Human tumor necrosis factor alpha-induced protein eight-like 1 exhibited potent anti-tumor effect through modulation of proliferation, survival, migration and invasion of lung cancer cells

The emerging role of human papillomavirus in lung cancer

Lung cancer stands as one of the most lethal diseases and is the foremost cause of cancer-related mortalities worldwide. The pathophysiology of lung cancer is multifaceted, and it includes multiple cell signaling pathways and other complex factors such as oxidative stress and genetics. The association of HPV with lung carcinogenesis was first proposed in 1979, and since then, scientists worldwide have been putting forward several hypotheses to establish a relationship between this virus and lung cancer. Although studies have reported the presence of HPV in lung cancer, the exact mechanism of entry and the route of transmission have not been elucidated clearly till date. Numerous studies across the globe have detected differentially expressed HPV oncoproteins in lung cancer patients and found their association with the critical cell signaling pathways that leads to the development and progression of lung cancer. Many reports have also provided evidence stating the involvement of HPV in determining the survival status of lung cancer patients. The present review recapitulates the studies evincing the association of HPV and lung cancer, its route of transmission and mechanism of action; the detection of the virus and treatment opportunities for HPV-positive lung cancer; and the severity associated with this disease. Therefore, this will provide an explicit idea and would help to develop preventive measures and specific as well as effective treatment for HPV-associated lung carcinogenesis.

High glucose-induced injury in human umbilical vein endothelial cells is alleviated by vitamin D supplementation through downregulation of TIPE1

BACKGROUND

Diabetes mellitus (DM) and its associated vascular complications have become a worldwide health concern. The effects and mechanism of vitamin D supplementation on endothelial function under high glucose condition remain elusive.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with 35 mM glucose, then 100 nM vitamin D were added. Transwell migration assay, CCK-8, immunofluorescence, flow cytometry, autophagy flux and transmission electric microscope were performed.

RESULTS

Vitamin D reduced apoptosis, promoted migration and enhanced viability of HUVECs, decreased TIPE1 (Tumor necrosis factor-α-induced protein 8-like 1) under high glucose conditions. Overexpression of TIPE1 reverses the effects of vitamin D by increasing ROS production, inflammation, cell apoptosis, and suppressing autophagy, cell migration and viability. And vitamin D negatively correlated with TIPE1 mRNA level in DM patients.

CONCLUSIONS

Vitamin D reverses the harmful effects of high glucose on HUVECs by reducing TIPE1 expression. And vitamin D supplementation could help to alleviate high glucose-induced injury in type 2 diabetes mellitus patients with microvascular complications.

Epithelial TIPE1 Protein Guards against Colitis by Inhibiting TNF-α-Mediated Inflammation

Intestinal epithelial cells (IECs) at the internal/external interface orchestrate the mucosal immune response, and IEC dysfunction has been linked to multiple inflammatory diseases, including inflammatory bowel disease. In this study, we found that a member of the TNF-α-induced protein 8 (TNFAIP8 or TIPE) family called TIPE1 is indispensable for maintaining epithelial cell barrier integrity and homeostasis under inflammatory conditions. TIPE1-deficient mice, or chimeric mice that were deficient in TIPE1 in their nonhematopoietic cells, were more sensitive to dextran sulfate sodium-induced experimental colitis; however, TIPE1 deficiency had no impact on the development of inflammation-associated and sporadic colorectal cancers. Mechanistically, TIPE1 prevented experimental colitis through modulation of TNF-α-dependent inflammatory response in IECs. Importantly, genetic deletion of both TIPE1 and its related protein TNFAIP8 in mice led to the development of spontaneous chronic colitis, indicating that both of these two TIPE family members play crucial roles in maintaining intestinal homeostasis. Collectively, our findings highlight an important mechanism by which TIPE family proteins maintain intestinal homeostasis and prevent inflammatory disorders in the gut.

