Tafolecimab, a novel potential long-acting PCSK9 monoclonal antibody: efficacy and safety in healthy and hypercholesterolemia subjects

Background

LDL cholesterol (LDL-C) is a well-established risk factor for cardiovascular disease. PCSK9 binds LDL receptors, targeting them for degradation. The dosing intervals for currently available PCSK9 monoclonal antibodies are once every 2 or 4 weeks. Tafolecimab, a novel recombinant human PCSK9 monoclonal antibody, was found to have higher affinity with PCSK9 and show longer LDL-C reduction compared to evolocumab in preclinical studies.

Purposes

The objectives for the SAD and MAD studies were to investigate the safety and efficacy of tafolecimab and explore the optimal dosing schedule.

Methods

The phase 1 study was a randomized, placebo-controlled, double-blind, single-ascending dose study (SAD) in Chinese healthy subjects, who were randomized 3:1 to tafolecimab and placebo (n=58). SAD subjects received tafolecimab subcutaneously at 25/75/150/300/450/600mg, or intravenously at 75/450mg, monitored up to day 84. The phase 2 study was a randomized, double-blind, placebo-controlled, repeated-dosing, multiple ascending dose (MAD) study in patients with hypercholesterolemia, who were randomized 4:1 to tafolecimab and placebo (n=60). MAD subjects received tafolecimab subcutaneously at 75/140mg every 2 weeks, 300/420mg every 4weeks, 450/600mg every 6 weeks up to day 84 or 98 with 3 months follow-up.

Results

In the SAD, the maximum mean reduction in LDL-C ranged from 52.2% to 72.1% and was achieved as early as 5 days (figure 1a). The duration of LDL-C reduction was tafolecimab dose dependent. In the MAD, the mean LDL-C concentrations were reduced by tafolecimab for each dose at 12 weeks relative to baseline (ranging from 54.30% to 72.26%; p<0.001). Particularly, a 56.52% (−72.50%, −40.54%) reduction of LDL-C was observed in the cohort of 600mg Q6W. The effect sustained till week 14 (8 weeks after the last dose) where there was still a 43.46% (−60.96%, −25.96%) reduction from baseline (figure 1b). The mean reduction of Lp(a) at week 12 ranged from 24.04% to 50.59% relative to baseline. Tafolecimab reduced the other lipids when comparing with placebo. The pharmacokinetics/pharmadynamics (LDL-C) profiles of tafolecimab were well characterised and support the potential dosing interval of 6–8 weeks subcutaneously.

Both healthy and hypercholesterolemia subjects are generally tolerable to tafolecimab. Reported treatment-emergent adverse events (TEAEs) were: tafolecimab 23 (52.3%) vs. placebo 8 (57.1%); tafolecimab 34 (70.8%) vs. placebo 9 (75.0%) in the SAD and MAD respectively. There were no serious TEAEs or events leading to death or treatment discontinuation in both SAD and MAD.

Conclusions

Tafolecimab was well tolerated in both healthy and hypercholesterolemia in Chinese subjects, and improved lipid profile including LDL-C, Lp(a) and other lipids. The sustained effects on LDL-C suggests the potential of tafolecimab as a long-lasting PCSK9 inhibitor with dosing interval of 6–8 weeks or beyond.

Figure 1. LDL-C: Percent change from baseline

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Innovent Biologics (Suzhou), China

LncRNA MALAT1 inhibits osteogenic differentiation of mesenchymal stem cells in osteoporosis rats through MAPK signaling pathway

OBJECTIVE

The aim of this study was to explore whether long non-coding ribonucleic acid metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) could lead to osteoporosis (OP) by stimulating the activation of the mitogen-activated protein kinase (MAPK) signaling pathway.

MATERIALS AND METHODS

The OP model was first successfully established in rats. The expression of lncRNA MALAT1 in OP rats and normal rats was detected via quantitative Polymerase Chain Reaction (qPCR). Bone marrow mesenchymal stem cells (BMSCs) were cultured and transfected to establish the MALAT1 knockdown model. Subsequently, the apoptosis of mesenchymal stem cells in MALAT1 siRNA group and NC siRNA group was detected via flow cytometry. Meanwhile, the expressions of the MAPK signaling pathway proteins related to OP were detected via Western blotting. After alkaline phosphatase (ALP) staining in cells of both groups, early osteogenic differentiation of BMSCs was observed.

