Ghrelin inhibited pressure overload-induced cardiac hypertrophy by promoting autophagy via CaMKK/AMPK signaling pathway

Ghrelin, a novel gut hormone, has been shown to exert protective effects on cardiac dysfunction and remodeling. However, the underlying mechanisms of its protective effects remain unclear. Here, we investigated the effects of ghrelin on cardiac hypertrophy and explored the mechanisms involved. Ghrelin (30 μg.kg^-1. day^-1) was systemically administered to rats with cardiac hypertrophy induced by abdominal aortic constriction (AAC) by a mini-osmotic pump the next day after surgery continuously for 4 weeks. The AAC treated rats without ghrelin infusion showed decreased ghrelin content and expression of its receptors in the hearts. Exogenous ghrelin greatly attenuated cardiac hypertrophy as shown by heart weight to tibial length (HW/TL), hemodynamics, echocardiography, histological analyses, and expression of hypertrophic markers induced by AAC. This corresponded with decreased cardiac fibrosis and inflammation in the hearts of AAC rats treated with ghrelin. Moreover, ghrelin significantly increased the myocardial expression of autophagy markers, which was further confirmed in cultured cardiomyocytes. Concurrently, cardiomyocyte apoptosis in vivo and in vitro was ameliorated by ghrelin, which was reversed by inhibition of autophagy. The enhancement of autophagy and inhibition of apoptosis by ghrelin were eliminated on pretreatment with compound C, an AMP-activated protein kinase (AMPK) inhibitor. Furthermore, inhibition of Ca²⁺/Calmodulin-dependent protein kinase kinase (CaMKK), an upstream kinase of AMPK, made ghrelin fail to activate AMPK and simultaneously reversed ghrelin's promotion of autophagy. In conclusion, ghrelin could exert its cardioprotective effects on cardiac hypertrophy by promoting autophagy, possibly via CaMKK/AMPK signaling pathway.

Monitoring Astrocytic Ca2+ Activity in Freely Behaving Mice

Monitoring astrocytic Ca²⁺ activity is essential to understand the physiological and pathological roles of astrocytes in the brain. However, previous commonly used methods for studying astrocytic Ca²⁺ activities can be applied in only anesthetized or head-fixed animals, which significantly affects in vivo astrocytic Ca²⁺ dynamics. In the current study, we combined optic fiber recordings with genetically encoded Ca²⁺ indicators (GECIs) to monitor astrocytic activity in freely behaving mice. This approach enabled selective and reliable measurement of astrocytic Ca²⁺ activity, which was verified by the astrocyte-specific labeling of GECIs and few movement artifacts. Additionally, astrocytic Ca²⁺ activities induced by locomotion or footshock were stably recorded in the cortices and hippocampi of freely behaving mice. Furthermore, this method allowed for the longitudinal study of astrocytic activities over several weeks. This work provides a powerful approach to record astrocytic activity selectively, stably, and chronically in freely behaving mice.

Oxytocin Elicits Itch Scratching Behavior via Spinal GRP/GRPR System

Oxytocin (OT), a neuropeptide involved in the regulation of complex social and sexual behavior in mammals, has been proposed as a treatment for a number of psychiatric disorders including pain. It has been well documented that central administration of OT elicits strong scratching and grooming behaviors in rodents. However, these behaviors were only described as symptoms, few studies have investigated their underlying neural mechanisms. Thus, we readdressed this question and undertook an analysis of spinal circuits underlying OT-induced scratching behavior in the present study. We demonstrated that intrathecal OT induced robust but transient hindpaw scratching behaviors by activating spinal OT receptors (OTRs). Combining the pre-clinical and clinical evidence, we speculated that OT-induced scratching may be an itch symptom. Further RNAscope studies revealed that near 80% spinal GRP neurons expressed OTRs. OT activated the expression of c-fos mRNA in spinal GRP neurons. Chemical ablation of GRPR neurons significantly reduced intrathecal OT-induced scratching behaviors. Given GRP/GRPR pathway plays an important role in spinal itch transmission, we proposed that OT binds to the OTRs expressed on the GRP neurons, and activates GRP/GRPR pathway to trigger itch-scratching behaviors in mice. These findings provide novel evidence relevant for advancing understanding of OT-induced behavioral changes, which will be important for the development of OT-based drugs to treat a variety of psychiatric disorders.

