Myocardial CKIP-1 Overexpression Protects from Simulated Microgravity-Induced Cardiac Remodeling

Ckip-1 3'UTR alleviates prolonged sleep deprivation induced cardiac dysfunction by activating CaMKK2/AMPK/cTNI pathway

Sleep deprivation (SD) has emerged as a critical concern impacting human health, leading to significant damage to the cardiovascular system. However, the underlying mechanisms are still unclear, and the development of targeted drugs is lagging. Here, we used mice to explore the effects of prolonged SD on cardiac structure and function. Echocardiography analysis revealed that cardiac function was significantly decreased in mice after five weeks of SD. Real-time quantitative PCR (RT-q-PCR) and Masson staining analysis showed that cardiac remodeling marker gene Anp (atrial natriuretic peptide) and fibrosis were increased, Elisa assay of serum showed that the levels of creatine kinase (CK), creatine kinase-MB (CK-MB), ANP, brain natriuretic peptide (BNP) and cardiac troponin T (cTn-T) were increased after SD, suggesting that cardiac remodeling and injury occurred. Transcript sequencing analysis indicated that genes involved in the regulation of calcium signaling pathway, dilated cardiomyopathy, and cardiac muscle contraction were changed after SD. Accordingly, Western blotting analysis demonstrated that the cardiac-contraction associated CaMKK2/AMPK/cTNI pathway was inhibited. Since our preliminary research has confirmed the vital role of Casein Kinase-2 -Interacting Protein-1 (CKIP-1, also known as PLEKHO1) in cardiac remodeling regulation. Here, we found the levels of the 3' untranslated region of Ckip-1 (Ckip-1 3'UTR) decreased, while the coding sequence of Ckip-1 (Ckip-1 CDS) remained unchanged after SD. Significantly, adenovirus-mediated overexpression of Ckip-1 3'UTR alleviated SD-induced cardiac dysfunction and remodeling by activating CaMKK2/AMPK/cTNI pathway, which proposed the therapeutic potential of Ckip-1 3'UTR in treating SD-induced heart disease.

Paeonol can improve hypoxic-induced H9c2 cells injury and ion channel activity by up-regulating the expression of CKIP-1

BACKGROUND

Paeonol is a representative active ingredient of the traditional Chinese medicinal herbs Cortex Moutan, which has a well-established cardioprotective effect on ischemic heart disease. However, there is little evidence of the protective effect of paeonol, and its pharmacological mechanism is also unclear. This study aims to explore the protective effect and mechanism of Paeonol on myocardial infarction rat and hypoxic H9c2 cells.

METHODS

Myocardial ischemia/reperfusion (I/R) was induced by occlusion of the left anterior descending coronary artery for 1 h followed by 3 h of reperfusion, and then gavage with Paeonol for 7 days. H9c2 cells were applied for the in vitro experiments and hypoxia/reoxygenation (H/R) model was established. CKIP-1 expression was evaluated by qPCR and western blot. The expression of genes involved in apoptosis, inflammation and ion channel was measured by western blot. The currents levels of Nav1.5 and Kir2.1 were measured by whole-cell patch-clamp recording.

RESULTS

CKIP-1 expression was decreased in H/R-induced H9c2 cells, which was inversely increased after Paeonol treatment. Paeonol treatment could increase the viability of H/R-induced H9c2 cells and diminish the apoptosis and inflammation of H/R-induced H9c2 cells, while si-CKIP-1 treatment inhibited the phenomena. Moreover, the currents levels of Nav1.5 and Kir2.1 were reduced in H/R-induced H9c2 cells, which were inhibited after Paeonol treatment. Intragastric Paeonol can reduce the ventricular arrhythmias in rats with myocardial infarction.

CONCLUSIONS

The protective effects of Paeonol on myocardial infarction rats and hypoxic H9c2 cells were achieved by up-regulating CKIP-1.

