Cardiac cAMP-PKA Signaling Compartmentalization in Myocardial Infarction

Orai1/STIMs modulators in pulmonary vascular diseases

Calcium (Ca2+) is a secondary messenger that regulates various cellular processes. However, Ca2+ mishandling could lead to pathological conditions. Orai1 is a Ca2+channel contributing to the store-operated calcium entry (SOCE) and plays a critical role in Ca2+ homeostasis in several cell types. Dysregulation of Orai1 contributed to severe combined immune deficiency syndrome, some cancers, pulmonary arterial hypertension (PAH), and other cardiorespiratory diseases. During its activation process, Orai1 is mainly regulated by stromal interacting molecule (STIM) proteins, especially STIM1; however, many other regulatory partners have also been recently described. Increasing knowledge about these regulatory partners provides a better view of the downstream signalling pathways of SOCE and offers an excellent opportunity to decipher Orai1 dysregulation in these diseases. These proteins participate in other cellular functions, making them attractive therapeutic targets. This review mainly focuses on Orai1 regulatory partners in the physiological and pathological conditions of the pulmonary circulation and inflammation.

AKAP12 Upregulation Associates With PDE8A to Accelerate Cardiac Dysfunction

BACKGROUND

In heart failure, signaling downstream the β2-adrenergic receptor is critical. Sympathetic stimulation of β2-adrenergic receptor alters cAMP (cyclic adenosine 3',5'-monophosphate) and triggers PKA (protein kinase A)-dependent phosphorylation of proteins that regulate cardiac function. cAMP levels are regulated in part by PDEs (phosphodiesterases). Several AKAPs (A kinase anchoring proteins) regulate cardiac function and are proposed as targets for precise pharmacology. AKAP12 is expressed in the heart and has been reported to directly bind β2-adrenergic receptor, PKA, and PDE4D. However, its roles in cardiac function are unclear.

METHODS

cAMP accumulation in real time downstream of the β2-adrenergic receptor was detected for 60 minutes in live cells using the luciferase-based biosensor (GloSensor) in AC16 human-derived cardiomyocyte cell lines overexpressing AKAP12 versus controls. Cardiomyocyte intracellular calcium and contractility were studied in adult primary cardiomyocytes from male and female mice overexpressing cardiac AKAP12 (AKAP12OX) and wild-type littermates post acute treatment with 100-nM isoproterenol (ISO). Systolic cardiac function was assessed in mice after 14 days of subcutaneous ISO administration (60 mg/kg per day). AKAP12 gene and protein expression levels were evaluated in left ventricular samples from patients with end-stage heart failure.

RESULTS

AKAP12 upregulation significantly reduced total intracellular cAMP levels in AC16 cells through PDE8. Adult primary cardiomyocytes from AKAP12OX mice had significantly reduced contractility and impaired calcium handling in response to ISO, which was reversed in the presence of the selective PDE8 inhibitor (PF-04957325). AKAP12OX mice had deteriorated systolic cardiac function and enlarged left ventricles. Patients with end-stage heart failure had upregulated gene and protein levels of AKAP12.

CONCLUSIONS

AKAP12 upregulation in cardiac tissue is associated with accelerated cardiac dysfunction through the AKAP12-PDE8 axis.

Adenylyl cyclase isoforms 5 and 6 in the cardiovascular system: complex regulation and divergent roles

Adenylyl cyclases (ACs) are crucial effector enzymes that transduce divergent signals from upstream receptor pathways and are responsible for catalyzing the conversion of ATP to cAMP. The ten AC isoforms are categorized into four main groups; the class III or calcium-inhibited family of ACs comprises AC5 and AC6. These enzymes are very closely related in structure and have a paucity of selective activators or inhibitors, making it difficult to distinguish them experimentally. AC5 and AC6 are highly expressed in the heart and vasculature, as well as the spinal cord and brain; AC6 is also abundant in the lungs, kidney, and liver. However, while AC5 and AC6 have similar expression patterns with some redundant functions, they have distinct physiological roles due to differing regulation and cAMP signaling compartmentation. AC5 is critical in cardiac and vascular function; AC6 is a key effector of vasodilatory pathways in vascular myocytes and is enriched in fetal/neonatal tissues. Expression of both AC5 and AC6 decreases in heart failure; however, AC5 disruption is cardio-protective, while overexpression of AC6 rescues cardiac function in cardiac injury. This is a comprehensive review of the complex regulation of AC5 and AC6 in the cardiovascular system, highlighting overexpression and knockout studies as well as transgenic models illuminating each enzyme and focusing on post-translational modifications that regulate their cellular localization and biological functions. We also describe pharmacological challenges in the design of isoform-selective activators or inhibitors for AC5 and AC6, which may be relevant to developing new therapeutic approaches for several cardiovascular diseases.

