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physiology: explore 10 source-linked works published from 2026 to 2026, with original documents and citations.

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Sources: biorxiv. Collection updated 2026-09-17. Counts describe this index, not the complete source archives.

IBD-Derived Colonic Fibroblasts Exhibit an Osteopontin-Enriched Secretome, and Osteopontin Restrains Human Colonic Organoid Maturation

Background: Intestinal fibroblasts are extensively remodeled in inflammatory bowel disease (IBD), yet the soluble stromal signals that directly influence epithelial maturation remain incompletely understood. We examined whether fibroblasts derived from inflamed IBD colon display an osteopontin (OPN; SPP1)-enriched secretory phenotype and whether extracellular OPN directly modifies non-neoplastic human colonic epithelium. Methods: Conditioned media from 5 noninflamed-associated fibroblast (NAF) and 4 inflammatory-associated fibroblast (IAF) cultures were analyzed in the validated multi-donor cytokine-array matrix, with orthogonal SPP1 RT-qPCR validation in a complementary fibroblast cohort. Recombinant OPN was then tested in human colonic organoids from 3 donors using donor-resolved molecular and functional analyses under standard, fibroblast-conditioned, and WNT-modified culture conditions. Donor identity defined biological replication. Results: OPN showed the strongest positive rank-based separation between IAF and NAF cultures: all 4 IAF values were higher than all 5 NAF values (Cliff's delta=1.00; exact Mann-Whitney P=0.0159; median ratio=3.64; Benjamini-Hochberg q=.19). Fibroblast RT-qPCR showed approximately 10-fold higher mean SPP1 expression in IAF than NAF cultures (P<.05). In organoids, OPN consistently reduced KRT20, FABP1, CA2, and MUC2 from Day 5 to Day 9. SOX9, HES1, and NOTCH1 increased at Day 9, whereas LGR5 and ALDH provided no evidence of canonical stem-cell expansion. Organoid-area and EdU responses were modest and donor dependent. Conclusions: IBD-derived colonic fibroblasts can display an OPN-enriched secretory phenotype. In human colonic organoids, OPN is sufficient to impair epithelial maturation, whereas its effects on growth and proliferation are variable and depend on the surrounding niche.

physiology↗

A multiscale analysis of liver lobule fibrosis and its impact on drug propagation and metabolism - a DLA approach

Employing DLA methods, this paper explores the self-assembly of collagen fibers and resulting fibrosis at three scales up to the scale of regular lobule models. This allows a mechanistic exploration of the effects of collagen on drug transport (flow and diffusion) and metabolism. In addition, this method permits an analysis of fiber growth characteristics. First, variations of the DLA method of Parkinson et al (1994) will be used to generate multiple explicit collagen microfibril self-assembly using DLA particles in one dimension using cubic grid blocks of (4 mm)3 in a 240 x 20 x 20 grid model. The second stage will be to assess the consequences of various densities of these fibers in three dimensions on flow reductions at a higher scale. Here we utilize DLA methods in cubic grid blocks of (80 nm)3 to mimic 3D collagen self-assembly of fibrils. We then apply a pressure gradient or specified flow rates across a spatially gridded version of these models to quantify flow effects. This region represents a local zone of liver tissue affected by fibrosis. Analytic models of fibrotic effects on flow are employed for comparison. A third stage explores the implications of fibrosis in a liver lobule model using multiple grid blocks of size 3200 mm to represent the lobule tissue. Here, a continuum model of fiber density is employed, based on the previous two scales. The model also includes the effects of additional grid blocks representing sinusoidal flow paths found in the lobule. We contrast and quantify drug propagation and metabolism of molecular dissolved versus nanoparticle delivery vehicles in fibrotic media, achieved by upscaling explicit collagen distributions to appropriate average values.

physiology↗

Pulmonary pressure load shapes right ventricular molecular remodelling in dilated cardiomyopathy

