Project description:Oral cancer causes pain associated with cancer progression. The mechanism(s) underlying the pain is not fully understood. We report here that the function of the Ca2+ channel ORAI1 is an important regulator of oral cancer pain. ORAI1 was highly expressed in tumor samples from oral cancer patients and ORAI1 activation caused sustained Ca2+ influx in human oral cancer cells. RNA-seq analysis showed broad modulation of oral cancer markers such MMPs and pain modulators by ORAI1. Inoculation of oral cancer cells lacking ORAI1 into mouse paws reduced ectopic tumor growth and allodynia, reducing secreted MMP1 levels and the excitation of trigeminal ganglia (TG) neurons. The stimulation of TG neurons with MMP1 evoked an increase in action potentials. These data demonstrate an important role of ORAI1 in oral cancer progression likely by controlling the expression of MMP1 resulting in increased cancer progression and pain
Project description:Platelet-derived growth factor (PDGF) signalling and the subsequent activation of the calcium ion channel, ORAI1 are critical drivers of pathological remodelling of native vascular smooth muscle cells to proliferative state, which is a process associated with various vascular diseases. This study aims to reveal transcriptional networks altered following ORAI1 inhibition in vascular smooth muscle cells. To study the effect of ORAI1 inhibition on VSMC biology, we performed RNA-Seq analysis of PDGF-stimulated primary human aortic smooth muscle cells treated with either ORAI1 inhibitor, (n=4) or with vehicle (n=4), and investigated the effect of ORAI1 inhibition on the transcriptional response of cells.
Project description:Tubular aggregate myopathy (TAM) and Stormorken syndrome (STRMK) are clinically overlapping disorders characterized by childhood-onset muscle weakness and a variable occurrence of multi-systemic signs including short stature, thrombocytopenia, and hyposplenism. TAM/STRMK is caused by gain-of-function mutations in the Ca2+ sensor STIM1 or the Ca2+ channel ORAI1, both regulating Ca2+ homeostasis through the ubiquitous SOCE (store-operated Ca2+ entry) mechanism. Functional experiments in cells have demonstrated that the TAM/STRMK mutations induce SOCE overactivation, resulting in excessive influx of extracellular Ca2+. There is currently no treatment for TAM/STRMK, but SOCE is amenable to manipulation. Here we crossed Stim1R304W/+ mice harboring the most common TAM/STRMK mutation with Orai1R93W/+ mice carrying an ORAI1 mutation partially obstructing Ca2+ influx. Compared with Stim1R304W/+ littermates, Stim1R304W/+Orai1R93W/+ offspring showed a normalization of bone architecture, spleen histology, and muscle morphology, an increase of thrombocytes, and improved muscle contraction and relaxation kinetics. Accordingly, comparative RNA- sequencing detected more than 1200 dysregulated genes in Stim1R304W/+ mice and revealed a major restoration of gene expression in Stim1R304W/+Orai1R93W/+ mice. Altogether, we provide physiological, morphological, functional, and molecular data highlighting the therapeutic potential of ORAI1 inhibition to rescue the multi-systemic TAM/STRMK signs, and we identified myostatin as a suitable biomarker for TAM/STRMK in human and mouse.
Project description:Systemic lupus erythematous (SLE) is a prototype of autoimmune disease. Lupus nephritis (LN) is one of the most serious complications of SLE. The development of autoreactive B cells and the production of autoantibodies have been critical for the initiation and progression of LN. Store-operated Ca2+ entry (SOCE) is the main Ca2+ influx pathway in lymphocytes and is essential for immune response . SOCE is mediated by Ca2+ release-activated Ca2+ (CRAC) channels which are comprised of stromal interaction molecule (STIM) and calcium release-activated calcium modulators (ORAI) . Mutations in genes encoding the CRAC channel abolish SOCE in cells of the immune system and cause severe combined immunodeficiency . Calcium signaling via ORAI1 has been involved in the pathogenesis of autoimmune diseases by driving Th17 differentiation . STIM1 deficiency significantly reduced Th1/Th17 responses and resulted in complete protection from experimental autoimmune encephalomyelitis . Compared to T cells, the roles of CRAC channel in B cells is far less clear. Ca²⁺/calmodulin (CaM)-dependent protein kinase2 (CaMK2) is a serine/threonine-specific protein kinase that is regulated by the Ca²⁺/CaM complex. CaMK2 has been involved in many signaling pathways and is necessary for Ca²⁺ homeostasis, T cell development and activation. CaMK4, another member of the CaMK family, has been shown to compromises podocyte function and promote renal diseases in LN. In the current study, we found that CRAC channel mediated calcium signaling is enhanced in B cells from patients with LN. CRAC channel inhibition by YM-58483 and knocked down of CRAC channel by ORAI1 or STIM2 siRNA led to suppression of CaMK2 signaling and decreased B cell differentiation. Lupus mice treated with CRAC channel inhibitor showed reduced anti-double stranded DNA antibodies (anti-dsDNA), decreased immune deposition in the glomeruli and improved renal function. CRAC channel mediates the development and progression of LN by promoting the differentiation of B cells into plasma cells.
