Biology subjects

Vriens, J.

Publications and source records attributed to Vriens, J..

6 recordsLinked to original sources

bioRxiv2025

Stereoselectivity and functional plasticity of a common ligand-binding pocket in TRPM3

The transient receptor potential melastatin 3 (TRPM3) channel is a key mediator of peripheral pain signaling, and pathogenic mutations in TRPM3 are linked to neurodevelopmental delay and epilepsy. Despite the therapeutic promise of TRPM3 modulators, the molecular mechanisms by which ligands modulate channel gating remain poorly understood. Here, we combine cryo-electron microscopy (cryo-EM) with functional analyses to characterize a promiscuous ligand-binding pocket formed by transmembrane helices S1-S4. This pocket accommodates several chemically diverse plant-derived and synthetic agonists and antagonists. We uncover unanticipated stereoselectivity of TRPM3 for the non-natural enantiomer of the flavonoid antagonist isosakuranetin and the (R)-enantiomer of the synthetic agonist CIM0216. Mutations within this pocket--including newly identified patient variants--alter ligand affinity and, in some cases, invert the functional outcome of ligand binding. These findings reveal the stereoselectivity and functional plasticity of the TRPM3 ligand-binding pocket, highlighting how subtle changes in the molecular interactions can produce divergent effects on channel gating, with important ramifications for TRPM3-targeted drug development and therapy.

biochemistry↗

bioRxiv2024

Investigating endometriosis development and endometriosis-related pain over time and in relation to estrogen in a laparoscopic mouse model

BackgroundEndometriosis is a complex disease, and its pathophysiology is still unclear. Therefore, endometriosis animal models need to be carefully selected and examined to be useful for identification of novel therapies for women with endometriosis. In this study, we evaluated endometriosis-associated pain, and time- and estrogen-related development of endometriotic lesions after laparoscopic implantation of menstrual endometrium in a homologous mouse model for endometriosis. MethodsEndometriosis was induced by laparoscopic introduction of 10 menstrual endometrial tissue pieces into the peritoneum of ovariectomized recipient mice (59 estrogen-substituted; 59 estrogen-depleted). Sham animals (57 estrogen-substituted; 60 estrogen-depleted) received 10 pieces of perigonadal adipose tissue. The animals were sacrificed at 1, 2, 3, 4, 6 or 8 weeks after induction, the attached peritoneal implants localized and excised and immunohistochemically analyzed. Additionally, endometriosis-related pain was evaluated by measuring mechanical allodynia, thermal hyperalgesia, locomotor activity and anxiety-like behavior before and after tissue implantation. ResultsAt least one implant per mouse could be retrieved in 94% (111/118) of the endometrial tissue animals and in 78% (91/117) of the adipose tissue animals (p<0.001). Peritoneal implant take rate was significantly higher in endometrial tissue animals (2.5{+/-}1.4) compared to adipose tissue animals (1.6{+/-}1.5) (p<0.0001), regardless of estrogen supplementation and time of sacrifice. Hemosiderin could be observed more often (p<0.0001) in attached peritoneal implants of the endometrial tissue animals (67%, 68/101), compared to the adipose tissue animals (37%, 31/83). Ki67 staining showed a higher proliferation index in the attached peritoneal implants retrieved after one week, compared to the other time points of both endometrial tissue and adipose tissue animals. The behavioral test showed no significant difference in mechanical and thermal sensitivity, locomotor activity and anxiety-behavior between the menstrual endometrial tissue and adipose tissue implanted animals. Nevertheless, the estrogen-substituted animals showed decreased activity in the tests featuring thermal nociception and anxiety-like behavior, compared to the estrogen-depleted animals. Additionally, time after implantation showed to have a positive effect on thermal sensitivity, locomotor activity and anxiety-related behavior in all animals, as the mice became less sensitive to thermal stimuli, more active in the open field test and buried less marbles in the marble burying test. ConclusionThis study showed an increased attachment of menstrual endometrium compared to adipose tissue in the peritoneum when using laparoscopic induction. There was no apparent influence of estrogen on tissue attachment, proliferation or appearance. A decrease in cell proliferation in peritoneal implants occurred over time. Locomotor activity, anxiety-like behavior, and mechanical and thermal sensitivity of the animals was not affected after induction of endometriosis, regardless of the type of implanted tissue. Altogether, we showed that the current methodology used to induce endometriosis was not sufficient to develop endometriotic lesions that contained both stromal and epithelial cells. Moreover, the current methodology was not able to detect specific endometriosis-related pain. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/583957v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@119ad34org.highwire.dtl.DTLVardef@ba5b8borg.highwire.dtl.DTLVardef@d020ccorg.highwire.dtl.DTLVardef@1941e8_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2023

Osmolar modulation drives reversible cell cycle exit and human pluripotent cell differentiation via NF-κB and WNT signaling

