TNIK in disease: from molecular insights to therapeutic prospects.

TRAF2 and NCK interacting kinase (TNIK), a critical interacting protein kinase, is currently receiving wide attention. TNIK is found in various human body organs and tissues and participates in cell motility, proliferation, and differentiation. On the one hand, its aberrant expression is related to the onset and progression of numerous malignant tumors. On the other hand, TNIK is important in neuronal growth, proliferation, differentiation, and synaptic formation. Thus, the novel therapeutic strategies for targeting TNIK offer a promising direction for cancer, neurological or psychotic disorders. Here, we briefly summarized the biological information of TNIK, reviewed the role and regulatory mechanism in cancer and neuropsychiatric diseases, and introduced the research progress of inhibitors targeting TNIK. Taken together, this review hopes to contribute to the in-depth understanding of the function and regulatory mechanism of TNIK, which is of great significance for revealing the role of TNIK in the occurrence and treatment of diseases.

METTL3-mediated upregulation of FAM135B promotes EMT of esophageal squamous cell carcinoma via regulating the Wnt/ß-catenin pathway.

Family with sequence similarity 135 member B (FAM135B) is a novel driver gene in esophageal squamous cell carcinoma (ESCC). However, little is known regarding its biological functions and mechanisms in ESCC. Here, we identified that the high expression of FAM135B was associated with lymph node metastasis and infiltrating development of ESCC. Elevated FAM135B expression promoted ESCC migration and invasion in vitro and lung metastasis in vivo. Furthermore, epithelial-mesenchymal transition (EMT)-related pathways were enriched in ESCC samples with high levels of FAM135B and FAM135B positively regulated EMT markers. Mechanistically, we observed that FAM135B interacted with the intermediate domain of TRAF2 and NCK-interacting kinase (TNIK), activating the Wnt/ß-catenin signaling pathway. The facilitation of TNIK on ESCC migration and invasion was reversed by FAM135B siRNA. In addition, the N6-methyladenosine (m6A) modification positively regulated FAM135B expression, with methyltransferase like 3 (METTL3) acting as its substantial m6A writer. The pro-EMT effects of METTL3 overexpression were reversed by silencing FAM135B. Collectively, these findings illustrate the critical role of ABCDE in ESCC progression and provide new insights into the upstream and downstream mechanisms of FAM135B.NEW & NOTEWORTHY This study reveals for the first time that the novel cancer-related gene, FAM135B, promotes ESCC metastasis both in vitro and in vivo. Besides, we substantiate FAM135B's action on the ß-catenin pathway through interacting with TNIK, thereby elucidating the promotional effect of FAM135B on ESCC EMT. Furthermore, we provide initial evidence demonstrating that METTL3-mediated m6A modification upregulates the expression of FAM135B in ESCC cells.

TNIK's emerging role in cancer, metabolism, and age-related diseases.

Traf2- and Nck-interacting kinase (TNIK) has emerged as a key regulator of pathological metabolic signaling in several diseases and is a promising drug target. Originally studied for its role in cell migration and proliferation, TNIK possesses several newly identified functions that drive the pathogenesis of multiple diseases. Specifically, we evaluate TNIK's newfound roles in cancer, metabolic disorders, and neuronal function. We emphasize the implications of TNIK signaling in metabolic signaling and evaluate the translational potential of these discoveries. We also highlight how TNIK's role in many biological processes converges upon several hallmarks of aging. We conclude by discussing the therapeutic landscape of TNIK-targeting drugs and the recent success of clinical trials targeting TNIK.

Therapeutic targeting of TNIK in papillary thyroid carcinoma: a novel approach for tumor growth suppression.