Structural insight into TIPE1 functioning as a lipid transfer protein

As a member of the tumor necrosis factor-α-induced protein 8 (TNFAIP8/TIPE) family, TIPE1 has been found to be associated with many cellular signaling pathways in regulating apoptosis, autophagy, and tumorigenesis. However, the position of TIPE1 in the signaling network remains elusive. Here we present the crystal structure of zebrafish TIPE1 in complex with phosphatidylethanolamine (PE) at a resolution of 1.38 Å. By comparison with structures of other three TIPE family proteins, a universal phospholipid-binding mode was proposed. Namely, the hydrophobic cavity binds to fatty acid tails, while 'X-R-R' triad nearby the entrance of cavity recognizes the phosphate group head. Using molecular dynamics (MD) simulations, we further elaborated the mechanism of how the lysine-rich N-terminal domain assisting TIPE1 to favorably bind to phosphatidylinositol (PI). Beside small molecule substrate, we identified Gαi3 as a direct-binding partner of TIPE1 using GST pull-down assay and size-exclusion chromatography. Analyses of key-residue mutations and predicted complex structure revealed that the binding mode of TIPE1 to Gαi3 could be non-canonical. In summary, our findings narrowed down TIPE1's position in Gαi3-related and PI-inducing signaling pathways.Communicated by Ramaswamy H. Sarma.

Targeting Autophagy Using Long Non-Coding RNAs (LncRNAs): New Landscapes in the Arena of Cancer Therapeutics

Cancer has become a global health hazard accounting for 10 million deaths in the year 2020. Although different treatment approaches have increased patient overall survival, treatment for advanced stages still suffers from poor clinical outcomes. The ever-increasing prevalence of cancer has led to a reanalysis of cellular and molecular events in the hope to identify and develop a cure for this multigenic disease. Autophagy, an evolutionary conserved catabolic process, eliminates protein aggregates and damaged organelles to maintain cellular homeostasis. Accumulating evidence has implicated the deregulation of autophagic pathways to be associated with various hallmarks of cancer. Autophagy exhibits both tumor-promoting and suppressive effects based on the tumor stage and grades. Majorly, it maintains the cancer microenvironment homeostasis by promoting viability and nutrient recycling under hypoxic and nutrient-deprived conditions. Recent investigations have discovered long non-coding RNAs (lncRNAs) as master regulators of autophagic gene expression. lncRNAs, by sequestering autophagy-related microRNAs, have been known to modulate various hallmarks of cancer, such as survival, proliferation, EMT, migration, invasion, angiogenesis, and metastasis. This review delineates the mechanistic role of various lncRNAs involved in modulating autophagy and their related proteins in different cancers.

Molecular cloning, characterization, and expression analysis of TIPE1 in chicken (Gallus gallus): Its applications in fatty liver hemorrhagic syndrome

Tumor necrosis factor-α-induced protein eight like 1 (TIPE1) plays important role in autophagy, immunity, and lipid metabolism. The potential role of TIPE1 in fatty liver hemorrhage syndrome (FLHS) is elusory. In the present study, the full-length coding sequence of TIPE1 was cloned, and the polyclonal antibody of TIPE1 was produced by the recombinant TIPE1 protein. The bioinformatic analysis showed that the chicken TIPE1 protein, which was predicted to be a hydrophobic and non-transmembrane protein without signal peptide was highly different from that of mammals. Furthermore, proceeded by using TIPE1 polyclonal antibody, the tissue distribution analysis showed that TIPE1 protein is ubiquitously expressed in various tissues in adult hens and chicks, with its level being higher in the liver and, spleen, moderate in intestinal, brain, and heart. Besides, immunohistochemistry and immunofluorescence observation demonstrated that TIPE1 mainly existed in the cytoplasm in liver, duodenum, and cecum cell. Notably, the TIPE1 expressions were significantly decreased in laying hens suffering from FLHS. Collectively, these results showed that the chicken TIPE1 polyclonal antibody was successfully prepared and further used to analyze the expression profiles of chicken. And the expression of TIPE1 was reduced in FLHS which provided the foundation for further investigation in FLHS.