Vascular smooth muscle cell-specific miRNA-214 deficiency alleviates simulated microgravity-induced vascular remodeling

The human cardiovascular system has evolved to accommodate the gravity of Earth. Microgravity during spaceflight has been shown to induce vascular remodeling, leading to a decline in vascular function. The underlying mechanisms are not yet fully understood. Our previous study demonstrated that miR-214 plays a critical role in angiotensin II-induced vascular remodeling by reducing the levels of Smad7 and increasing the phosphorylation of Smad3. However, its role in vascular remodeling evoked by microgravity is not yet known. This study aimed to determine the contribution of miR-214 to the regulation of microgravity-induced vascular remodeling. The results of our study revealed that miR-214 expression was increased in the forebody arteries of both mice and monkeys after simulated microgravity treatment. In vitro, rotation-simulated microgravity-induced VSMC migration, hypertrophy, fibrosis, and inflammation were repressed by miR-214 knockout (KO) in VSMCs. Additionally, miR-214 KO increased the level of Smad7 and decreased the phosphorylation of Smad3, leading to a decrease in downstream gene expression. Furthermore, miR-214 cKO protected against simulated microgravity induced the decline in aorta function and the increase in stiffness. Histological analysis showed that miR-214 cKO inhibited the increases in vascular medial thickness that occurred after simulated microgravity treatment. Altogether, these results demonstrate that miR-214 has potential as a therapeutic target for the treatment of vascular remodeling caused by simulated microgravity.

Biomanufacturing of 3D Tissue Constructs in Microgravity and their Applications in Human Pathophysiological Studies

The growing interest in bioengineering in-vivo-like 3D functional tissues has led to novel approaches to the biomanufacturing process as well as expanded applications for these unique tissue constructs. Microgravity, as seen in spaceflight, is a unique environment that may be beneficial to the tissue-engineering process but cannot be completely replicated on Earth. Additionally, the expense and practical challenges of conducting human and animal research in space make bioengineered microphysiological systems an attractive research model. In this review, published research that exploits real and simulated microgravity to improve the biomanufacturing of a wide range of tissue types as well as those studies that use microphysiological systems, such as organ/tissue chips and multicellular organoids, for modeling human diseases in space are summarized. This review discusses real and simulated microgravity platforms and applications in tissue-engineered microphysiological systems across three topics: 1) application of microgravity to improve the biomanufacturing of tissue constructs, 2) use of tissue constructs fabricated in microgravity as models for human diseases on Earth, and 3) investigating the effects of microgravity on human tissues using biofabricated in vitro models. These current achievements represent important progress in understanding the physiological effects of microgravity and exploiting their advantages for tissue biomanufacturing.

CKIP-1 mediates P. gingivalis-suppressed osteogenic/cementogenic differentiation of periodontal ligament cells partially via p38 signaling pathway

Objectives

Casein kinase 2 interacting protein-1 (CKIP-1) is a versatile player involved in various biological processes. However, whether CKIP-1 mediates the osteogenic/cementogenic differentiation of periodontal ligament cells (PDLCs) under Porphyromonas gingivalis (Pg) stimulation remains unknown.

Material and Methods

The effect of Pg on PDLC differentiation was first verified. CKIP-1 expression in Pg-infected PDLCs or in PDL of apical periodontitis (AP) mice was detected. The changes of CKIP-1 during PDLC differentiation was also determined. PDLC differentiation capacity in CKIP-1 knockout (KO) mice and CKIP-1-silenced PDLCs with or without Pg stimulation were further studied. Inhibitor was finally applied to verify the involvement of p38 signaling pathway in PDLC differentiation.

Results

The suppression effect of Pg on PDLC differentiation was demonstrated. CKIP-1 increased in the PDL of AP mice and Pg-induced PDLCs, and decreased gradually during PDLC differentiation. Increased OSX and RUNX2 expression in PDL were observed in CKIP-1 KO mice. Also, CKIP-1 silencing facilitated and rescued Pg-inhibited PDLC differentiation. Inhibitor for p38 signaling pathway blocked CKIP-1 silencing-facilitated PDLC differentiation.

Conclusions

CKIP-1 mediated the osteogenic/cementogenic differentiation of PDLCs partially through p38 signaling pathway, which may provide evidence for the regeneration of periodontal hard tissues damaged by Pg.

