cfh, while cfi and cfp transcripts were most abundant in neurons. The main complement negative regulator in the human retina was cfi, while cfh dominated in the murine retina. Importantly, the expression of c1s, cfb, cfp, cfi increased and that of cfh decreased with aging. Impaired photoreceptor recycling led to an enhanced c3 expression in RPE and to a reduced cfi expression in microglia/macrophages. Expression of complement components was massively upregulated after transient retinal ischemia in murine microglia, Muller cells and RPE. The individual signature of complement expression in distinct murine and human retinal cell types indicates a local, well-orchestrated regulation of the complement system in both species.

neuroscience↗