Upregulation of TIPE1 in tubular epithelial cell aggravates diabetic nephropathy by disrupting PHB2 mediated mitophagy

Renal tubular epithelial cells (RTECs) are one of the most mitochondria-rich cell types, and are thus vulnerable to mitochondrial dysregulation, which is defined as a pivotal event in tubular damage in diabetic nephropathy (DN). However, the underlying mechanisms remain largely unknown. Here, we investigated the role and mechanisms of tumor necrosis factor alpha-induced protein 8-like 1 (TNFAIP8L1/TIPE1) in high glucose (HG)-induced mitochondrial dysfunction in RTECs and DN progression. TIPE1 expression was predominantly upregulated in RTECs in patients with DN and mice with streptozotocin (STZ)-induced DN. Conditional knockout of Tipe1 in RTECs significantly decreased the urine protein creatinine ratio, renal tubular damage, epithelial-mesenchymal transition, and interstitial fibrosis in STZ-induced mice. RNA sequencing revealed that citrate cycle-related genes were positively enriched in the renal tissues of RTEC-specific Tipe1 knockout mice. Tipe1 deficiency upregulated ATP levels, mitochondrial membrane potential, and respiration rate, but downregulated mitochondrial ROS levels in RTECs. Furthermore, Tipe1 ablation led to enhanced mitophagy in RTECs, indicative of increased LC3II, PINK1, and Parkin expression, but decreased p62 expression in mitochondria. Mechanistically, mass spectrometry screening and co-immunoprecipitation assays revealed the interaction of TIPE1 with prohibitin 2 (PHB2), a crucial mitophagy receptor. Intriguingly, TIPE1 promoted the ubiquitination and proteasomal degradation of PHB2. Subsequently, PHB2 knockdown almost abrogated the improvement of Tipe1 loss on HG-induced tubular cell mitophagy and damage. Thus, TIPE1 disrupts mitochondrial homeostasis in RTECs and promotes tubular damage by destabilizing PHB2 under HG conditions. Hence, TIPE1 may act as a potential therapeutic target to prevent DN progression.

•

TIPE1 is highly expressed in RTECs of DN.

•

TIPE1 aggravates diabetic renal injury and fibrosis.

•

TIPE1 disrupts the mitochondria homeostasis of RTECs by inhibiting mitophagy.

•

TIPE1 interacts with and promotes the proteasomal degradation of PHB2.

Loss of TIPE3 reduced the proliferation, survival and migration of lung cancer cells through inactivation of Akt/mTOR, NF-κB, STAT-3 signaling cascade

Lung cancer is the foremost cause of cancer related mortality among men and one of the most fatal cancers among women. Notably, the 5-year survival rate of lung cancer is very less; 5% in developing countries. This low survival rate can be attributed to factors like late stage diagnosis, rapid postoperative recurrences in the patients undergoing treatment and development of chemoresistance against different agents used for treating lung cancer. Therefore, in this study we evaluated the potential of a recently identified protein namely TIPE3 which is known as a transfer protein of lipid second messengers as a lung cancer biomarker. TIPE3 was found to be significantly upregulated in lung cancer tissues indicating its role in the positive regulation of lung cancer. Supporting this finding, knockout of TIPE3 was also found to reduce the proliferation, survival and migration of lung cancer cells and arrested the G2 phase of cell cycle through inactivation of Akt/mTOR, NF-κB, STAT-3 signaling. It is well evinced that tobacco is the major risk factor of lung cancer which affects both males and females. Therefore, this study also evaluated the involvement of TIPE3 in tobacco mediated lung carcinogenesis. Notably, this study shows for the first time that TIPE3 positively regulates tobacco induced proliferation, survival and migration of lung cancer through modulation of Akt/mTOR signaling. Thus, TIPE3 plays critical role in the pathogenesis of lung cancer and hence it can be specifically targeted to develop novel therapeutic strategies.