Comprehensive analysis of transcriptomics and metabolomics to understand tail-suspension-induced myocardial injury in rat

Background/Aims

The effect and underlying mechanism of microgravity on myocardium still poorly understood. The present study aims to reveal the effect and underlying mechanism of tail-suspension-induced microgravity on myocardium of rats.

Methods

Tail-suspension was conducted to simulate microgravity in rats. Echocardiography assay was used to detect cardiac function. The cardiac weight index was measured. Hematoxylin and eosin (HE) staining and transmission electron microscopy assay were conducted to observe the structure of the tissues. RNA sequencing and non-targeted metabolomics was employed to obtain transcriptome and metabolic signatures of heart from tail-suspension-induced microgravity and control rats.

Results

Microgravity induced myocardial atrophy and decreased cardiac function in rats. Structure and ultrastructure changes were observed in myocardium of rats stimulated with microgravity. RNA sequencing for protein coding genes was performed and identified a total of 605 genes were differentially expressed in myocardium of rats with tail suspension, with 250 upregulated and 355 downregulated (P < 0.05 and | log2fold change| > 1). A total of 55 differentially expressed metabolites were identified between the two groups (VIP > 1 and P < 0.05) by the metabolic profiles of heart tissues from microgravity groups and control. Several major pathways altered aberrantly at both transcriptional and metabolic levels, including FoxO signaling pathway, Amyotrophic lateral sclerosis, Histidine metabolism, Arginine and proline metabolism.

Conclusion

Microgravity can induce myocardial atrophy and decreases cardiac function in rats and the molecular alterations at the metabolic and transcriptomic levels was observed, which indicated major altered pathways in rats with tail suspension. The differentially expressed genes and metabolites-involved in the pathways maybe potential biomarkers for microgravity-induced myocardial atrophy.

Ckip-1 3′-UTR Attenuates Simulated Microgravity-Induced Cardiac Atrophy

Microgravity prominently affected cardiovascular health, which was the gravity-dependent physical factor. Deep space exploration had been increasing in frequency, but heart function was susceptible to conspicuous damage and cardiac mass declined in weightlessness. Understanding of the etiology of cardiac atrophy exposed to microgravity currently remains limited. The 3′-untranslated region (UTR) of casein kinase-2 interacting protein-1 (Ckip-1) was a pivotal mediator in pressure overload-induced cardiac remodeling. However, the role of Ckip-1 3′-UTR in the heart during microgravity was unknown. We analyzed Ckip-1 mRNA 3′-UTR and coding sequence (CDS) expression levels in ground-based analogs such as mice hindlimb unloading (HU) and rhesus monkey head-down bed rest model. Ckip-1 3′-UTR had transcribed levels in the opposite change trend with cognate CDS expression in the hearts. We then subjected wild-type (WT) mice and cardiac-specific Ckip-1 3′-UTR-overexpressing mice to hindlimb unloading for 28 days. Our results uncovered that Ckip-1 3′-UTR remarkably attenuated cardiac dysfunction and mass loss in simulated microgravity environments. Mechanistically, Ckip-1 3′-UTR inhibited lipid accumulation and elevated fatty acid oxidation-related gene expression in the hearts through targeting calcium/calmodulin-dependent kinase 2 (CaMKK2) and activation of the AMPK-PPARα-CPT1b signaling pathway. These findings demonstrated Ckip-1 3′-UTR was an important regulator in atrophic heart growth after simulated microgravity.