Exploring Cardiac Exosomal RNAs of Acute Myocardial Infarction

BACKGROUND

Myocardial infarction (MI), often a frequent symptom of coronary artery disease (CAD), is a leading cause of death and disability worldwide. Acute myocardial infarction (AMI), a major form of cardiovascular disease, necessitates a deep understanding of its complex pathophysiology to develop innovative therapeutic strategies. Exosomal RNAs (exoRNA), particularly microRNAs (miRNAs) within cardiac tissues, play a critical role in intercellular communication and pathophysiological processes of AMI.

METHODS

This study aimed to delineate the exoRNA landscape, focusing especially on miRNAs in animal models using high-throughput sequencing. The approach included sequencing analysis to identify significant miRNAs in AMI, followed by validation of the functions of selected miRNAs through in vitro studies involving primary cardiomyocytes and fibroblasts.

RESULTS

Numerous differentially expressed miRNAs in AMI were identified using five mice per group. The functions of 20 selected miRNAs were validated through in vitro studies with primary cardiomyocytes and fibroblasts.

CONCLUSIONS

This research enhances understanding of post-AMI molecular changes in cardiac tissues and investigates the potential of exoRNAs as biomarkers or therapeutic targets. These findings offer new insights into the molecular mechanisms of AMIs, paving the way for RNA-based diagnostics and therapeutics and therapies and contributing to the advancement of cardiovascular medicine.

Integrated omics analysis of coronary artery calcifications and myocardial infarction: the Framingham Heart Study

Gene function can be described using various measures. We integrated association studies of three types of omics data to provide insights into the pathophysiology of subclinical coronary disease and myocardial infarction (MI). Using multivariable regression models, we associated: (1) single nucleotide polymorphism, (2) DNA methylation, and (3) gene expression with coronary artery calcification (CAC) scores and MI. Among 3106 participants of the Framingham Heart Study, 65 (2.1%) had prevalent MI and 60 (1.9%) had incident MI, median CAC value was 67.8 [IQR 10.8, 274.9], and 1403 (45.2%) had CAC scores > 0 (prevalent CAC). Prevalent CAC was associated with AHRR (linked to smoking) and EXOC3 (affecting platelet function and promoting hemostasis). CAC score was associated with VWA1 (extracellular matrix protein associated with cartilage structure in endomysium). For prevalent MI we identified FYTTD1 (down-regulated in familial hypercholesterolemia) and PINK1 (linked to cardiac tissue homeostasis and ischemia-reperfusion injury). Incident MI was associated with IRX3 (enhancing browning of white adipose tissue) and STXBP3 (controlling trafficking of glucose transporter type 4 to plasma). Using an integrative trans-omics approach, we identified both putatively novel and known candidate genes associated with CAC and MI. Replication of findings is warranted.

Integrative Proteomic Analysis Reveals the Cytoskeleton Regulation and Mitophagy Difference Between Ischemic Cardiomyopathy and Dilated Cardiomyopathy

Ischemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM) are the two primary etiologies of end-stage heart failure. However, there remains a dearth of comprehensive understanding the global perspective and the dynamics of the proteome and phosphoproteome in ICM and DCM, which hinders the profound comprehension of pivotal biological characteristics as well as differences in signal transduction activation mechanisms between these two major types of heart failure. We conducted high-throughput quantification proteomics and phosphoproteomics analysis of clinical heart tissues with ICM or DCM, which provided us the system-wide molecular insights into pathogenesis of clinical heart failure in both ICM and DCM. Both protein and phosphorylation expression levels exhibit distinct separation between heart failure and normal control heart tissues, highlighting the prominent characteristics of ICM and DCM. By integrating with omics results, Western blots, phosphosite-specific mutation, chemical intervention, and immunofluorescence validation, we found a significant activation of the PRKACA-GSK3β signaling pathway in ICM. This signaling pathway influenced remolding of the microtubule network and regulated the critical actin filaments in cardiac construction. Additionally, DCM exhibited significantly elevated mitochondria energy supply injury compared to ICM, which induced the ROCK1-vimentin signaling pathway activation and promoted mitophagy. Our study not only delineated the major distinguishing features between ICM and DCM but also revealed the crucial discrepancy in the mechanisms between ICM and DCM. This study facilitates a more profound comprehension of pathophysiologic heterogeneity between ICM and DCM and provides a novel perspective to assist in the discovery of potential therapeutic targets for different types of heart failure.

Integrative analysis identifies AKAP8L as an immunological and prognostic biomarker of pan-cancer

A-kinase anchoring protein 8L (AKAP8L) belong to the A-kinase anchoring protein (AKAP) family. Recent studies have proved that AKAP8L is associated with the progression of various tumors. To establish a more complete understanding of the significance of AKAP8L across various types of cancers, we conducted a detailed analysis of multiple histological datasets, including the level of gene expression in pancancer, biological function, molecular characteristics, as well as the diagnostic and prognostic value of AKAP8L in pancancer. Furthermore, we focused on renal clear cell carcinoma (KIRC), and of explored the correlation of AKAP8L with clinical characteristics, prognosis of distinct patient subsets, co-expression genes and differentially expressed genes (DEG). We also performed the immunohistochemical staining and semi-quantitative verification of the monoclonal antibody established by AKAP8L. Our findings indicate that AKAP8L expression varied significantly not only across most cancer types, but also across different cancer molecules and immune subtypes. In addition, the robust ability to accurately predict cancer and its strong correlation with the prognosis of cancer strongly suggest that AKAP8L may be a potential biomarker for cancer diagnosis and prognosis. Furthermore, the high expression levels of AKAP8L were related to the worse overall survival (OS), disease-specific survival (DSS) as well as progression-free interval (PFI) of KIRC with statistical significance, especially among distinct clinical subgroups of KIRC. To sum up, AKAP8L has the potential to serve as a critical molecular biomarker for the diagnosis and prognosis of pancancer, an independent prognostic risk factor of KIRC, and a novel molecular target for cancer therapies.

Stress granule activation attenuates lipopolysaccharide-induced cardiomyocyte dysfunction

BACKGROUND

Sepsis is the leading cause of death in intensive care units. Sepsis-induced myocardial dysfunction, one of the most serious complications of sepsis, is associated with higher mortality rates. As the pathogenesis of sepsis-induced cardiomyopathy has not been fully elucidated, there is no specific therapeutic approach. Stress granules (SG) are cytoplasmic membrane-less compartments that form in response to cellular stress and play important roles in various cell signaling pathways. The role of SG in sepsis-induced myocardial dysfunction has not been determined. Therefore, this study aimed to determine the effects of SG activation in septic cardiomyocytes (CMs).

METHODS

Neonatal CMs were treated with lipopolysaccharide (LPS). SG activation was visualized by immunofluorescence staining to detect the co-localization of GTPase-activating protein SH3 domain binding protein 1 (G3BP1) and T cell-restricted intracellular antigen 1 (TIA-1). Eukaryotic translation initiation factor alpha (eIF2α) phosphorylation, an indicator of SG formation, was assessed by western blotting. Tumor necrosis factor alpha (TNF-α) production was assessed by PCR and enzyme-linked immunosorbent assays. CMs function was evaluated by intracellular cyclic adenosine monophosphate (cAMP) levels in response to dobutamine. Pharmacological inhibition (ISRIB), a G3BP1 CRISPR activation plasmid, and a G3BP1 KO plasmid were employed to modulate SG activation. The fluorescence intensity of JC-1 was used to evaluate mitochondrial membrane potential.

