TNF receptor 2 knockout mouse had reduced lung cancer growth and schizophrenia-like behavior through a decrease in TrkB-dependent BDNF level.

The relationship between schizophrenia (SCZ) and cancer development remains controversial. Based on the disease-gene association platform, it has been revealed that tumor necrosis factor receptor (TNFR) could be an important mediatory factor in both cancer and SCZ development. TNF-α also increases the expression of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) in the development of SCZ and tumor, but the role of TNFR in mediating the association between the two diseases remains unclear. We studied the vital roles of TNFR2 in the progression of tumor and SCZ-like behavior using A549 lung cancer cell xenografted TNFR2 knockout mice. TNFR2 knockout mice showed significantly decreased tumor size and weight as well as schizophrenia-like behaviors compared to wild-type mice. Consistent with the reduced tumor growth and SCZ-like behaviors, the levels of TrkB and BDNF expression were significantly decreased in the lung tumor tissues and pre-frontal cortex of TNFR2 knockout mice. However, intravenous injection of BDNF (160 µg/kg) to TNFR2 knockout mice for 4 weeks increased tumor growth and SCZ-like behaviors as well as TrkB expression. In in vitro study, significantly decreased cell growth and expression of TrkB and BDNF by siTNFR2 transfection were found in A549 lung cancer cells. However, the addition of BDNF (100 ng/ml) into TNFR2 siRNA transfected A549 lung cancer cells recovered cell growth and the expression of TrkB. These results suggest that TNFR2 could be an important factor in mediating the comorbidity between lung tumor growth and SCZ development through increased TrkB-dependent BDNF levels.

Case report: Pembrolizumab as an alternative to atezolizumab following a severe infusion reaction.

The emergence of immune-checkpoint inhibitors (ICIs) has revolutionized the field of oncology, providing promising results in various malignancies. However, ICIs can sometimes lead to severe injection reactions, requiring alternative treatment options. In this case report, we introduce a case of a severe infusion reaction induced by atezolizumab. After atezolizumab infusion, the patient experienced symptoms that were suggestive of anaphylactic shock, including chest tightness, low blood pressure, and loss of consciousness, all of which were restored by immediate administration of steroid, antihistamine, and epinephrine. When selecting a new ICI, we were concerned about cross-reactivity with atezolizumab. As such, we conducted a skin test to establish the underlying mechanism of the previous reaction to atezolizumab infusion, the results of which were highly suggestive of Ig-E-mediated hypersensitivity. The skin test for pembrolizumab, another ICI, was negative. Therefore, we replaced atezolizumab with pembrolizumab, and the infusion proceeded safely. To date, the patient has undergone 13 cycles of pembrolizumab, and the disease has remained stable. This case demonstrates that patients who exhibit severe injection reactions to ICIs can continue treatment safely, without cross-reactions, with alternative ICIs. This case will help provide patients who have experienced drug-related hypersensitivity reactions with a choice to use alternative ICIs, thus expanding their options for chemotherapy.

Significance of chitinase-3-like protein 1 in the pathogenesis of inflammatory diseases and cancer.

Chitinase-3-like protein 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly upregulated by various inflammatory and immunological diseases, including several cancers, Alzheimer's disease, and atherosclerosis. Several studies have shown that CHI3L1 can be considered as a marker of disease diagnosis, prognosis, disease activity, and severity. In addition, the proinflammatory action of CHI3L1 may be mediated via responses to various proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1ß, interleukin-6, and interferon-γ. Therefore, CHI3L1 may contribute to a vast array of inflammatory diseases. However, its pathophysiological and pharmacological roles in the development of inflammatory diseases remain unclear. In this article, we review recent findings regarding the roles of CHI3L1 in the development of inflammatory diseases and suggest therapeutic approaches that target CHI3L1.

(E)-2-methoxy-4-(3-(4-methoxyphenyl)prop-1-en-1-yl)phenol alleviates inflammatory responses in LPS-induced mice liver sepsis through inhibition of STAT3 phosphorylation.

