P6342Subcutaneous delivery of NPA7, first-in-class novel bispecific designer peptide: enhances cardiorenal function and suppresses renin and aldosterone in vivo and in vitro

Introduction

The rapid increase of patients of heart failure (HF) is a major health burden worldwide. Most importantly is the need to develop innovative new drugs for treatment of HF, such as sacubitril/valsartan which in part functions by enhancing the natriuretic peptides (NPs). We engineered NPA7 as a novel 30 amino acid bispecific designer peptide which activates the particulate guanylyl cyclase A receptor (pGC-A)/cGMP and for which the NPs both ANP and BNP are ligands and the Mas-receptor (MasR)/cAMP pathways for Angiotensin 1–7 (Ang1–7) is the endogenous ligand. We previously reported that acute intravenous (IV) administration of NPA7 shows cardiorenal protective and renin-aldosterone suppressing actions that go beyond the native peptides, BNP or Ang 1–7, which may have therapeutic potential for HF.

Purpose

To support the clinical development of NPA7 as a potential therapy in HF which promotes NP and MasR pathways, we investigated the actions and stability of subcutaneous (SQ) administration of NPA7 in normal canines. We also defined NPA7's peptide stability and metabolites in canine plasma.

Methods

Plasma and urinary cGMP, cardiorenal and renin-aldosterone responses to SQ injection (10μg/kg) were determined over 4 hours in normal canines (n=5) in vivo. Ex vivo, we established stability of NPA7 and key metabolites in canine serum using liquid chromatography-mass spectrometry (LC-MS). Data are expressed as mean ± SEM. * P<0.05 vs. BL.

Results

In vivo, SQ NPA7 resulted in a sustained increase at 2 hours in plasma (BL: 10±3; 120 min: 30±6* pmol/ml) and urinary (BL: 1033±198; 120 min: 5792±857* pmol/min) cGMP, GFR (BL: 29±6; 120 min: 70±12* ml/min) and sodium excretion (BL: 18±10; 120 min: 144±33* ueq/min). We observed a gradual reduction in BP at 60 min (BL: 109±4; 60 min: 99±7* mmHg) with a sustained decrease in PCWP at 4 hours (BL: 5±0.9; 240 min: 3.1±0.6* mmHg). SQ NPA7 also suppressed plasma renin and aldosterone up to 3 hours after SQ injection. LC-MS revealed that NPA7 was highly stable with both the pGC-A and MasR activating moieties intact ex vivo in canine serum with a disappearance time of 2 hours. We also identified 2 major NPA7 metabolites NPA71–27 and NPA71–28.

Conclusions

SQ NPA7 possesses cGMP activating, cardiac unloading, diuretic, natriuretic, and renin-aldosterone suppressing actions in normal canines. NPA7 is also highly stable in serum. These studies support SQ administration as an effective delivery strategy for NPA7, a first-in-class innovative bispecific dual pGC-A/MasR activator now in preclinical development for HF.

Effects of gangliosides on expressions of caspase-3 and NGF in rats with acute spinal cord injury

OBJECTIVE

To investigate the effects of ganglioside [monostalotetra-hexosylganglioside (GM1)] on the expressions of caspase-3 and nerve growth factor (NGF) in rats with acute spinal cord injury (SCI).

MATERIALS AND METHODS

Male Sprague- Dawley (SD) rats were selected and randomly divided into Sham group, SCI group and GM1 administration group. The rats in Sham group, SCI group and GM1 group were subjected to behavioral examinations of Basso Beattie Bresnahan (BBB) and oblique-plate test at 1, 7 and 14 d after operation. The content of methylene dioxyamphetamine (MDA) and the activity of superoxide dismutase (SOD) of every rat in each group were measured by enzyme-linked immunosorbent assay (ELISA). Immunofluorescence staining assay was used to detect the expression levels of caspase-3 and NGF of rats in each group. The messenger ribonucleic acid (mRNA) and protein expressions of caspase-3 and NGF of rats in Sham group, SCI group and GM1 group were detected using reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting assay.

RESULTS

The BBB scores and the results of oblique-plate test in Sham group, SCI group and GM1 group at 1, 7 and 14 d showed that the BBB scores and the results of oblique-plate test of rats in each group were significantly decreased at 1 d after SCI, and had different degrees of recovery at 7 and 14 d after injury. The results of ELISA detection revealed that SCI group had increased content of MDA and clearly decreased activity of SOD in comparison with Sham group; at the same time, MDA content in GM1 group was overtly lower than that in SCI group, while SOD activity was enhanced evidently in GM1 group compared with that in SCI group. According to immunofluorescence assay, significantly increased expression of caspase-3 and distinctly decreased expression of NGF were found in SCI group. However, this phenomenon was significantly reversed by GM1. RT-PCR and Western blotting assay severally proved that the mRNA and protein expressions of caspase-3 were raised in SCI group and decreased clearly after the administration of GM1; while the mRNA and protein expressions of NGF was significantly reduced in SCI group and overtly elevated after the administration of GM1. ANOVA showed that there were statistically significant differences in expressions of caspase-3 and NGF among Sham group, SCI group and GM1 group (p<0.05).