Right ventricular (RV) adaptation to pulmonary hypertension determines outcome in dilated cardiomyopathy (DCM), but the molecular mechanisms of the transition to decompensation remain unclear. We analysed RV tissue from explanted hearts of patients with end-stage DCM using single-nucleus RNA sequencing (n=21), mass spectrometry and Olink Reveal proteomics (both n=44), and integrated these molecular profiles with echocardiographic and right-heart catheterisation measures to identify molecular correlates of RV dysfunction. Mean pulmonary arterial pressure was the dominant correlate of RV transcriptional remodelling, particularly in cardiomyocytes, where higher pressure was associated with contractile remodelling, autophagy, vesicle trafficking and glucose metabolism. In contrast, RV decompensation was characterised by immune activation and reduced oxidative phosphorylation exclusively at the proteomic level. Integrative multi-omics factor analysis (MOFA) further identified fibrosis as the dominant molecular program shared across transcriptomic and proteomic layers. Together, these findings indicate molecular adaptation to pressure load and tissue fibrosis during progression towards RV failure.

physiology↗

Trait-Dependent and Site-Specific Effects of Foliar IAA and Kinetin on Two Chickpea Varieties Grown Under Contrasting Conditions

Chickpea (Cicer arietinum L.) yield in Algeria still falls short of domestic demand, and low-cost agronomic tools such as plant growth regulators are one of the few levers producers can adjust without heavy investment. We tested the separate and combined effects of foliar-applied indole-3-acetic acid (IAA) and kinetin (0, 10, and 20 mg/L) on two chickpea varieties, FLIP 84-92 and ILC 32-79, grown side by side in the field at the ITGC station of El Khroub and in pots at the Institute of Natural Sciences of Oum El Bouaghi during the 2024/2025 season. Nine hormone treatments were applied to each variety at each site, with three replicates apiece. No single treatment came out on top across the board. A20+K20 gave the largest pot leaf area at both sampling dates (5.67 and 7.20 cm2) and the highest field dry matter weight (95.21 g), yet A10+K10 produced the largest field leaf area after the first spray (16.47 cm2) and the highest pot dry matter weight (6.12 g). Kinetin alone at 20 mg/L (K20) gave the most field pods (21.28) and the most field leaves after the first spray (115.41), while A10+K20 gave the heaviest pot grains (100-grain weight of 21.16 g). Field and pot means are not directly comparable given how different the two growing environments and sampling routines were. Between varieties, FLIP 84-92 germinated better (86% vs. 83%) and produced heavier grains, while ILC 32-79 grew taller stems. Because the manuscript we worked from supplied only treatment means, with no replicate-level data or variance estimates, we report these as descriptive numerical differences rather than statistically tested effects. Read that way, the pattern that emerges is that IAA and kinetin responses are trait- and environment-specific rather than uniformly additive, and a properly replicated factorial analysis will be needed before any interaction or synergy between the two hormones can be claimed.

physiology↗

Personalized phosphoproteomics establish mTORC1 as a regulator of exercise-induced insulin sensitization in human skeletal muscle

Exercise enhances skeletal muscle insulin sensitivity, but the signaling mechanisms responsible are poorly understood. Understanding them may open new therapeutic avenues for individuals with limited exercise capacity. Here, we used rapamycin to inhibit mTORC1 in combination with exercise and insulin stimulation in healthy men. A single dose of rapamycin enhanced the insulin-sensitizing effect of exercise by 53% on average compared to placebo. Responses varied widely across individuals (-40% to 218%), and we leveraged this variance through personalized phosphoproteomics to map the mTORC1-dependent signaling network in skeletal muscle. This identified the protein kinase MKNK2 as a candidate downstream effector, which we then targeted for functional validation. Pharmacological inhibition of MKNK2 with eFT508 in insulin-clamped mice reduced both whole-body and skeletal muscle insulin sensitivity, confirming a functional role for MKNK2 activity in muscle glucose uptake. We then used eFT508 in ex vivo incubated human skeletal muscle to map the signaling network downstream of MKNK2, identifying the translational initiator eIF4G1 as a further regulatory node. Together, these findings indicate that exercise-induced insulin sensitization is actively constrained by a negative feedback pathway running from mTORC1 through the translational regulators MKNK2 and eIF4G1, raising the possibility that rapid translation of unidentified target proteins contributes to fine-tuning glucose uptake.

