The brinker repressor system regulates injury-induced nociceptive sensitization in Drosophila melanogaster

Chronic pain is a debilitating condition affecting millions of people worldwide, and an improved understanding of the pathophysiology of chronic pain is urgently needed. Nociceptors are the sensory neurons that alert the nervous system to potentially harmful stimuli such as mechanical pressure or noxious thermal temperature. When an injury occurs, the nociceptive threshold for pain is reduced and an increased pain signal is produced. This process is called nociceptive sensitization. This sensitization normally subsides after the injury is healed. However, dysregulation can occur which results in sensitization that persists after the injury has healed. This process is thought to perpetuate chronic pain. The Hedgehog (Hh) signaling pathway has been previously implicated in nociceptive sensitization in response to injury in Drosophila melanogaster. Downstream of Hh signaling, the Bone Morphogenetic Protein (BMP) pathway has also been shown to be necessary for this process. Here, we describe a role for nuclear components of BMP’s signaling pathway in the formation of injury-induced nociceptive sensitization. Brinker (Brk), and Schnurri (Shn) were suppressed in nociceptors using an RNA-interference (RNAi) “knockdown” approach. Knockdown of Brk resulted in hypersensitivity in the absence of injury, indicating that it normally acts to suppress nociceptive sensitivity. Animals in which transcriptional activator Shn was knocked down in nociceptors failed to develop normal allodynia after ultraviolet irradiation injury, indicating that Shn normally acts to promote hypersensitivity after injury. These results indicate that Brk-related transcription regulators play a crucial role in the formation of nociceptive sensitization and may therefore represent valuable new targets for pain-relieving medications.

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A genome-wide RNA interference screen in Drosophila melanogaster cells for new components of the Hh signaling pathway

Nature Genetics ◽

10.1038/ng1682 ◽

2005 ◽

Vol 37 (12) ◽

pp. 1323-1332 ◽

Cited By ~ 135

Author(s):

Kent Nybakken ◽

Steven A Vokes ◽

Ting-Yi Lin ◽

Andrew P McMahon ◽

Norbert Perrimon

Keyword(s):

Drosophila Melanogaster ◽

Rna Interference ◽

Signaling Pathway ◽

Genome Wide ◽

A Genome ◽

Hh Signaling

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Roles of the Hedgehog Signaling Pathway in Skin Development, Homeostasis and Cancer

10.20944/preprints201711.0096.v1 ◽

2017 ◽

Author(s):

Yoshinori Abe ◽

Nobuyuki Tanaka

Keyword(s):

Basal Cell Carcinoma ◽

Cell Carcinoma ◽

Signaling Pathway ◽

Basal Cell ◽

Hedgehog Signaling ◽

Current Knowledge ◽

Skin Development ◽

Morphogenetic Protein ◽

Hh Signaling

The epidermis is the outermost layer of skin and provides a protective barrier against environmental insults. It is a rapidly renewing tissue undergoing constant regeneration, maintained by several types of stem cells. Hedgehog (HH) ligands activate one of the fundamental signaling pathways that contribute to epidermal development, homeostasis and repair. The HH pathway interacts with other signal transduction pathways such as those activated by Wnt and bone morphogenetic protein. Furthermore, aberrant activation of HH signaling is associated with various tumors, including basal cell carcinoma. Therefore, an understanding of the regulatory mechanisms of the HH signaling pathway is important to elucidate fundamental mechanisms underlying both organogenesis and carcinogenesis. In this review, we discuss the role of the HH signaling pathway in skin development, homeostasis and basal cell carcinoma formation, providing an update of current knowledge in this field.

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Aberrant BMP2 Signaling in Patients Diagnosed with Osteoporosis

International Journal of Molecular Sciences ◽

10.3390/ijms21186909 ◽

2020 ◽

Vol 21 (18) ◽

pp. 6909 ◽

Cited By ~ 1

Author(s):

Hilary W. Durbano ◽

Daniel Halloran ◽

John Nguyen ◽

Victoria Stone ◽

Sean McTague ◽

...