Sepsis is a life-threatening disease with limited treatment options, and the inflammatory process represents an important factor affecting its progression. Many studies have demonstrated the critical roles of signal transducer and activator of transcription 3 (STAT3) in sepsis pathophysiology and pro-inflammatory responses. Inhibition of STAT3 activity may therefore represent a promising treatment option for sepsis. We here used a mouse model to demonstrate that (E)-2-methoxy-4-(3-(4-methoxyphenyl)prop-1-en-1-yl)phenol (MMPP) treatment prevented the liver sepsis-related mortality induced by 30 mg/kg lipopolysaccharide (LPS) treatment and reduced LPS-induced increase in alanine transaminase, aspartate transaminase, and lactate dehydrogenase levels, all of which are markers of liver sepsis progression. These recovery effects were associated with decreased LPS-induced STAT3, p65, and JAK1 phosphorylation and proinflammatory cytokine (interleukin 1 beta, interleukin 6, and tumor necrosis factor alpha) level; expression of cyclooxygenase-2 and induced nitric oxide synthase were also reduced by MMPP. In an in vitro study using the normal liver cell line THLE-2, MMPP treatment prevented the LPS-induced increase of STAT3, p65, and JAK1 phosphorylation and inflammatory protein expression in a dose-dependent manner, and this effect was enhanced by combination treatment with MMPP and STAT3 inhibitor. The results clearly indicate that MMPP treatment prevents LPS-induced mortality by inhibiting the inflammatory response via STAT3 activity inhibition. Thus, MMPP represents a novel agent for alleviating LPS-induced liver sepsis.

CHI3L1 induces autophagy through the JNK pathway in lung cancer cells.

CHI3L1 is closely related to the molecular mechanisms of cancer cell migration, growth, and death. According to recent research, autophagy regulates tumor growth during various stages of cancer development. This study examined the association between CHI3L1 and autophagy in human lung cancer cells. In CHI3L1-overexpressing lung cancer cells, the expression of LC3, an autophagosome marker, and the accumulation of LC3 puncta increased. In contrast, CHI3L1 depletion in lung cancer cells decreased the formation of autophagosomes. Additionally, CHI3L1 overexpression promoted the formation of autophagosomes in various cancer cell lines: it also increased the co-localization of LC3 and the lysosome marker protein LAMP-1, indicating an increase in the production of autolysosomes. In mechanism study, CHI3L1 promotes autophagy via activation of JNK signaling. JNK may be crucial for CHI3L1-induced autophagy since pretreatment with the JNK inhibitor reduced the autophagic effect. Consistent with the in vitro model, the expression of autophagy-related proteins was downregulated in the tumor tissues of CHI3L1-knockout mice. Furthermore, the expression of autophagy-related proteins and CHI3L1 increased in lung cancer tissues compared with normal lung tissues. These findings show that CHI3L1-induced autophagy is triggered by JNK signals and that CHI3L1-induced autophagy could be a novel therapeutic approach to lung cancer.

Induction of ER stress-mediated apoptosis through SOD1 upregulation by deficiency of CHI3L1 inhibits lung metastasis.

