Age-related cholesterol and colorectal cancer progression: Validating squalene epoxidase for high-risk cases.

As people age, the risk and progression of colorectal cancer (CRC), along with cholesterol levels, tend to increase. Nevertheless, epidemiological studies on serum lipids and CRC have produced conflicting results. We previously demonstrated that the reduction of squalene epoxidase (SQLE) due to accumulated cholesterol within cells accelerates CRC progression through the activation of the ß-catenin pathway. This study aimed to investigate the mechanism by which age-related cholesterol accumulation within tissue accelerates CRC progression and to assess the clinical significance of SQLE in older individuals with elevated CRC risk. Using machine learning-based digital image analysis with fluorescence-immunohistochemistry, we assessed SQLE, GSK3ßpS9 (GSK3ß activity inhibition through serine 9 phosphorylation at GSK3ß), p53 wild-type (p53WT), and p53 mutant (p53MT) levels in CRC tissues. Our analysis revealed a significant reduction in SQLE, p53WT, and p53MT and increase in GSK3ßpS9 levels, all associated with the substantial accumulation of intra-tissue cholesterol in aged CRCs. Cox analysis underscored the significant influence of SQLE on overall survival and progression-free survival in grade 2-3 CRC patients aged over 50. SQLE and GSK3ßpS9 consistently exhibited outstanding prognostic and diagnostic performance, particularly in older individuals. Furthermore, combining SQLE with p53WT, p53MT, and GSK3ßpS9 demonstrated a robust diagnostic ability in the older population. In conclusion, we have identified that individuals aged over 50 face an increased risk of CRC progression due to aging-linked cholesterol accumulation within tissue and the subsequent reduction in SQLE levels. This study also provides valuable biomarkers, including SQLE and GSK3ßpS9, for older patients at elevated risk of CRC.

TREX1 Deficiency Induces ER Stress-Mediated Neuronal Cell Death by Disrupting Ca2+ Homeostasis.

TREX1 is an exonuclease that degrades extranuclear DNA species in mammalian cells. Herein, we show a novel mechanism by which TREX1 interacts with the BiP/GRP78 and TREX1 deficiency triggers ER stress through the accumulation of single-stranded DNA and activates unfolded protein response (UPR) signaling via the disruption of the TREX1-BiP/GRP78 interaction. In TREX1 knockdown cells, the activation of ER stress signaling disrupted ER Ca2+ homeostasis via the ERO1α-IP3R1-CaMKII pathway, leading to neuronal cell death. Moreover, TREX1 knockdown dysregulated the Golgi-microtubule network through Golgi fragmentation and decreased Ac-α-tubulin levels, contributing to neuronal injury. These alterations were also observed in neuronal cells harboring a TREX1 mutation (V91M) that has been identified in hereditary spastic paraplegia (HSP) patients in Korea. Notably, this mutation leads to defects in the TREX1-BiP/GRP78 interaction and mislocalization of TREX1 from the ER and possible disruption of the Golgi-microtubule network. In summary, the current study reveals TREX1 as a novel regulator of the BiP/GRP78 interaction and shows that TREX1 deficiency promotes ER stress-mediated neuronal cell death, which indicates that TREX1 may hold promise as a therapeutic target for neurodegenerative diseases such as HSP.

The emerging genetic diversity of hereditary spastic paraplegia in Korean patients.

Hereditary Spastic Paraplegias (HSP) are a group of rare inherited neurological disorders characterized by progressive loss of corticospinal motor-tract function. Numerous patients with HSP remain undiagnosed despite screening for known genetic causes of HSP. Therefore, identification of novel genetic variations related to HSP is needed. In this study, we identified 88 genetic variants in 54 genes from whole-exome data of 82 clinically well-defined Korean HSP families. Fifty-six percent were known HSP genes, and 44% were composed of putative candidate HSP genes involved in the HSPome and originally reported neuron-related genes, not previously diagnosed in HSP patients. Their inheritance modes were 39, de novo; 33, autosomal dominant; and 10, autosomal recessive. Notably, ALDH18A1 showed the second highest frequency. Fourteen known HSP genes were firstly reported in Koreans, with some of their variants being predictive of HSP-causing protein malfunction. SPAST and REEP1 mutants with unknown function induced neurite abnormality. Further, 54 HSP-related genes were closely linked to the HSP progression-related network. Additionally, the genetic spectrum and variation of known HSP genes differed across ethnic groups. These results expand the genetic spectrum for HSP and may contribute to the accurate diagnosis and treatment for rare HSP.

