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Biology subjects

Wang, T.-W.

Publications and source records attributed to Wang, T.-W..

6 recordsLinked to original sources

A senescent iCAF-like fibroblast state governs therapy resistance in rheumatoid arthritis

ObjectivesRheumatoid arthritis (RA) synovitis frequently persists despite cytokine-targeted therapies, suggesting the existence of pathogenic stromal programs that sustain chronic inflammation independently of canonical immune pathways. Although synovial fibroblasts (SF) are increasingly implicated in treatment resistance, the pathogenic fibroblast states driving refractory disease and their therapeutic vulnerabilities remain poorly defined. MethodsWe integrated multimodal single-cell and spatial profiling of synovial tissue from 54 patients with RA with prospective treatment-response data and functional studies in human fibroblasts and experimental arthritis models. ResultsWe identified a C-X-C motif chemokine 12 (CXCL12)hi Apolipoprotein C1 (APOC1)+ fibroblast population selectively enriched in treatment-refractory synovitis. Spatial analyses demonstrated that these fibroblasts establish CXCL12-dependent plasmablast niches within inflamed synovium, resembling inflammatory cancer-associated fibroblasts (iCAF) that orchestrate immune cell recruitment in the tumor microenvironment. CXCL12hi APOC1+ fibroblasts exhibited a senescence-associated iCAF-like transcriptional program characterized by STAT3-C/EBP activation and APOC1 expression and were associated with poor response to TNF and IL-6 pathway inhibition. Mechanistically, APOC1 knockdown in RA-SF attenuated invasive mesenchymal behavior and disrupted senescence-associated inflammatory programs, identifying APOC1 as a central regulator of pathogenic fibroblast reprogramming. Importantly, genetic or pharmacological elimination of senescent cells ameliorated experimental arthritis and enhanced the efficacy of TNF blockade. ConclusionsThese findings implicate iCAF-like fibroblasts with senescent properties as a mechanistic driver of refractory RA synovitis and highlight stromal senescence programs as preclinically actionable therapeutic targets beyond cytokine inhibition.

immunology↗

Single-cell-based evidence for GLS1 inhibitor as a bona fide senolytic agent in vivo

A plethora of senolytic compounds and technologies have been identified. However, the efficacy of these treatments in eliminating senescent cells and the suppression of chronic inflammation remains to be substantiated in vivo. Here, we employ single-cell RNA sequencing and find the selective elimination of highly inflammatory fibroblasts, endothelial cells in the lung, and proximal tubule cells in the kidney from the GLS1 inhibitor BPTES-treated aged mice. The eliminated fibroblasts share typical phenotypes with in vitro human senescent cells. These cells predominantly express Dpp4 (CD26) and Cadm3, showing activated IFN signaling and lysosomal membrane damage. Cells eliminated by BPTES in lungs exhibit transcriptomes similar to those eliminated in p16-DTR mice, where DTR expression is limited in p16-expressing cells. BPTES treatment results in the T cell population shift from cytotoxic to a protective state, suggesting the suppression of age-related chronic inflammation. CellChat analysis revealed that multiple cytokine signals are transmitted from inflammatory fibroblasts and proximal tubular cells to immune cells in lungs and kidneys. These results provide evidence that GLS1 inhibitor functions as a bona fide senolytic drug to eliminate inflammatory cells, including a subset of senescent cells, and suppresses age-related chronic inflammation.

cell biology↗

Distinct neurochemical influences on fMRI response polarity in the striatum

The striatum is the primary input nucleus of the basal ganglia, widely studied for its complex roles in health and disease. Functional magnetic resonance imaging (fMRI) studies are essential for discerning striatal function, however the relationship between neuronal and hemodynamic activity, critical for interpreting fMRI signals, has not been rigorously examined in striatum. We find that optogenetic stimulation of striatal neurons or afferents evokes negative striatal fMRI responses in rats that can occur despite broad increases in local neuronal activity. Intra-striatal pharmacological manipulations suggest that opioidergic, but not dopaminergic transmission contributes to negative striatal fMRI signals (the latter instead associated with positive signals). Striatal neuronal activity peaks are also associated with negative hemodynamic signals in behaving rats. Negative fMRI responses are observed in human striatum under conditions of anticipated neuronal activity increases. Our results prompt consideration of local cellular and neurochemical environments along with neuronal activity in fMRI signal interpretation.