CONCLUSIONS

GM1 has an evident effect on the expressions of caspase-3 and NGF in rats with acute SCI, and is able to down-regulate the expression of caspase-3 and up-regulate the expression of NGF, so as to achieve its therapeutic effect on SCI.

Downregulation of microRNA-218 is cardioprotective against cardiac fibrosis and cardiac function impairment in myocardial infarction by binding to MITF

OBJECTIVE

This study is intended to figure out the function of microRNA-218 (miR-218) together with microphthalmia-associated transcription factor (MITF) on the cardiac fibrosis and cardiac function impairment in rat models of myocardial infarction (MI).

RESULTS

The rats with MI exhibited cardiac function impairment, cardiac fibrosis, oxidative stress, cardiomyocyte apoptosis, as well as inflammatory injury. Additionally, upregulated miR-218 and downregulated MITF were detected in cardiac tissues of MI rats. MI rats injected with miR-218 inhibitors or overexpressed MITF exhibited elevated MITF expression, improved cardiac function, and diminished pathological damages, infarct size, cardiomyocyte apoptosis, cardiac fibrosis, oxidative stress as well as inflammatory injury in cardiac tissues. Furthermore, downregulated miR-218 and MITF aggravated the conditions than downregulation of miR-218 alone in MI rats.

METHODS

MI models were performed in rats, and then the rats were injected with miR-218 inhibitors and/or MITF overexpression plasmid to elucidate the role of miR-218 and/or MITF on the cardiac function, pathological damage, cardiac fibrosis, angiogenesis, oxidative stress and inflammatory injury of cardiac tissues in MI rats by performing a series of assays.

CONCLUSION

Collectively, we found that the suppression of miR-218 alleviates cardiac fibrosis and cardiac function impairment, and stimulates angiogenesis in MI rats through inhibiting MITF.

Prolonged dengue outbreak at a high-rise apartment in Petaling Jaya, Selangor, Malaysia: A case study

There was an increasing trend in dengue infection in Malaysia with many outbreaks that occurred in Petaling District, Selangor in 2013 - 2014. A high rise apartment in Petaling Jaya reported ten episodes of dengue outbreaks from June 2013 to June 2014. We studied the prolonged dengue hotspot at this residential complex in Petaling Jaya, Selangor and made recommendations to prevent future prolonged dengue outbreaks. This was a retrospective exploratory study by analysing secondary data on dengue outbreaks from years 2013 to 2014. Small group discussions, interview sessions with staff and site visits were carried out to obtain necessary information. Two hundred and ninety-one cases were notified during the dengue outbreaks from Epid week (EW) 25 in 2013 to EW 26 in 2014 with no mortality reported. Information entered into dengue databases might be incomplete or mixed up. Active case detection and environmental risks assessment based on cases were not carry out due to the massive outbreak. Basic information on the population in the outbreak locality was unavailable. Various control activities were carried out with varying outcomes. Community participation was poor with little cooperation from residents during health education and community-based mosquito breeding prevention activities. To ensure better management of dengue outbreaks and to prevent prolonged dengue outbreaks in the future, integrated case findings, effective control activities, extensive environmental assessment on the outbreak locality and adopting innovative community outreach initiative with sufficient staff are required to curb dengue vector.

[Association between serum lipid level and depression in patients with chronic heart failure]

Objective: To investigate the association between serum lipid level and depression in patients with chronic heart failure (CHF). Methods: A total of 348 patients with CHF from the First department of Cardiology of the people's hospital of Shaanxi province from September 2016 to June 2017 were included.The Hamilton Depression Scale (HAMD) was used to evaluate the degree of depression and some related clinical data were tested.The serum lipid level and depression scores in the patients were analyzed using Pearson correlation analysis, and Logistic regression analysis was used to analyze the confounding factors of depression. Results: There was significant difference in the proportion of depression between normal serum lipid group and dyslipidemia group (P=0.044). Pearson correlation analysis showed that depression score was linearly related to total cholesterol (r=0.326, P<0.001) and low density lipoprotein cholesterol (r=0.354, P<0.001), and Logistic regression analysis showed that after adjusting for age, BMI, triglyceride, low density lipoprotein cholesterol, creatinine, total bilirubin, albumin, B type natriuretic peptide, total cholesterol (OR=3.523, P=0.007) and high density lipoprotein cholesterol (OR=0.205, P=0.041) were associated with depression in CHF patients. Conclusion: Total cholesterol can increase the risk of depression, and high density lipoprotein cholesterol can reduce the risk of depression in CHF patients.

