A Retrospective Tribute to Dr. Harish Pant (1938-2023) and His Seminal Work on Cyclin Dependent Kinase 5.

Dr. Harish Chandra Pant was Chief of the Section on Neuronal Cytoskeletal Protein Regulation within the National Institute of Neurological Disorders and Stroke at the NIH. A main focus of his group was understanding the mechanisms regulating neuronal cytoskeletal phosphorylation.

Transcriptome Analysis of Rheumatoid Arthritis Uncovers Genes Linked to Inflammation-Induced Pain.

Autoimmune diseases such as rheumatoid arthritis (RA) can promote states of chronic Inflammation with accompanying tissue destruction and pain. RA can cause inflammatory synovitis in peripheral joints, particularly within the hands and feet, but can also sometimes trigger temporomandibular joint (TMJ) arthralgia. To better understand the effects of ongoing Inflammation-induced pain signaling, dorsal root ganglia (DRGs) were acquired from individuals with RA for transcriptomic study.

Genotyping Protocols for Genetically Engineered Mice.

Historically, the laboratory mouse has been the mammalian species of choice for studying gene function and for modeling diseases in humans. This was mainly due to their availability from mouse fanciers. In addition, their short generation time, small size, and minimal food consumption compared to that of larger mammals were definite advantages.

Activation of cyclin-dependent kinase 5 broadens action potentials in human sensory neurons.

Chronic pain is one of the most devastating and unpleasant conditions, associated with many pathological states. Tissue or nerve injuries induce extensive neurobiological plasticity in nociceptive neurons, which leads to chronic pain. Recent studies suggest that cyclin-dependent kinase 5 (CDK5) in primary afferents is a key neuronal kinase that modulates nociception through phosphorylation under pathological conditions.

Multiprotein Assemblies, Phosphorylation and Dephosphorylation in Neuronal Cytoskeleton.

Filament systems are comprised of fibrous and globular cytoskeletal proteins and are key elements regulating cell shape, rigidity, and dynamics. The cellular localization and assembly of neurofilaments depend on phosphorylation by kinases. The involvement of the BRCA1 (Breast cancer associated protein 1)/BARD1 (BRCA1-associated RING domain 1) pathways in Alzheimer disease (AD) is suggested by colocalization studies.

ACTIVATION OF CYCLIN-DEPENDENT KINASE 5 BROADENS ACTION POTENTIALS IN HUMAN SENSORY NEURONS.

Chronic pain is one of the most devastating and unpleasant conditions, associated with many pathological conditions. Tissue or nerve injuries induce comprehensive neurobiological plasticity in nociceptive neurons, which leads to chronic pain. Recent studies suggest that cyclin-dependent kinase 5 (CDK5) in primary afferents is a key neuronal kinase that modulates nociception through phosphorylation-dependent manner under pathological conditions.

Integrative multiomic analyses of dorsal root ganglia in diabetic neuropathic pain using proteomics, phospho-proteomics, and metabolomics.

Diabetic peripheral neuropathy (DPN) is characterized by spontaneous pain in the extremities. Incidence of DPN continues to rise with the global diabetes epidemic. However, there remains a lack of safe, effective analgesics to control this chronic painful condition.

Nociceptive signaling through transient receptor potential vanilloid 1 is regulated by Cyclin Dependent Kinase 5-mediated phosphorylation of T407 in vivo.

Cyclin dependent kinase 5 (Cdk5) is a key neuronal kinase whose activity can modulate thermo-, mechano-, and chemo-nociception. Cdk5 can modulate nociceptor firing by phosphorylating pain transducing ion channels like the transient receptor potential vanilloid 1 (TRPV1), a thermoreceptor that is activated by noxious heat, acidity, and capsaicin. TRPV1 is phosphorylated by Cdk5 at threonine-407 (T407), which then inhibits Ca dependent desensitization.

Transcriptomic analysis of human sensory neurons in painful diabetic neuropathy reveals inflammation and neuronal loss.

Pathological sensations caused by peripheral painful neuropathy occurring in Type 2 diabetes mellitus (T2DM) are often described as 'sharp' and 'burning' and are commonly spontaneous in origin. Proposed etiologies implicate dysfunction of nociceptive sensory neurons in dorsal root ganglia (DRG) induced by generation of reactive oxygen species, microvascular defects, and ongoing axonal degeneration and regeneration. To investigate the molecular mechanisms contributing to diabetic pain, DRGs were acquired postmortem from patients who had been experiencing painful diabetic peripheral neuropathy (DPN) and subjected to transcriptome analyses to identify genes contributing to pathological processes and neuropathic pain.