WWP1 Deficiency Alleviates Cardiac Remodeling Induced by Simulated Microgravity

Cardiac muscle is extremely sensitive to changes in loading conditions; the microgravity during space flight can cause cardiac remodeling and function decline. At present, the mechanism of microgravity-induced cardiac remodeling remains to be revealed. WW domain-containing E3 ubiquitin protein ligase 1 (WWP1) is an important activator of pressure overload-induced cardiac remodeling by stabilizing disheveled segment polarity proteins 2 (DVL2) and activating the calcium-calmodulin-dependent protein kinase II (CaMKII)/histone deacetylase 4 (HDAC4)/myocyte-specific enhancer factor 2C (MEF2C) axis. However, the role of WWP1 in cardiac remodeling induced by microgravity is unknown. The purpose of this study was to determine whether WWP1 was also involved in the regulation of cardiac remodeling caused by microgravity. Firstly, we detected the expression of WWP1 and DVL2 in the heart from mice and monkeys after simulated microgravity using western blotting and immunohistochemistry. Secondly, WWP1 knockout (KO) and wild-type (WT) mice were subjected to tail suspension (TS) to simulate microgravity effect. We assessed the cardiac remodeling in morphology and function through a histological analysis and echocardiography. Finally, we detected the phosphorylation levels of CaMKII and HDAC4 in the hearts from WT and WWP1 KO mice after TS. The results revealed the increased expression of WWP1 and DVL2 in the hearts both from mice and monkeys after simulated microgravity. WWP1 deficiency alleviated simulated microgravity-induced cardiac atrophy and function decline. The histological analysis demonstrated WWP1 KO inhibited the decreases in the size of individual cardiomyocytes of mice after tail suspension. WWP1 KO can inhibit the activation of the DVL2/CaMKII/HDAC4 pathway in the hearts of mice induced by simulated microgravity. These results demonstrated WWP1 as a potential therapeutic target for cardiac remodeling and function decline induced by simulated microgravity.

3' untranslated region of Ckip-1 inhibits cardiac hypertrophy independently of its cognate protein

AIMS

3' untranslated region (3' UTR) of mRNA is more conserved than other non-coding sequences in vertebrate genomes, and its sequence space has substantially expanded during the evolution of higher organisms, which substantiates their significance in biological regulation. However, the independent role of 3' UTR in cardiovascular disease was largely unknown.

METHODS AND RESULTS

Using bioinformatics, RNA fluorescent in situ hybridization and quantitative real-time polymerase chain reaction, we found that 3' UTR and coding sequence regions of Ckip-1 mRNA exhibited diverse expression and localization in cardiomyocytes. We generated cardiac-specific Ckip-1 3' UTR overexpression mice under wild type and casein kinase 2 interacting protein-1 (CKIP-1) knockout background. Cardiac remodelling was assessed by histological, echocardiography, and molecular analyses at 4 weeks after transverse aortic constriction (TAC) surgery. The results showed that cardiac Ckip-1 3' UTR significantly inhibited TAC-induced cardiac hypertrophy independent of CKIP-1 protein. To determine the mechanism of Ckip-1 3' UTR in cardiac hypertrophy, we performed transcriptome and metabolomics analyses, RNA immunoprecipitation, biotin-based RNA pull-down, and reporter gene assays. We found that Ckip-1 3' UTR promoted fatty acid metabolism through AMPK-PPARα-CPT1b axis, leading to its protection against pathological cardiac hypertrophy. Moreover, Ckip-1 3' UTR RNA therapy using adeno-associated virus obviously alleviates cardiac hypertrophy and improves heart function.

CONCLUSIONS

These findings disclose that Ckip-1 3' UTR inhibits cardiac hypertrophy independently of its cognate protein. Ckip-1 3' UTR is an effective RNA-based therapy tool for treating cardiac hypertrophy and heart failure.

Casein Kinase-2 Interacting Protein-1 Regulates Physiological Cardiac Hypertrophy via Inhibition of Histone Deacetylase 4 Phosphorylation