physiology↗

Bacterial Peptidoglycan Extends Lifespan by Activating Lysosomal Activity through V-ATPase Binding

Lysosomal dysfunction is a hallmark of aging, yet whether microbial components actively regulate this organelle to influence longevity remains unknown. Here, we identify bacterial peptidoglycan (PGN), a major cell wall component degraded by host lysozyme, as an evolutionarily conserved activator of lysosomal function that extends lifespan in both C. elegans and mice. We show that aging leads to an intestinal decline in lysozyme expression, which impairs bacterial cell-wall digestion and results in systemic PGN deficiency. Late-life PGN supplementation (starting at 18 months of age) significantly prolongs mouse lifespan and improves healthspan. Mechanistically, PGN localizes to lysosomes and directly binds V-ATPase subunits, enhancing ATP hydrolysis activity and promoting lysosomal acidification. This effect is abolished by V-ATPase inhibition (bafilomycin A1) or genetic disruption of lysosomal components (cup-5 and vha-12 mutants), confirming that functional V-ATPase is strictly required for lysosomal function and the longevity benefit. Importantly, PGN restores lysosomal acidification in aged cells, alleviates cellular senescence markers, and improves multiple hallmarks of aging including locomotion and muscle integrity. Collectively, these findings reveal an evolutionarily conserved mechanism whereby hosts exploit bacterial cell wall components to maintain cellular homeostasis, establishing a gut microbiome-lysosome-longevity axis with implications for microbiome-based anti-aging interventions.

physiology↗

Sympathetic activation and the force-frequency relationship in heart failure with reduced ejection fraction

Background Limited heart rate rise contributes to reduced exercise tolerance for people who have heart failure with reduced ejection fraction (HFrEF), yet rate-adaptive pacing does not improve functional capacity due to an attenuated force-frequency relationship (FFR). How the FFR relates to total peripheral resistance and sympathetic tone in HFrEF is unknown. Methods In a prospective, observational study, participants with HFrEF and controls underwent an incremental pacing protocol, during which heart rate was increased from 50 to 140 beats per minute. At each heart rate increment LV contractility was measured by echocardiography to determine the FFR, as well as continuous beat-to-beat measurement of systolic and diastolic blood pressures with a plethysmography device to determine cardiac output, total peripheral resistance and blood pressure variability (BPV). A microneurography study was then conducted to measure muscle sympathetic nerve activity (MSNA) during incremental pacing. Results A total of 157 participants with HFrEF and 55 controls (mean age 71.1{+/-}1.4 years, 172 (81.1%) male) underwent the pacing protocol. We observed single units in seven of 11 participants who participated in the microneurography study. In both groups, LV contractility and cardiac output increased until the peak of the FFR, after which these declined. We observed a reduction in total peripheral resistance, blood pressure variability, MSNA frequency and incidence coinciding with the peak of the FFR, beyond which these increased. Whilst these relationships were present in both groups, they were more evident in participants with HFrEF. Conclusions For people with HFrEF there is a bidirectional relationship between heart rate and sympathetic activation, with a nadir of sympathetic tone occurring at the peak of the FFR. Both excessively low and high heart rates are accompanied by greater sympathetic activation. Taken together, these data suggest that optimal heart rate targets for HFrEF are likely to be individual.