Papillary thyroid carcinoma (PTC) is a common endocrine malignancy. The pathology of PTC is far from clear. As a kinase that can be targeted, the role of TNIK in PTC has not been investigated. This study was focused on the effects and molecular mechanisms of TNIK in PTC. Both public datasets and clinical specimens were used to verify TNIK expression. The effects of TNIK were investigated in both cell lines and mice models. Transcriptome analysis was used to explore the underlying mechanism of TNIK. Immunofluorescence, wound healing, and qRT-PCR assays were used to validate the mechanism of TNIK in PTC. The therapeutic effects of TNIK inhibitor NCB-0846 were evaluated by flow cytometry, western blot, and subcutaneous xenografts mice. TNIK expression was upregulated in PTC tissues. TNIK knockdown could suppress cell proliferation and tumor growth in no matter cell models or nude mice. The transcriptome analysis, GO enrichment analysis, and GSEA analysis results indicated TNIK was highly correlated with cytoskeleton, cell motility, and Wnt pathways. The mechanistic studies demonstrated that TNIK regulated cytoskeleton remodeling and promoted cell migration. NCB-0846 significantly inhibited TNIK kinase activity, induced cell apoptosis, and activated apoptosis-related proteins in a dose-dependent manner. In addition, NCB-0846 inhibited tumor growth in tumor-bearing mice. In summary, we proposed a novel regulatory mechanism in which TNIK-mediated cytoskeleton remodeling and cell migration to regulate tumor progression in PTC. TNIK is a therapeutic target in PTC and NCB-0846 would act as a novel targeted drug for PTC therapy.

TNIK depletion induces inflammation and apoptosis in injured renal proximal tubule epithelial cells.

In the aftermath of acute kidney injury (AKI), surviving proximal tubule epithelia repopulate injured tubules to promote repair. However, a portion of cells fail to repair [termed failed-repair proximal tubule cells (FR-PTCs)] and exert ongoing proinflammatory and profibrotic effects. To better understand the molecular drivers of the FR-PTC state, we reanalyzed a mouse ischemia-reperfusion injury single-nucleus RNA-sequencing (snRNA-seq) atlas to identify Traf2 and Nck interacting kinase (Tnik) to be exclusively expressed in FR-PTCs but not in healthy or acutely injured proximal tubules after AKI (2 and 6 wk) in mice. We confirmed expression of Tnik protein in injured mouse and human tissues by immunofluorescence. Then, to determine the functional role of Tnik in FR-PTCs, we depleted TNIK with siRNA in two human renal proximal tubule epithelial cell lines (primary and immortalized hRPTECs) and analyzed each by bulk RNA-sequencing. Pathway analysis revealed significant upregulation of inflammatory signaling pathways, whereas pathways associated with differentiated proximal tubules such as organic acid transport were significantly downregulated. TNIK gene knockdown drove reduced cell viability and increased apoptosis, including differentially expressed poly(ADP-ribose) polymerase (PARP) family members, cleaved PARP-1 fragments, and increased annexin V binding to phosphatidylserine. Together, these results indicate that Tnik upregulation in FR-PTCs acts in a compensatory fashion to suppress inflammation and promote proximal tubule epithelial cell survival after injury. Modulating TNIK activity may represent a prorepair therapeutic strategy after AKI.NEW & NOTEWORTHY The molecular drivers of successful and failed repair in the proximal tubule after acute kidney injury (AKI) are incompletely understood. We identified Traf2 and Nck interacting kinase (Tnik) to be exclusively expressed in failed-repair proximal tubule cells after AKI. We tested the effect of siTNIK depletion in two proximal tubule cell lines followed by bulk RNA-sequencing analysis. Our results indicate that TNIK acts to suppress inflammatory signaling and apoptosis in injured renal proximal tubule epithelial cells to promote cell survival.

Fragment growth-based discovery of novel TNIK inhibitors for the treatment of colorectal cancer.

Traf2-and Nck-interacting protein kinase (TNIK) plays an important role in regulating signal transduction of the Wnt/ß-catenin pathway and is considered an important target for the treatment of colorectal cancer. Inhibiting TNIK has potential to block abnormal Wnt/ß-catenin signal transduction caused by colorectal cancer mutations. We discovered a series of 6-(1-methyl-1H-imidazole-5-yl) quinoline derivatives as TNIK inhibitors through Deep Fragment Growth and virtual screening. Among them, 35b exhibited excellent TNIK kinase and HCT116 cell inhibitory activity with IC50 values of 6 nM and 2.11 µM, respectively. 35b also shown excellent kinase selectivity, PK profiles, and oral bioavailability (84.64%). At a p. o. dosage of 50 mg/kg twice daily 35b suppressed tumor growth on the HCT116 xenograft model. Taken together, 35b is a promising lead compound of TNIK inhibitors, which merits further investigation.