The Human TOR Signaling Regulator Is the Key Indicator of Liver Cancer Patients' Overall Survival: TIPRL/LC3/CD133/CD44 as Potential Biomarkers for Early Liver Cancers.

Recently, we reported the involvement of TIPRL/LC3/CD133 in liver cancer aggressiveness. This study assessed the human TOR signaling regulator (TIPRL)/microtubule-associated light chain 3 (LC3)/prominin-1 (CD133)/cluster of differentiation 44 (CD44) as potential diagnostic and prognostic biomarkers for early liver cancer. For the assessment, we stained tissues of human liver disease/cancer with antibodies against TIPRL/LC3/CD133/CD44/CD46, followed by confocal observation. The roles of TIPRL/LC3/CD133/CD44/CD46 in liver normal and cancer cell lines were determined by in vitro studies. We analyzed the prognostic and diagnostic potentials of TIPRL/LC3/CD133/CD44/CD46 using the receiver-operating characteristic curve, a Kaplan-Meier and uni-/multi-Cox analyses. TIPRL and LC3 were upregulated in tissues of HCCs and adult hepatocytes-derived liver diseases while downregulated in iCCA. Intriguingly, TIPRL levels were found to be critically associated with liver cancer patients' survivability, and TIPRL is the key player in liver cancer cell proliferation and viability via stemness and self-renewal induction. Furthermore, we demonstrate that TIPRL/LC3/CD133 have shown prominent efficiency for diagnosing patients with grade 1 iCCA. TIPRL/LC3/CD133/CD44 have also provided excellent potential for prognosticating patients with grade 1 iCCA and grade 1 HCCs, together with demonstrating that TIPRL/LC3/CD133/CD44 are, either individually or in conjunction, potential biomarkers for early liver cancer.

Corrigendum: Characteristics of Genetic Variations Associated With Lennox-Gastaut Syndrome in Korean Families.

[This corrects the article DOI: 10.3389/fgene.2020.590924.].

Reduction of Squalene Epoxidase by Cholesterol Accumulation Accelerates Colorectal Cancer Progression and Metastasis.

BACKGROUND & AIMS: Squalene epoxidase (SQLE), a rate-limiting enzyme in cholesterol biosynthesis, is suggested as a proto-oncogene. Paradoxically, SQLE is degraded by excess cholesterol, and low SQLE is associated with aggressive colorectal cancer (CRC). Therefore, we studied the functional consequences of SQLE reduction in CRC progression. METHODS: Gene and protein expression data and clinical features of CRCs were obtained from public databases and 293 human tissues, analyzed by immunohistochemistry. In vitro studies showed underlying mechanisms of CRC progression mediated by SQLE reduction. Mice were fed a 2% high-cholesterol or a control diet before and after cecum implantation of SQLE genetic knockdown/control CRC cells. Metastatic dissemination and circulating cancer stem cells were demonstrated by in vivo tracking and flow cytometry analysis, respectively. RESULTS: In vitro studies showed that SQLE reduction helped cancer cells overcome constraints by inducing the epithelial-mesenchymal transition required to generate cancer stem cells. Surprisingly, SQLE interacted with GSK3ß and p53. Active GSK3ß contributes to the stability of SQLE, thereby increasing cell cholesterol content, whereas SQLE depletion disrupted the GSK3ß/p53 complex, resulting in a metastatic phenotype. This was confirmed in a spontaneous CRC metastasis mice model, where SQLE reduction, by a high-cholesterol regimen or genetic knockdown, strikingly promoted CRC aggressiveness through the production of migratory cancer stem cells. CONCLUSIONS: We showed that SQLE reduction caused by cholesterol accumulation aggravates CRC progression via the activation of the ß-catenin oncogenic pathway and deactivation of the p53 tumor suppressor pathway. Our findings provide new insights into the link between cholesterol and CRC, identifying SQLE as a key regulator in CRC aggressiveness and a prognostic biomarker.