Chitinase-3-like protein 1 (CHI3L1), which is secreted by immune and inflammatory cells, is associated with several inflammatory diseases. However, the basic cellular pathophysiological functions of CHI3L1 are not well characterized. To investigate the novel pathophysiological function of CHI3L1, we performed LC-MS/MS analysis of cells transfected with Myc-vector and Myc-CHI3L1. We analyzed the changes in the protein distribution in Myc-CHI3L1 transfected-cells, and identified 451 differentially expressed proteins (DEPs) compared with Myc-vector-transfected-cells. The biological function of the 451 DEPs was analyzed and it was found that the proteins with endoplasmic reticulum (ER)-associated function were much more highly expressed in CHI3L1-overexpressing cells. We then compared and analyzed the effect of CHI3L1 on the ER chaperon levels in normal lung cells and cancer cells. We identified that CHI3L1 is localized in the ER. In normal cells, the depletion of CHI3L1 did not induce ER stress. However, the depletion of CHI3L1 induces ER stress and eventually activates the unfolded protein response, especially the activation of Protein kinase R-like endoplasmic reticulum kinase (PERK), which regulates protein synthesis in cancer cells. CHI3L1 may not affect ER stress owing to the lack of misfolded proteins in normal cells, but instead activate ER stress as a defense mechanism only in cancer cells. Under ER stress conditions induced by the application of thapsigargin, the depletion of CHI3L1 induces ER stress through the upregulation of PERK and PERK downstream factors (eIF2α and ATF4) in both normal and cancer cells. However, these signaling activations occur more often in cancer cells than in normal cells. The expression of Grp78 and PERK in the tissues of patients with lung cancer was higher compared with healthy tissues. It is well known that ER stress-mediated PERK-eIF2α-ATF4 signaling activation causes apoptotic cell death. ER stress-mediated apoptosis induced by the depletion of CHI3L1 occurs in cancer cells, but rarely occurs in normal cells. Consistent with results from the in vitro model, ER stress-mediated apoptosis was greatly increased during tumor growth and in the lung metastatic tissue of CHI3L1-knockout (KO) mice. The analysis of "big data" identified superoxide dismutase-1 (SOD1) as a novel target of CHI3L1 and interacted with CHI3L1. The depletion of CHI3L1 increased SOD1 expression, resulting in ER stress. Furthermore, the depletion of SOD1 reduced the expression of ER chaperones and ER-mediated apoptotic marker proteins, as well as apoptotic cell death induced by the depletion of CHI3L1 in in vivo and in vitro models. These results suggest that the depletion of CHI3L1 increases ER stress-mediated apoptotic cell death through SOD1 expression, and subsequently inhibits lung metastasis.

Snake venom induces an autophagic cell death via activation of the JNK pathway in colorectal cancer cells.

Snake venom contains many proteins that help treat or prevent thrombosis, cardiovascular disease, and cancer, and many studies have been reported in this regard. It has recently been reported that autophagy exerts anticancer effects by inducing tumor cell death and inhibiting cell growth. In this study, we investigated the effect of snake venom on autophagy. Unlike normal colon cells, LC3-II protein levels and LC3 puncta accumulation are increased in snake venom-treated colorectal cancer cells. Inhibition of autophagy by treating cells with hydroxychloroquine, an autophagy inhibitor, prevented snake venom-induced cell death, indicating that snake venom indeed induces autophagic cell death in human colorectal cancer cells. In addition, we demonstrated that activated JNK, and not mTOR signaling, is an upstream effector controlling autophagy. Pretreatment with SP600125, a JNK inhibitor, reversed snake venom-induced autophagy and cell death, indicating that JNK plays a critical role in snake venom-induced autophagy. This study demonstrated that snake venom can function as an anticarcinogenby induction autophagy.

Anti-Chi3L1 antibody suppresses lung tumor growth and metastasis through inhibition of M2 polarization.

Chitinase 3-like 1 (Chi3L1) is associated with various biological processes, such as inflammation, tissue repair, proliferation, cell survival, invasion, and extracellular matrix remodeling. Recent studies indicated that Chi3L1 is critical for cancer development and metastasis. In this study, we demonstrate that Chi3L1 serum and tissue levels were significantly increased in lung cancer patients compared with controls. We previously developed an anti-Chi3L1-humanized antibody, and here, we investigate its antitumor and antimetastatic effect. The anti-Chi3L1 antibody attenuated tumor growth and metastasis both in vitro and in vivo in a lung cancer mouse model. These inhibitory effects are associated with signal transducer and activator of transcription 6 (STAT6)-dependent M2 polarization inhibition. Proteomics analysis revealed that plasminogen (PLG) interacts with Chi3L1 and affects M2 polarization. Chi3L1 plays a critical role in lung cancer progression, and the anti-Chi3L1 antibody could be a new anticancer therapy.