Temporal expression of interleukin-22, interleukin-22 receptor 1 and interleukin-22-binding protein during experimental periodontitis in rats

BACKGROUND AND OBJECTIVE

Interleukin-22 (IL-22), mainly produced by CD4+ T-helper subtypes and innate lymphoid cells at barrier surfaces, is found to involve in several diseases, including diabetes, rheumatoid arthritis, peri-implantitis and chronic rhinosinusitis with nasal polyps. The purpose of this study was to investigate histological changes and the levels of interleukin-22, interleukin-22 receptor 1 (IL-22R1) and interleukin-22-binding protein (IL-22BP) in experimental periodontitis.

MATERIAL AND METHODS

Sixty male 8-week-old Sprague Dawley rats were randomly allocated to six groups of 10 rats each. In the periodontitis groups, experimental periodontitis was established and the rats were killed on days 3, 5, 7, 11 and 15 after ligation, while the rats without ligation were killed on day 0, representing the healthy control group (day 0 group). Histopathologic changes were detected by hematoxylin and eosin (H&E) staining, and alveolar bone loss was determined by micro-computed tomography (micro-CT). Tartrate-resistant acid phosphatase (TRAP) staining was used to investigate osteoclast formation. Real-time quantitative PCR (qPCR) and immunohistochemistry were used to investigate the expression and location of IL-22, IL-22R1 and IL-22BP in gingival tissues.

RESULTS

H&E staining showed increasingly severe destruction of the epithelial layer between day 3 and day 7, and the hyperplasia of pocket epithelium and the formation of periodontal pockets could be detected from day 11 to day 15. Micro-CT indicated an exponential increase in alveolar bone loss from day 3 to day 11 (P < .01). Bone resorption tended to be stationary after this period. TRAP staining showed that the number of multinucleate osteoclasts peaked at day 3 (P < .001, compared with day 0) and decreased at subsequent time points between day 5 and day 15. IL-22BP was expressed strongly under steady-state conditions in epithelial cells. IL-22-positive cells could be clearly observed both in the epithelial layer and around the lamina propria, whereas IL-22R1 was mainly localized in the epithelial layer of the damage period. Real-time qPCR revealed up-regulation of IL-22 and IL-22R1, as well as down-regulation of IL-22BP in gingival tissues during the destructive phase of periodontitis.

CONCLUSION

This study shows the expression and localization of IL-22, IL-22R1 and IL-22BP, as well as the relevant histopathological alterations during the development of experimental periodontitis.

The HMGB1 is increased in CSF of patients with an Anti-NMDAR encephalitis

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder of the central nervous system (CNS). Interleukin (IL)-6 and IL-17A may play important roles in the pathogenesis of this disease. High-mobility group box protein 1 (HMGB1), a small but highly conserved ubiquitous protein, is recognized to be a potent innate inflammatory mediator that can activate the nuclear factor light chain enhancer of activated B cells and release cytokines such as IL-6 and IL-17A when released extracellularly. However, whether cerebrospinal fluid (CSF) HMGB1 levels are altered in anti-NMDAR encephalitis is still unclear.

OBJECTIVE

The aim of this study was to determine whether a correlation exists between the CSF concentrations of HMGB1 and IL-6 and IL-17A in anti-NMDAR encephalitis patients. We also sought to assess whether HMGB1 influences the clinical outcomes in anti-NMDAR encephalitis patients.

METHODS

Thirty-three patients with anti-NMDAR antibodies and 38 controls were recruited. CSF HMGB1 was measured using an enzyme-linked immunosorbent assay. The main clinical outcomes were evaluated using the modified Rankin scale (mRS). The data were extracted using microarray analysis software.

RESULTS AND CONCLUSION

Our results showed significant increases in CSF HMGB1, IL-6, and IL-17A (P < .05) in anti-NMDAR encephalitis patients. But between 3 months' mRS scores in anti-NMDAR encephalitis patients and CSF data, there was no correlation. Our study suggests that HMGB1 CSF levels are increased in patients with anti-NMDAR encephalitis and reflect the underlying neuroinflammatory process.