Keyword(s):

Signaling Pathway ◽

Bmp Signaling ◽

Bone Morphogenetic Protein 2 ◽

Osteoblast Activity ◽

Morphogenetic Protein ◽

Osteogenic Response ◽

Type Ia ◽

Bmp Pathway ◽

Negative Side Effects ◽

Potent Growth

The most common bone disease in humans is osteoporosis (OP). Current therapeutics targeting OP have several negative side effects. Bone morphogenetic protein 2 (BMP2) is a potent growth factor that is known to activate both osteoblasts and osteoclasts. It completes these actions through both SMAD-dependent and SMAD-independent signaling. A novel interaction between the BMP type Ia receptor (BMPRIa) and casein kinase II (CK2) was discovered, and several CK2 phosphorylation sites were identified. A corresponding blocking peptide (named CK2.3) was designed to further elucidate the phosphorylation site’s function. Previously, CK2.3 demonstrated an increased osteoblast activity and decreased osteoclast activity in a variety of animal models, cell lines, and isolated human osteoblasts. It is hypothesized that CK2.3 completes these actions through the BMP signaling pathway. Furthermore, it was recently discovered that BMP2 did not elicit an osteogenic response in osteoblasts from patients diagnosed with OP, while CK2.3 did. In this study, we explore where in the BMP pathway the signaling disparity or defect lies in those diagnosed with OP. We found that osteoblasts isolated from patients diagnosed with OP did not activate SMAD or ERK signaling after BMP2 stimulation. When OP osteoblasts were stimulated with BMP2, both BMPRIa and CK2 expression significantly decreased. This indicates a major disparity within the BMP signaling pathway in patients diagnosed with osteoporosis.

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BMP Signaling Downstream of the Highwire E3 Ligase Sensitizes Nociceptors

10.1101/251991 ◽

2018 ◽

Author(s):

Ken Honjo ◽

W. Daniel Tracey

Keyword(s):

Chronic Pain ◽

Signaling Pathway ◽

Sensory Neurons ◽

Molecular Mechanisms ◽

Critical Role ◽

Bmp Signaling ◽

Sensory Transduction ◽

Noxious Heat ◽

Nociceptive Responses ◽

Bmp Pathway

AbstractA comprehensive understanding of the molecular machinery important for nociception is essential to improving the treatment of pain. Here, we show that the BMP signaling pathway regulates nociception downstream of the E3 ubiquitin ligase highwire (hiw). Hiw loss of function in nociceptors caused antagonistic and pleiotropic phenotypes with simultaneous insensitivity to noxious heat but sensitized responses to optogenetic activation of nociceptors. Thus, hiw functions to both positively and negatively regulate nociceptors. We find that a sensory transduction-independent sensitization pathway was associated with BMP signaling. BMP signaling in nociceptors was up-regulated in hiw mutants, and nociceptor-specific expression of hiw rescued all nociception phenotypes including the increased BMP signaling. Blocking the transcriptional output of the BMP pathway with dominant negative Mad suppressed nociceptive hypersensitivity that was induced by interfering with hiw. The up-regulated BMP signaling phenotype in hiw genetic mutants could not be suppressed by mutation in wallenda suggesting that hiw regulates BMP in nociceptors via a wallenda independent pathway. In a newly established Ca2+ imaging preparation, we observed that up-regulated BMP signaling caused a significantly enhanced Ca2+ signal in the axon terminals of nociceptors that were stimulated by noxious heat. This response likely accounts for the nociceptive hypersensitivity induced by elevated BMP signaling in nociceptors. Finally, we showed that acute activation of BMP signaling in nociceptors was sufficient to sensitize nociceptive responses to optogenetically-triggered nociceptor activation without altering nociceptor morphology. Overall, this study demonstrates the previously unrevealed roles of the Hiw-BMP pathway in the regulation of nociception and provides the first direct evidence that up-regulated BMP signaling physiologically sensitizes responses of nociceptors and nociception behaviors.Author SummaryAlthough pain is a universally experienced sensation that has a significant impact on human lives and society, the molecular mechanisms of pain remain poorly understood. Elucidating these mechanisms is particularly important to gaining insight into the clinical development of currently incurable chronic pain diseases. Taking an advantage of the powerful genetic model organism Drosophila melanogaster (fruit flies), we unveil the Highwire-BMP signaling pathway as a novel molecular pathway that regulates the sensitivity of nociceptive sensory neurons. Highwire and the molecular components of the BMP signaling pathway are known to be widely conserved among animal phyla, from nematode worms to humans. Since abnormal sensitivity of nociceptive sensory neurons can play a critical role in the development of chronic pain conditions, a deeper understanding of the regulation of nociceptor sensitivity has the potential to advance effective therapeutic strategies to treat difficult pain conditions.