RESULTS

The results of qPCR showed that the expression of lncRNA MALAT1 in OP rats was significantly lower than that of normal rats. It was observed under a fluorescence microscope that there were a large number of siRNA particles in BMSCs. The expression of lncRNA MALAT1 in cells was detected via Real Time-fluorescence qPCR as well. The results indicated that siRNA transfection could effectively inhibit the expression of lncRNA MALAT1, indicating successful transfection. Flow cytometry revealed that no significant difference was observed in the apoptosis of BMSCs between the MALAT1 siRNA group and NC siRNA group. Besides, the results of Western blotting showed that the expression levels of the MAPK signaling pathway-related proteins extracellular signal-regulated kinase 1/2 (ERK1/2) and P38 in MALAT1 siRNA group were significantly higher than those of the NC siRNA group. This indicated that inhibiting the expression of lncRNA MALAT1 might promote the activation of the OP-related MAPK pathway. According to the results of ALP staining, the depth of staining in MALAT1 siRNA group was markedly declined when compared with the NC siRNA group. Quantification of ALP activity demonstrated that ALP activity in the MALAT1 siRNA group was markedly declined compared with the NC siRNA group. The above results suggested that suppressing the expression of lncRNA MALAT1 could reduce the ALP activity of BMSCs. Furthermore, lncRNA MALAT1 inhibited osteogenic differentiation of BMSCs.

CONCLUSIONS

LncRNA MALAT1 was lowly expressed in OP rats. Moreover, it inhibited osteogenic differentiation of BMSCs by enhancing the activation of the MAPK signaling pathway, thereby promoting OP progression.

Second harmonic generation microscopy using pixel reassignment

Second harmonic generation (SHG) microscopy is expected to be a powerful tool for observing the cellular-level functionality and morphology information of thick tissue owe to its unique imaging properties. However, the maximum attainable resolution obtainable by SHG microscopy is limited by the use of long-wavelength, near-infrared excitation. In this paper, we report the use of pixel reassignment to improve the spatial resolution of SHG microscopy. The SHG signal is imaged onto a position-sensitive camera, instead of a point detector typically used in conventional SHG microscope. The data processing is performed through pixel reassignment and subsequent deblurring operation. We present the basic principle and a rigorous theoretical model for SHG microscopy using pixel reassignment (SHG-PR). And for the first time, the optimal reassignment factor for SHG-PR is derived based on the coherent characteristics and the dependence of wavelength in SHG microscopy. To evaluate the spatial resolution improvement, images of nano-beads separated by different distances and of a microtubule array have been simulated. We gain about a 1.5-fold spatial resolution enhancement compared to conventional SHG microscopy. When a further deblurring operation is implemented, this method allows for a total spatial resolution enhancement of about 1.87. Additionally, we demonstrate the validity of SHG-PR for raw data with noise. LAY DESCRIPTION: Second harmonic generation (SHG) microscopy has emerged as a powerful imaging technique in clinical diagnostics and biological research. SHG microscopy is label-free and provides intrinsic optical sectioning for three-dimensional (3D) imaging. However, a near-infrared excitation wavelength results a restriction in the maximum attainable spatial resolution of SHG microscopy. In this paper, we present a simple resolution-enhanced SHG imaging method, SHG microscopy using pixel reassignment (SHG-PR). We demonstrate a rigorous theoretical model for SHG-PR and derive the optimal reassignment factor. The simulation result shows the clear improvement of the image resolution and contrast in the SHG-PR after deblurring operation. The FWHM value of single microtubule shows that SHG-PR enables a spatial resolution enhancement by a factor of 1.5, compared to conventional SHG microscopy. After a proper deblurring operation, this method allows for a total spatial resolution enhancement of about 1.87. The improvements of spatial resolution and contrast are still valid for raw data with noise. It is expected that this method can contribute towards new insights in unstained tissue morphology, interaction of cells, and diseases diagnosis.