Project description:Oral cancer patients experience pain at the site of the primary cancer. Patients with metastatic oral cancers report greater pain. Lack of pain identifies patients at low risk of metastasis with sensitivity = 0.94 and negative predictive value = 0.89. In the same cohort, sensitivity and negative predictive value of depth of invasion, currently the best predictor, were 0.95 and 0.92, respectively. Cancer pain is attributed to cancer-derived mediators that sensitize neurons and is associated with increased neuronal density. We hypothesized that pain mediators would be overexpressed in metastatic cancers from patients reporting high pain. We identified 40 genes overexpressed in metastatic cancers from patients reporting high pain (n=5) compared to N0 cancers (n=10) and normal tissue (n=5). The genes are enriched for functions in extracellular matrix organization and angiogenesis. They have oncogenic and neuronal functions and are reported in exosomes. Hierarchical clustering according to expression of neurotrophic and axon guidance genes also separated cancers according to pain and nodal status. Depletion of exosomes from cancer cell line supernatant reduced nociceptive behavior in a paw withdrawal assay, supporting a role for exosomes in cancer pain. The identified genes and exosomes are potential therapeutic targets for stopping cancer and attenuating pain.
Project description:Nociception is protective and prevents tissue damage but can also facilitate chronic pain. If a general principle governs these two types of pain is unknown. Here, we show that both basal mechanical and neuropathic pain are controlled by microRNA-183 cluster in mice. This single cluster controls more than 80% of neuropathic pain-regulated genes and scales basal mechanical sensitivity and mechanical allodynia by regulating auxiliary voltage-gated calcium channel subunits a2d. Basal sensitivity is controlled in nociceptors and allodynia involves TrkB+ light-touch mechanoreceptors. These light-touch sensitive neurons that normally do not elicit pain produce pain during neuropathy that is reversed by gabapentin. Thus, a single miRNA cluster continuously scales acute noxious mechanical sensitivity in nociceptive neurons and suppresses neuropathic pain transduction in a specific, light-touch sensitive neuronal type recruited during mechanical allodynia.
Project description:We showed that the overexpression of ORAI1 in the neurons of murine brain leads to spontaneous occurrence of seizure-like events in aged animals. We aimed to identify the mechanism responsible for this phenomenon. Using modified Ca2+-addback assay in the slices of CA1 hippocampal region and FURA-2AM calcium indicator we found that overexpression of ORAI1 in neurons leads to altered Ca2+ response. Next, by RNASeq we identified set of genes, whose expression was changed in FVB/NJ-Tg(ORAI1)Ibd mice.
Project description:G protein-coupled receptor 37-like 1 (GPR37L1) is an orphan GPCR, and its function remains largely unknown. Here we report that Gpr37l1 and GPR37L1 are among the most highly expressed GPCR transcripts in mouse and human dorsal root ganglia (DRGs) and are selectively expressed in satellite glial cells (SGCs). Peripheral neuropathy following PTX-induced pain resulted in a downregulation of GPR37L1 plasma membrane expression in DRGs. Transgenic mice with Gpr37l1 deficiency exhibited impaired resolution of neuropathic pain symptoms following PTX-induced pain, whereas overexpression of Gpr37l1 in mouse DRGs reversed pain. GPR37L1 regulates the surface expression and function of these potassium channels. Thus, GPR37L1 in SGCs offers a new target for neuropathy protection and pain control.
Project description:Previous studies have suggested that astrocyte activation in the spinal dorsal horn may play an important role in the development of chronic neuropathic pain; but the mechanisms involved in astrocyte activation and their modulatory effects remain unknown. The inward rectifying potassium channel protein 4.1 (Kir4.1) is the most important background K+ channel in astrocytes. However, how Kir4.1 is regulated and contributes to behavioral hyperalgesia in chronic pain is unknown. In this study, single-cell RNA sequencing analysis indicated that the expression of Kir4.1 and Methyl-CpG-binding protein 2 (MeCP2) were both decreased in spinal astrocytes after chronic constriction injury (CCI) in a mouse model. Conditional knockout of the Kir4.1 channel in spinal astrocytes led to hyperalgesia; and overexpression of the Kir4.1 channel in spinal cord relieved CCI-induced hyperalgesia. Expression of spinal Kir4.1 after CCI was regulated by MeCP2. Electrophysiological recording in spinal slices showed that knockdown of Kir4.1 significantly regulated the excitability of astrocytes and then functionally changed the firing patterns of neurons in dorsal spinal cord. Therefore, targeting spinal Kir4.1 maybe an underlying treatment for hyperalgesia in chronic neuropathic pain.
Project description:Oral cancer causes pain associated with cancer progression. We report here that the function of the Ca2+ channel ORAI1 is an important regulator of oral cancer pain. ORAI1 was highly expressed in tumor samples from patients with oral cancer, and ORAI1 activation caused sustained Ca2+ influx in human oral cancer cells. RNA-seq analysis showed that ORAI1 regulated many genes encoding oral cancer markers such as metalloproteases (MMPs) and pain modulators. Compared with control cells, oral cancer cells lacking ORAI1 formed smaller tumors that elicited decreased allodynia when inoculated into mouse paws. Exposure of trigeminal ganglia neurons to MMP1 evoked an increase in action potentials. These data demonstrate an important role of ORAI1 in oral cancer progression and pain, potentially by controlling MMP1 abundance.