Semi-quantitative analysis for the dynamic chest CT imaging features from onset to recovery in severe and critical COVID-19

OBJECTIVE

To investigate in the CT manifestations of severe and critical Coronavirus Disease 2019 (COVID-19) patients.

METHODS

Medical data was collected for 2 severe patients and 4 critical COVID-19 patients from onset to their recovery. Three or four CT scans for each patient were taken. The semi-quantitative analysis method was introduced for lesion and its distribution area.

RESULTS

The ground-glass opacities (GGO) and mixed GGO with consolidation were found as the most frequent features. Consolidation followed, and the appearance of stripes which showed an increasing trend before the patient was discharged. Consolidation was associated with clinical severity and disease progression, and the rapid change of the lesion in a short period of time was also a notable feature within 2-3 weeks. After being discharged, the efficacy of treatment could be demonstrated by a follow up CT scan. The distribution of lesion also showed dynamic progress in the follow up CT scan.

CONCLUSION

CT scans in the whole course provided the entire inflammation information to assess clinical severity, disease progression and the treatment efficacy for COVID-19.

Single-neuron representation of learned complex sounds in the auditory cortex

The sensory responses of cortical neuronal populations following training have been extensively studied. However, the spike firing properties of individual cortical neurons following training remain unknown. Here, we have combined two-photon Ca²⁺ imaging and single-cell electrophysiology in awake behaving mice following auditory associative training. We find a sparse set (~5%) of layer 2/3 neurons in the primary auditory cortex, each of which reliably exhibits high-rate prolonged burst firing responses to the trained sound. Such bursts are largely absent in the auditory cortex of untrained mice. Strikingly, in mice trained with different multitone chords, we discover distinct subsets of neurons that exhibit bursting responses specifically to a chord but neither to any constituent tone nor to the other chord. Thus, our results demonstrate an integrated representation of learned complex sounds in a small subset of cortical neurons.

Using a combination of two-photon imaging and single-cell electrophysiology, the authors discover that associative learning induces the emergence of a unique subset of neurons in the auditory cortex, exhibiting high-rate bursting responses to the learned complex sounds but not to any of the constituents.

Composition and diurnal variation of floral scent emission in Rosa rugosa Thunb. and Tulipa gesneriana L

This study was aimed to explore the composition and diurnal variation analyses of floral scent emission from Rosa rugosa Thunb. and Tulipa gesneriana L. The floral scent from the fresh flower were collected at different time points (9:00, 12:00, 15:00, 18:00, and 21:00) using dynamic headspace collection and were analyzed using autothermal desorber-gas chromatography/mass spectrometry (ATD-GC/MS). The results showed that a total of 62 volatile flavor compounds were detected from Rosa rugosa Thunb and a total of 70 volatile flavor compounds were detected from Tulipa gesneriana L. They were identified with eight functional categories: alcohols, fatty hydrocarbons, terpenes, aldehydes, ketones, esters, and other substances. The total release amount first decreased, and then increased with time, and arrived at the lowest at 15:00. The release amounts of different categories present distinct change patterns. Among the components, phenylethyl alcohol, citronellol, methylene chloride, hexane, and acetone showed relatively higher release amounts and were thought as the main components in floral scent of Rosa rugosa Thunb. Alpha-Farnesene, ethanol, pentadecane, beta-ocimene, longifolene, caryophyllene, and acetone showed relatively higher release amounts and were thought as the main components in floral scent of Tulipa gesneriana L. Research of roses and tulips in aromatic in the garden provides a theoretical basis and research and improvement of the aroma components of aroma.