[Progress of cohort studies in countries from Asia and Europe]

Objective: To share related knowledge and experiences with countries along the line, literature regarding current cohort studies was summarized. Distribution, establishment and development of cohort studies among large prospective general population were analyzed in 17 countries of Western Asia and the 16 countries of Central and Eastern Europe. Methods: Literature review was conducted to collect basic information on cohort studies, with descriptive study used to analyze the characteristics of these cohort studies. Results: There were 562 cohort studies with sample size as more than 1 000 stated in Western Asia and Central and Eastern Europe, including 468 (83.27%) carried out in the nation itself and 94 (16.73%) with international multicentered collaboration. According to the nature of cohort studies, 347 (61.74%) were etiologically based. As for the contents involved, 310 (55.16%) of them targeted on chronic/non-communicable diseases, 125 (22.24%) concentrated on maternal and child health. Among those on chronic/non-communicable diseases, 51 (16.45%) were on cancers and 83 (26.77%) on cardiovascular disease studies. There appeared 10 large prospective cohort studies targeting on general population, mainly ongoing in Iran and European countries, with a duration of 8-29 years, including 4 of them with sample size as more than 50 000. In terms of the contents, epidemiological investigation, physical examination and biological samples collection took the major parts. Few papers were published in 9 out of the 10 cohort studies at the early stage of those projects but the number of papers increased annually and stabilized to certain extent. Conclusions: The regional distribution of cohort studies carried out in countries from the Western Asia and Central and Eastern European areas appeared unbalanced. Contents of these designs would mainly involve etiological studies, with focus on non-communicable diseases as cancer, cardiovascular disease, diabetes, respiratory diseases, mental and psychological diseases, and maternal and infant health etc.. However, only few large prospective cohort studies would base on general population.

[Changes of urinary monocyte chemotactic protein 1 and epidermal growth factor and their correlations with clinicopathology in idiopathic membranous nephropathy patients]

Objective: To explore the changes and clinical value of urinary monocyte chemotactic protein 1 (MCP-1), epidermal growth factor (EGF) and their ratio in patients with idiopathic membranous nephropathy (IMN). Methods: A total of 67 IMN patients were enrolled according to kidney biopsy in the Department of Nephrology of the First Affiliated Hospital of Zhengzhou University from January 2017 to December 2018. The patients included 28 males and 39 females, with an average age of (47.6±14.2) years. Eighteen age-and sex-matched healthy controls were also enrolled. Clinical and pathological data, blood and urine samples of all subjects were collected. Urinary MCP-1 and EGF level were detected by enzyme-linked immunosorbent assay (ELISA). And then the levels of urinary MCP-1, EGF and the ratio of EGF/MCP-1 and their correlations with clinicopathology were analyzed. Results: There was no statistical difference of the urine EGF levels between the two groups [8.3(6.0,12.6) vs 8.4(6.5,10.2) ng/mg Cr, P=0.575]. The urine MCP-1 levels of IMN patients were 0.37 (0.21, 0.69) ng/mg Cr, which was statistical significantly higher than those of the control group [0.09 (0.02, 0.19) ng/mg Cr] (P<0.001), while the EGF/MCP-1 ratio was lower than that of the control group [22.2(15.1,36.6) vs 87.6(71.2,132.7), P<0.001]. Urine MCP-1 was negatively correlated with eGFR (r=-0.303, P=0.012), but positively correlated with the urinary ratio of albumin to creatinin (r=0.368, P=0.002). EGF was positively correlated with eGFR (r=0.722, P<0.001), but negatively correlated with the severity of interstitial fibrosis and renal tubular atrophy (IFTA) (r=-0.312, P=0.011). EGF/MCP-1 ratio was positively correlated with eGFR (r=0.693, P<0.001), but negatively correlated with the severity of the urinary ratio of albumin to creatinin and IFTA (r=-0.261, P=0.028 and r=-0.684, P<0.001, respectively). Further multivariate logistic regression analysis showed that EGF/MCP-1 was a protective factor for moderate-to-severe IFTA (OR=0.891, 95%CI: 0.844-0.949, P=0.008). Conclusion: Patients with IMN have elevated urine MCP-1 level and decreased EGF/MCP-1 ratio, which correlate with clinical indicators. In particular, EGF/MCP-1 ratio is independently related to moderate-severe IFTA, and may be a potential clinical biomarker for diagnosis of IMN.

