Phosphorylation-dependent Akt-Inversin interaction at the basal body of primary cilia.

A primary cilium is a microtubule-based sensory organelle that plays an important role in human development and disease. However, regulation of Akt in cilia and its role in ciliary development has not been demonstrated. Using yeast two-hybrid screening, we demonstrate that Inversin (INVS) interacts with Akt. Mutation in the INVS gene causes nephronophthisis type II (NPHP2), an autosomal recessive chronic tubulointerstitial nephropathy. Co-immunoprecipitation assays show that Akt interacts with INVS via the C-terminus. In vitro kinase assays demonstrate that Akt phosphorylates INVS at amino acids 864-866 that are required not only for Akt interaction, but also for INVS dimerization. Co-localization of INVS and phosphorylated form of Akt at the basal body is augmented by PDGF-AA Akt-null MEF cells as well as siRNA-mediated inhibition of Akt attenuated ciliary growth, which was reversed by Akt reintroduction. Mutant phosphodead- or NPHP2-related truncated INVS, which lack Akt phosphorylation sites, suppress cell growth and exhibit distorted lumen formation and misalignment of spindle axis during cell division. Further studies will be required for elucidating functional interactions of Akt-INVS at the primary cilia for identifying the molecular mechanisms underlying NPHP2.

Inhibition of Akt kinase activity suppresses entry and replication of influenza virus.

The possibility of the pandemic spread of influenza viruses highlights the need for an effective cure for this life-threatening disease. Influenza A virus, belonging to a family of orthomyxoviruses, is a negative-strand RNA virus which encodes 11 viral proteins. A numbers of intracellular signaling pathways in the host cells interact with influenza the viral proteins, which affect various stages of viral infection and replication. In this study, we investigated how inhibition of Akt kinase activity impacts on influenza virus infection by using "Akt-in", a peptide Akt inhibitor. In PR8 influenza-infected A549 cells, Akt interacted with the NS1 (Non structural protein 1), and hence increased phosphorylation of Akt kinase activity and NS1. Treatment of cells with either "TCL1- or TCL1b-based Akt-in" efficiently suppressed Akt kinase activity while decreasing the levels of phosphorylated NS1; this, in turn, inhibited viral replication in a dose- and time-dependent manner. The inhibitory effect on viral replication appears to not be due to inhibition of the production of inflammatory cytokines, including IL-6 and IL-8, in the host cells. Inhibition of Akt kinase activity in the host cells inhibited the efficiency of viral entry, which is associated with decreased levels of phosphorylated glycogen synthase kinase 3, a substrate of Akt. Thus inhibition of Akt kinase activity in host cells may have therapeutic advantages for influenza virus infection by inhibiting viral entry and replication.

Secondary trigeminal neuralgia caused by lung adenocarcinoma metastasis on trigeminal nerve roots successfully relieved by opioids: A case report.

Secondary trigeminal neuralgia (TN) is caused by identifiable diseases or lesions of the trigeminal nerve root, Gasserian ganglion and/or pons. TN is a neuropathic pain disorder characterized by electric shock-like or stabbing pain in the facial region, which can lead to impaired health-related quality of life. The present case report describes a rare case of secondary TN caused by trigeminal nerve metastases from lung adenocarcinoma, in which opioids provided symptomatic relief. The patient was a 46-year-old man with stage IV lung adenocarcinoma. They were admitted to hospital for the introduction of fifth-line chemotherapy because of previous chemotherapy-refractory disease progression. Electric shock-like or stabbing pain in the left facial area and bilateral auditory disturbances coincided with intracranial peri-brainstem metastases. Facial pain was triggered by mastication, making it difficult for the patient to eat. A fentanyl transdermal patch (25 mcg/h) was initiated following a diagnosis of TN secondary to lung adenocarcinoma metastases on the trigeminal nerves by magnetic resonance imaging. Subsequently, the facial pain improved rapidly. In conclusion, unlike classic and idiopathic TN, which is usually treated with carbamazepine as a first-line drug, oncologic secondary TN can be treated with opioids.

Efficacy of treatments for pain and numbness in cancer survivors: a systematic review and meta-analysis.

BACKGROUND: Pain and numbness in cancer survivors frequently have negative impacts on quality of life (QoL). This meta-analysis aimed to identify the current treatment options for pain and numbness in cancer survivors and to evaluate their effects. METHODS: Cancer survivors were defined as patients diagnosed with cancer who had completed active cancer treatment, whose conditions were stable, and who had no evidence of recurrent or progressive disease. A systematic search through the PubMed, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, PsycInfo, and CINAHL databases was conducted, which targeted randomized controlled trials (RCTs) published until April 2022 that evaluated any type of treatment for pain or numbness in cancer survivors. A meta-analysis was conducted using the random-effects model to obtain the effect sizes of 7 types of treatments: opioid therapy, nonopioid pharmacotherapy, interventional therapy, acupuncture, education/cognitive behavioral therapy (CBT), physical exercise, and alternative medicine. RESULTS: A total of 36 studies involving 2,870 cancer survivors were included. Among them, 35 (n=2,813) were included in the meta-analysis for pain. The analysis suggested that physical exercise [n=761; 13 studies; standardized mean difference (SMD) -0.84; 95% confidence interval (CI): -1.14 to -0.55], acupuncture (n=409; 3 studies; SMD -0.80; 95% CI: -1.04 to -0.56), and alternative medicine (n=206; 6 studies; SMD -0.44; 95% CI: -0.71 to -0.16) could significantly reduce pain. Nonopioid pharmacotherapy and education/CBT did not demonstrate significant effects. No studies were identified that investigated the effects of opioid therapy or interventional therapy on pain. Regarding numbness, 5 studies (n=566) were included in the meta-analysis. Acupuncture (n=99; 2 studies) did not demonstrate significant effects on numbness, and the effects of nonopioid pharmacotherapy, education/CBT, and physical exercise could not be determined due to the small number of included studies. No studies were identified that investigated the effects of opioid therapy, interventional therapy, or alternative medicine on numbness. CONCLUSIONS: This meta-analysis suggested that physical exercise, acupuncture, and alternative medicine may reduce pain in cancer survivors, with a very small to moderate amount of evidence. The effect of treatments for numbness could not be determined due to the limited number of included studies. Further studies are needed, particularly on widely used pharmacotherapy.

