Toxicokinetics of Arenobufagin and its Cardiotoxicity Mechanism Exploration Based on Lipidomics and Proteomics Approaches in Rats

Arenobufagin (ArBu), one of the main active bufadienolides of toad venom with cardiotonic effect, analgesic effect, and outstanding anti-tumor potentiality, is also a potential cardiotoxic component. In the present study, the cardiac effect of ArBu and its underlying mechanism were explored by integrating data such as heart rates, toxicokinetics, myocardial enzyme and brain natriuretic peptide (BNP) activity, pathological sections, lipidomics and proteomics. Under different doses, the cardiac effects turned out to be different. The oral dose of 60 mg/kg of ArBu sped up the heart rate. However, 120 mg/kg ArBu mainly reduced the heart rate. Over time, they all returned to normal, consisting of the trend of ArBu concentration-time curve. High concentrations of myocardial enzymes and BNP indicated that ArBu inhibited or impaired the cardiac function of rats. Pathological sections of hearts also showed that ArBu caused myocardial fiber disorder and rupture, in which the high-dose group was more serious. At the same time, serum and heart tissue lipidomics were used to explore the changes in body lipid metabolism under different doses. The data indicated a larger difference in the high-dose ArBu group. There were likewise many significant differences in the proteomics of the heart. Furthermore, a multi-layered network was used to integrate the above information to explore the potential mechanism. Finally, 4 proteins that were shown to be significantly and differentially expressed were validated by targeted proteomics using parallel reaction monitoring (PRM) analysis. Our findings indicated that ArBu behaved as a bidirectional regulation of the heart. The potential mechanism of cardiac action was revealed with the increased dose, which provided a useful reference for the safety of clinical application of ArBu.

Insulin-Like Growth Factor Binding Proteins in Kidney Disease

The seven members of the insulin-like growth factor (IGF) binding protein family (IGFBPs) were initially considered to be the regulatory proteins of IGFs in the blood circulation, mainly as the subsequent reserve for bidirectional regulation of IGF function during environmental changes. However, in recent years, IGFBPs has been found to have many functions independent of IGFs. The role of IGFBPs in regulating transcription, inducing cell migration and apoptosis is closely related to the occurrence and development of kidney disease. IGFBP-1, IGFBP-3, IGFBP-4 are closely associated with diabetes and diabetic nephropathy. IGFBP-3, IGFBP-4, IGFBP-5, IGFBP-6 are involved in different kidney disease such as diabetes, FSGS and CKD physiological process as apoptosis proteins, IGFBP-7 has been used in clinical practice as a biomarker for early diagnosis and prognosis of AKI. This review focuses on the differential expression and pathogenesis of IGFBPs in kidney disease.

Neurotransmitters Affect Larval Development by Regulating the Activity of Prothoracicotropic Hormone-Releasing Neurons in Drosophila melanogaster

Ecdysone, an essential insect steroid hormone, promotes larval metamorphosis by coordinating growth and maturation. In Drosophila melanogaster, prothoracicotropic hormone (PTTH)-releasing neurons are considered to be the primary promoting factor in ecdysone biosynthesis. Recently, studies have reported that the regulatory mechanisms of PTTH release in Drosophila larvae are controlled by different neuropeptides, including allatostatin A and corazonin. However, it remains unclear whether neurotransmitters provide input to PTTH neurons and control the metamorphosis in Drosophila larvae. Here, we report that the neurotransmitters acetylcholine (ACh) affect larval development by modulating the activity of PTTH neurons. By downregulating the expression of different subunits of nicotinic ACh receptors in PTTH neurons, pupal volume was significantly increased, whereas pupariation timing was relatively unchanged. We also identified that PTTH neurons were excited by ACh application ex vivo in a dose-dependent manner via ionotropic nicotinic ACh receptors. Moreover, in our Ca2+ imaging experiments, relatively low doses of OA caused increased Ca2+ levels in PTTH neurons, whereas higher doses led to decreased Ca2+ levels. We also demonstrated that a low dose of OA was conveyed through OA β-type receptors. Additionally, our electrophysiological experiments revealed that PTTH neurons produced spontaneous activity in vivo, which provides the possibility of the bidirectional regulation, coming from neurons upstream of PTTH cells in Drosophila larvae. In summary, our findings indicate that several different neurotransmitters are involved in the regulation of larval metamorphosis by altering the activity of PTTH neurons in Drosophila.