Leucine rich amelogenin peptide prevents ovariectomy-induced bone loss in mice.

Amelogenins, major extra cellular matrix proteins of developing tooth enamel, are predominantly expressed by ameloblasts and play significant roles in the formation of enamel. Recently, amelogenin has been detected in various epithelial and mesenchymal tissues, implicating that it might have distinct functions in various tissues. We have previously reported that leucine rich amelogenin peptide (LRAP), one of the alternate splice forms of amelogenin, regulates receptor activator of NF-kappa B ligand (RANKL) expression in cementoblast/periodontal ligament cells, suggesting that the amelogenins, especially LRAP, might function as a signaling molecule in bone metabolism.

Protocols for Characterization of Cdk5 Kinase Activity.

Cyclin-dependent kinases (Cdks) are generally known to be involved in controlling the cell cycle, but Cdk5 is a unique member of this protein family for being most active in post-mitotic neurons. Cdk5 is developmentally important in regulating neuronal migration, neurite outgrowth, and axon guidance. Cdk5 is enriched in synaptic membranes and is known to modulate synaptic activity.

Accelerated burn wound healing with photobiomodulation therapy involves activation of endogenous latent TGF-β1.

The severity of tissue injury in burn wounds from associated inflammatory and immune sequelae presents a significant clinical management challenge. Among various biophysical wound management approaches, low dose biophotonics treatments, termed Photobiomodulation (PBM) therapy, has gained recent attention. One of the PBM molecular mechanisms of PBM treatments involves photoactivation of latent TGF-β1 that is capable of promoting tissue healing and regeneration.

Genome Editing in Mice Using CRISPR/Cas9 Technology.

CRISPR/Cas9 technology has revolutionized genome editing in mice, allowing for simple and rapid development of knockouts and knockins. CRISPR relies on small guide RNAs that direct the RNA-guided nuclease Cas9 to a designated genomic site using ∼20 bp of corresponding sequence. Cas9 then creates a double-strand break in the targeted loci that is either patched in an error-prone fashion to produce a frame-shift mutation, a knockout, or is repaired by recombination with donor DNA containing homology arms, a knockin.

Phosphorylation of the Transient Receptor Potential Ankyrin 1 by Cyclin-dependent Kinase 5 affects Chemo-nociception.

Cyclin-dependent kinase 5 (Cdk5) is a key neuronal kinase that is upregulated during inflammation, and can subsequently modulate sensitivity to nociceptive stimuli. We conducted an in silico screen for Cdk5 phosphorylation sites within proteins whose expression was enriched in nociceptors and identified the chemo-responsive ion channel Transient Receptor Potential Ankyrin 1 (TRPA1) as a possible Cdk5 substrate. Immunoprecipitated full length TRPA1 was shown to be phosphorylated by Cdk5 and this interaction was blocked by TFP5, an inhibitor that prevents activation of Cdk5.

Peripheral and orofacial pain sensation is unaffected by the loss of p39.

Cdk5 is a key neuronal kinase necessary for proper brain development, which has recently been implicated in modulating nociception. Conditional deletion of Cdk5 in pain-sensing neurons attenuates pain responses to heat in both the periphery and orofacial regions. Cdk5 activity is regulated by binding to the activators p35 and p39, both of which possess a cyclin box.

Cyclin-dependent kinase 5 modulates the P2X2a receptor channel gating through phosphorylation of C-terminal threonine 372.

The purinergic P2X2 receptor (P2X2R) is an adenosine triphosphate-gated ion channel widely expressed in the nervous system. Here, we identified a putative cyclin-dependent kinase 5 (Cdk5) phosphorylation site in the full-size variant P2X2aR (TPKH), which is absent in the splice variant P2X2bR. We therefore investigated the effects of Cdk5 and its neuronal activator, p35, on P2X2aR function.

Targeting STAT3 signaling reduces immunosuppressive myeloid cells in head and neck squamous cell carcinoma.

