Biology subjects

Boyle, K. A.

Publications and source records attributed to Boyle, K. A..

6 recordsLinked to original sources

bioRxiv2026

Targeting REV1 Exposes Context-Dependent Therapeutic Responses in Colorectal Cancer

Translesion synthesis (TLS) promotes DNA damage tolerance and contributes to chemotherapy resistance by enabling replication across damaged DNA templates. REV1, a central TLS regulator, is a potential therapeutic target to enhance the efficacy of genotoxic chemotherapy. Here, we investigated the therapeutic consequences of pharmacologic and genetic REV1 targeting in colorectal cancer (CRC) and evaluated the sensitivity of patient-derived CRC organoids to the REV1 inhibitor JH-RE-06. JH-RE-06 enhanced oxaliplatin sensitivity in HCT116 cells and 5-fluorouracil (5-FU) sensitivity in HT-29 cells, whereas reciprocal combinations produced limited sensitization, indicating treatment- and cellular context-dependent responses. siRNA-mediated REV1 depletion similarly enhanced chemotherapy sensitivity, supporting REV1 involvement in these responses. MNNG sensitivity assays and MLH1 expression analyses did not reveal consistent treatment-associated changes in mismatch repair function, while targeted HPRT1 sequencing identified no detectable sequence alterations in the region examined. Chemosensitization was not accompanied by consistent increases in caspase-3/7 activation under the conditions tested. REV1 inhibition also caused LC3-II accumulation and, after prolonged inhibitor exposure, reduced beta-tubulin abundance, indicating additional autophagy-associated and cytoskeletal responses. In two patient-derived CRC organoid models, JH-RE-06 exhibited single-agent growth-inhibitory activity, with mean IC50 values of 2.01 micromolar and 1.4 micromolar, respectively. Together, these findings demonstrate context-dependent chemosensitization and organoid growth inhibition following REV1 targeting, suggesting that its therapeutic consequences may extend beyond canonical TLS-mediated DNA damage tolerance.

cancer biology↗

bioRxiv2026

A neuronal pathway for the supraspinal relay of warm and cool sensation

Cutaneous thermosensation is a fundamental sense allowing discrimination of external temperature changes and driving adaptive responses essential for survival and well-being. This sensory process begins with the activation of peripheral thermoreceptors, which encode the quality and intensity of thermal stimuli into neuronal activity that is further integrated by spinal cord circuits and relayed to supraspinal centres through the anterolateral tract (ALT). While classical experiments identified thermal responsive ALT neurons in the superficial spinal dorsal horn, the functional logic of innocuous temperature relay remains poorly understood. We show that, in mice, the majority of Phox2a-lineage lamina I ALT are selectively tuned to innocuous warming or cooling, and receive direct inputs from peripheral thermoreceptors. Their genetic ablation, chemogenetic or optogenetic manipulation impaired temperature discrimination. Our findings contrast with the previous finding that the majority of ALT neurons being mechano- and thermo-nociceptive and provide novel evidence for the existence of a large ensemble of genetically defined warming- and cooling- responsive ALT neurons. The large representation of innocuous temperature in supraspinal-relaying ALT neurons indicates substantial spinal amplification of thermal information and underscores the importance of innocuous thermosensation in the ascending sensory pathway.

neuroscience↗

bioRxiv2023

Calretinin-expressing islet cells: a source of pre- and post-synaptic inhibition of non-peptidergic nociceptor input to the mouse spinal cord

Unmyelinated non-peptidergic nociceptors (NP afferents) arborise in lamina II of the spinal cord and receive GABAergic axoaxonic synapses, which mediate presynaptic inhibition. However, until now the source of this axoaxonic synaptic input was not known. Here we provide evidence that it originates from a population of inhibitory calretinin-expressing interneurons (iCRs), which correspond to lamina II islet cells. The NP afferents can be assigned to 3 functionally distinct classes (NP1-3). NP1 afferents have been implicated in pathological pain states, while NP2 and NP3 afferents also function as pruritoceptors. Our findings suggest that all 3 of these afferent types innervate iCRs and receive axoaxonic synapses from them, providing feedback inhibition of NP input. The iCRs also form axodendritic synapses, and their targets include cells that are themselves innervated by the NP afferents, thus allowing for feedforward inhibition. The iCRs are therefore ideally placed to control the input from non-peptidergic nociceptors and pruritoceptors to other dorsal horn neurons, and thus represent a potential therapeutic target for the treatment of chronic pain and itch.

neuroscience↗

bioRxiv2023

Neuropeptide Y-expressing dorsal horn inhibitory interneurons gate spinal pain and itch signalling

Somatosensory information is processed by a complex network of interneurons in the spinal dorsal horn. It has been reported that inhibitory interneurons that express neuropeptide Y (NPY), either permanently or during development, suppress mechanical itch, with no effect on pain. Here we investigate the role of interneurons that continue to express NPY (NPY-INs) in adulthood. We find that chemogenetic activation of NPY-INs reduces behaviours associated with acute pain and pruritogen-evoked itch, whereas silencing them causes exaggerated itch responses that depend on cells expressing the gastrin-releasing peptide receptor. As predicted by our previous studies, silencing of another population of inhibitory interneurons (those expressing dynorphin) also increases itch, but to a lesser extent. Importantly, NPY- IN activation also reduces behavioural signs of inflammatory and neuropathic pain. These results demonstrate that NPY-INs gate pain and itch transmission at the spinal level, and therefore represent a potential treatment target for pathological pain and itch.

neuroscience↗

bioRxiv2020

Three neurotransmitters regulate diverse inhibitory and excitatory Parvalbumin interneuron circuits in the dorsal horn

Parvalbumin-expressing interneurons (PVINs) in the spinal dorsal horn are found primarily in laminae II inner and III. Inhibitory PVINs (iPVINs) play an important in segregating innocuous tactile input from pain-processing circuits, achieved through presynaptic inhibition of myelinated low-threshold mechanoreceptors and postsynaptic inhibition of distinct spinal circuits. By comparison, relatively little is known of the role of excitatory PVINs (ePVINs) in sensory processing. Here we use neuroanatomical and optogenetic approaches to show that ePVINs comprise a larger proportion of the PVIN population than previously reported, and that both ePVIN and iPVIN populations form synaptic connections amongst (and between) themselves. We find that these cells contribute to neuronal networks that influence activity within several functionally distinct circuits, and that aberrant activity of ePVINs under pathological conditions contributes to the development of mechanical hypersensitivity.

neuroscience↗

bioRxiv2019

Calretinin positive neurons form an excitatory amplifier network in the spinal cord dorsal horn

The passage of nociceptive information is relayed through the spinal cord dorsal horn, a critical area in sensory processing. The neuronal circuits in this region that underpin sensory perception must be clarified to better understand how dysfunction can lead to pathological pain. This study used an optogenetic approach to selectively activate neurons that contain the calcium-binding protein calretinin (CR). We show that CR+ interneurons form an interconnected network that can initiate and sustain enhanced excitatory signaling, and directly relays signals to lamina I projection neurons. In vivo photoactivation of CR+ interneurons resulted in a significant nocifensive behavior that was morphine sensitive and cause a conditioned place aversion. Furthermore, halorhodopsin-mediated inhibition of CR+ interneurons elevated sensory thresholds. These results suggest that neuronal circuits in the superficial dorsal horn that involve excitatory CR+ neurons are important for the generation and amplification of pain, and identify these interneurons as a future analgesic target.

neuroscience↗