Novel BMP4 Truncations Resulted in Opposite Ocular Anomalies: Pathologic Myopia Rather Than Microphthalmia

BMP4 variants have been reported to be associated with syndromic microphthalmia (MCOPS6, OMIM 607932). This study aims to describe BMP4 truncation mutations contributing to a novel phenotype in eight patients from four Chinese families. In this study, BMP4 variants were collected from a large dataset from in-house exome sequencing. Candidate variants were filtered by multiple in silico tools as well as comparison with data from multiple databases. Potential pathogenic variants were further confirmed by Sanger sequencing and cosegregation analysis. Four novel truncation variants in BMP4 were detected in four out of 7,314 unrelated probands with different eye conditions. These four mutations in the four families solely cosegregated in all eight patients with a specific form of pathologic myopia, characterized by significantly extended axial length, posterior staphyloma, macula patchy, chorioretinal atrophy, myopic optic neuropathy or glaucoma, vitreous opacity, and unique peripheral snow-grain retinopathy. The extreme rarity of the truncations in BMP4 (classified as intolerant in the gnomAD database, pLI = 0.96), the exclusive presence of these variants in the four families with pathologic myopia, variants fully co-segregated with the same specific phenotypes in eight patients from the four families, and the association of the pathogenicity of truncations with syndromic microphthalmia in previous studies, all support a novel association of BMP4 truncations with a specific form of pathologic myopia. The data presented in this study demonstrated that heterozygous BMP4 truncations contributed to a novel phenotype: pathologic myopia rather than microphthalmia. Mutations in the same gene resulting in both high myopia and microphthalmia have been observed for a few other genes like FZD5 and PAX6, suggesting bidirectional roles of these genes in early ocular development. Further studies are expected to elucidate the molecular mechanism of the bidirectional regulation.

Storax, A Promising Botanical Medicine for Treating Cardio-Cerebrovascular Diseases: A Review

In recent years, the incidence and mortality of cardio-cerebrovascular diseases have been increasing year by year, which has become global burden and challenge. Based on the holistic thinking of “brain disease affects the heart” and “heart disease affects the brain,” as well as the characteristics of multi-target and multi-path effects of Chinese medicine, Chinese medicine is more advantageous in the treatment of cardio-cerebrovascular diseases. As a botanical medicine, storax is known for its resuscitation, filth avoidance and pain-relieving effects in the treatment of cardio-cerebrovascular diseases. By reviewing and collating the relevant domestic and international literature in the past 10 years, we have sorted out an overview of the medicinal parts, traditional uses and chemical composition of storax. For the first time, based on the idea of “cerebral and cardiac simultaneous treatment,” the pharmacological activities and mechanisms of heart and brain protection of storax for treating cardio-cerebrovascular diseases were summarized and analyzed, showing that storax has the pharmacological effects of anti-cerebral ischemia, regulation of blood-brain barrier, bidirectional regulation of the central nervous system, anti-myocardial ischemia, anti-arrhythmia, anti-thrombosis and anti-platelet aggregation. It mainly exerts its protective effects on the brain and heart through mechanisms such as inhibition of inflammatory immune factors, anti-oxidative stress, anti-apoptosis, pro-neovascularization and regulation of NO release. On the basis of the current findings and limitations, the future research strategies and perspectives of storax are proposed, with a view to providing a reference for further application and development of this medicine, as well as contributing new thoughts and visions for the clinical application of “treating brain-heart synchronously”.

Bidirectional regulation of calcium release–activated calcium (CRAC) channel by SARAF

Store-operated calcium entry (SOCE) through the Ca2+ release–activated Ca2+ (CRAC) channel is a central mechanism by which cells generate Ca2+ signals and mediate Ca2+-dependent gene expression. The molecular basis for CRAC channel regulation by the SOCE-associated regulatory factor (SARAF) remained insufficiently understood. Here we found that following ER Ca2+ depletion, SARAF facilitates a conformational change in the ER Ca2+ sensor STIM1 that relieves an activation constraint enforced by the STIM1 inactivation domain (ID; aa 475–483) and promotes initial activation of STIM1, its translocation to ER–plasma membrane junctions, and coupling to Orai1 channels. Following intracellular Ca2+ rise, cooperation between SARAF and the STIM1 ID controls CRAC channel slow Ca2+-dependent inactivation. We further show that in T lymphocytes, SARAF is required for proper T cell receptor evoked transcription. Taking all these data together, we uncover a dual regulatory role for SARAF during both activation and inactivation of CRAC channels and show that SARAF fine-tunes intracellular Ca2+ responses and downstream gene expression in cells.