A small molecule targeting CHI3L1 inhibits lung metastasis by blocking IL-13Rα2-mediated JNK-AP-1 signals.

Our previous big data analyses showed a high level of association between chitinase 3 like1 (CHI3L1) expression and lung tumor development. In the present study, we investigated whether a CHI3L1-inhibiting chemical, 2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284), could inhibit lung metastasis and studied its mechanism of action. We investigated the antitumor effect of K284 both in vitro and in vivo. K284 (0.5 mg·kg-1 body weight) significantly inhibited lung metastasis in in vivo models after injection of murine melanoma cells (B16F10) or adenocarcinomic human alveolar basal epithelial cells (A549). K284 significantly and concentration-dependently also inhibited cancer cell proliferation and migration in the A549 and H460 lung cancer cell lines. We found that the binding of K284 to the chitin-binding domain (CBD) of CHI3L1 prevented the binding of CHI3L1 to its receptor, interleukin-13 receptor subunit alpha-2 (IL-13Rα2), thereby suppressing the CHI3L1 signal. This blocking of the CHI3L1-IL-13Rα2 signal caused the inhibition of c-Jun N-terminal kinase (JNK)-activator protein 1 (AP-1) signals, resulting in the prevention of lung metastasis and cancer cell growth. Our data demonstrate that K284 may serve as a potential candidate anticancer compound targeting CHI3L1.

Bee Venom Triggers Autophagy-Induced Apoptosis in Human Lung Cancer Cells via the mTOR Signaling Pathway.

In oriental medicine, bee venom has long been used as a therapeutic agent against inflammatory diseases. Several studies have reported that isolated and purified bee venom components are effective in treating dementia, arthritis, inflammation, bacterial infections, and cancer. In previous studies, we reported that bee venom inhibits cell growth and induces apoptotic cell death in lung cancer cells. In the present study, we assessed whether bee venom affects autophagy and thereby induces apoptosis. Bee venom treatment increased the levels of autophagy-related proteins (Atg5, Beclin-1, and LC3-II) and the accumulation of LC3 puncta. We found that bee venom could induce autophagy by inhibiting the mTOR signaling pathway. In addition, we found that hydroxychloroquine (HCQ)- or si-ATG5-induced autophagy inhibition further demoted bee venom-induced apoptosis. Bee venom-induced autophagy promotes apoptosis in lung cancer cells and may become a new approach to cancer treatment.

A Natural CHI3L1-Targeting Compound, Ebractenoid F, Inhibits Lung Cancer Cell Growth and Migration and Induces Apoptosis by Blocking CHI3L1/AKT Signals.

Our previous big data analyses reported a strong association between CHI3L1 expression and lung tumor development. In this present study, we investigated whether a CHI3L1-inhibiting natural compound, ebractenoid F, inhibits lung cancer cell growth and migration and induces apoptosis. Ebractenoid F concentration-dependently (0, 17, 35, 70 µM) and significantly inhibited the proliferation and migration of A549 and H460 lung cancer cells and induced apoptosis. In the mechanism study, we found that ebractenoid F bound to CHI3L1 and suppressed CHI3L1-associated AKT signaling. Combined treatment with an AKT inhibitor, LY294002, and ebractenoid F synergistically decreased the expression of CHI3L1. Moreover, the combination treatment further inhibited the growth and migration of lung cancer cells and further induced apoptosis, as well as the expression levels of apoptosis-related proteins. Thus, our data demonstrate that ebractenoid F may serve as a potential anti-lung cancer compound targeting CHI3L1-associated AKT signaling.

Epigallocatechin-3-Gallate as a Novel Vaccine Adjuvant.