The Traf2 and NcK interacting kinase inhibitor NCB-0846 suppresses seizure activity involving the decrease of GRIA1.

Epilepsy, one of the most common neurological disorders, is characterized by spontaneous recurrent seizures. Temporal lobe epilepsy (TLE) is one of the most common medically intractable seizure disorders. Traf2-and NcK-interacting kinase (TNIK) has recently attracted attention as a critical modulation target of many neurological and psychiatric disorders, but its role in epilepsy remains unclear. In this study, we hypothesized the involvement of TNIK in epilepsy and investigated TNIK expression in patients with intractable TLE and in a pilocarpine-induced rat model of epilepsy by western blotting, immunofluorescence, and immunohistochemistry. A pentylenetetrazole (PTZ)-induced epilepsy rat model was used to determine the effect of the TNIK inhibitor NCB-0846 on behavioral manifestations of epilepsy. Coimmunoprecipitation (Co-IP)/mass spectrometry (MS) was used to identify the potential mechanism. Through Co-IP, we detected and confirmed the main potential TNIK interactors. Subcellular fractionation was used to establish the effect of NCB-0846 on the expression of the main interactors in postsynaptic density (PSD) fractions. We found that TNIK was primarily located in neurons and decreased significantly in epilepsy model rats and TLE patients compared with controls. NCB-0846 delayed kindling progression and decreased seizure severity. Co-IP/MS identified 63 candidate TNIK interactors in rat hippocampi, notably CaMKII. Co-IP showed that TNIK might correlate with endogenous GRIA1, SYN2, PSD-95, CaMKIV, GABRG1, and GABRG2. In addition, the significant decrease in GRIA1 in hippocampal total lysate and PSDs after NCB-0846 treatment might help modify the progression of PTZ kindling. Our results suggest that TNIK contributes to epileptic pathology and is a potential antiepileptic drug target.

LKB1 loss promotes colorectal cancer cell metastasis through regulating TNIK expression and actin cytoskeleton remodeling.

Colorectal cancer (CRC) is one of the most common malignant tumors. Approximately 5%-6% of CRC cases are associated with hereditary CRC syndromes, including the Peutz-Jeghers syndrome (PJS). Liver kinase B1 (LKB1), also known as STK11, is the major gene responsible for PJS. LKB1 heterozygotic deficiency is involved in intestinal polyps in mice, while the mechanism of LKB1 in CRC remains elusive. In this study, we generated LKB1 knockout (KO) CRC cell lines by using CRISPR-Cas9. LKB1 KO promoted CRC cell motility in vitro and tumor metastases in vivo. LKB1 attenuated expression of TRAF2 and NCK-interacting protein kinase (TNIK) as accessed by RNA-seq and western blots, and similar suppression was also detected in the tumor tissues of azoxymethane/dextran sodium sulfate-induced intestinal-specific LKB1-KO mice. LKB1 repressed TNIK expression through its kinase activity. Moreover, attenuating TNIK by shRNA inhibited cell migration and invasion of CRC cells. LKB1 loss-induced high metastatic potential of CRC cells was depended on TNIK upregulation. Furthermore, TNIK interacted with ARHGAP29 and further affected actin cytoskeleton remodeling. Taken together, LKB1 deficiency promoted CRC cell metastasis via TNIK upregulation and subsequently mediated cytoskeleton remodeling. These results suggest that LKB1-TNIK axis may play a crucial role in CRC progression.

Expression analysis of TRAF2­ and NCK­interacting protein kinase (TNIK) and phosphorylated TNIK in papillary thyroid carcinoma.

