Search bioRxiv⌕ Search

Biology subjects

Alshanqiti, I.

Publications and source records attributed to Alshanqiti, I..

2 recordsLinked to original sources

Multiscale 3D whole joint cellular and molecular mapping dissects the relationship between structure and pain

Understanding musculoskeletal joints from a 3D multiscale perspective, from molecular to anatomical levels, is essential for resolving the confounding relationships between structure and pain, elucidating the intricate mechanisms regulating joint health and diseases, and developing new treatment strategies. Here, we introduce a musculoskeletal joint immunostaining and clearing (MUSIC) method specifically designed to overcome key challenges of immunostaining and optical clearing of intact joints. Coupled with large-field light sheet microscopy, our approach enables 3D high-resolution, microscale neurovascular mapping within the context of whole-joint anatomy without the need for image coregistration across various joints, including temporomandibular joints, knees, and spines, and multiple species, including mouse, rat, and pig. Our findings reveal 3D heterogeneous distributions of neurovascular networks and previously uncharacterized neurovascular pathways within joints. Using the proteoglycan 4 knockout (Prg4-/-) mouse model of joint degeneration, we identified significant alterations in joint-wide neurovascular architecture, highlighting neurovascular changes along degenerative processes. Furthermore, in a traumatic joint injury mouse model, we observed long-lasting pain behavior and a time-course 3D neurovascular remodeling preceding detectable joint morphological change, bridging microscale alterations with potential pain mechanisms. This platform offers a powerful tool for multiscale 3D analysis, enabling new insights into joint pathophysiology and intricate interplay among joint tissues.

bioengineering↗

Forced mouth opening induces post-traumatic hyperalgesia and associated peripheral sensitization after temporomandibular joints injury in mice

Temporomandibular disorder (TMD) is the most prevalent painful condition in the craniofacial area. The pathophysiology of TMD is not fully understood, and it is necessary to understand pathophysiology underlying painful TMD conditions to develop more effective treatment methods. Recent studies suggested that external or intrinsic trauma to TMJ is associated with chronic TMD in patients. Here, we investigated the effects of the TMJ trauma through forced-mouth opening (FMO) in mice to determine pain behaviors and peripheral sensitization of trigeminal nociceptors. FMO increased mechanical hyperalgesia assessed by von Frey test, spontaneous pain-like behaviors assessed by mouse grimace scale, and anxiety-like behaviors assessed by open-field test. In vivo GCaMP Ca2+ imaging of intact trigeminal ganglia (TG) showed increased spontaneous Ca2+ activity and mechanical hypersensitivity of TG neurons in the FMO compared to the sham group. Ca2+ responses evoked by cold, heat, and capsaicin stimuli were also increased. FMO-induced hyperalgesia and neuronal hyperactivities were not sex dependent. TG neurons sensitized following FMO were primarily small to medium-sized nociceptive afferents. Consistently, most TMJ afferents in the TG were small-sized peptidergic neurons expressing calcitonin gene-related peptides, whereas nonpeptidergic TMJ afferents were relatively low. FMO-induced intraneural inflammation in the surrounding tissues of the TMJ indicates potentially novel mechanisms of peripheral sensitization following TMJ injury. These results suggest that the TMJ injury leads to persistent post-traumatic hyperalgesia associated with peripheral sensitization of trigeminal nociceptors.

neuroscience↗