Coiled-coil domain containing 50-V2 protein positively regulates neurite outgrowth.

The coiled-coil domain containing 50 (CCDC50) protein is a phosphotyrosine-dependent signalling protein stimulated by epidermal growth factor. It is highly expressed in neuronal cells in the central nervous system; however, the roles of CCDC50 in neuronal development are largely unknown. In this study, we showed that the depletion of CCDC50-V2 impeded the neuronal development process, including arbor formation, spine density development, and axonal outgrowth, in primary neurons. Mechanistic studies revealed that CCDC50-V2 positively regulated the nerve growth factor receptor, while it downregulated the epidermal growth factor receptor pathway. Importantly, JNK/c-Jun activation was found to be induced by the CCDC50-V2 overexpression, in which the interaction between CCDC50-V2 and JNK2 was also observed. Overall, the present study demonstrates a novel mechanism of CCDC50 function in neuronal development and provides new insight into the link between CCDC50 function and the aetiology of neurological disorders.

Characteristics of Genetic Variations Associated With Lennox-Gastaut Syndrome in Korean Families.

Lennox-Gastaut syndrome (LGS) is a severe type of childhood-onset epilepsy characterized by multiple types of seizures, specific discharges on electroencephalography, and intellectual disability. Most patients with LGS do not respond well to drug treatment and show poor long-term prognosis. Approximately 30% of patients without brain abnormalities have unidentifiable causes. Therefore, accurate diagnosis and treatment of LGS remain challenging. To identify causative mutations of LGS, we analyzed the whole-exome sequencing data of 17 unrelated Korean families, including patients with LGS and LGS-like epilepsy without brain abnormalities, using the Genome Analysis Toolkit. We identified 14 mutations in 14 genes as causes of LGS or LGS-like epilepsy. 64 percent of the identified genes were reported as LGS or epilepsy-related genes. Many of these variations were novel and considered as pathogenic or likely pathogenic. Network analysis was performed to classify the identified genes into two network clusters: neuronal signal transmission or neuronal development. Additionally, knockdown of two candidate genes with insufficient evidence of neuronal functions, SLC25A39 and TBC1D8, decreased neurite outgrowth and the expression level of MAP2, a neuronal marker. These results expand the spectrum of genetic variations and may aid the diagnosis and management of individuals with LGS.

A Novel X-Linked Variant of IQSEC2 is Associated with Lennox-Gastaut Syndrome and Mild Intellectual Disability in Three Generations of a Korean Family.

Aim: Lennox-Gastaut syndrome (LGS) is a severe type of childhood-onset epilepsy with multiple types of seizures, specific discharges on electroencephalography, and intellectual disability. However, LGS-related genes are largely unknown. To identify causative genes related to LGS, we collected and analyzed data from a three-generation Korean family in which one member had LGS and two had intellectual disability. Methods: Genomic DNAs were extracted from blood samples of all participants and used in whole-exome sequencing (WES). Genetic variants were detected by the Genome Analysis Toolkit and confirmed by Sanger sequencing. Variant pathogenicity was evaluated by prediction programs and the American College of Medical Genetics criteria. The LGS patient had generalized slow spike-and-wave discharges, multiple types of seizures, and developmental delay. Results: Analyses of the WES data from the family revealed a novel variant (c.1048G>A, p.Ala350Thr) in the IQ motif and Sec7 domain 2 (IQSEC2). This variant is within a highly evolutionarily conserved IQ-like motif, indicating a decrease in the calmodulin-binding capacity or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid transmission. The hemizygous variant in the male with LGS was a maternally inherited X-linked variant from the heterozygous maternal grandmother and mother, both of whom had intellectual disability. Conclusion: These findings indicate that the variant of IQSEC2 triggered both LGS and intellectual disability dependent on sex in this family. We report a novel X-linked inherited IQSEC2 variant for LGS and intellectual disability, which enhances the spectrum of variants in the IQ-like motif of IQSEC2.