The aim of the present study was to evaluate the expression of TRAF2- and NCK-interacting kinase (TNIK) and the levels of the active form of TNIK, phosphorylated (p)-TNIK, in papillary thyroid carcinoma (PTC), and to identify and compare the levels of TNIK and p-TNIK among PTC, benign thyroid tumors and normal tissues. The levels of TNIK and p-TNIK were examined by reverse transcription-quantitative (RT-q)PCR and immunohistochemical analysis (IHC) in PTC, benign thyroid tumors and normal tissues, and their association with clinicopathological features was evaluated. First, analysis of the Gene Expression Profiling Interactive Analysis and The Cancer Genome Atlas datasets suggested that the mRNA expression of TNIK was markedly increased in PTC tissues compared with that in normal tissues. RT-qPCR analyses then indicated that the relative mRNA expression of TNIK in PTC tissues was 4.47±6.16, which was significantly higher than that in adjacent tissues 2.57±5.83. The IHC results suggested that the levels of TNIK and p-TNIK in PTC tissues were markedly elevated compared with those in benign thyroid tumors and normal tissues. The levels of p-TNIK in patients with PTC were significantly associated with extrathyroidal extension (χ2=4.199, P=0.040). Positive staining for TNIK was observed in 187 out of 202 (92.6%) cases in the cytoplasm, nucleus or cytomembrane of PTC cells. Among the 187 positive cases, cytoplasm expression was identified in 162 cases (86.6%), nuclear expression in 17 cases (9.1%) and cytomembrane expression in 8 cases (4.3%). Positive staining for p-TNIK was observed in 179 out of 202 (88.6%) cases in the nuclei, cytoplasm or cytomembrane of PTC cells. In the 179 p-TNIK-positive cases, localization in the nuclei plus cytoplasm was identified in 142 cases (79.3%), nuclear localization in 9 cases (5.0%), presence in the cytoplasm in 21 cases (11.7%) and cytomembrane localization in 7 cases (3.9%). Both TNIK and p-TNIK were upregulated in PTC tissues and p-TNIK was significantly associated with extrathyroidal extension. It may act as a crucial oncogene to participate in PTC carcinogenesis and progression.

Deficiency of germinal center kinase TRAF2 and NCK-interacting kinase (TNIK) in B cells does not affect atherosclerosis.

Background: Atherosclerosis is the underlying cause of many cardiovascular diseases, such as myocardial infarction or stroke. B cells, and their production of pro- and anti-atherogenic antibodies, play an important role in atherosclerosis. In B cells, TRAF2 and NCK-interacting Kinase (TNIK), a germinal center kinase, was shown to bind to TNF-receptor associated factor 6 (TRAF6), and to be involved in JNK and NF-κB signaling in human B cells, a pathway associated with antibody production. Objective: We here investigate the role of TNIK-deficient B cells in atherosclerosis. Results: ApoE-/-TNIKfl/fl (TNIKBWT) and ApoE-/-TNIKfl/flCD19-cre (TNIKBKO) mice received a high cholesterol diet for 10 weeks. Atherosclerotic plaque area did not differ between TNIKBKO and TNIKBWT mice, nor was there any difference in plaque necrotic core, macrophage, T cell, α-SMA and collagen content. B1 and B2 cell numbers did not change in TNIKBKO mice, and marginal zone, follicular or germinal center B cells were unaffected. Total IgM and IgG levels, as well as oxidation specific epitope (OSE) IgM and IgG levels, did not change in absence of B cell TNIK. In contrast, plasma IgA levels were decreased in TNIKBKO mice, whereas the number of IgA+ B cells in intestinal Peyer's patches increased. No effects could be detected on T cell or myeloid cell numbers or subsets. Conclusion: We here conclude that in hyperlipidemic ApoE-/- mice, B cell specific TNIK deficiency does not affect atherosclerosis.

TNIK regulation of interferon signaling and endothelial cell response to virus infection.