RESULTS

LPS challenge in CMs induced SG activation and resulted in eIF2α phosphorylation, increased TNF-α production, and decreased intracellular cAMP in response to dobutamine. The pharmacological inhibition of SG (ISRIB) increased TNF-α expression and decreased intracellular cAMP levels in CMs treated with LPS. The overexpression of G3BP1 increased SG activation, attenuated the LPS-induced increase in TNF-α expression, and improved CMs contractility (as evidenced by increased intracellular cAMP). Furthermore, SG prevented LPS-induced mitochondrial membrane potential dissipation in CMs.

CONCLUSION

SG formation plays a protective role in CMs function in sepsis and is a candidate therapeutic target.

Phosphorylation, compartmentalization, and cardiac function

Protein phosphorylation is a fundamental element of cell signaling. First discovered as a biochemical switch in glycogen metabolism, we now know that this posttranslational modification permeates all aspects of cellular behavior. In humans, over 540 protein kinases attach phosphate to acceptor amino acids, whereas around 160 phosphoprotein phosphatases remove phosphate to terminate signaling. Aberrant phosphorylation underlies disease, and kinase inhibitor drugs are increasingly used clinically as targeted therapies. Specificity in protein phosphorylation is achieved in part because kinases and phosphatases are spatially organized inside cells. A prototypic example is compartmentalization of the cyclic adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase A through association with A-kinase anchoring proteins. This configuration creates autonomous signaling islands where the anchored kinase is constrained in proximity to activators, effectors, and selected substates. This article primarily focuses on A kinase anchoring protein (AKAP) signaling in the heart with an emphasis on anchoring proteins that spatiotemporally coordinate excitation-contraction coupling and hypertrophic responses.

When Just One Phosphate Is One Too Many: The Multifaceted Interplay between Myc and Kinases

Myc transcription factors are key regulators of many cellular processes, with Myc target genes crucially implicated in the management of cell proliferation and stem pluripotency, energy metabolism, protein synthesis, angiogenesis, DNA damage response, and apoptosis. Given the wide involvement of Myc in cellular dynamics, it is not surprising that its overexpression is frequently associated with cancer. Noteworthy, in cancer cells where high Myc levels are maintained, the overexpression of Myc-associated kinases is often observed and required to foster tumour cells' proliferation. A mutual interplay exists between Myc and kinases: the latter, which are Myc transcriptional targets, phosphorylate Myc, allowing its transcriptional activity, highlighting a clear regulatory loop. At the protein level, Myc activity and turnover is also tightly regulated by kinases, with a finely tuned balance between translation and rapid protein degradation. In this perspective, we focus on the cross-regulation of Myc and its associated protein kinases underlying similar and redundant mechanisms of regulation at different levels, from transcriptional to post-translational events. Furthermore, a review of the indirect effects of known kinase inhibitors on Myc provides an opportunity to identify alternative and combined therapeutic approaches for cancer treatment.

GSK3β Inhibition Is the Molecular Pivot That Underlies the Mir-210-Induced Attenuation of Intrinsic Apoptosis Cascade during Hypoxia

Apoptotic cell death is a deleterious consequence of hypoxia-induced cellular stress. The master hypoxamiR, microRNA-210 (miR-210), is considered the primary driver of the cellular response to hypoxia stress. We have recently demonstrated that miR-210 attenuates hypoxia-induced apoptotic cell death. In this paper, we unveil that the miR-210-induced inhibition of the serine/threonine kinase Glycogen Synthase Kinase 3 beta (GSK3β) in AC-16 cardiomyocytes subjected to hypoxia stress underlies the salutary protective response of miR-210 in mitigating the hypoxia-induced apoptotic cell death. Using transient overexpression vectors to augment miR-210 expression concomitant with the ectopic expression of the constitutive active GSK3β S9A mutant (ca-GSK3β S9A), we exhaustively performed biochemical and molecular assays to determine the status of the hypoxia-induced intrinsic apoptosis cascade. Caspase-3 activity analysis coupled with DNA fragmentation assays cogently demonstrate that the inhibition of GSK3β kinase activity underlies the miR-210-induced attenuation in the hypoxia-driven apoptotic cell death. Further elucidation and delineation of the upstream cellular events unveiled an indispensable role of the inhibition of GSK3β kinase activity in mediating the miR-210-induced mitigation of the hypoxia-driven BAX and BAK insertion into the outer mitochondria membrane (OMM) and the ensuing Cytochrome C release into the cytosol. Our study is the first to unveil that the inhibition of GSK3β kinase activity is indispensable in mediating the miR-210-orchestrated protective cellular response to hypoxia-induced apoptotic cell death.