TIPRL potentiates survival of lung cancer by inducing autophagy through the eIF2α-ATF4 pathway.

Autophagy, an intracellular system of degrading damaged organelles and misfolded proteins, is essential for cancer cell survival. Despite the progress made towards understanding the mechanism, identification of novel autophagy regulators presents a major obstacle in developing anticancer therapies. Here, we examine the association between the TOR signaling pathway regulator-like (TIPRL) protein and autophagy in malignant transformation of tumors. We show that TIPRL upregulation in non-small cell lung cancer (NSCLC) potentiated autophagy activity and enabled autophagic clearance of metabolic and cellular stress, conferring a survival advantage to cancer cells. Importantly, the interaction of TIPRL with eukaryotic initiation factor 2α (eIF2α) led to eIF2α phosphorylation and activation of the eIF2α-ATF4 pathway, thereby inducing autophagy. Conversely, TIPRL depletion increased apoptosis by reducing autophagic clearance, which was markedly enhanced in TIPRL-depleted A549 xenografts treated with 2-deoxy-D-glucose. Overall, the study indicated that TIPRL is a potential regulator of autophagy and an important drug target for lung cancer therapy.

The positive correlation of TIPRL with LC3 and CD133 contributes to cancer aggressiveness: potential biomarkers for early liver cancer.

Studies have reported dysregulation of TIPRL, LC3 and CD133 in liver cancer tissues. However, their respective relationships to liver cancer and roles as biomarkers for prognosis and diagnosis of liver cancer have never been studied. Here we report that the level of TIPRL is significantly correlated with levels of LC3 (Spearman r = 0.9) and CD133 (r = 0.7) in liver cancer tissues. We observed significant upregulations of TIPRL, LC3 and CD133 in hepatocellular carcinomas (HCCs) compared with adjacent normal tissues. Importantly, TIPRL, tested among additional variables, showed a significant impact on the prognosis of HCC patients. TIPRL knockdown significantly reduced expressions of LC3, CD133, stemness-related genes, as well as viability and stemness of liver cancer cell-lines, which were promoted by ectopic TIPRL expression. Either alone or as a combination, TIPRL, LC3 and CD133 showed significant values of area under the curve (AUC) and sensitivity/specificity in early liver cancer tissues. Furthermore, the statistical association and the diagnostic efficacies of TIPRL, LC3 and CD133 in HCC tissues were confirmed in a different IHC cohort. This data demonstrates that the complex involvement of TIPRL/LC3/CD133 in liver cancer aggressiveness can together or individually serve as potential biomarkers for the early detection of liver cancer.

Community Capacity Building Exercise Maintenance Program for Frail Elderly Women.

PURPOSE: The purpose of this study was to examine the effects of community capacity building exercise maintenance program for frail elderly women. METHODS: A quasiexperimental pretest-posttest design was used with nonequivalent control group. The experimental group (n = 22) received community capacity building exercise maintenance program, whereas the control group (n = 23) received health physical exercise program for 16 sessions over 8 weeks. The data of physical fitness, body compositions, self-efficacy, and health-related quality of life were collected three times for both group: before the intervention, immediately after the intervention, and 8 weeks after the intervention. Analyses were conducted using χ2 test, t test, Fisher's exact test, and repeated measures analysis of variance. RESULTS: Compared to the control group, muscular strength (p = .002), static balance (p = .013), muscular endurance (p = .003), self-efficacy (p < .001), and health-related quality of life (p = .030) were significantly improved in the experimental group. In addition, body fat percentage (p = .005) in this group was significantly decreased after the community capacity building exercise maintenance program. CONCLUSION: Theses results indicated that a community capacity building exercise maintenance program is feasible, and associated with exercise maintenance among frail elderly women.