Background: Traf2 and Nck-interacting kinase (TNIK) is known for its regulatory role in various processes within cancer cells. However, its role within endothelial cells (ECs) has remained relatively unexplored. Methods: Leveraging RNA-seq data and Ingenuity Pathway Analysis (IPA), we probed the potential impact of TNIK depletion on ECs. Results: Examination of RNA-seq data uncovered more than 450 Differentially Expressed Genes (DEGs) in TNIK-depleted ECs, displaying a fold change exceeding 2 with a false discovery rate (FDR) below 0.05. IPA analysis unveiled that TNIK depletion leads to the inhibition of the interferon (IFN) pathway [-log (p-value) >11], downregulation of IFN-related genes, and inhibition of Hypercytokinemia/Hyperchemokinemia [-log (p-value) >8]. The validation process encompassed qRT-PCR to evaluate mRNA expression of crucial IFN-related genes, immunoblotting to gauge STAT1 and STAT2 protein levels, and ELISA for the quantification of IFN and cytokine secretion in siTNIK-depleted ECs. These assessments consistently revealed substantial reductions upon TNIK depletion. When transducing HUVECs with replication incompetent E1-E4 deleted adenovirus expressing green fluorescent protein (Ad-GFP), it was demonstrated that TNIK depletion did not affect the uptake of Ad-GFP. Nonetheless, TNIK depletion induced cytopathic effects (CPE) in ECs transduced with wild-type human adenovirus serotype 5 (Ad-WT). Summary: Our findings suggest that TNIK plays a crucial role in regulating the EC response to virus infections through modulation of the IFN pathway.

Structural Insight into TNIK Inhibition.

TRAF2- and NCK-interacting kinase (TNIK) has emerged as a promising therapeutic target for colorectal cancer because of its essential role in regulating the Wnt/ß-catenin signaling pathway. Colorectal cancers contain many mutations in the Wnt/ß-catenin signaling pathway genes upstream of TNIK, such as the adenomatous polyposis coli (APC) tumor suppressor gene. TNIK is a regulatory component of the transcriptional complex composed of ß-catenin and T-cell factor 4 (TCF4). Inhibition of TNIK is expected to block the aberrant Wnt/ß-catenin signaling caused by colorectal cancer mutations. Here we present structural insights into TNIK inhibitors targeting the ATP-binding site. We will discuss the effects of the binding of different chemical scaffolds of nanomolar inhibitors on the structure and function of TNIK.

Computational study on new natural compound inhibitors of Traf2 and Nck-interacting kinase (TNIK).

Traf2 and Nck-interacting kinase (TNIK) is the downstream molecule of Wnt/ß-catenin signal pathway. As the activation kinase of ß-catenin/T-cell factor 4 transcription complex, it can fully activate Wnt signalling and promote the growth and invasion of tumor cells. We conducted computer-assisted virtual screening and a series of analyses to find potential inhibitors of TNIK. First, LibDock was used for molecular docking of natural small molecules. Then, ADME (Adsorption, Distribution, Metabolism and Excretion) analysis and toxicity prediction were performed on the top 80 small molecules which have higher scores. Additionally, in order to further determine the affinity and binding mechanism of TNIK-ligands, we analyzed the pharmacophores and used CDOCKER for more accurate molecular docking. Last but not least, molecular, dynamics simulation was used to evaluate the stability of receptor-ligand complexes in natural environment. The results showed that natural small molecules (ZINC000040976869 and ZINC000008214460) had high affinity and low interaction energy with TNIK. They were predicted to have excellent pharmacological properties, such as high plasma protein binding capacity and water solubility, no hepatotoxicity, no blood-brain barrier permeability and tolerant with cytochrome P450 2D6 (CYP2D6). In addition, they have less rodent carcinogenicity, AMES mutagenicity, and developmental toxicity potential. Molecular dynamics simulations showed that the two compounds could achieve the stability of potential energy and Root-Mean-Square Deviation (RMSD) at different time nodes. This study proves that ZINC000040976869 and ZINC000008214460 are ideal lead compounds with inhibition targeting to TNIK. These compounds provide valuable ideas and information for the development of new colorectal cancer targeting drugs.

The influence of TNIK gene polymorphisms on risperidone response in a Chinese Han population.

Aim: To investigate whether the TNIK gene affects risperidone treatment outcomes in the Chinese population. Methods: A total of 148 unrelated inpatients who received risperidone for six weeks were enrolled. The selected single nucleotide polymorphisms (SNPs; rs2088885, rs7627954 and rs13065441) were genotyped using the MassARRAY® SNP IPLEX platform. Results: The analysis showed that one novel SNP of TNIK, rs7627954, had a significant association with the response to risperidone (χ2 = 4.472; p = 0.034). This work also identified rs2088885 as significantly associated with risperidone response (χ2 = 5.257; p = 0.022). The result revealed that the rs2088885-rs7627954 C-T haplotype was more prevalent in good responders than in poor responders (p = 0.0278). Conclusion: This study revealed that the rs2088885 and rs7627954 SNPs of TNIK are associated with risperidone treatment response.