physiology↗

SEDATION DIFFERENTIALLY AFFECTS DISTORTION-PRODUCT AND STIMULUS-FREQUENCY OTOACOUSTIC EMISSIONS IN CHINCHILLAS

Purpose: Otoacoustic emissions (OAEs) are used to assess outer hair cell (OHC) function. Clinical interpretation of OAE responses, however, is often limited to a present/absent binary since both physiological factors and measurement variability affect the measured OAE amplitude. Prior work showed elevated OAE responses in sedated compared to awake chinchillas, pointing to the potential influence of the medial olivocochlear (MOC) efferents on amplitudes, but this finding is inconsistent across species and OAE type. Here, we aimed to further investigate the effect of anesthesia on distortion- and reflection-type emissions in chinchillas using swept stimuli and more reliable calibration methods. Methods: Swept distortion-product (DP) and stimulus-frequency (SF) OAEs were measured in chinchillas with and without ketamine/xylazine sedation. Stimuli were presented using in-ear forward pressure level calibrations. DPOAE and SFOAE amplitudes and estimated Qerb from SFOAE group delays were compared across the two conditions. Results: We found that low-frequency DPOAE amplitudes were elevated when animals were sedated. The difference in SFOAE amplitudes was more variable across animals but appeared mildly reduced in sedated animals. Qerb estimates were slightly higher in sedated animals at some frequencies. The effect of sedation was not different across sexes. Conclusion: Taken together, these findings suggest that sedation impacts OAE measurements in chinchillas. MOC modulation could account for the present findings and differences across species. For diagnostic precision, OAE responses should be considered in the context of not only intrinsic OHC function but also extrinsic physiological processes that can modulate OHCs.

physiology↗

HDAC6 is a novel regulator of endothelial-to-mesenchymal transition in venous thrombosis

Background: Venous thromboembolism (VTE), which encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE), is a frequent disease associated with thrombus formation and vein wall remodeling. Hence, fibrosis might result from endothelial-to-mesenchymal transition (EndMT), characterized by the loss of endothelial markers and the acquisition of mesenchymal markers. In chronic thromboembolic pulmonary hypertension, transforming growth factor (TGF{beta}), the most potent inducer of EndMT, impairs thrombus resolution. However, the molecular mechanisms implicated in TGF[beta] signaling in the context of VTE are unknown. We hypothesized that epigenetic processes regulate the TGF{beta} signaling pathway in endothelial cells promoting EndMT and vascular fibrosis. Aims: To determine if the histone deacetylase 6 (HDAC6) regulates the TGF{beta} signaling pathway in endothelial cells promoting EndMT and delays venous thrombosis. Methods: To study the role of HDAC6 in EndMT, endothelial cells were treated with a pharmacological inhibitor (TCS20b) and incubated with TGF{beta} and thrombin for 2, 3, and 5 days. Real time PCR and Western blot were performed to analyze endothelial and mesenchymal marker expression and TGF{beta} signaling. An experimental model of VTE was used to study the role of HDAC6 on thrombus size overtime. Animals were treated or not with a specific HDAC6 inhibitor (tubastatin A) for 7 to 21 days. Analysis of RNAseq data sets publicly available were used to confirm our main results. Within group and treatment differences were analyzed using two-way ANOVA and Tukeys multiple comparisons. Results: Expression of the mesenchymal markers, calponin and transgelin, was increased by TGF{beta} and thrombin. Interestingly these changes were inhibited in presence of TCS20b. TGF{beta} mediated these effects through ERK1/2 and HDAC6 activation. Inhibition of HDAC6 in vivo reduced thrombus size 7 days after surgery compared to controls. This was associated with reduced expression of the EndMT marker transgelin in endothelial cells compared to the control animals. We found that FN1-EDA expression was associated with EndMT and regulated by HDAC6 in vitro. This marker was also associated with thrombosis in the RNAseq data set that we analyzed and potentially in patients with recurrent DVT. Conclusion: We found that HDAC6 regulates EndMT in venous thrombosis and impairs thrombus resolution. HDAC6 also regulates expression FN1-EDA that appears to be a strong marker associated with DVT and DVT recurrence. Thus, HDAC6 might represent an attractive therapeutic target for patients with a high risk of recurrent VTE.