Novel indazole-based small compounds enhance TRAIL-induced apoptosis by inhibiting the MKK7-TIPRL interaction in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most malignant tumors. Although various treatments, such as surgery and chemotherapy, have been developed, a novel alternative therapeutic approach for HCC therapy is urgently needed. Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) is a promising anti-cancer agent, but many cancer cells are resistant to TRAIL-induced apoptosis. To help overcome TRAIL resistance in HCC cancer cells, we have identified novel chemical compounds that act as TRAIL sensitizers. We first identified the hit compound, TRT-0002, from a chemical library of 6,000 compounds using a previously developed high-throughput enzyme-linked immunosorbent assay (ELISA) screening system, which was based on the interaction of mitogen-activated protein kinase kinase 7 (MKK7) and TOR signaling pathway regulator-like (TIPRL) proteins and a cell viability assay. To increase the efficacy of this TRAIL sensitizer, we synthesized 280 analogs of TRT-0002 and finally identified two lead compounds (TRT-0029 and TRT-0173). Co-treating cultured Huh7 cells with either TRT-0029 or TRT-0173 and TRAIL resulted in TRAIL-induced apoptosis due to the inhibition of the MKK7-TIPRL interaction and subsequent phosphorylation of MKK7 and c-Jun N-terminal kinase (JNK). In vivo, injection of these compounds and TRAIL into HCC xenograft tumors resulted in tumor regression. Taken together, our results suggest that the identified lead compounds serve as TRAIL sensitizers and represent a novel strategy to overcome TRAIL resistance in HCC.

RETRACTED: The Mediating Effect of Social Capital on the Relationship Between Public Health Managers' Transformational Leadership and Public Health Nurses' Organizational Empowerment in Korea Public Health.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). The Editor-in-Chief and ANR editorial board have decided to retract this article because the scientific integrity of the content cannot be guaranteed. The article shows evidence of redundant publication and falsification of instruments. This article was a duplicate of a paper that had already been published in Journal of the Korean Data & Information Science Society Vol 29, No. 3, May 2017. doi 10.7465/jkdi.2017.28.3.585) The identical data collection period, study sample, variables, and instruments between these two papers show strong evidence of plagiarism. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. This article is published based on a master's thesis (Kim YE. The effects of the transformational leadership of managers perceived by public health nurses and their social capital on empowerment [master's thesis]. Dague (Korea): Kyungpook National University; 2016. p. 1-57.) and the author of this dissertation is deleted. Inappropriate use of master's thesis without appropriate disclosure and/or citation was made. The instruments [Multifactor leadership questionnaire (Kim DW. The relationship between transformational leadership and quality of nurses' care Service with nurses' organization citizenship behavior as a moderator. Health Soc Welf Rev. 2011;31(2):206e36. Korean), social capital (Han JW, Woo HY, Ju ES, Lim SH, Han SS. Effects of nurses' social capital on turnover intention: focused on the mediating effects organizational commitment and organizational cynicism. J Korean Acad Nurs. 2013;43(4):517e25. https://doi.org/10.4040/jkan.2013.43.4.517. Korean), and Organizational empowerment (Oh EH, Chung BY. The effect of empowerment on nursing performance, job satisfaction, organizational commitment, and turnover intention in hospital nurses. J Korean Acad Nurs Admin. 2011;17(4):391e401. https://doi.org/10.11111/jkana.2011.17.4.391. Korean.)] used in this article were manipulated. The author admitted scientific misconduct and breach of publication ethics. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Plasma glutamate carboxypeptidase is a negative regulator in liver cancer metastasis.

Tumor metastasis is the leading cause of cancer death. In the metastatic process, EMT is a unique phenotypic change that plays an important role in cell invasion and changes in cell morphology. Despite the clinical significance, the mechanism underlying tumor metastasis is still poorly understood. Here we report a novel mechanism by which secreted plasma glutamate carboxypeptidase(PGCP) negatively involves Wnt/ß-catenin signaling by DKK4 regulation in liver cancer metastasis. Pathway analysis of the RNA sequencing data showed that PGCP knockdown in liver cancer cell lines enriched the functions of cell migration, motility and mesenchymal cell differentiation. Depletion of PGCP promoted cell migration and invasion via activation of Wnt/ß-catenin signaling pathway components such as phospho-LRP6 and ß-catenin. Also, addition of DKK4 antagonized the Wnt/ß-catenin signaling cascade in a thyroxine (T4)-dependent manner. In an in vivo study, metastatic nodules were observed in the lungs of the mice after injection of shPGCP stable cell lines. Our findings suggest that PGCP negatively associates with Wnt/ß-catenin signaling during metastasis. Targeting this regulation may represent a novel and effective therapeutic option for liver cancer by preventing metastatic activity of primary tumor cells.