Terminally differentiated cells are regarded as the most stable and common cell state in adult organisms as they reside in growth arrest and carry out their cellular function. Improving our understanding of the mechanisms involved in promoting cell cycle exit would facilitate our ability to manipulate pluripotent cells into mature tissues for both pharmacological and therapeutic use. Here, we demonstrated that a hyperosmolar environment enforced a protective p53-independent quiescent state in dedifferentiated hepatoma cells and pluripotent stem cells (PSCs)-derived models of human hepatocytes and endothelial cells, representing the endodermal and mesodermal lineages. Prolonged culture in hyperosmolar conditions stimulated transcriptional and functional cell maturation. Interestingly, hyperosmolar conditions did not only trigger cell cycle exit and cellular maturation but were also necessary to maintain this maturated state, as switching back to plasma osmolarity caused the loss of maturation markers and the gain of proliferative markers. Transcriptome analysis revealed activation of NF-{kappa}[V] and repression of WNT signaling as the two main pathways downstream of osmolarity-regulated growth arrest and cell maturation, respectively. This study revealed that increased osmolarity serves as a biochemical signal to promote long-term growth arrest, transcriptional changes, and maturation into different lineages, serving as a practical method to generate differentiated hiPSCs that resemble their mature counterpart more closely.

developmental biology↗

bioRxiv2022

TRPM3 as novel target to alleviate acute oxaliplatin-induced peripheral neuropathic pain

Chemotherapy-induced peripheral neuropathic pain (CIPNP) is an adverse effect observed in up to 80% of cancer patients upon treatment with cytostatic drugs including paclitaxel and oxaliplatin. CIPNP can be so severe that it limits dose and choice of chemotherapy, and has a significant negative consequences on the quality of life of survivors. Current treatments for CIPNP are limited and unsatisfactory. TRPM3 is a Ca2+-permeable ion channel functionally expressed in peripheral sensory neurons involved in the detection of thermal stimuli. Here, we focus on the possible involvement of TRPM3 in acute oxaliplatin-induced mechanical allodynia and cold hypersensitivity. In vitro calcium microfluorimetry and whole-cell patch-clamp experiments showed that TRPM3 is functionally upregulated in both heterologous and homologous expression systems after acute (24h) oxaliplatin treatment, while direct application of oxaliplatin was without effect. In vivo behavioral studies using an acute oxaliplatin model for CIPNP showed the development of cold and mechano-hypersensitivity in control mice, which was lacking in TRPM3 deficient mice. In addition, the levels of pERK, a marker for neuronal activity, were significantly reduced in DRG neurons derived from TRPM3 deficient mice compared to control after oxaliplatin administration. Moreover, intraperitoneal injection of a TRPM3 antagonist, isosakuranetin, effectively reduced the oxaliplatin-induced pain behavior in response to cold and mechanical stimulation in mice with an acute form of oxaliplatin-induced peripheral neuropathy. In summary, TRPM3 thus represents a potential new target for the treatment of neuropathic pain in patients undergoing chemotherapy.

neuroscience↗

bioRxiv2020

Upregulation of TRPM3 drives hyperexcitability in nociceptors innervating inflamed tissue.

Genetic ablation or pharmacological inhibition of the heat-activated cation channel TRPM3 alleviates heat hyperhyperalgesia in animal models of inflammation, but the mechanisms whereby the channel contributes to inflammatory pain are unknown. Here, we induced unilateral inflammation of the hind paw in mice, and directly compared expression and function of TRPM3 and two other heat-activated TRP channels (TRPV1 and TRPA1) in sensory neurons innervating the ipsilateral and contralateral paw. We detected increased Trpm3 mRNA levels in dorsal root ganglion neurons innervating the inflamed paw, as well as augmented TRP channel-mediated calcium responses, both in the cell bodies and the intact peripheral endings of nociceptors. Notably, inflammation provoked a pronounced increase in nociceptors co-expressing functional TRPM3 with TRPV1 and TRPA1, and pharmacological inhibition of TRPM3 caused normalization of TRPV1- and TRPA1-mediated responses. These new insights into the mechanisms underlying inflammatory heat hypersensitivity provide a rationale for developing TRPM3 antagonists to treat pathological pain.

neuroscience↗

bioRxiv2020

Gain of channel function and modified gating properties in TRPM3 mutants causing intellectual disability and epilepsy

Developmental and epileptic encephalopathies (DEE) are a heterogeneous group of disorders characterized by epilepsy with comorbid intellectual disability. Recently, two de novo heterozygous mutations in the gene encoding TRPM3, a calcium permeable ion channel, were identified as the cause of DEE in eight probands, but the functional consequences of the mutations remained elusive. Here we demonstrate that both mutations (V990M and P1090Q) have distinct effects on TRPM3 gating, including increased basal activity, higher sensitivity to stimulation by the endogenous neurosteroid pregnenolone sulphate (PS) and heat, and altered response to ligand modulation. Most strikingly, the V990M mutation affected the gating of the non-canonical pore of TRPM3, resulting in large inward cation currents via the voltage sensor domain in response to PS stimulation. Taken together, these data indicate that the two DEE mutations in TRPM3 result in a profound gain of channel function, which may lie at the basis of epileptic activity and neurodevelopmental symptoms in the patients.

neuroscience↗