Vaccine adjuvants from natural resources have been utilized for enhancing vaccine efficacy against infectious diseases. This study examined the potential use of catechins, polyphenolic materials derived from green tea, as adjuvants for subunit and inactivated vaccines. Previously, catechins have been documented to have irreversible virucidal function, with the possible applicability in the inactivated viral vaccine platform. In a mouse model, the coadministration of epigallocatechin-3-gallate (EGCG) with influenza hemagglutinin (HA) antigens induced high levels of neutralizing antibodies, comparable to that induced by alum, providing complete protection against the lethal challenge. Adjuvant effects were observed for all types of HA antigens, including recombinant full-length HA and HA1 globular domain, and egg-derived inactivated split influenza vaccines. The combination of alum and EGCG further increased neutralizing (NT) antibody titers with the corresponding hemagglutination inhibition (HI) titers, demonstrating a dose-sparing effect. Remarkably, EGCG induced immunoglobulin isotype switching from IgG1 to IgG2a (approximately >64-700 fold increase), exerting a more balanced TH1/TH2 response compared to alum. The upregulation of IgG2a correlated with significant enhancement of antibody-dependent cellular cytotoxicity (ADCC) function (approximately 14 fold increase), providing a potent effector-mediated protection in addition to NT and HI. As the first report on a novel class of vaccine adjuvants with built-in virucidal activities, the results of this study will help improve the efficacy and safety of vaccines for pandemic preparedness.

Phosphorylation of ß-catenin Ser60 by polo-like kinase 1 drives the completion of cytokinesis.

ß-Catenin is a multifunctional protein and participates in numerous processes required for embryonic development, cell proliferation, and homeostasis through various molecular interactions and signaling pathways. To date, however, there is no direct evidence that ß-catenin contributes to cytokinesis. Here, we identify a novel p-S60 epitope on ß-catenin generated by Plk1 kinase activity, which can be found at the actomyosin contractile ring of early telophase cells and at the midbody of late telophase cells. Depletion of ß-catenin leads to cytokinesis-defective phenotypes, which eventually result in apoptotic cell death. In addition, phosphorylation of ß-catenin Ser60 by Plk1 is essential for the recruitment of Ect2 to the midbody, activation of RhoA, and interaction between ß-catenin, Plk1, and Ect2. Time-lapse image analysis confirmed the importance of ß-catenin phospho-Ser60 in furrow ingression and the completion of cytokinesis. Taken together, we propose that phosphorylation of ß-catenin Ser60 by Plk1 in cooperation with Ect2 is essential for the completion of cytokinesis. These findings may provide fundamental knowledge for the research of cytokinesis failure-derived human diseases.

Wnt5a-induced docking of Plk1 on HEF1 promotes HEF1 translocation and tumorigenesis.

BACKGROUND: Upregulation of human enhancer filamentation 1 (HEF1/NEDD9/Cas-L) and Polo-like kinase 1 (Plk1) is closely correlated with metastasis of human cancer. However, the mechanism by which the overexpression of HEF1 or Plk1 stimulates cancer metastasis and induces tumorigenesis remains enigmatic. In addition, the accumulation of HEF1 at the focal adhesion (FA) is known to be an essential event in cancer cell migration, but the mechanism of how HEF1 is targeted to the FA remains yet to be unveiled. OBJECTIVE: This study was performed to elucidate the FA docking mechanism of HEF1 and to determine its effect on tumorigenesis. METHODS: To confirm the effect of the kinase on HEF1 translocation, various expression-knockdown stable cell lines were generated using a lentivirus system, and the effect of the HEF1-Plk1 complex on tumorigenesis was confirmed using a xenograft mouse model. RESULTS: Here, we show that Wnt5a-dependent Plk1 binding to HEF1 is critically required for HEF1 translocation to the FA. We also confirmed that Plk1 and CK1δ activities essential for HEF1 translocation are induced by Wnt5a. Finally, we confirmed the induction of tumorigenesis by the HEF1-Plk1 complex in the xenograft mouse model. CONCLUSION: Our data collectively unveil the Wnt5a-CK1δ-HEF1-Plk1-FA remodeling pathway that governs HEF1 transportation to the FA to induce cell migration and tumorigenesis. This study sheds light on a mechanism underlying tumorigenesis and provides new strategies for anticancer therapy.

Variation of clinical manifestations according to culprit drugs in DRESS syndrome.