The role of extracellular matrix metalloproteinase inducer glycosylation in regulating matrix metalloproteinases in periodontitis

BACKGROUND AND OBJECTIVE

Extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that may induce activation of matrix metalloproteinases (MMPs) and lead to the destruction of periodontal tissue. The level of EMMPRIN glycosylation might be involved in this process. This study aims to investigate the role of EMMPRIN glycosylation in regulating MMP-2 and MMP-9 during the progression of periodontitis.

MATERIAL AND METHODS

Gingival tissues were collected from patients with chronic periodontitis and from patients undergoing crown-lengthening procedures (healthy gingival tissue). Tissues were used for immunohistochemistry and double immunofluorescence. A human immortalized oral epithelial cell (HIOEC) line was stably transfected by an N-acetylglucosaminyltransferase-V (GnT-V) RNA interference (RNAi) lentivirus to suppress EMMPRIN glycosylation. Gene silence efficiency was detected by western blot, quantitative real-time PCR and immunofluorescence (IF) staining. An HIOEC/human gingival fibroblast (HGF) co-culture model and an individual culture model were used in this study. After exposure of cells to Porphyromonas gingivalis lipopolysaccharide (Pg. LPS), the expression of EMMPRIN, MMP-2 and MMP-9 were assessed by western blot, quantitative real-time PCR and IF, and the secretion of MMP-2 and MMP-9 were detected by gelatin-degradation assays.

RESULTS

Compared with the periodontally healthy group, patients with periodontitis showed increased expression of EMMPRIN on the gingival epithelial cell membrane. GnT-V, a key regulator of EMMPRIN glycosylation, was co-expressed with EMMPRIN in gingival epithelial cells in patients with periodontitis. Knockdown of GnT-V reduced the level of EMMPRIN glycosylation in HIOECs. Furthermore, in the HIOEC/HGF co-culture model, stimulation with Pg. LPS (10 μg/mL, 4 hours) promoted EMMPRIN glycosylation and increased the activities of MMP-2 and MMP-9, while suppression of EMMPRIN glycosylation by GnT-V knockdown reduced the synthesis and activities of MMP-2 and MMP-9 under Pg. LPS stimulation. Moreover, the gelatin-degradation assay showed that inhibition of EMMPRIN glycosylation suppressed the Pg. LPS-induced degradation of gelatin in the co-culture model.

CONCLUSION

We conclude that EMMPRIN glycosylation participates in the regulation of MMP-2 and MMP-9 production through mediating the interaction of HIOECs and HGFs. Inhibiting EMMPRIN glycosylation can reduce the activation of MMP-2 and MMP-9 and suppress the degradation of extracellular matrix (ECM) in the HIOEC/HGF co-culture model. Therefore, this study suggests that EMMPRIN glycosylation may affect the host immune-inflammatory response by regulating MMPs in periodontitis.

Regulation of oncogenes and gap junction intercellular communication during the proliferative response of zearalenone in TM3 cells

Zearalenone (ZEA) is a nonsteroidal estrogenic mycotoxin produced by Fusarium species. The exposure risk to humans and animals is the consumption of contaminated food and animal feeds. The aim of this study was to investigate ZEA-induced effects and its tumorigenic mechanism in TM3 cells (mouse Leydig cells). Cell proliferation, apoptosis, and gap junction intercellular communication (GJIC) were assessed in this study. Results showed that low concentrations of ZEA could significantly promote the growth of TM3 cells. The percentage of cell distribution was decreased significantly in G1/G0 phase and was increased significantly in S phase with 10 and 20 μg/L of ZEA for 72 h ( p < 0.05, p < 0.01). The expressions of cyclin D1 and Cdk4 were significantly increased in the exposure groups compared with the control group ( p < 0.05, p < 0.01). Compared with the control group, the apoptosis was significantly decreased in 10 and 20 μg/L groups ( p < 0.01), and the ratio of Bax/Bcl-2 protein level was significantly decreased in a dose-dependent manner. The protein levels of proto-oncogene c-Myc, c-Jun, and c-Fos were significantly elevated and the protein levels of anti-oncogene p53 and phosphatase and tensin homolog (PTEN) were decreased obviously compared with the control group ( p < 0.05, p < 0.01). ZEA affected the expressions of connexins and inhibited the activity of GJIC. These results demonstrated that ZEA can disturb the dynamic balance between proliferation and apoptosis and causes abnormal regulation of oncogenes, GJIC, and connexins in TM3 cells, which may easily induce the translation of normal cells into tumor cells.

Exploiting electronic strategies to stabilize a planar tetracoordinate carbon in cyclic aromatic hydrocarbons

A new approach to stabilize compounds containing a planar tetracoordinate carbon (ptC), embedded in aromatic hydrocarbons, is presented herein.