Exercise-induced signaling pathways to counteracting cardiac apoptotic processes

Cardiovascular diseases are the most common cause of death in the world. One of the major causes of cardiac death is excessive apoptosis. However, multiple pathways through moderate exercise can reduce myocardial apoptosis. After moderate exercise, the expression of anti-apoptotic proteins such as IGF-1, IGF-1R, p-PI3K, p-Akt, ERK-1/2, SIRT3, PGC-1α, and Bcl-2 increases in the heart. While apoptotic proteins such as PTEN, PHLPP-1, GSK-3, JNK, P38MAPK, and FOXO are reduced in the heart. Exercise-induced mechanical stress activates the β and α5 integrins and subsequently, focal adhesion kinase phosphorylation activates the Akt/mTORC1 and ERK-1/2 pathways, leading to an anti-apoptotic response. One of the reasons for the decrease in exercise-induced apoptosis is the decrease in Fas-ligand protein, Fas-death receptor, TNF-α receptor, Fas-associated death domain (FADD), caspase-8, and caspase-3. In addition, after exercise mitochondrial-dependent apoptotic factors such as Bid, t-Bid, Bad, p-Bad, Bak, cytochrome c, and caspase-9 are reduced. These changes lead to a reduction in oxidative damage, a reduction in infarct size, a reduction in cardiac apoptosis, and an increase in myocardial function. After exercising in the heart, the levels of RhoA, ROCK1, Rac1, and ROCK2 decrease, while the levels of PKCε, PKCδ, and PKCɑ are activated to regulate calcium and prevent mPTP perforation. Exercise has an anti-apoptotic effect on heart failure by increasing the PKA-Akt-eNOS and FSTL1-USP10-Notch1 pathways, reducing the negative effects of CaMKIIδ, and increasing the calcineurin/NFAT pathway. Exercise plays a protective role in the heart by increasing HSP20, HSP27, HSP40, HSP70, HSP72, and HSP90 along with increasing JAK2 and STAT3 phosphorylation. However, research on exercise and factors such as Pim-1, Notch, and FAK in cardiac apoptosis is scarce, so further research is needed. Future research is recommended to discover more anti-apoptotic pathways. It is also recommended to study the synergistic effect of exercise with gene therapy, dietary supplements, and cell therapy for future research.

Mitochondrial a Kinase Anchor Proteins in Cardiovascular Health and Disease: A Review Article on Behalf of the Working Group on Cellular and Molecular Biology of the Heart of the Italian Society of Cardiology

Second messenger cyclic adenosine monophosphate (cAMP) has been found to regulate multiple mitochondrial functions, including respiration, dynamics, reactive oxygen species production, cell survival and death through the activation of cAMP-dependent protein kinase A (PKA) and other effectors. Several members of the large family of A kinase anchor proteins (AKAPs) have been previously shown to locally amplify cAMP/PKA signaling to mitochondria, promoting the assembly of signalosomes, regulating multiple cardiac functions under both physiological and pathological conditions. In this review, we will discuss roles and regulation of major mitochondria-targeted AKAPs, along with opportunities and challenges to modulate their functions for translational purposes in the cardiovascular system.

Abnormal Cyclic Nucleotide Signaling at the Outer Mitochondrial Membrane In Sympathetic Neurons During the Early Stages of Hypertension

Disruption of cyclic nucleotide signaling in sympathetic postganglionic neurons contributes to impaired intracellular calcium handling (Ca²⁺) and the development of dysautonomia during the early stages of hypertension, although how this occurs is poorly understood. Emerging evidence supports the uncoupling of signalosomes in distinct cellular compartments involving cyclic nucleotide–sensitive PDEs (phosphodiesterases), which may underpin the autonomic phenotype in stellate neurons.