Cumulative evidence suggests that constitutively activated signal transducer and activator of transcription (STAT3) may contribute to sustaining immunosuppressive status, and that inhibiting STAT3 signaling represents a potential strategy to improve antitumor immunity. In the present study, we observed that high levels phosphorylated of STAT3 are significantly associated with the markers for both myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) in human head and neck squamous cell carcinoma (HNSCC). Additionally, we showed that targeting STAT3 signaling with a tolerable selective inhibitor S3I-201 significantly decreased immature myeloid cells such as MDSCs, TAMs and iDCs in genetically defined mice HNSCC model.

Modulating Innate and Adaptive Immunity by (R)-Roscovitine: Potential Therapeutic Opportunity in Cystic Fibrosis.

(R)-Roscovitine, a pharmacological inhibitor of kinases, is currently in phase II clinical trial as a drug candidate for the treatment of cancers, Cushing's disease and rheumatoid arthritis. We here review the data that support the investigation of (R)-roscovitine as a potential therapeutic agent for the treatment of cystic fibrosis (CF). (R)-Roscovitine displays four independent properties that may favorably combine against CF: (1) it partially protects F508del-CFTR from proteolytic degradation and favors its trafficking to the plasma membrane; (2) by increasing membrane targeting of the TRPC6 ion channel, it rescues acidification in phagolysosomes of CF alveolar macrophages (which show abnormally high pH) and consequently restores their bactericidal activity; (3) its effects on neutrophils (induction of apoptosis), eosinophils (inhibition of degranulation/induction of apoptosis) and lymphocytes (modification of the Th17/Treg balance in favor of the differentiation of anti-inflammatory lymphocytes and reduced production of various interleukins, notably IL-17A) contribute to the resolution of inflammation and restoration of innate immunity, and (4) roscovitine displays analgesic properties in animal pain models.

TRPV1 function is modulated by Cdk5-mediated phosphorylation: insights into the molecular mechanism of nociception.

TRPV1 is a polymodally activated cation channel acting as key receptor in nociceptive neurons. Its function is strongly affected by kinase-mediated phosphorylation leading to hyperalgesia and allodynia. We present behavioral and molecular data indicating that TRPV1 is strongly modulated by Cdk5-mediated phosphorylation at position threonine-407(mouse)/T406(rat).

Activation of cyclin-dependent kinase 5 mediates orofacial mechanical hyperalgesia.

Background: Cyclin-dependent kinase 5 (Cdk5) is a unique member of the serine/threonine kinase family. This kinase plays an important role in neuronal development, and deregulation of its activity leads to neurodegenerative disorders. Cdk5 also serves an important function in the regulation of nociceptive signaling.

TGF-ß regulates enamel mineralization and maturation through KLK4 expression.

Transforming growth factor-ß (TGF-ß) signaling plays an important role in regulating crucial biological processes such as cell proliferation, differentiation, apoptosis, and extracellular matrix remodeling. Many of these processes are also an integral part of amelogenesis. In order to delineate a precise role of TGF-ß signaling during amelogenesis, we developed a transgenic mouse line that harbors bovine amelogenin promoter-driven Cre recombinase, and bred this line with TGF-ß receptor II floxed mice to generate ameloblast-specific TGF-ß receptor II conditional knockout (cKO) mice.

Inhibition of mTOR reduces anal carcinogenesis in transgenic mouse model.

The molecular mechanism of human anal squamous cell carcinoma (ASCC) is unclear, and the accumulating evidence indicate association of ASCC with the activation of the Akt/mTOR pathway. Here we describe a mouse model with spontaneous anal squamous cell cancer, wherein a combined deletion of Tgfbr1 and Pten in stratified squamous epithelia was induced using inducible K14-Cre. Histopathologic analyses confirmed that 33.

Transforming growth factor-β3 (TGF-β3) knock-in ameliorates inflammation due to TGF-β1 deficiency while promoting glucose tolerance.

Three homologues of TGF-β exist in mammals as follows: TGF-β1, TGF-β2, and TGF-β3. All three proteins share high homology in their amino acid sequence, yet each TGF-β isoform has unique heterologous motifs that are highly conserved during evolution. Although these TGF-β proteins share similar properties in vitro, isoform-specific properties have been suggested through in vivo studies and by the unique phenotypes for each TGF-β knock-out mouse.