The protective role of omentin-1 in IL-1β-induced chondrocyte senescence

Osteoarthritis is a common type of degenerative joint disease. Inflammation-related chondrocyte senescence plays a major role in the pathogenesis of osteoarthritis. Omentin-1 is a newly identified anti-inflammatory adipokine involved in lipid metabolism. In this study, we examined the biological function of omentin-1 in cultured chondrocytes. The presence of omentin-1 potently suppresses IL-1β-induced cellular senescence as revealed by staining with senescence-associated beta-galactosidase (SA-β-Gal). At the cellular level, omentin-1 attenuates IL-1β-induced G1 phase cell-cycle arrest. Mechanistically, we demonstrate that omentin-1 reduced IL-1β-induced expression of senescent factors including caveolin-1, p21, and PAI-1 as well as p53 acetylation through ameliorating SIRT1 reduction. Notably, silencing of SIRT1 abolishes IL-1β-induced senescence along with the induction of p21 and PAI-1, suggesting that the action of omentin-1 in chondrocytes is dependent on SIRT1. Collectively, our results revealed the molecular mechanism through which the adipokine omentin-1 exerts a beneficial effect, thereby protecting chondrocytes from senescence. Thus, omentin-1 could have clinical implication in the treatment of osteoarthritis.

Enhancing selective photosensitizer accumulation and oxygen supply for high-efficacy photodynamic therapy toward glioma by 5-aminolevulinic acid loaded nanoplatform

The complex biology of glioma compromises therapeutic efficacy and results in poor prognosis. Photodynamic therapy (PDT) has emerged as a promising modality for localized tumor ablation with limited damage to healthy brain tissues. However, low photosensitizer concentration and hypoxic microenvironment in glioma tissue hamper the practical applications of PDT. To address the challenges, biocompatible periodic mesoporous organosilica coated Prussian blue nanoparticles (PB@PMOs) are constructed to load a biosafe prodrug 5-aminolevulinic acid (5-ALA), which is pronouncedly converted to protoporphyrin IX (PpIX) in malignant cells. PB@PMO-5-ALA induces a higher accumulation of PpIX in glioma cells compared to free 5-ALA. Meanwhile, the PB@PMOs, with a mean edge length of 81 nm and good biocompatibility, effectively decompose hydrogen peroxide to oxygen in a temperature-responsive manner. Oxygen supply further contributes to the promotion of 5-ALA-PDT. Thus, the photodynamic effect of PB@PMO-5-ALA is significantly improved, imposing augmented cytotoxicity to glioma U87MG cells. Furthermore, ex vivo fluorescence imaging elucidates the tumor PpIX increases by 75% in PB@PMO-5-ALA treated mice than that in 5-ALA treated ones post 12 h injection. Magnetic resonance imaging (MRI) and iron staining strongly demonstrate the accumulation of PB@PMO-5-ALA in glioma tissues with negative contrast enhancement and blue staining deposits, respectively. The nanoparticle accumulation and high PpIX level collaboratively enhance PDT efficacy through PB@PMO-5-ALA, which efficiently suppresses tumor growth, providing a promising option with safety for local glioma ablation.

Facile synthesis of biodegradable flower-like hydroxyapatite for drug and gene delivery

Controlled synthesis of hierarchical hydroxyapatite materials is a hot research topic because of the excellent biocompatibility and bioactivity of the materials. In this study, flower-like hydroxyapatite spheres (FHAPS) were facile synthesized in one pot using Al(OH)₃ as a structure-directing agent. The prepared FHAPS comprised nanosheets possessing a uniform diameter of approximately 4 µm. Notably, the FHAPS can be degraded in solutions with a pH of 5.5 for 144 h or incubated with cells for 48 h. In addition, the FHAPS have rough surfaces, which exhibit high loading contents for the anticancer drug doxorubicin (DOX, 9.1%) and siRNA (2.0%). Thus, the FHAPS can effectively deliver DOX into drug-resistant breast cancer cells to exert an excellent killing effect compared with free DOX and transfect siRNA into tumor cells to interfere with the expression of the target protein. Taken together, this work successfully prepared FHAPS via a convenient synthesis route that shows high delivery efficiency for anticancer drugs and siRNA.

Caution on Kidney Dysfunctions of COVID-19 Patients.. [PMID: 0 DOI: 10.1101/2020.02.08.20021212]

Background

To date, large amounts of epidemiological and case study data have been available for the Coronavirus Disease 2019 (COVID-19), which suggested that the mortality was related to not just respiratory complications. Here, we specifically analyzed kidney functions in COVID-19 patients and their relations to mortality.