Alterations of Cardiac Protein Kinases in Cyclic Nucleotide-Dependent Signaling Pathways in Human Ischemic Heart Failure

Objectives

Impaired protein kinase signaling is a hallmark of ischemic heart disease (IHD). Inadequate understanding of the pathological mechanisms limits the development of therapeutic approaches. We aimed to identify the key cardiac kinases and signaling pathways in patients with IHD with an effort to discover potential therapeutic strategies.

Methods

Cardiac kinase activity in IHD left ventricle (LV) and the related signaling pathways were investigated by kinomics, transcriptomics, proteomics, and integrated multi-omics approach.

Results

Protein kinase A (PKA) and protein kinase G (PKG) ranked on top in the activity shift among the cardiac kinases. In the IHD LVs, PKA activity decreased markedly compared with that of controls (62% reduction, p = 0.0034), whereas PKG activity remained stable, although the amount of PKG protein increased remarkably (65%, p = 0.003). mRNA levels of adenylate cyclases (ADCY 1, 3, 5, 9) and cAMP-hydrolysing phosphodiesterases (PDE4A, PDE4D) decreased significantly, although no statistically significant alterations were observed in that of PKGs (PRKG1 and PRKG2) and guanylate cyclases (GUCYs). The gene expression of natriuretic peptide CNP decreased remarkably, whereas those of BNP, ANP, and neprilysin increased significantly in the IHD LVs. Proteomics analysis revealed a significant reduction in protein levels of “Energy metabolism” and “Muscle contraction” in the patients. Multi-omics integration highlighted intracellular signaling by second messengers as the top enriched Reactome pathway.

Conclusion

The deficiency in cAMP/PKA signaling pathway is strongly implicated in the pathogenesis of IHD. Natriuretic peptide CNP could be a potential therapeutic target for the modulation of cGMP/PKG signaling.

cAMP сoncentrations in cardiac mitochondria and serum in the С57ВL/6 mice under independent melanoma В16/F10 growth versus melanoma В16/F10 growth linked to chronic neurogenic pain

The aim of this research work is to study the cAMP level in the cardiac mitochondria and serum in the С57ВL/6 strain mice of both genders under the independent melanoma В16/F10 growth versus the melanoma В16/F10 growth linked to chronic neurogenic pain (CNP). Materials and methods. Mice of strain С57ВL/6 (n=336) have been grouped as follows: the intact group of the mice (♂n=21; ♀n=21), the reference group (♂n=21; ♀n=21) with the reproduced CNP model, the comparison group (♂n=63; ♀n=63) to include the mice with melanoma В16/F10, and the main test group (♂n=63; ♀n=63) to cover the mice with the melanoma growth against the CNP background. Upon expiration of 1 week, 2 and 3 weeks of the melanoma growth, in the animals of the above experimental groups the cardiac mitochondria have been isolated with the centrifugation using high-performance refrigerated centrifuge Avanti J-E, BECMAN COULTER, USA. With ELISA Kit (RayBio USA) we have determined cAMP concentrations in serum and in the cardiac mitochondria. Results. CNP has induced a decrease in the cAMP level in the cardiac mitochondria by a factor of 3,6 in the female mice only. In the animals of the comparison group the cAMP level in the heart has been increasing beginning with week 2 of the tumor growth on average by a factor of 4, while in the main test group starting from week 1 of the tumor growth it has been recorded 2-4 times higher and was depleted by the end of the experiment. As to the cAMP concentration in serum, the dynamics thereof has not been found to be in correlation with the cardiac mitochondrial data, and its concentration decrease has been recorded both in the females and the males. Conclusion. So, the changes in the cAMP concentration in the cardiac mitochondria demonstrate their gender-specific feature; the female mice as against the males have responded to an independent impact produced by CNP. As to the main test group, CNP has stimulated an increase in the cAMP level in the cardiac mitochondria 1 week earlier than it is the case with the comparison group, and it has resulted in the full cAMP depletion by the 3rd week of the experiment.