Identification and Elucidation of the Protective isomiRs in Lung Cancer Patient Prognosis

MicroRNAs (miRNAs) are approximately 20–22 nucleotides in length, which are well known to participate in the post-transcriptional modification. The mature miRNAs were observed to be varied on 5′ or 3′ that raise another term—the isoforms of mature miRNAs (isomiRs), which have been proven not the artifacts and discussed widely recently. In our research, we focused on studying the 5′ isomiRs in lung adenocarcinoma (LUAD) in The Cancer Genome Atlas (TCGA). We characterized 75 isomiRs significantly associated with better prognosis and 43 isomiRs with poor prognosis. The 75 protective isomiRs can successfully distinguish tumors from normal samples and are expressed differently between patients of early and late stages. We also found that most of the protective isomiRs tend to be with downstream shift and upregulated compared with those with upstream shift, implying that a possible selection occurs during cancer development. Among these protective isomiRs, we observed a highly positive and significant correlation, as well as in harmful isomiRs, suggesting cooperation within the group. However, between protective and harmful, there is no such a concordance but conversely more negative correlation, suggesting the possible antagonistic effect between protective and harmful isomiRs. We also identified that two isomiRs miR-181a-3p|-3 and miR-181a-3p|2, respectively, belong to the harmful and protective groups, suggesting a bidirectional regulation of their originated archetype—miR-181a-3p. Additionally, we found that the protective isomiRs of miR-21-5p, which is an oncomiR, may be evolved as the tumor suppressors through producing isomiRs to hinder metastasis. In summary, these results displayed the characteristics of the protective isomiRs and their potential for developing the treatment of lung cancer.

Abstract P144: Local Signaling And Cardiac Hypertrophy:specificity In The Face Of Pleiotropy

Rationale: Most likely, the overall myocyte cell growth during the pathological state of cardiac hypertrophy is regulated by a local muscle A-kinase anchoring protein β (mAKAPβ) complex. The mAKAPβ may act as a significant coordinator of myocyte hypertrophic signals. It may critically integrate the hypertrophic signals due to β-adrenergic and leukemia inhibitory factor (LIF)/gp-130 receptor stimulation. Observations suggest that mAKAPβ signalosome may act as a gate-keeper for regulating nuclear factor of activated T cells (NFATc) activity and nuclear localization of this complex might be directly linked to the induction of cardiac hypertrophy. The mAKAPβ complex might function through modulating the profiles of a local cyclic adenosine 3’,5’ monophosphate (cAMP) microdomain at perinuclear region in cardiomyocytes. The acute stimulation of cAMP may be beneficial for the heart, whereas chronic stimulation might cause damage. The transition between the chronic and acute function of cAMP is probably modulated by the ability of myocytes to tightly regulate the cAMP levels in local microdomains across the cell. Any dysfunction in this process may lead to net accumulation and a global rise of cAMP levels, leading to deleterious effects on the heart. Objective: cAMP is a single messenger but delivers multiple messages in myocytes. How is this managed? Here, we aim to investigate a key question that how mAKAPβ signalosome might ensure the microdomain specificity despite the pleiotropic nature of the second messenger. Methods and Results: Our results may explain how, in the context of hypertrophy, mAKAPβ complex coordinates the interactions between two coupled cAMP-induced feedback loops and LIF-induced activation of the MAPK pathway. Our results may also explain that mAKAPβ complex functions through anchoring protein kinase A (PKA) and ERK5 in the signalosome thus, modulating the bidirectional regulation of phosphodiesterase and hence the control of localized cAMP metabolism as well as the shape and temporal profile of the second messenger in a specific domain. Conclusion: Here, we propose a mechanistic model which suggests that stress-induced reprofiling of cAMP flux at discrete cellular locations may lead to cardiovascular disease.

Reciprocal Relationship Between Calcium Signaling and Circadian Clocks: Implications for Calcium Homeostasis, Clock Function, and Therapeutics

Graphical AbstractReciprocal relationship between Ca2+ signaling and the circadian clock. In Drosophila and mice, circadian clocks impose a daily rhythmicity to Ca2+ signaling; and, conversely, Ca2+ rhythms and signaling contribute to transmitting daily external signals to the clock TTFL. This bidirectional regulation is critical to the daily rhythmicity of many physiological and behavioral processes.