Method

In this multi-centered, retrospective, observational study, we included 193 adult patients with laboratory-confirmed COVID-19 from 2 hospitals in Wuhan, 1 hospital in Huangshi (Hubei province, 83 km from Wuhan) and 1 hospital in Chongqing (754 km from Wuhan). Demographic data, symptoms, laboratory values, comorbidities, treatments, and clinical outcomes were all collected, including data regarding to kidney functions. Data were compared among three groups: non-severe COVID-19 patients (128), severe COVID-19 patients (65) and a control group of other pneumonia (28). For the data from computed tomographic (CT) scans, we also included a control group of healthy subjects (110 cases, without abnormalities in the lung and without kidney diseases). The primary outcome was a common presence of kidney dysfunctions in COVID-19 patients and the occurrence of acute kidney injury (AKI) in a fraction of COVID-19 patients. Secondary outcomes included a survival analysis of COVID-19 patients in conditions of AKI or comorbid chronic illnesses.

Findings

We included 193 COVID-19 patients (128 non-severe, 65 severe (including 32 non-survivors), between January 6th and February 21th,2020; the final date of follow-up was March 4th, 2020) and 28 patients of other pneumonia (15 of viral pneumonia, 13 of mycoplasma pneumonia) before the COVID-19 outbreak. On hospitaladmission, a remarkable fraction of patients had signs of kidney dysfunctions, including 59% with proteinuria, 44% with hematuria, 14% with increased levels of blood urea nitrogen, and 10% with increased levels of serum creatinine, although mild but worse than that in cases with other pneumonia. While these kidney dysfunctions might not be readily diagnosed as AKI at admission, over the progress during hospitalization they could be gradually worsened and diagnosed as AKI. A univariate Cox regression analysis showed that proteinuria, hematuria, and elevated levels of blood urea nitrogen, serum creatinine, uric acid as well as D-dimer were significantly associated with the death of COVID-19 patients respectively. Importantly, the Cox regression analysis also suggested that COVID-19 patients that developed AKI had a ∼5.3-times mortality risk of those without AKI, much higher than that of comorbid chronic illnesses (∼1.5 times risk of those without comorbid chronic illnesses).

Interpretation

To prevent fatality in such conditions, we suggested a high degree of caution in monitoring the kidney functions of severe COVID-19 patients regardless of the past disease history. In addition, upon day-by-day monitoring, clinicians should consider any potential interventions to protect kidney functions at the early stage of the disease and renal replacement therapies in severely ill patients, particularly for those with strong inflammatory reactions or a cytokine storm.

Funding

None.

[Clinical analysis of seven cases with primary hyperoxaluria type 1 in children]

Objective: To investigate the clinical, imaging and molecular characteristics of primary hyperoxaluria type 1 (PH1) in children and to sum up existing evidence for further understanding the phenotype-genotype correlation of infantile PH1. Methods: This retrospective analysis was based on the medical records of children with PH1 diagnosed by gene test in the Department of Nephrology, Guangzhou Women and Children's Medical Center from June 2016 to May 2019. Targeted exome sequencing was performed on tubular disease-related genes of the probands and Sanger sequencing was conducted to validate suspected pathogenic variants of family members. Logistic regression analysis of NC and CCr was adopted to show the relation between NC and renal function. The literature review was conducted, and the clinical, imaging and molecular biogenetic characteristics of the disease were analyzed and summarized. Results: A total of 7 children from 6 families were enrolled. The median age of onset was 5 months. The median age of diagnosis was 8 months. Five cases had progressed to end-stage renal disease (ESRD), one case had chronic kidney disease (CKD) stage 1, and the other one had CKD stage 2. Four cases died, one case maintained on hemodialysis, and the other two non-dialysis cases were followed up. Among the 7 cases, 4 patients had infantile PH1, 1 patient had child and adolescent type, 1 patient had family type and the other one had unknown classification. There were two siblings (the younger brother had uremia and the sister had normal renal function) who had the delayed diagnosis for 5 and 3 years respectively. All patients in this cohort had proteinuria and microscopic hematuria, but no patients had gross hematuria. Three cases had hypercalciuria. Comprehensive diagnostic imaging evaluation include CT scan, MR scan, radiography and ultrasound led to the diagnosis of nephrocalcinosis (NC) in 5 cases, including 4 cases of simple NL and 1 case of NC with nephrolithiasis (NL), 1 case of multiple NL and 1 case of microcrystal deposition in renal medulla. However, only one case of NC was identified by ultrasound, the other 4 cases of NC were identified by radiograph examination. In the logistic regression analysis involving NC and creatinine clearnce rate (CCr), the results showed that NC was an independent risk factor for renal dysfunction (OR 2.5, 95%CI 0.7-1.2, P<0.05). All the 7 cases had AGXT gene variant, including homozygous variant in 4 cases and compound heterozygous variant in 3 cases. A total of 9 variant genotypes were found, and exon 6 variants were found in 4 children. Among them, there were 3 cases with c.679_680delAA. To our knowledge, both c.679_680delAA and c.190A>T in the cohort have not been reported previously. Conclusions: Infantile PH1 is the most common type of PH1 in children, which progresses rapidly or even begins with renal failure, with poor prognosis. It is also highly heterogeneous in phenotype and genotype. NC is an independent risk factor leading to renal failure. Radiograph examination showed high specificity for the diagnosis of NC. At present, the misdiagnosis and delayed diagnosis of PH1 are still common in China. It is of great significance to carry out quantitative determination of uric oxalate in order to reduce the misdiagnosis rate and enhance follow-up technologies for evaluating the therapeutic effect.