Novel TRAIL sensitizer Taraxacum officinale F.H. Wigg enhances TRAIL-induced apoptosis in Huh7 cells.

TRAIL (TNF-related apoptosis inducing ligand) is a promising anti-cancer drug target that selectively induces apoptosis in cancer cells. However, many cancer cells are resistant to TRAIL-induced apoptosis. Therefore, reversing TRAIL resistance is an important step for the development of effective TRAIL-based anti-cancer therapies. We previously reported that knockdown of the TOR signaling pathway regulator-like (TIPRL) protein caused TRAIL-induced apoptosis by activation of the MKK7-c-Jun N-terminal Kinase (JNK) pathway through disruption of the MKK7-TIPRL interaction. Here, we identified Taraxacum officinale F.H. Wigg (TO) as a novel TRAIL sensitizer from a set of 500 natural products using an ELISA system and validated its activity by GST pull-down analysis. Furthermore, combination treatment of Huh7 cells with TRAIL and TO resulted in TRAIL-induced apoptosis mediated through inhibition of the MKK7-TIPRL interaction and subsequent activation of MKK7-JNK phosphorylation. Interestingly, HPLC analysis identified chicoric acid as a major component of the TO extract, and combination treatment with chicoric acid and TRAIL induced TRAIL-induced cell apoptosis via JNK activation due to inhibition of the MKK7-TIPRL interaction. Our results suggest that TO plays an important role in TRAIL-induced apoptosis, and further functional studies are warranted to confirm the importance of TO as a novel TRAIL sensitizer for cancer therapy. © 2015 Wiley Periodicals, Inc.

Tussilago farfara L. augments TRAIL-induced apoptosis through MKK7/JNK activation by inhibition of MKK7­TIPRL in human hepatocellular carcinoma cells.

Induction of apoptosis through activation of the TRAIL pathway is considered to be a promising anticancer strategy due to its ability to selectively induce apoptosis in cancer cells. However, the ability of cancer cells to acquire TRAIL resistance has limited the clinical translation of this approach. We previously reported that the TOR signaling pathway regulator-like (TIPRL) protein contributes to the resistance to TRAIL-induced apoptosis by inhibiting the MKK7-c-Jun N-terminal kinase (JNK) pathway via MKK7­TIPRL interaction. In the present study, we identified Tussilago farfara L. (TF) as a novel TRAIL sensitizer among 500 natural products using an ELISA system that specifically detects the MKK7-TIPRL interaction, and we validated candidates by GST-pull down assay. Co-treatment of Huh7 cells with TF and TRAIL induced apoptosis via inhibition of the MKK7-TIPRL interaction and an increase in MKK7/JNK phosphorylation. This is the first report to describe TF as a novel TRAIL sensitizer, unveiling a potentially novel therapeutic strategy in cancer therapy.

Construction and characterization of recombinant Bacillus subtilis JY123 able to transport xylose efficiently.

It has been known that wild type Bacillus subtilis cannot grow rapidly in a minimal medium containing xylose as a sole carbon source because it does not have a xylose-specific transporter. In this study, the arabinose:H(+) symporter, AraE protein from B. subtilis was expressed in B. subtilis 168 in order to transport xylose efficiently. The AraE expression cassette was constructed to contain the xylose-inducible xylA promoter, araE gene and fba terminator, and integrated into the chromosomal amyE gene in B. subtilis 168. Batch cultures in a defined medium with xylose only or a mixture of xylose and glucose showed that expression of AraE led to fast and complete consumption of initially added xylose and hence a considerable increase in cell growth of the recombinant B. subtilis JY123 expressing AraE. Considering the systematic analysis of cell growth, sugar consumption, respiratory quotient and xylulokinase activity, it was certain that AraE protein could transport xylose into B. subtilis efficiently.