neuroscience↗

Allee effects mediate the impact of land-use change on the thermal niche of social species

Land-use change not only affects habitat availability, it can also reduce population density and limit opportunities for interactions with conspecifics, further influencing species resilience to environmental challenges. For social species whose conspecific interactions are typically cooperative in nature, little is known about how land-use change influences demography and social behavior, and how this interaction impacts a species climatic niche. Here, we develop a spatially explicit, individual-based model to explore how land-use changes influence population size and niche width in social organisms through the Allee effect, the positive impact of higher population density on individual fitness. We then empirically test key model predictions by studying the distribution and cooperative behavior of burying beetles (Nicrophorus nepalensis) along elevational gradients in Taiwan. In support of our model predictions, we find that beetle densities are lower in areas of greater land-use change, making it harder for individuals in these hotter environments to form cooperative groups to compete against blowflies, their primary interspecific competitor. Consequently, the beetles lower distributional boundary is higher in areas with greater land-use change, indicating that the beetles thermal niche is reduced via Allee effects in human-altered landscapes. Ultimately, land-use change not only reduces habitat availability, it also shrinks the thermal niche of social species, making them more vulnerable to climate change.

ecology↗

Spectral fiber-photometry derives hemoglobin-absorption changes for accurate measurement of fluorescent sensors

Fiber-photometry is an emerging technique for recording fluorescent sensor activity in the brain. However, significant hemoglobin-absorption artifacts in fiber-photometry data may be misinterpreted as sensor activity changes. Because hemoglobin exists in nearly every location in the brain and its concentration varies over time, such artifacts could impede the accuracy of many photometry recording results. Here we present a novel use of spectral photometry technique and propose computational methods to quantify photon absorption effects by using activity-independent fluorescence signals, which can be used to derive oxy- and deoxy-hemoglobin concentration changes. Following time-locked neuronal activation in vivo, we observed that a 20% increase in CBV contributes to about a 4% decrease in green fluorescence signal and a 2% decrease in red fluorescence signal. While these hemoglobin concentration changes are often temporally delayed than the fast-responding fluorescence spikes, we found that erroneous interpretation may occur when examining pharmacology-induced sustained activity changes, and in some cases, hemoglobin-absorption could flip the GCaMP signal polarity. We provided hemoglobin-based correction methods to restore fluorescence signals across spectra and compare our results against the commonly used regression approach. We also demonstrated the utility of spectral fiber-photometry for delineating brain regional differences in hemodynamic response functions. HighlightsO_LIHemoglobin-absorption compromises fiber-photometry recording in vivo C_LIO_LISpectral photometry allows quantification of hemoglobin concentration changes for correction C_LIO_LIThe proposed platform allows measuring regional differences in neurovascular transfer function C_LI

neuroscience↗

HDGF supports anti-apoptosis and pro-fibrosis in pancreatic stellate cells of pancreatic cancer

Pancreatic cancer is refractory and characterized by extensively surrounding- and intra-tumor fibrotic reactions that are contributed by activated pancreatic stellate cells (PSCs). Activation of PSCs plays a pivotal role for developing fibrotic reactions to affect themselves or pancreatic cancer cells (PCCs). In the current study, we demonstrated that hepatoma-derived growth factor (HDGF) was secreted from transforming growth factor-{beta}1 (TGF-{beta}1)-treated PSCs. We found that HDGF contributed to anti-apoptosis of PSCs and led to synthesis and depositions of extracellular matrix proteins for stabilizing PSCs/PCCs tumor foci. CCAAT/enhancer binding protein {delta} (CEBPD) responds to TGF-{beta}1 through a reciprocal loop regulation and further activated hypoxia inducible factor-1 (HIF-1) contributed to up-regulation of HDGF gene. It agrees with the observation that severe stromal growth positively correlated with stromal HDGF and CEBPD in pancreatic cancer specimens. Collectively, the identification of TGF-{beta}1-activated CEBPD/HIF-1/HDGF axis provides new insights for the novel discoveries of HDGF in anti-apoptosis and pro-fibrosis of PSCs and outgrowth of pancreatic cancer cells.

cancer biology↗