Different kinds of mechanical stimuli acting on the heart lead to different myocardial phenotypes. Physiological stress, such as exercise, leads to adaptive cardiac hypertrophy, which is characterized by a normal cardiac structure and improved cardiac function. Pathological stress, such as sustained cardiac pressure overload, causes maladaptive cardiac remodeling and, eventually, heart failure. Casein kinase-2 interacting protein-1 (CKIP-1) is an important regulator of pathological cardiac remodeling. However, the role of CKIP-1 in physiological cardiac hypertrophy is unknown. We subjected wild-type (WT) mice to a swimming exercise program for 21 days, which caused an increase in myocardial CKIP-1 protein and mRNA expression. We then subjected CKIP-1 knockout (KO) mice and myocardial-specific CKIP-1-overexpressing mice to the 21-day swimming exercise program. Histological and echocardiography analyses revealed that CKIP-1 KO mice underwent pathological cardiac remodeling after swimming, whereas the CKIP-1-overexpressing mice had a similar cardiac phenotype to the WT controls. Histone deacetylase 4 (HDAC4) is a key molecule in the signaling cascade associated with pathological hypertrophy; the phosphorylation levels of HDAC4 were markedly higher in CKIP-1 KO mouse hearts after the swimming exercise program. The phosphorylation levels of HDAC4 did not change after swimming in the hearts of CKIP-1-overexpressing or WT mice. Our results indicate that swimming, a mechanical stress that leads to physiological hypertrophy, triggers pathological cardiac remodeling in CKIP-1 KO mice. CKIP-1 is necessary for physiological cardiac hypertrophy in vivo, and for modulating the phosphorylation level of HDAC4 after physiological stress. Genetically engineering CKIP-1 expression affected heart health in response to exercise.

Spaceflight Induced Disorders: Potential Nutritional Countermeasures

Space travel is an extreme experience even for the astronaut who has received extensive basic training in various fields, from aeronautics to engineering, from medicine to physics and biology. Microgravity puts a strain on members of space crews, both physically and mentally: short-term or long-term travel in orbit the International Space Station may have serious repercussions on the human body, which may undergo physiological changes affecting almost all organs and systems, particularly at the muscular, cardiovascular and bone compartments. This review aims to highlight recent studies describing damages of human body induced by the space environment for microgravity, and radiation. All novel conditions, to ally unknown to the Darwinian selection strategies on Earth, to which we should add the psychological stress that astronauts suffer due to the inevitable forced cohabitation in claustrophobic environments, the deprivation from their affections and the need to adapt to a new lifestyle with molecular changes due to the confinement. In this context, significant nutritional deficiencies with consequent molecular mechanism changes in the cells that induce to the onset of physiological and cognitive impairment have been considered.

Casein Kinase 2-Interacting Protein-1 Alleviates High Glucose-Reduced Autophagy, Oxidative Stress, and Apoptosis in Retinal Pigment Epithelial Cells via Activating the p62/KEAP1/NRF2 Signaling Pathway

Background

Casein kinase 2-interacting protein-1 (CKIP-1) has been proved to be associated with complications of diabetes. Diabetic retinopathy is a main diabetic complication which usually leads to blindness. The current study aims to investigate the role of CKIP-1 in high glucose-treated retinal pigment epithelial (RPE) cells which is a component of blood-retinal barriers.

Methods

The RPE cells, ARPE-19, are treated with high glucose to mimic the diabetic stimulation. CKIP-1 was overexpressed in ARPE-19 cells to evaluate its effects on autophagy, oxidative stress, and apoptosis induced by high glucose treatment, using Western blot, immunofluorescence, and flow cytometry assays, respectively.

Results

CKIP-1 was expressed at a lower level in high glucose-treated cells than in normal glucose cells. Overexpression of CKIP-1 enhanced the Nrf2 translocation to the nucleus. Furthermore, high glucose-induced autophagy, oxidative stress, and apoptosis were inhibited after overexpression of CKIP-1. Also, CKIP-1 regulates the p62/Keap1/Nrf2 signaling, which might be the potential mechanism in this model.

Conclusion

In conclusion, CKIP-1 may be a potential therapeutic target that protects RPE cells from injury and subsequent diabetic retinopathy induced by high glucose.

Alteration of calcium signalling in cardiomyocyte induced by simulated microgravity and hypergravity

Objectives

Cardiac Ca²⁺ signalling plays an essential role in regulating excitation‐contraction coupling and cardiac remodelling. However, the response of cardiomyocytes to simulated microgravity and hypergravity and the effects on Ca²⁺ signalling remain unknown. Here, we elucidate the mechanisms underlying the proliferation and remodelling of HL‐1 cardiomyocytes subjected to rotation‐simulated microgravity and 4G hypergravity.