Determine what to measure and how to measure in clinical trials for the treatment of pressure injury: A protocol for the development of a core outcome set

BACKGROUND

A core outcome set (COS) is an agreed minimum set of outcomes that should be reported in all clinical trials in specific areas of health care. A considerable amount of trials did not report essential outcomes or outcomes measurement methods, which makes it challenging to evaluate the efficacy and safety of treatment strategies for pressure injury (PI) and produced significant heterogeneity of reported outcomes. It is necessary to develop a COS, which can be used for clinical trials in PI treatment.

METHODS/DESIGN

The development of this COS will be guided by an advisory group composed of clinicians, senior nurses, patients, and methodologists. We will search six databases and 2 registry platforms to identify currently reported PI treatment outcomes and outcome measurement instruments in randomized controlled trials, meta-analysis, and systematic reviews. We will also conduct a semi-structured interview with clinicians, nurses, and adult PI patients to collect their opinions on important outcomes. Each outcome of the initial list generated from systematic review and interviews will be scored and reach a consensus through two rounds of international Delphi survey with all key stakeholders. A face-to-face consensus meeting with key stakeholders will be conducted to finish a final COS and recommend measurement instruments for each outcome.

RESULTS

We will develop a COS that should be reported in future clinical trials to evaluate the effectiveness of PI treatment.

DISCUSSION

The COS will follow current guidance to develop a high-quality COS in the field of PI treatment to reduce heterogeneity in trial reporting, facilitate valid comparisons of new therapies, and improve the quality of clinical trials.

JQ1-Loaded Polydopamine Nanoplatform Inhibits c-MYC/Programmed Cell Death Ligand 1 to Enhance Photothermal Therapy for Triple-Negative Breast Cancer

Programmed cell death ligand 1 (PD-L1) blockade has achieved great success in cancer immunotherapy; however, the response of triple-negative breast cancer (TNBC) to PD-L1 antibodies is limited. To address this challenge, we use the bromodomain and extra-terminal inhibitor JQ1 to down-regulate the expression of PD-L1 and thus elicit the immune response to TNBC instead of using antibodies to block PD-L1. JQ1 also inhibits the growth of TNBC as a targeted therapeutic agent by inhibiting the BRD4-c-MYC axis. The polydopamine nanoparticles (PDMNs) are introduced as a biodegradable and adaptable platform to load JQ1 and induce photothermal therapy (PTT) as another synergistic therapeutic modality. Because the JQ1-loaded PDMNs (PDMN-JQ1) are self-degradable and release JQ1 continuously, this synergistic treatment can lead to remarkable activation of cytotoxic T lymphocytes and induce a strong immune-memory effect to protect mice from tumor re-challenge. Taken together, our study demonstrates a compact and simple nanoplatform for triple therapy, including targeted therapy, PTT, and immunotherapy, for TNBC treatment.