Does dual-energy CT differentiate benign and malignant ovarian tumours?

AIM

To assess the ability of dual-energy computed tomography (DECT) to distinguish benign from malignant ovarian tumours (OTs).

MATERIALS AND METHODS

Following approval of the institutional review board, the institutional database was mined for treatment-naive patients who underwent primary cytoreduction for OT. Thirty-seven patients were included and divided into those with benign OTs (n = 11) and malignant OTs (n = 26), including high-grade (n = 20) and low-grade (n = 6) malignant OTs. Advanced processing and region of interest delineation on the ovarian mass were performed using the preoperative staging DECT examination using the Advantage Workstation. The pixel-level data of the CT attenuation values at 50, 70, and 120 keV and the effective atomic number (Z_eff), water content (WC), and iodine content (IC) in the ovarian mass were recorded. The Wilcoxon rank-sum test was used to compare CT attenuation data at different voltages, Z_eff, and WC and IC levels between benign and malignant OTs and between high- and low-grade malignant OTs. Simple logistic regression was used to correlate the imaging characteristics with malignant status and grade.

RESULTS

Malignant OTs had significantly higher Z_eff and IC compared with benign OTs. The threshold values for the diagnosis of malignant OT were IC≥9.74 (100 μg/cm³) with 81% sensitivity and 73% specificity and Z_eff ≥8.16 with 85% sensitivity and 73% specificity. High-grade OTs had significantly higher WC compared with low-grade OTs, and a threshold of ≥1,013.92 mg/cm³ differentiated them with 80% sensitivity and 83% specificity.

CONCLUSION

DECT may be a tool to help distinguish malignant and benign OTs and predict tumour grade.

20-Hydroxyecdysone receptor-activated Bombyx mori CCAAT/enhancer-binding protein gamma regulates the expression of BmCBP and subsequent histone H3 lysine 27 acetylation in Bo. mori

Cyclic adenosine monophosphate (cAMP) response element binding protein (CREB)-binding protein (CBP or CREBBP) plays important roles in regulating gene transcription and animal development. However, the process by which CBP is up-regulated to impact insect development is unknown. In this study, the regulatory mechanism of Bombyx mori CBP (BmCBP) expression induced by 20-hydroxyecdysone (20E) was investigated. In the Bo. mori cell line, DZNU-Bm-12, 20E enhanced BmCBP transcription and histone H3K27 acetylation. BmCBP RNA interference (RNAi) resulted in decreased histone H3K27 acetylation. Additionally, the luciferase activity analysis revealed that the transcription factor, Bo. mori CCAAT/enhancer-binding protein gamma (BmC/EBPg), activated BmCBP transcription, which was suppressed by BmC/EBPg RNAi and promoted by BmC/EBPg overexpression. Electrophoretic mobility shift assay and chromatin immunoprecipitation results demonstrated that BmC/EBPg could bind to the C/EBP cis-regulatory elements in two positions of the BmCBP promoter. Moreover, BmC/EBPg transcription was enhanced by the 20E receptor (BmEcR), which bound to the BmC/EBPg promoter. BmEcR RNAi significantly inhibited the transcriptional levels of BmC/EBPg and BmCBP in the presence of 20E. Furthermore, the BmEcR-BmC/EBPg pathway regulated the acetylation levels of histone H3K27. Altogether, these results indicate that BmEcR enhances the expression of BmC/EBPg, which binds to the BmCBP promoter, activates BmCBP expression and leads to histone H3K27 acetylation.

Pancreatic senescence and its clinical manifestations

The pancreas is a vital organ which has both endocrine and exocrine functions and plays an essential role in food digestion and glucose metabolism. Pancreatic structure and function undergo a series of changes with aging and senescence. Pancreatic exocrine and endocrine function gradually change, which may lead to conditions such as dyspepsia and diabetes mellitus. Hence, clinicians need to be familiar with the characteristics of pancreatic senescence. This article reviews the manifestations of pancreatic senescence and its significance for clinical practice.

