Genetic Analysis of PICK1 Gene in Alzheimer's Disease: A Study for Finding a New Gene Target

Unconventional PDZ Recognition Revealed in α7 nAChR-PICK1 Complexes

PDZ domains are modular domains that conventionally bind to C terminal or internal motifs of target proteins to control cellular functions through the regulation of protein complex assemblies. Almost all reported structures of PDZ-target protein complexes rely on fragments or peptides as target proteins. No intact target protein complexed with PDZ was structurally characterized. In this study, we used NMR spectroscopy and other biochemistry and biophysics tools to uncover insights into structural coupling between the PDZ domain of protein interacting with C-kinase 1 (PICK1) and α7 nicotinic acetylcholine receptors (α7 nAChR). Notably, the intracellular domains of both α7 nAChR and PICK1 PDZ exhibit a high degree of plasticity in their coupling. Specifically, the MA helix of α7 nAChR interacts with residues lining the canonical binding site of the PICK1 PDZ, while flexible loops also engage in protein-protein interactions. Both hydrophobic and electrostatic interactions mediate the coupling. Overall, the resulting structure of the α7 nAChR-PICK1 complex reveals an unconventional PDZ binding mode, significantly expanding the repertoire of functionally important PDZ interactions.

Postsynaptic signaling at glutamatergic synapses as therapeutic targets

Dysregulation of glutamatergic synapses plays an important role in the pathogenesis of neurological diseases. In addition to mediating excitatory synaptic transmission, postsynaptic glutamate receptors interact with various membrane and intracellular proteins. They form structural and/or signaling synaptic protein complexes and thereby play diverse postsynaptic functions. Recently, several postsynaptic protein complexes have been associated with various neurological diseases and hence, have been characterized as important therapeutic targets. Moreover, novel small molecules and therapeutic peptides targeting and modulating the activities of these protein complexes have been discovered, some of which have advanced through preclinical translational research and/or clinical studies. This article describes the recent investigation of eight key protein complexes associated with the postsynaptic ionotropic and metabotropic glutamate receptors as therapeutic targets for central nervous system diseases.

The Scaffold Protein PICK1 as a Target in Chronic Pain

Well-tolerated and effective drugs for treating chronic pain conditions are urgently needed. Most chronic pain patients are not effectively relieved from their pain and suffer from debilitating drug side effects. This has not only drastic negative consequences for the patients’ quality of life, but also constitute an enormous burden on society. It is therefore of great interest to explore new potent targets for effective pain treatment with fewer side effects and without addiction liability. A critical component of chronic pain conditions is central sensitization, which involves the reorganization and strengthening of synaptic transmission within nociceptive pathways. Such changes are considered as maladaptive and depend on changes in the surface expression and signaling of AMPA-type glutamate receptors (AMPARs). The PDZ-domain scaffold protein PICK1 binds the AMPARs and has been suggested to play a key role in these maladaptive changes. In the present paper, we review the regulation of AMPARs by PICK1 and its relation to pain pathology. Moreover, we highlight other pain-relevant PICK1 interactions, and we evaluate various compounds that target PICK1 and have been successfully tested in pain models. Finally, we evaluate the potential on-target side effects of interfering with the action of PICK1 action in CNS and beyond. We conclude that PICK1 constitutes a valid drug target for the treatment of inflammatory and neuropathic pain conditions without the side effects and abuse liability associated with current pain medication.

Effect of neurological screening on early dementia detection in southern Italy

OBJECTIVE

Population screening can facilitate early diagnosis of dementia and improve disease management. This study examined the effects of a screening campaign for neurodegenerative disorders on the early diagnosis of dementia using 2-year follow-up data.

METHODS

A 5-day screening campaign was conducted that comprised neurological, neuropsychological and other specialist examinations. Identification of alterations during the neurological examination was followed-up by further diagnostic examinations to confirm the neurological impairment.

RESULTS

Neurological alterations were observed in 39% of the screened subjects, who were mostly diagnosed with mild cognitive impairment and referred to a dementia and cognitive disorders centre. Suspicion of neurological impairment was a risk factor for inclusion in a specific neurological ambulatory follow-up and a condition for exemption from payment for medical examinations.

CONCLUSIONS

Neurodegenerative screening initiatives should include subjects selected by general practitioners. It would be useful to create a network including primary care physicians and cognitive disorder centres. Telemedicine tools (e.g., teleconsulting) could also be used to facilitate early diagnosis.

External validation of a panel of plasma microRNA biomarkers for lung cancer

Aim: We externally validate plasma miRNAs biomarkers for lung cancer in a large and retrospective sample set collected from a geographically distant population. Methods: Plasma samples are tested blindly to the clinical annotations by using PCR for quantitation of the four miRNAs in cohort 1 consisting of 232 lung cancer cases and 243 controls and cohort 2 comprising 239 cases and 246 controls. Results: Combined use of the four plasma miRNAs has 91% sensitivity and 95% specificity for diagnosis of lung cancer, and 85% sensitivity for early-stage lung cancer, while maintaining a specificity of 95%. Conclusion: The diagnostic values of the biomarkers are reproducibly confirmed in the independent and large sample sets, providing an assay for lung cancer detection.