Multi-omic analysis of microRNA-mediated regulation reveals a proliferative axis involving miR-10b in fibrolamellar carcinoma

Fibrolamellar carcinoma (FLC) is an aggressive liver cancer primarily afflicting adolescents and young adults. Most patients with FLC harbor a heterozygous deletion on chromosome 19 that leads to the oncogenic gene fusion, DNAJB1-PRKACA. There are currently no effective therapeutics for FLC. To address that, it is critical to gain deeper mechanistic insight into FLC pathogenesis. We assembled a large sample set of FLC and nonmalignant liver tissue (n = 52) and performed integrative multiomic analysis. Specifically, we carried out small RNA sequencing to define altered microRNA expression patterns in tumor samples and then coupled this analysis with RNA sequencing and chromatin run-on sequencing data to identify candidate master microRNA regulators of gene expression in FLC. We also evaluated the relationship between DNAJB1-PRKACA and microRNAs of interest in several human and mouse cell models. Finally, we performed loss-of-function experiments for a specific microRNA in cells established from a patient-derived xenograft (PDX) model. We identified miR-10b-5p as the top candidate pro-proliferative microRNA in FLC. In multiple human cell models, overexpression of DNAJB1-PRKACA led to significant upregulation of miR-10b-5p. Inhibition of miR-10b in PDX-derived cells increased the expression of several potentially novel target genes, concomitant with a significant reduction in metabolic activity, proliferation, and anchorage-independent growth. This study highlights a potentially novel proliferative axis in FLC and provides a rich resource for further investigation of FLC etiology.

Phosphorylated ATF1 at Thr184 promotes metastasis and regulates MMP2 expression in gastric cancer

Background

Studies have revealed an important role of activating transcription factor 1 (ATF1) and phosphorylated ATF1 at Ser63 in tumors. Our previous study identified Thr184 as a novel phosphorylation site of ATF1. However, the role of phosphorylated ATF1 at Thr184 (p-ATF1-T184) in tumor is unclear. This study figured out the role of p-ATF1-T184 in the metastasis of gastric cancer (GC) and in the regulation of Matrix metallopeptidase 2 (MMP2).

Methods

Immunohistochemical analysis (IHC) was performed to analyze the level of p-ATF1-T184 and its relationship with clinicopathological characteristics. Wound scratch test, Transwell assay were used to observe the role of p-ATF1-T184 in the invasion and metastasis of GC. The regulation of MMP2 by p-ATF1-T184 was investigated by a series of experiments including quantitative RT-PCR, western blot, gelatin zymography assay, Chromatin immunoprecipitation (ChIP), luciferase reporter assay and cycloheximide experiment. The Cancer Genome Atlas (TCGA) data were used to analyze the expression and prognostic role of ATF1 and MMP2 in GC. Mass spectrometry (MS) following co-immunoprecipitation (co-IP) assay was performed to identify potential upstream kinases that would phosphorylate ATF1 at Thr184.

Results

High expression level of p-ATF1-T184 was found and significantly associated with lymph node metastasis and poor survival in a GC cohort of 126 patients. P-ATF1-T184 promoted migration and invasion of gastric cancer cells. Phosphorylation of ATF1-T184 could regulate the mRNA, protein expression and extracellular activity of MMP2. P-ATF1-T184 further increased the DNA binding ability, transcription activity, and stabilized the protein expression of ATF1. Moreover, TCGA data and IHC results suggested that the mRNA level of ATF1 and MMP2, and protein level of p-ATF1-T184 and MMP2 could be prognosis markers of GC. Two protein kinase related genes, LRBA and S100A8, were identified to be correlated with the expression ATF1 in GC.

Conclusion

Our results indicated that p-ATF1-T184 promoted metastasis of GC by regulating MMP2.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03361-3.

miR-542-3p-Targeted PDE4D Regulates cAMP/PKA Signaling Pathway and Improves Cardiomyocyte Injury

Objective

To investigate the protective effect of miR-542-3p on cardiomyocyte injury and related mechanisms.

Methods

A cardiomyocyte hypoxia/reoxygenation model was established. The expression levels of miR-542-3p and PDE4D were detected using qRT-PCR; the luciferase reporter assay system was used to detect the targeting relationship between miR-542-3p and PDE4D; overexpressing miR-542-3p was transfected into cardiomyocytes, and ROS release was detected by immunofluorescence while cellular apoptosis was detected by TUNEL; and the western blot assay was applied to detect the expression of PDE4D, phosphorylated protein kinase A (p-PKA), and phosphorylated cyclic adenosine monophosphate (cAMP) response element-binding protein (p-CREB).