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Specific activation of the p38 mitogen-activated protein kinase signaling pathway and induction of neurite outgrowth in PC12 cells by bone morphogenetic protein-2.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)46537-9 ◽

1999 ◽

Vol 274 (47) ◽

pp. 33826

Author(s):

Shoji Iwasaki ◽

Makoto Iguchi ◽

Kazushi Watanabe ◽

Rika Hoshino ◽

Masafumi Tsujimoto ◽

...

Keyword(s):

Protein Kinase ◽

Neurite Outgrowth ◽

Signaling Pathway ◽

Pc12 Cells ◽

Mitogen Activated Protein Kinase ◽

Bone Morphogenetic Protein 2 ◽

Morphogenetic Protein ◽

Mitogen Activated Protein ◽

Protein Kinase Signaling ◽

Kinase Signaling Pathway

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miR-636 inhibits EMT, cell proliferation and cell cycle of ovarian cancer by directly targeting transcription factor Gli2 involved in Hedgehog pathway

Cancer Cell International ◽

10.1186/s12935-020-01725-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jiong Ma ◽

Chunxia Zhou ◽

Xuejun Chen

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Protein Expression ◽

Signaling Pathway ◽

Luciferase Reporter ◽

Cell Proliferation And Migration ◽

Hh Signaling ◽

And Migration ◽

Proliferation And Migration

Abstract Background Hedgehog (Hh) signaling pathway, which is essential for cell proliferation and differentiation, is noted to be aberrantly activated in tumor from increasing studies in recent years. MicroRNAs (miRNAs) as an important non-coding RNA in cells have been proven to possess a regulatory role specific to the Hh signaling pathway. Here, in vitro and in vivo cellular/molecular experiments were adopted to clarify the regulatory mechanism linking miR-636 to the Hh signaling pathway in ovarian cancer (OVC). Methods Protein–protein interaction analysis was performed to identify the hub gene in the Hh pathway. TargetScan database was used to predict the potential upstream regulators for Gli2. qRT-PCR was performed to test the expression of miR-636, while Western blot was conducted to detect the expression of proteins related to the Hh pathway and epithelial-mesenchymal transition (EMT). For cell functional experiments, HO-8910PM OVC cell line was used. MTT assay and wound healing assay were used to measure the effect of miR-636 on cell proliferation and migration. Flow cytometry was carried out to examine the effect of miR-636 on cell cycle, and Western blot was used to identify the change in expression of Hh and EMT-related proteins. Dual-luciferase reporter gene assay was implemented to detect the targeting relationship between miR-636 and Gli2. Xenotransplantation models were established for in vivo examination. Results Gli2 was identified as the hub gene of the Hh pathway and it was validated to be regulated by miR-636 based on the data from TargetScan and GEO databases. In vitro experiments discovered that miR-636 was significantly lowly expressed in OVC cell lines, and overexpressing miR-636 significantly inhibited HO-8910PM cell proliferation, migration and induced cell cycle arrest in G0/G1 phase, while the inhibition of miR-636 caused opposite results. Dual-luciferase reporter gene assay revealed that Gli2 was the target gene of miR-636 in OVC. Besides, overexpressed miR-636 decreased protein expression of Gli2, and affected the expression of proteins related to the Hh signaling pathway and EMT. Rescue experiments verified that overexpression of Gli2 reversed the inhibitory effect of miR-636 on HO-8910PM cell proliferation and migration, and attenuated the blocking effect of miR-636 on cell cycle. The xenotransplantation experiment suggested that miR-636 inhibited cell growth of OVC by decreasing Gli2 expression. Besides, overexpressing Gli2 potentiated the EMT process of OVC cells via decreasing E-cadherin protein expression and increasing Vimentin protein expression, and it reversed the inhibitory effect of miR-636 on OVC cell proliferation in vivo. Conclusion miR-636 mediates the activation of the Hh pathway via binding to Gli2, thus inhibiting EMT, suppressing cell proliferation and migration of OVC. Trial registration: The experimental protocol was established, according to the ethical guidelines of the Helsinki Declaration and was approved by the Human Ethics Committee of The Second Affiliated hospital of Zhejiang University School of Medicine (IR2019001235). Written informed consent was obtained from individual or guardian participants.

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