Materials and Methods

The cardiomyocyte cell line HL‐1 was used in this study. A clinostat and centrifuge were used to study the effects of microgravity and hypergravity, respectively, on cells. Calcium signalling was detected with laser scanning confocal microscopy. Protein and mRNA levels were detected by Western blotting and real‐time PCR, respectively. Wheat germ agglutinin (WGA) staining was used to analyse cell size.

Results

Our data showed that spontaneous calcium oscillations and cytosolic calcium concentration are both increased in HL‐1 cells after simulated microgravity and 4G hypergravity. Increased cytosolic calcium leads to activation of calmodulin‐dependent protein kinase II/histone deacetylase 4 (CaMKII/HDAC4) signalling and upregulation of the foetal genes ANP and BNP, indicating cardiac remodelling. WGA staining indicated that cell size was decreased following rotation‐simulated microgravity and increased following 4G hypergravity. Moreover, HL‐1 cell proliferation was increased significantly under hypergravity but not rotation‐simulated microgravity.

Conclusions

Our study demonstrates for the first time that Ca²⁺/CaMKII/HDAC4 signalling plays a pivotal role in myocardial remodelling under rotation‐simulated microgravity and hypergravity.

Physiological functions of CKIP-1: From molecular mechanisms to therapy implications

The casein kinase 2 interacting protein-1 (CKIP-1, also known as PLEKHO1) is initially identified as a specific CK2α subunit-interacting protein. Subsequently, various proteins, including CPα, PAK1, Arp2/3, HDAC1, c-Jun, ATM, Smurf1, Rpt6, Akt, IFP35, TRAF6, REGγ and CARMA1, were reported to interact with CKIP-1. Owing to the great diversity of interacted proteins, CKIP-1 exhibits multiple biologic functions in cell morphology, cell differentiation and cell apoptosis. Besides, these functions are subcellular localization, cell type, and regulatory signaling dependent. CKIP-1 is involved in biological processes consisting of bone formation, tumorigenesis and immune regulation. Importantly, deregulation of CKIP-1 results in osteoporosis, tumor, and atherosclerosis. In this review, we introduce the molecular functions, biological processes and promising of therapeutic strategies. Through summarizing the intrinsic mechanisms, we expect to open new therapeutic avenues for CKIP-1.

Casein Kinase 2 Interacting Protein-1 Suppresses Glioma Cell Proliferation via Regulating the AKT/GSK3β/β-Catenin Pathway

Objective

Casein kinase 2 interacting protein-1 (CKIP-1) has exhibited multiple functions in regulating cell proliferation, apoptosis, differentiation, and cytoskeleton. CKIP-1 also plays an important role as a critical regulator in tumorigenesis. The aim of this study is to further examine the function of CKIP-1 in glioma cells.

Methods

The expression level of CKIP-1 protein was determined in gliomas tissues and cell lines by immunohistochemistry stain and western blotting while the association of CKIP-1 expression with prognosis was analyzed by Kaplan-Meier method and compared by log-rank test. CKIP-1 was overexpressed or silenced in gliomas cell lines. CCK-8, colony formation assay, and BrdU incorporation assay were used to determine cell proliferation and DNA synthesis. Cell cycle and apoptosis rate were determined with fluorescence-activated cell sorting (FACS) method. Then, expression of key members in AKT/GSK3β/β-catenin pathway was detected by western blot analysis.

Results

In the present study, we reported new evidence that CKIP-1 was reversely associated with the proliferation of glioma cells and survival in glioma patients. Additionally, the overexpressed CKIP-1 significantly inhibited glioma cell proliferation. Further experiments revealed that CKIP-1 functioned through its antiproliferative and proapoptotic activity in glioma cells. Importantly, mechanistic investigations suggested that CKIP-1 sharply suppressed the activity of AKT by inhibiting the phosphorylation, markedly downregulated the phosphorylated GSK3β at Ser9, and promoted β-catenin degradation.

Conclusions

Overall, our results provided new insights into the clinical significance and molecular mechanism of CKIP-1 in glioma, which indicated CKIP1 might function as a therapeutic target for clinical treatment of glioma.