MATRIEX imaging: multiarea two-photon real-time in vivo explorer

Two-photon laser scanning microscopy has been extensively applied to study in vivo neuronal activity at cellular and subcellular resolutions in mammalian brains. However, the extent of such studies is typically confined to a single functional region of the brain. Here, we demonstrate a novel technique, termed the multiarea two-photon real-time in vivo explorer (MATRIEX), that allows the user to target multiple functional brain regions distributed within a zone of up to 12 mm in diameter, each with a field of view (FOV) of ~200 μm in diameter, thus performing two-photon Ca²⁺ imaging with single-cell resolution in all of the regions simultaneously. For example, we demonstrate real-time functional imaging of single-neuron activities in the primary visual cortex, primary motor cortex and hippocampal CA1 region of mice in both anesthetized and awake states. A unique advantage of the MATRIEX technique is the configuration of multiple microscopic FOVs that are distributed in three-dimensional space over macroscopic distances (>1 mm) both laterally and axially but that are imaged by a single conventional laser scanning device. In particular, the MATRIEX technique can be effectively implemented as an add-on optical module for an existing conventional single-beam-scanning two-photon microscope without requiring any modification to the microscope itself. Thus, the MATRIEX technique can be readily applied to substantially facilitate the exploration of multiarea neuronal activity in vivo for studies of brain-wide neural circuit function with single-cell resolution.

Dysregulation of miR-195-5p/-218-5p/BIRC5 axis predicts a poor prognosis in patients with gastric cancer

MicroRNAs (miRNAs) function by negatively regulating their target genes. Aberrant expression of baculoviral IAP repeat containing 5 (BIRC5) is associated with the tumor growth and metastasis, however, the clinical significance of miRNAs/BIRC5 axis in gastric cancer (GC) remains unknown. The association of BIRC5 or miR-195-5p/-218-5p expression levels with the clinicopathological characteristics and prognosis in patients with GC was analysed by using a tissue microarray and TCGA dataset. Pearson correlation analysis was used for analysing the correlation of BIRC5 with miR-195-5p/-218-5p expression in GC tissues. Cox proportional hazard regression model was conducted to assess whether BIRC5 or miR-195-5p/-218-5p was an independent prognostic factor in patients with GC. We found that BIRC5 expression levels were increased in GC tissues as compared with the adjacent normal tissues, and acted as an independent prognostic factor of tumor recurrence in patients with GC. Increased expression of BIRC5 was traceable to the dysregulation of miR-195-5p/-218-5p rather than its genetic and epigenetic alterations in GC tissues. MiR-195-5p/-218-5p displayed a negative correlation with BIRC5 expression, and acted as independent prognostic factors of poor prognosis in patients with GC. In conclusion, dysregulation of miR-195-5p/-218-5p/BIRC5 axis predicts a poor prognosis in patients with gastric cancer.

Association on polymorphisms in LncRNA HOTAIR and susceptibility to HNSCC in Chinese population

OBJECTIVE

More and more evidence has shown that the critical functions of long non-coding RNA (lncRNA) polymorphism in the carcinogenicity mechanism of a variety of cancers. The association between lncRNA HOX transcript antisense intergenic RNA (HOTAIR) polymorphism and the risk of head and neck squamous cell carcinoma (HNSCC) in Chinese population has not been reported. To investigated the effects of HOTAIR polymorphism on cancer susceptibility, the influence of HOTAIR variants on the risk of HNSCC was analyzed in this study.

PATIENTS AND METHODS

In this case-control study, the tagging SNPs (rs874945, rs4759314, and rs7958904) in HOTAIR gene were genotyped in Chinese population consisting of 366HNSCC cases and 732 controls.

RESULTS

It was found that rs4759314 was associated with a significantly increased risk of HNSCC in Chinese population [GG vs. AA: adjusted odds ratio (OR) = 1.23, 95% confidence interval (CI) = 1.01-1.50; additive model: OR = 1.21, 95%CI = 1.01-1.46]. However, there were no significant associations of rs874945 and rs7958904 with HNSCC risk.

CONCLUSIONS

HOTAIR rs4759314 may influence HNSCC susceptibility and serve as a diagnostic biomarker.