Estimation of error variance via ridge regression

We propose a novel estimator of error variance and establish its asymptotic properties based on ridge regression and random matrix theory. The proposed estimator is valid under both low- and high-dimensional models, and performs well not only in nonsparse cases, but also in sparse ones. The finite-sample performance of the proposed method is assessed through an intensive numerical study, which indicates that the method is promising compared with its competitors in many interesting scenarios.

Determination of serum 25-hydroxyvitamin D status among population in southern China by a high accuracy LC-MS/MS method traced to reference measurement procedure

Objective

We aimed to describe the 25-hydroxyvitamin D (25(OH)D) status of southern Chinese individuals by a high-accuracy liquid chromatography tandem mass spectrometry (LC-MS/MS) method which can trace to reference measurement procedure.

Materials and methods

From January 2018 to June 2019, a total of 4775 southern Chinese individuals were evaluated in our study. The serum levels of parathyroid hormone (PTH) were detected simultaneously in 162 cases. 25(OH)D was determined by LC-MS/MS, and PTH was detected using routine automated analysers. The distribution of the concentration, prevalence and seasonal variability of 25(OH)D in males and females of different age groups were studied.

Results

The mean 25(OH)D concentration in our study was 32.57 ng/mL (4.20-101.40 ng/mL). The global 25(OH)D concentration in males was higher than that in females of different age group. The prevalence of vitamin D deficiency (< 20 ng/mL) in females (16.65%) was higher than that in males (6.83%). The prevalence of vitamin D deficiency (< 20 ng/mL) was most common in winter (22.98% of all women and 15.49% of all men). 25(OH)D concentrations were higher in those from whom blood samples were collected in summer and autumn than in winter and spring. 25(OH)D₂ was detected in 672 serum samples (14.07%). In addition, there was a negative correlation between the concentrations of 25(OH)D and serum PTH (r = - 0.149, P < 0.05).

Conclusion

Our study demonstrated that the average serum 25(OH)D concentration in southern Chinese individuals was higher than that in other Chinese cohorts by a high-accuracy LC-MS/MS method. The global 25(OH)D concentration in males was higher than that in females of different ages, and the prevalence of vitamin D deficiency in females was higher than that in males. Seasonal change was an important aspect of 25(OH)D concentration in young and middle-aged people but became less relevant for that in older subjects. 25(OH)D₂ detection was of minor practical significance in our study. In addition, we also found that there was a negative correlation between the serum levels of 25(OH)D and PTH in southern Chinese individuals.

Correction: Long non-coding RNA MEG3 inhibits cell proliferation, migration, invasion and enhances apoptosis in non-small cell lung cancer cells by regulating the miR-31-5p/TIMP3 axis

Correction for ‘Long non-coding RNA MEG3 inhibits cell proliferation, migration, invasion and enhances apoptosis in non-small cell lung cancer cells by regulating the miR-31-5p/TIMP3 axis’ by Kui Li et al., RSC Adv., 2019, 9, 38200–38208, DOI: 10.1039/C9RA07880K.

Research progress on immune aging and its mechanisms affecting geriatric diseases

Immunosenescence, also known as immune aging, refers to the degeneration, compensation, and reconstruction of the immune system with aging. Immune aging is an important factor in the increased susceptibility of the elderly to infectious diseases, malignant tumors, and a variety of chronic diseases and has long been a hotspot in geriatrics and immunology research. In this paper, the characteristics and progression of immune aging are briefly reviewed for clinicians' reference.

Retracted Article: Long non-coding RNA MEG3 inhibits cell proliferation, migration, invasion and enhances apoptosis in non-small cell lung cancer cells by regulating the miR-31-5p/TIMP3 axis