Inhibition of MKK7-JNK by the TOR signaling pathway regulator-like protein contributes to resistance of HCC cells to TRAIL-induced apoptosis.

BACKGROUND & AIMS: The TOR signaling pathway regulator-like (TIPRL) protein, the mammalian ortholog of yeast TIP41, was identified in an expression profiling screen for factors that regulate human liver carcinogenesis. We investigated the role of human TIPRL protein in hepatocellular carcinoma (HCC). METHODS: We measured the level of TIPRL in HCC and adjacent nontumor tissues from patients. We used small interfering RNAs and zebrafish to study the function of TIPRL. We used annexin V propidium iodide staining and immunoblot analyses to measure apoptosis and activation of apoptotic signaling pathways. We used confocal microscopy, coimmunoprecipitation, and glutathione-S transferase pull-down analyses to determine interactions among mitogen-activated protein kinase kinase 7 (MKK7 or MAP2K7), TIPRL, and the protein phosphatase type 2A (PP2Ac). We studied the effects of TIPRL in tumor xenografts in mice. RESULTS: Levels of TIPRL were higher in HCC tissues and cell lines than nontumor tissues and primary hepatocytes. Knockdown of tiprl expression in zebrafish led to large amounts of apoptosis throughout the embryos. Incubation of HCC cells, but not primary human hepatocytes, with small interfering RNA against TIPRL (siTIPRL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) caused prolonged activation (phosphorylation) of MKK7 and c-Jun N-terminal kinase (JNK) and led to apoptosis, indicated by cleavage of procaspase-8,-3 and of poly-(adenosine diphosphate-ribose) polymerase. TIPRL bound to MKK7 and PP2Ac and promoted the interaction between MKK7 and PP2Ac. In mice, injection of HCC xenograft tumors with siTIPRL and TRAIL led to tumor apoptosis and regression. CONCLUSIONS: TIPRL is highly up-regulated in human HCC samples and cell lines, compared with noncancerous liver tissues. TIPRL prevents prolonged activation of MKK7 and JNK and TRAIL-induced apoptosis by mediating the interaction between MKK7 and PP2Ac.

TGF-{beta}1 protects against mesangial cell apoptosis via induction of autophagy.

Autophagy can lead to cell death in response to stress, but it can also act as a protective mechanism for cell survival. We show that TGF-ß1 induces autophagy and protects glomerular mesangial cells from undergoing apoptosis during serum deprivation. Serum withdrawal rapidly induced autophagy within 1 h in mouse mesangial cells (MMC) as determined by increased microtubule-associated protein 1 light chain 3 (LC3) levels and punctate distribution of the autophagic vesicle-associated-form LC3-II. We demonstrate that after 1 h there was a time-dependent decrease in LC3 levels that was accompanied by induction of apoptosis, evidenced by increases in cleaved caspase 3. However, treatment with TGF-ß1 resulted in induction of the autophagy protein LC3 while suppressing caspase 3 activation. TGF-ß1 failed to rescue MMC from serum deprivation-induced apoptosis upon knockdown of LC3 by siRNA and in MMC from LC3 null (LC3(-/-)) mice. We show that TGF-ß1 induced autophagy through TAK1 and Akt activation, and inhibition of PI3K-Akt pathway by LY294002 or dominant-negative Akt suppressed LC3 levels and enhanced caspase 3 activation. TGF-ß1 also up-regulated cyclin D1 and E protein levels while down-regulating p27, thus stimulating cell cycle progression. Bafilomycin A1, but not MG132, blocked TGF-ß1 down-regulation of p27, suggesting that p27 levels were regulated through autophagy. Taken together, our data indicate that TGF-ß1 rescues MMC from serum deprivation-induced apoptosis via induction of autophagy through activation of the Akt pathway. The autophagic process may constitute an adaptive mechanism to glomerular injury by inhibiting apoptosis and promoting mesangial cell survival.