P1889Quantitative global proteomics and lysine acetylome analysis of changes in left atrial appendage tissue from valvular heart disease patients with atrial fibrillation

Background

Previous studies have shown that acetylation plays a critical role in regulating the progress of cardiovascular diseases by acetylated histone and non-histones protein. However, the global lysine acetylome during atrial fibrillation (AF) were not fully understood.

Purpose

The aim of the present study was to identify the underlying mechanisms of AF via profiling of the quantitative changes of global proteomics and lysine acetylome in the left atrial appendage (LAA) tissues from valvular heart disease patients with AF.

Methods

This study obtained LAA specimens from patients undergoing cardiac surgery for severe valvular heart disease. The LAA specimens were obtained from both 9 patients with AF and with sinus rhythm (SR). The changes of proteome and acetylome in the AF-LAA vs SR-LAA tissues were studied using dimethyl-labeling, HPLC fractionation, affinity enrichment, LC-MS/MS analysis, database Search and bioinformatic analysis. The acetylated levels of each lysine acetylated site were normalized on the basis of the corresponding protein abundance.

Results

The bioinformatic analysis indicates 294 up-regulated (AF/SR ratio >1.3) proteins and 169 down-regulated (AF/SR ratio <1/1.3) proteins in the AF-LAA vs SR-LAA were detected. Moreover, 3,880 sites in 1,044 proteins were quantified. Motif analysis of the identified acetylated peptides indicated that a total of 14 significantly enriched amino acid sequence motifs from −10 to +10 surrounding the acetylated lysine (Kac) were defined according to 3412 peptides from 1115 proteins. Among the quantified acetylated sites and proteins, 231 up-regulated acetylated sites in 130 proteins and 121 down-regulated acetylated sites in 74 proteins were detected. The enrichment-based clustering analysis showed that energy metabolism and cardiac contraction-related proteins were highly differentially expressed in the AF-LAA vs SR-LAA. Meanwhile, the protein-protein interaction network of the differentially expressed acetylated proteins demonstrated that there were 146 nodes and 569 interactions in the network and quite a lot of interactions in energy metabolism-related proteins and in cardiac contraction-related proteins. Furthermore, the acetylated levels of most differentially expressed energy metabolism-related proteins involving in oxidative phosphorylation, TCA cycle, respiratory ETC, fatty acid metabolism were up-regulated. On the contrary, the acetylated levels of most acetylated sites in differentially expressed cardiac contraction-related proteins including the key contraction proteins were down-regulated.

Interaction network of Ac-proteins

Conclusions

This study details and expands our understanding of the changes of proteome and lysine acetylome in the LAA tissues from valvular heart disease patients with AF. The data suggest important expression differences of acetylated proteins related to energy metabolism and cardiac contraction which may be involved in the matrix of AF formation and maintainence.

Acknowledgement/Funding

This work was supported by the grants from the National Natural Science Foundation of China (no. 81600273, no. 81570310, no.81770337 and no.81870258)

The Inhibitor of Cyclin-Dependent Kinase4a (INK4a) Signaling Pathway Induces Aging in Human Skeletal Muscle Myoblasts and Decreases the Mitochondrial Membrane Potential

The effect of the inhibitor of cyclin-dependent kinase4a (INK4a) signaling pathway on myoblastic aging was studied in this paper. Human skeletal muscle myoblasts were transfected with a recombinant lentiviral vector, pLVX-p16INK4a, encoding the p16INK4a gene, and RT-qPCR and western blotting were used to identify p16INK4a gene transcription and protein expression. The degree of cell senescence was assessed using Senescence-associated β-galactosidase staining. flow cytometry and JC-1 staining was used to analyze the mitochondrial membrane potential (MMP). The senescence phenotype was observed in myoblasts transfected with p16INK4a, the MMP was significantly decrease in p16INK4a-transfected myoblasts, while the MMP was decreased only slightly in control cells. Upregulation of the INK4a signaling pathway directly induced aging in human skeletal muscle myoblasts. Moreover, INK4a signaling pathway activated the mitochondrial pro-aging pathway by reducing the MMP, which indirectly accelerated aging in myoblasts.