Non-small cell lung cancer (NSCLC) is a malignant lung cancer and accounts for 80% of lung cancer-related deaths. Long non-coding RNA maternally expressed gene 3 (MEG3) has been identified as a tumor suppressor in multiple cancers. However, the regulatory mechanism of MEG3 in NSCLC development is still largely unknown. The expression levels of MEG3, microRNA-31-5p (miR-31-5p) and tissue inhibitor of metalloproteinase 3 (TIMP3) in NSCLC tumors and cells were measured by quantitative real time polymerase chain reaction (qRT-PCR). Cell viability, apoptosis, migration and invasion were detected by cell counting kit-8 (CCK-8), flow cytometry, western blotting and transwell assays, respectively. Xenograft mouse models were established by subcutaneously injecting NSCLC cells stably transfected with Lenti-pcDNA or Lenti-MEG3. The interaction between miR-31-5p and MEG3 or TIMP3 was validated by luciferase reporter and RNA immunoprecipitation (RIP) assays. MEG3 and TIMP3 levels were up-regulated, whereas miR-31-5p expression was down-regulated in NSCLC tumors and cells compared with normal tissues and cells. Overexpression of MEG3 repressed cell proliferation, migration and invasion, but induced apoptosis in NSCLC cells. More importantly, MEG3 effectively hindered tumor growth in vivo. Next, luciferase reporter and RIP assays confirmed the interaction between miR-31-5p and MEG3 or TIMP3. Pearson's correlation coefficient revealed that miR-31-5p was inversely correlated with MEG3 or TIMP3. Rescue experiments indicated that MEG3 regulated TIMP3 expression by sponging miR-31-5p in NSCLC cells. Thus, MEG3 inhibited cell proliferation, migration and invasion, but enhanced apoptosis in NSCLC cells through up-regulating TIMP3 expression by regulating miR-31-5p, indicating novel biomarkers for the therapy of NSCLC.

Non-small cell lung cancer (NSCLC) is a malignant lung cancer and accounts for 80% of lung cancer-related deaths.

Determination of Glyphosate and Aminomethylphosphonic Acid in Crops by Capillary Gas Chromatography with Mass-Selective Detection: Collaborative Study

A collaborative study was conducted to validate a method for the determination of glyphosate and aminomethylphosphonic acid (AMPA) in crops. The analytes are extracted from crops with water, and the crude extracts are then subjected to a cation exchange cleanup. The analytes are derivatized by the direct addition of the aqueous extract into a mixture of heptafluorobutanol and trifluoroacetic anhydride. The derivatized analytes are quantitated by capillary gas chromatography with mass-selective detection (MSD). The collaborative study involved 13 laboratories located in 5 countries 12 laboratories returned valid data sets. The crops tested were field corn grain, soya forage, and walnut nutmeat at concentrations of 0.050, 0.40, and 2.0 mg/kg. The study used a split-level pair replication scheme with blindly coded laboratory samples. Twelve materials were analyzed, including 1 control and 3 split-level pairs for each matrix, 1 pair at each nominal concentration. For glyphosate, the mean recovery was 91%, the average intralaboratory variance, the repeatability relative standard deviation (RSDr), was 11%, and the interlaboratory variance, the reproducibility relative standard deviation (RSDR), was 16%. For AMPA, the mean recovery was 87%, the RSDr was 16%, and the RSDR was 25% at mg/kg levels.

Sex differences in the prevalence and adverse outcomes of sarcopenia and sarcopenic obesity in community dwelling elderly in East China using the AWGS criteria

BACKGROUND

Sarcopenia and sarcopenic obesity (SO) have a greater impact on the elderly. This study aimed to explore whether there were sex differences in the prevalence and adverse outcomes of sarcopenia and SO in community-dwelling elderly individuals in East China.

METHODS

This was a cross-sectional study that enrolled 213 males and 418 females aged > 65 years. Demographic characteristics, body composition, hand grip, gait speed, and indices of glucose and lipid metabolism were collected. Sarcopenia and SO were diagnosed using the Asian Working Group for Sarcopenia criteria.

RESULTS

(1) The prevalence of sarcopenia was 19.2% in males and 8.6% in females. The prevalence of SO was 7.0% in males and 2.4% in females. (2) In males, the odds ratios (ORs) of osteoporosis and dyslipidemia in the SO group were 4.21-fold and 4.15-fold higher than those in the normal group, respectively. In females, the ORs of osteoporosis and hyperglycemia in the SO group were 1.12-fold and 4.21-fold higher than those in the normal group.

CONCLUSIONS

Males were more likely to be sarcopenic and to have SO than females using the AWGS criteria. Females with SO were more likely to have higher blood glucose, whereas males with SO were more likely to have osteoporosis and dyslipidemia.

Correction: S Zheng. Radiological progression of penicillin-sensitive Staphylococcus aureus aortitis

[This corrects the article DOI: 10.12809/hkmj187616].