TNIK Inhibition Has Dual Synergistic Effects on Tumor and Associated Immune Cells.

Treatment with checkpoint inhibitors can be extraordinarily effective in a fraction of patients, particularly those whose tumors are pre-infiltrated by T cells. In others, efficacy is considerably lower, which has led to interest in developing strategies for sensitization to immunotherapy. Using various colorectal cancer mouse models, it is shown that the use of Traf2 and Nck-interacting protein kinase inhibitors (TNIKi) unexpectedly increases tumor infiltration by PD-1+ CD8+ T cells, thus contributing to tumor control. This appears to happen by two independent mechanisms, by inducing immunogenic cell death and separately by directly activating CD8. The use of TNIKi achieves complete tumor control in 50% of mice when combined with checkpoint inhibitor targeting PD-1. These findings reveal immunogenic properties of TNIKi and indicate that the proportion of colorectal cancers responding to checkpoint therapy can be increased by combining it with immunogenic kinase inhibitors.

MicroRNA-144-3p Represses the Growth and EMT of Thyroid Cancer via the E2F2/TNIK Axis in Cells and Male BALB/c Nude Mice.

CONTEXT: microRNA (miR/miRNA)-144-3p has been implicated in thyroid cancer (TC) progression with poorly identified mechanisms. Furthermore, E2F2 has been documented to assume a role in the development of various cancers. OBJECTIVE: This research sought to ascertain the role of miR-144-3p in growth and epithelial-mesenchymal transition (EMT) in TC in cells and male BALB/c nude mice. METHODS: In the obtained TC cells, miR-144-3p expression was detected by quantitative reverse transcription polymerase chain reaction, and E2F2 and TNIK expression by Western blot analysis. After gain- and loss-of-function assays, cell viability, clone formation, migration, and invasion were assessed by cell counting kit-8, clone formation, scratch, and Transwell assays. The expression of EMT-related proteins (Snail, Vimentin, N-cadherin, and E-cadherin) was tested by Western blot analysis. The targeting relationship between miR-144-3p and E2F2 was evaluated by dual-luciferase reporter and radioimmunoprecipitation assays, and the binding relationship between E2F2 and TNIK by dual-luciferase reporter and chromatin immunoprecipitation assays. TC cell growth in vivo was determined by subcutaneous tumorigenesis assays in nude mice. RESULTS: miR-144-3p was downregulated, whereas E2F2 and TNIK were upregulated in TC cells. Mechanistically, miR-144-3p inversely targeted E2F2, which increased TNIK expression by binding to TNIK promoter in TC cells. Overexpression of miR-144-3p reduced proliferation, migration, invasion, and EMT of FRO and KTC3 cells, which was nullified by overexpressing E2F2 or TNIK expression. Upregulation of miR-144-3p diminished FRO cell growth and EMT in nude mice, which was abrogated by overexpressing TNIK. CONCLUSION: miR-144-3p inhibits cell growth and EMT in TC through E2F2/TNIK axis inactivation in cells and male BALB/c nude mice.

Discovery of benzo[d]oxazol-2(3H)-one derivatives as a new class of TNIK inhibitors for the treatment of colorectal cancer.

Colorectal cancer (CRC) is one of the most commonly diagnosed cancer types and Traf2- and Nck-interacting kinase (TNIK) has been thought as a potential target for CRC treatment. Herein we report the discovery and structure-activity relationship (SAR) of benzo[d]oxazol-2(3H)-one derivatives as a new class of TNIK inhibitors. The most potent compound 8g showed an IC50 value of 0.050 µM against TNIK. It effectively suppressed proliferation and migration of colorectal cancer cells. Western blot analysis indicated that 8g could inhibit aberrant transcription activation of Wnt signaling. Collectively, this study provides a potential lead compound for subsequent drug discovery targeting TNIK.