Results

Compared with the control group, the miR-542-3p expression level was decreased and the PDE4D expression level was increased in the cardiomyocyte hypoxia/reoxygenation model group. The dual-luciferase reporter assay system confirmed that miR-542-3p could target and regulate PDE4D; the transfection with cardiomyocytes using the overexpressing miR-542-3p could downregulate PDE4D expression, attenuate ROS release during cardiomyocyte injury, and reduce cellular apoptosis rate, while upregulating the expression of p-PKA and p-CREB.

Conclusion

The miR-542-3p can negatively regulate PDE4D protein expression and attenuate cardiomyocyte injury through a mechanism related to the activation of the cAMP/PKA signaling pathway.

Signature network-based survey of the effects of a traditional Chinese medicine on heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Heart failure (HF) after myocardial infarction (MI) is one of the most common disabling and painful diseases. A traditional Chinese medicine (TCM) formula, Shengmaisan, is known as a multitarget medicine that is widely used clinically to treat heart failure (HF) in Asian countries. However, its mechanism has not been comprehensively demonstrated.

AIM OF THE STUDY

To use a prediction network to figure out which disease link SMZ mainly alleviates in HF and find biomarkers related to myocardial fibrosis in the serum for clinical reference.

MATERIALS AND METHODS

In this article, we collected a large amount of actual measurement data and our own proteomics data, along with the biomarkers of heart failure staging under study to establish a precise network. Then, we tested and verified the medicinal effect of SMZ in treatment of HF after MI by Measurement of left ventricular wall thickness and ejection fraction by echocardiography. Then we tested the serum level of the potential targets of SMZ predicting by the network we developed using ELISA.

RESULTS

the cardiac ejection fraction and retarding the thinning of the anterior wall of the left ventricle increased after treating with SMZ. The serum level of EGFR and MAPK1 decreased in the groups treated with SMZ.

CONCLUSION

SMZ can improve the cardiac function of rats with MI by increasing the cardiac ejection fraction and retarding the thinning of the anterior wall of the left ventricle. In addition, SMZ could delay heart failure mainly by inhibiting the progression of myocardial fibrosis through decreasing the EGFR and MAPK1 levels.

Dynamic Regulation of Cysteine Oxidation and Phosphorylation in Myocardial Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion (I/R) injury significantly alters heart function following infarct and increases the risk of heart failure. Many studies have sought to preserve irreplaceable myocardium, termed cardioprotection, but few, if any, treatments have yielded a substantial reduction in clinical I/R injury. More research is needed to fully understand the molecular pathways that govern cardioprotection. Redox mechanisms, specifically cysteine oxidations, are acute and key regulators of molecular signaling cascades mediated by kinases. Here, we review the role of reactive oxygen species in modifying cysteine residues and how these modifications affect kinase function to impact cardioprotection. This exciting area of research may provide novel insight into mechanisms and likely lead to new treatments for I/R injury.

cAMP Compartmentalization in Cerebrovascular Endothelial Cells: New Therapeutic Opportunities in Alzheimer's Disease

The vascular hypothesis used to explain the pathophysiology of Alzheimer’s disease (AD) suggests that a dysfunction of the cerebral microvasculature could be the beginning of alterations that ultimately leads to neuronal damage, and an abnormal increase of the blood–brain barrier (BBB) permeability plays a prominent role in this process. It is generally accepted that, in physiological conditions, cyclic AMP (cAMP) plays a key role in maintaining BBB permeability by regulating the formation of tight junctions between endothelial cells of the brain microvasculature. It is also known that intracellular cAMP signaling is highly compartmentalized into small nanodomains and localized cAMP changes are sufficient at modifying the permeability of the endothelial barrier. This spatial and temporal distribution is maintained by the enzymes involved in cAMP synthesis and degradation, by the location of its effectors, and by the existence of anchor proteins, as well as by buffers or different cytoplasm viscosities and intracellular structures limiting its diffusion. This review compiles current knowledge on the influence of cAMP compartmentalization on the endothelial barrier and, more specifically, on the BBB, laying the foundation for a new therapeutic approach in the treatment of AD.