physiology↗

Zebrafish larval nitrogen excretion is flexible and resilient to loss of rhesus glycoproteins

Nitrogenous waste excretion is essential for all developmental stages of fish. Embryonic fish excrete urea, transitioning to cutaneous and later branchial ammonia excretion. In zebrafish, ammonia excretion involves rhesus glycoproteins Rhbg and Rhcgb in keratinocytes and ionocytes, but the developmental moment they appear in the gill remains unclear. Potential redundancy between Rhbg and Rhcgb in ammonia excretion is also not fully investigated, nor is the difference in response to low pH. We hypothesized that rhesus glycoproteins are partially redundant, and that they differ in their response to low pH as ammonia excretion enables ionocytes to exchange Na+ and H+ (Rh-NHE-metabolon). We predicted that a loss of rhbg or rhcgb induces compensatory responses. We characterized the transition from urea to branchial ammonia excretion from 0 to 8 days-post fertilization (dpf) and the response to pH 5.0 on the expression and localization of rhesus glycoproteins in control zebrafish and rhbg or rhcgb-crispants. Effects of high external ammonia (HEA, 500 M NH4Cl) and 10 mM HEPES-buffering were further characterized in rhcgb-crispants. Rhag and Rhbg appeared in the gill at 5 dpf, while Rhcgb appeared at 6 dpf. A loss of rhbg or rhcgb did not impact baseline N-excretion, illustrating that zebrafish can maintain ammonia excretion without the full complement of rhesus glycoproteins. We observed no compensatory increase in rhesus glycoproteins, but expression of the transporter hippocampus-abundant transcript 1b increased. HEA-exposed rhcgb-crispants switched to urea as primary nitrogen waste. Together, these findings underline the plasticity of the larval in dealing with nitrogenous waste.

physiology↗
Compare source metadata on this page
WorkPublishedSource identifierSource
IBD-Derived Colonic Fibroblasts Exhibit an Osteopontin-Enriched Secretome, and Osteopontin Restrains Human Colonic Organoid Maturation2026-09-0310.64898/2026.08.28.747568v1biorxiv
A multiscale analysis of liver lobule fibrosis and its impact on drug propagation and metabolism - a DLA approach2026-09-0310.64898/2026.08.28.747748v1biorxiv
Pulmonary pressure load shapes right ventricular molecular remodelling in dilated cardiomyopathy2026-09-0310.64898/2026.08.28.747817v1biorxiv
Trait-Dependent and Site-Specific Effects of Foliar IAA and Kinetin on Two Chickpea Varieties Grown Under Contrasting Conditions2026-09-0310.64898/2026.08.29.747965v1biorxiv
Personalized phosphoproteomics establish mTORC1 as a regulator of exercise-induced insulin sensitization in human skeletal muscle2026-09-0210.64898/2026.08.27.747624v1biorxiv
Bacterial Peptidoglycan Extends Lifespan by Activating Lysosomal Activity through V-ATPase Binding2026-09-0210.64898/2026.08.28.747948v1biorxiv
Sympathetic activation and the force-frequency relationship in heart failure with reduced ejection fraction2026-09-0110.64898/2026.08.24.746885v1biorxiv
SEDATION DIFFERENTIALLY AFFECTS DISTORTION-PRODUCT AND STIMULUS-FREQUENCY OTOACOUSTIC EMISSIONS IN CHINCHILLAS2026-09-0110.64898/2026.08.26.746474v1biorxiv
HDAC6 is a novel regulator of endothelial-to-mesenchymal transition in venous thrombosis2026-09-0110.64898/2026.08.27.747544v1biorxiv
Zebrafish larval nitrogen excretion is flexible and resilient to loss of rhesus glycoproteins2026-09-0110.64898/2026.08.28.747819v1biorxiv

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