Liquidambaric acid inhibits Wnt/ß-catenin signaling and colon cancer via targeting TNF receptor-associated factor 2.

Wnt/ß-catenin signaling is a well-established driver of colon cancer; however, a targeted therapeutic agent has not reached clinics yet. In the present study, we report that the natural compound liquidambaric acid (LDA) inhibits oncogenic Wnt/ß-catenin signaling in vitro and in vivo through its direct target tumor necrosis factor receptor-associated factor 2 (TRAF2). Mechanistically, TRAF2 positively regulates Wnt signaling by interacting with the N-terminal of ß-catenin via its TRAF-C domain; this interaction is disrupted in presence of LDA. Particularly, a TRAF2/ß-catenin/TCF4/TNIK complex is present in colon cancer cells, where TRAF2 is indispensable for the complex formation, and TRAF2/ß-catenin and ß-catenin/TCF4 interactions are disrupted upon LDA treatment. Our findings not only highlight that TRAF2 is an oncogenic regulator of Wnt/ß-catenin signaling and colon cancer but also provide a lead compound targeting TRAF2 for cancer therapy.

TNIK influence the effects of antipsychotics on Wnt/ß-catenin signaling pathway.

RationaleTraf2- and Nck-interacting kinase (TNIK), a member of germinal center kinase (GCK) family, has been implicated as a risk factor in schizophrenia and bipolar disorder as well as the action of antipsychotics. TNIK is an essential activator of Wnt/ß-catenin signaling pathway which has been identified involved in the mechanism underlying the effects of antipsychotics. Thus, the effects of TNIK on antipsychotics may be achieved by influencing Wnt/ß-catenin signaling pathway proteins.Objectives and methodsIn the current study, the effects of up- or downregulated TNIK on ß-catenin, T-cell factor 4 (TCF-4), glycogen synthase kinase-3ß (GSK3ß), and phosphorylated GSK3ß (p-GSK3ß) were examined in the human glioma U251 cells. Then, we observed the effects of antipsychotics (clozapine and risperidone) on the above proteins and evaluated the role of differentially expressed TNIK on antipsychotic-treated cell groups.ResultsThe result showed that clozapine treatment decreased ß-catenin and TCF-4 levels in U251 cells, and risperidone had the similar effects on ß-catenin and p-GSK3ß. The downregulated TNIK using siRNA impeded the regulation of antipsychotics on Wnt pathway proteins via increasing the expression levels of TCF-4, ß-catenin, or p-GSK3ß, whereas the upregulated TNIK made no significant change.ConclusionsThe influence of TNIK on the effects of antipsychotics may be partly through Wnt/ß-catenin signaling pathway.

Phosphorylation-dependent control of Activity-regulated cytoskeleton-associated protein (Arc) protein by TNIK.

Activity-regulated cytoskeleton-associated protein (Arc) is an immediate early gene product that support neuroplastic changes important for cognitive function and memory formation. As a protein with homology to the retroviral Gag protein, a particular characteristic of Arc is its capacity to self-assemble into virus-like capsids that can package mRNAs and transfer those transcripts to other cells. Although a lot has been uncovered about the contributions of Arc to neuron biology and behavior, very little is known about how different functions of Arc are coordinately regulated both temporally and spatially in neurons. The answer to this question we hypothesized must involve the occurrence of different protein post-translational modifications acting to confer specificity. In this study, we used mass spectrometry and sequence prediction strategies to map novel Arc phosphorylation sites. Our approach led us to recognize serine 67 (S67) and threonine 278 (T278) as residues that can be modified by TNIK, which is a kinase abundantly expressed in neurons that shares many functional overlaps with Arc and has, along with its interacting proteins such as the NMDA receptor, and been implicated as a risk factor for psychiatric disorders. Furthermore, characterization of each residue using site-directed mutagenesis to create S67 and T278 mutant variants revealed that TNIK action at those amino acids can strongly influence Arc's subcellular distribution and self-assembly as capsids. Together, our findings reveal an unsuspected connection between Arc and TNIK. Better understanding of the interplay between these two proteins in neuronal cells could lead to new insights about apparition and progression of psychiatric disorders. Cover Image for this issue: https://doi.org/10.1111/jnc.15077.