PURPOSE: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare but serious condition that systematically damages various internal organs through T-cell-mediated immunological drug reactions. We aimed to investigate whether clinical manifestations of DRESS syndrome differ according to culprit drugs. METHODS: We retrospectively analyzed data from 123 patients with probable/definite DRESS syndrome based on the RegiSCAR criteria (January 2011 to July 2016). The data were obtained from the Korean Severe Cutaneous Adverse Reaction Registry. Causality was assessed using the World Health Organization-Uppsala Monitoring Centre criteria. The culprit drugs were categorized as allopurinol, carbamazepine, anti-tuberculosis drug, vancomycin, cephalosporins, dapsone, and nonsteroidal anti-inflammatory drugs. RESULTS: Differences were observed among culprit drugs regarding the frequencies of hepatitis (P < 0.01), renal dysfunction (P < 0.0001), lymphadenopathy (P < 0.01), and atypical lymphocyte (P < 0.01). Latency period differed among culprit drugs (P < 0.0001), being shorter in vancomycin and cephalosporin. In terms of clinical severity, admission duration (P < 0.01) and treatment duration (P < 0.05) differed among culprit drugs, being longer in vancomycin and anti-tuberculosis drugs, respectively. CONCLUSIONS: Based on the findings, clinical manifestations, including latency period and clinical severity, may differ according to culprit drugs in DRESS syndrome.

Chaperna-Mediated Assembly of Ferritin-Based Middle East Respiratory Syndrome-Coronavirus Nanoparticles.

The folding of monomeric antigens and their subsequent assembly into higher ordered structures are crucial for robust and effective production of nanoparticle (NP) vaccines in a timely and reproducible manner. Despite significant advances in in silico design and structure-based assembly, most engineered NPs are refractory to soluble expression and fail to assemble as designed, presenting major challenges in the manufacturing process. The failure is due to a lack of understanding of the kinetic pathways and enabling technical platforms to ensure successful folding of the monomer antigens into regular assemblages. Capitalizing on a novel function of RNA as a molecular chaperone (chaperna: chaperone + RNA), we provide a robust protein-folding vehicle that may be implemented to NP assembly in bacterial hosts. The receptor-binding domain (RBD) of Middle East respiratory syndrome-coronavirus (MERS-CoV) was fused with the RNA-interaction domain (RID) and bacterioferritin, and expressed in Escherichia coli in a soluble form. Site-specific proteolytic removal of the RID prompted the assemblage of monomers into NPs, which was confirmed by electron microscopy and dynamic light scattering. The mutations that affected the RNA binding to RBD significantly increased the soluble aggregation into amorphous structures, reducing the overall yield of NPs of a defined size. This underscored the RNA-antigen interactions during NP assembly. The sera after mouse immunization effectively interfered with the binding of MERS-CoV RBD to the cellular receptor hDPP4. The results suggest that RNA-binding controls the overall kinetic network of the antigen folding pathway in favor of enhanced assemblage of NPs into highly regular and immunologically relevant conformations. The concentration of the ion Fe2+, salt, and fusion linker also contributed to the assembly in vitro, and the stability of the NPs. The kinetic "pace-keeping" role of chaperna in the super molecular assembly of antigen monomers holds promise for the development and delivery of NPs and virus-like particles as recombinant vaccines and for serological detection of viral infections.

A Case of Schnitzler's Syndrome without Monoclonal Gammopathy-Associated Chronic Urticaria Treated with Anakinra.