Different Profiles of the Triad of Lysophosphatidylcholine, Lysophosphatidic Acid, and Autotaxin in Patients with Neuropathic Pain Diseases: a Preliminary Observational Study.

The mechanisms underlying neuropathic pain remain unclear. Lysophosphatidic acid (LPA) is a bioactive phospholipid derived mainly from lysophosphatidylcholine (LPC) by extracellular autotaxin (ATX), and has attracted attention as a candidate biomarker of neuropathic pain. We aimed to investigate the levels of LPA, LPC, and ATX in patients with lumbar spinal canal stenosis (LSCS) or other neuropathic pain diseases, and to distinguish the underlying mechanism of LSCS from other neuropathic pain conditions. Furthermore, the levels of phosphorylated neurofilament heavy chain (pNF-H), an objective surrogate marker of axonal damage, were also measured. Cerebrospinal fluid (CSF) samples were obtained from 56 patients with LSCS (n = 31) and various etiologies other than LSCS (n = 25). Patients with LSCS complained of pain intensity comparable to that of patients without LSCS. The LPA levels were significantly higher in patients with LSCS than in non-LSCS patients, while the ATX levels were significantly lower. However, the differences in LPC and pNF-H levels between the two patient groups were not significant. The LPA/LPC ratio was significantly higher in the LSCS group. Notably, the difference in LPA between the two groups diminished in the analysis of covariance (ANCOVA) with ATX as a covariate. Thus, it helped to reveal that LPA synthesis in patients with LSCS depends more efficiently on ATX than in non-LSCS neuropathic pain patients with other etiologies. Our findings further suggest that the triad of LPA, LPC, and ATX in LSCS may contribute to the development and maintenance of neuropathic pain in a manner different from non-LSCS neuropathic conditions.

Capecitabine-induced hand-foot syndrome does not emerge in the complex regional pain syndrome-affected limb: A case report.

Hand-foot syndrome (HFS) is a frequent adverse effect of various anti-tumour drugs, such as capecitabine, that affects their dose-limiting toxicity. The mechanism of HFS remains unknown and there are currently no effective strategies to treat HFS, except for cessation. The current study presented a female case where one hand, affected by brachial plexus infiltration due to the subclavian lymph node metastasis of breast cancer, exhibited not only pain and partial motor paralysis but also anhidrosis, oedema and skin colour changes. The patient met the diagnostic criteria for complex regional pain syndrome (CRPS). After treatment with capecitabine, their anhidrosis hand completely prevented HFS. The other hand and both feet demonstrated typical symptoms of HFS, which improved consequent to capecitabine cessation. The CRPS-affected hand remained normal. Considering the limited presentation of HFS concomitant with anhidrosis, the exocrine release of condensed capecitabine through sweat glands might be a promising mechanism of HFS induction.

Functional characterization of lysosomal interaction of Akt with VRK2.

Serine-threonine kinase Akt (also known as PKB, protein kinase B), a core intracellular mediator of cell survival, is involved in various human cancers and has been suggested to play an important role in the regulation of autophagy in mammalian cells. Nonetheless, the physiological function of Akt in the lysosomes is currently unknown. We have reported previously that PtdIns(3)P-dependent lysosomal accumulation of the Akt-Phafin2 complex is a critical step for autophagy induction. Here, to characterize the molecular function of activated Akt in the lysosomes in the process of autophagy, we searched for the molecules that interact with the Akt complex at the lysosomes after induction of autophagy. By time-of-flight-mass spectrometry (TOF/MS) analysis, kinases of the VRK family, a unique serine-threonine family of kinases in the human kinome, were identified. VRK2 interacts with Akt1 and Akt2, but not with Akt3; the C terminus of Akt and the N terminus of VRK2 facilitate the interaction of Akt and VRK2 in mammalian cells. The kinase-dead form of VRK2A (KD VRK2A) failed to interact with Akt in coimmunoprecipitation assays. Bimolecular fluorescence complementation (BiFC) experiments showed that, in the lysosomes, Akt interacted with VRK2A but not with VRK2B or KD VRK2A. Immunofluorescent assays revealed that VRK2 and phosphorylated Akt accumulated in the lysosomes after autophagy induction. WT VRK2A, but not KD VRK2A or VRK2B, facilitated accumulation of phosphorylated Akt in the lysosomes. Downregulation of VRK2 abrogated the lysosomal accumulation of phosphorylated Akt and impaired nuclear localization of TFEB; these events coincided to inhibition of autophagy induction. The VRK2-Akt complex is required for control of lysosomal size, acidification, bacterial degradation, and for viral replication. Moreover, lysosomal VRK2-Akt controls cellular proliferation and mitochondrial outer-membrane stabilization. Given the roles of autophagy in the pathogenesis of human cancer, the current study provides a novel insight into the oncogenic activity of VRK2-Akt complexes in the lysosomes via modulation of autophagy.