Chronic urticaria may often be associated with interleukin (IL)-1-mediated autoinflammatory disease, which should be suspected if systemic inflammation signs are present. Here, we report a case of Schnitzler's syndrome without monoclonal gammopathy treated successfully with the IL-1 receptor antagonist anakinra. A 69-year-old man suffered from a pruritic urticarial rash for 12 years. It became aggravated episodically and was accompanied by high fever, arthralgia, leukocytosis, and an elevated C-reactive protein and erythrocyte sedimentation rate. The episodes each lasted for over one week. Neutrophilic and eosinophilic inflammation was found on skin biopsy. However, serum and urine electrophoresis showed no evidence of monoclonal gammopathy. The cutaneous lesions were unresponsive to various kinds of anti-histamines, systemic glucocorticoids, colchicine, cyclosporine, dapsone, and methotrexate, which were administered over a span of 3 years immediately preceding successful treatment. A dramatic response, however, was observed after a daily administration of anakinra. This observation suggests that the correct diagnosis of this case is Schnitzler's syndrome without monoclonal gammopathy. For an adult patient with refractory chronic urticaria and systemic inflammation, Schnitzler's syndrome could be considered as a possible differential diagnosis. Although the typical form of Schnitzler's syndrome exhibits the presence of monoclonal gammopathy as a diagnostic criterion, monoclonal gammopathy may be absent in an atypical form. In such a situation, an IL-1 antagonist should be effective for the management of chronic urticaria.

Amino-terminal arginylation targets endoplasmic reticulum chaperone BiP for autophagy through p62 binding.

We show that ATE1-encoded Arg-transfer RNA transferase (R-transferase) of the N-end rule pathway mediates N-terminal arginylation of multiple endoplasmic reticulum (ER)-residing chaperones, leading to their cytosolic relocalization and turnover. N-terminal arginylation of BiP (also known as GRP78), protein disulphide isomerase and calreticulin is co-induced with autophagy during innate immune responses to cytosolic foreign DNA or proteasomal inhibition, associated with increased ubiquitylation. Arginylated BiP (R-BiP) is induced by and associated with cytosolic misfolded proteins destined for p62 (also known as sequestosome 1, SQSTM1) bodies. R-BiP binds the autophagic adaptor p62 through the interaction of its N-terminal arginine with the p62 ZZ domain. This allosterically induces self-oligomerization and aggregation of p62 and increases p62 interaction with LC3, leading to p62 targeting to autophagosomes and selective lysosomal co-degradation of R-BiP and p62 together with associated cargoes. In this autophagic mechanism, Nt-arginine functions as a delivery determinant, a degron and an activating ligand. Bioinformatics analysis predicts that many ER residents use arginylation to regulate non-ER processes.

Adenovirus-mediated expression of human sodium-iodide symporter gene permits in vivo tracking of adipose tissue-derived stem cells in a canine myocardial infarction model.

INTRODUCTION: In vivo tracking of the transplanted stem cells is important in pre-clinical research of stem cell therapy for myocardial infarction. We examined the feasibility of adenovirus-mediated sodium iodide symporter (NIS) gene to cell tracking imaging of transplanted stem cells in a canine infarcted myocardium by clinical single photon emission computed tomography (SPECT). METHODS: Beagle dogs were injected intramyocardially with NIS-expressing adenovirus-transfected canine stem cells (Ad-hNIS-canine ADSCs) a week after myocardial infarction (MI) development. (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) and (99m)Tc-pertechnetate ((99m)TcO4(-)) SPECT imaging were performed for assessment of infarcted myocardium and viable stem cell tracking. Transthoracic echocardiography was performed to monitor any functional cardiac changes. RESULTS: Left ventricular ejection fraction (LVEF) was decreased after LAD ligation. There was no significant difference in EF between the groups with the stem cell or saline injection. (125)I uptake was higher in Ad-hNIS-canine ADSCs than in non-transfected ADSCs. Cell proliferation and differentiation were not affected by hNIS-carrying adenovirus transfection. (99m)Tc-MIBI myocardial SPECT imaging showed decreased radiotracer uptake in the infarcted apex and mid-anterolateral regions. Ad-hNIS-canine ADSCs were identified as a region of focally increased (99m)TcO4(-) uptake at the lateral wall and around the apex of the left ventricle, peaked at 2 days and was observed until day 9. CONCLUSIONS: Combination of adenovirus-mediated NIS gene transfection and clinical nuclear imaging modalities enables to trace the fate of transplanted stem cells in infarcted myocardium for translational in vivo cell tracking study for prolonged duration.