Myeloid-derived growth factor suppresses VSMC dedifferentiation and attenuates postinjury neointimal formation in rats by activating S1PR2 and its downstream signaling

Restenosis after angioplasty is caused usually by neointima formation characterized by aberrant vascular smooth muscle cell (VSMC) dedifferentiation. Myeloid-derived growth factor (MYDGF), secreted from bone marrow-derived monocytes and macrophages, has been found to have cardioprotective effects. In this study we investigated the effect of MYDGF to postinjury neointimal formation and the underlying mechanisms. Rat carotid arteries balloon-injured model was established. We found that plasma MYDGF content and the level of MYDGF in injured arteries were significantly decreased after balloon injury. Local application of exogenous MYDGF (50 μg/mL) around the injured vessel during balloon injury markedly ameliorated the development of neointimal formation evidenced by relieving the narrow endovascular diameter, improving hemodynamics, and reducing collagen deposition. In addition, local application of MYDGF inhibited VSMC dedifferentiation, which was proved by reversing the elevated levels of osteopontin (OPN) protein and decreased levels of α-smooth muscle actin (α-SMA) in the left carotid arteries. We showed that PDGF-BB (30 ng/mL) stimulated VSMC proliferation, migration and dedifferentiation in vitro; pretreatment with MYDGF (50-200 ng/mL) concentration-dependently eliminated PDGF-BB-induced cell proliferation, migration and dedifferentiation. Molecular docking revealed that MYDGF had the potential to bind with sphingosine-1-phosphate receptor 2 (S1PR2), which was confirmed by SPR assay and Co-IP analysis. Pretreatment with CCG-1423 (Rho signaling inhibitor), JTE-013 (S1PR2 antagonist) or Ripasudil (ROCK inhibitor) circumvented the inhibitory effects of MYDGF on VSMC phenotypic switching through inhibiting S1PR2 or its downstream RhoA-actin monomers (G-actin) /actin filaments (F-actin)-MRTF-A signaling. In summary, this study proves that MYDGF relieves neointimal formation of carotid arteries in response to balloon injury in rats, and suppresses VSMC dedifferentiation induced by PDGF-BB via S1PR2-RhoA-G/F-actin-MRTF-A signaling pathway. In addition, our results provide evidence for cross talk between bone marrow and vasculature.

[Nitrate: a pioneer from the mouth to the systemic health and diseases]

Dietary nitrate which mainly comes from green leafy vegetables, is absorbed into blood circulation by the intestinal mucosa. Parotid gland is an important organ for transporting nitrate. Nitrate in blood is taken up by sialin, a nitrate transporter and concentrated in salivary glands and secreted into saliva. The salivary nitrate is partially reduced to nitrite and nitric oxide by oral bacteria, and then salivary nitrate and nitrite return into blood circulation with swallowing and intestinal mucosal absorption. As a non-classic source of nitric oxide, nitrate-nitrite-nitric oxide pathway plays an important role on physiological and pathological conditions, especially on the condition of hypoxia and ischemia. These functions include body protection, such as gastrointestinal tract, cardiovascular system, anti-inflammation, regulation of glucose/lipid metabolism, improvement of sport ability, maintaining gut microbiome hemostasis, and alleviating senility. The traditional view on nitrate as a harmful substance to human body has been proved to be lack of scientific evidence. With further research and application, as a pioneer from the mouth to the whole body, nitrate is expected to play a crucial part in human health, and prevention and treatment of systemic diseases.

[Effects of Prrx2 gene silencing on the proliferation of breast cancer and its molecular mechanisms]

Objective: The aim of this study was to investigate the effects of silencing Paired related homoeobox 2 (Prrx2) expression on the proliferation of breast cancer and its molecular mechanisms. Methods: Short hairpin RNA knockdown of Prrx2 was used to examine cellular effects of Prrx2. The level of Prrx2 was verified by Western blot. MTT assay was used to analyze the proliferation of breast cancer cells in vitro. To investigate the effect of Prrx2 depletion on tumor growth in vivo, a nude mouse xenograft model was performed. Results: The expression of Prrx2 decreased 91.2% in MDA-MB-231 cells and 88.7% in MCF-7 cells after transfection with interfering vectors (P<0.05). MTT assay showed that the proliferation of cells in silenced Prrx2 expression group was significantly inhibited compared with the control group (P<0.05). Nude mice transplanted tumors showed that the growth of transplanted tumors was slow after silencing Prrx2 expression, and the weight of the tumors of silenced Prrx2 expression group were smaller than those of the control group ((160.2±26.3)mg vs (365.4±19.7)mg, P<0.05). Western blot showed that silencing Prrx2 expression inhibited the expression of β-catenin in breast cancer cell nucleus and down-regulated the activity of Wnt/β-catenin signaling pathway. Conclusions: Silencing Prrx2 expression can effectively inhibit the proliferation and growth of breast cancer, suggesting that Prrx2 may become a new target for the treatment of breast cancer.

Letter to the Editor "Association between the interleukin-6-174 G/C polymorphism and risk of ischemic stroke: a meta-analysis", published in Genet. Mol. Res. 14 (4): 13076-13083 (2015)

Dear Editor, We read the article "Association between the interleukin-6-174 G/C polymorphism and risk of ischemic stroke: a meta-analysis" by Jin et al. (2015) with great interest. The authors searched the literature for data sources to analyze the relationship between interlerukin-6-174G/C and ischemic stroke. Their meticulousness in study selection and data extraction is highly commendable. Of all the studies included in this meta-analysis, we were particularly interested in the extraction of data reported by Banerjee et al. (2008). For this study, Jin et al. (2015) considered all the 176 patients in the ischemic-stroke group, although 64 of them had hemorrhagic stroke. According to pathology, ischemic stroke and hemorrhagic stroke are two of the three main types of stroke (Rodgers, 2013). Each has several subtypes, with distinct underlying vascular pathologies; their pathogenesis has also been distinguished. Inflammation and genetic factors play an important role in the development of ischemic stroke (Gao et al., 2006; Jin et al., 2010). Moreover, ischemic stroke is characterized by thrombus, which is a complex process mainly induced by either hyper- or hypo-tension (Tong et al., 2016). On the contrary, hemorrhagic stroke is mainly attributed to various environmental and genetic risk factors, and is triggered by cerebral hemorrhage (Ikram et al., 2012). Ischemic stroke is usually accompanied by the occurrence of hemorrhagic transformation in patients, especially after thrombolytic therapy (Jickling et al., 2014). Thus, ischemic stroke and hemorrhagic stroke involve related, but different processes. Ideally, Jin et al. (2015) should have considered data for the 112 patients with ischemic stroke for their meta-analysis, instead of those for all the 176 patients. The result of this study would also have been more accurate and reliable. Further, in the second paragraph of the discussion section in this paper, the authors stated that, "This is the first systematic study of the association between the IL6 -174 G/C polymorphism and ischemic stroke risk using meta-analysis." However, we would like to bring to your notice that there have been a few meta-analytical studies on the association between IL6-174G/C polymorphism and ischemic stroke (Ye et al., 2012; Kumar et al., 2015). The literature included in Ye et al. (2012) meta-analysis is not as extensive as that in the study by Jin et al. (2015). The study by Kumar et al. (2015) included more relevant literatures. The results of these three studies are similar. All of them concluded that IL-6-174G/C gene polymorphisms may not be associated with an increased susceptibility to ischemic stroke. Thus, we suggest more attention should be paid to these relevant studies. Undoubtedly, a more systematic and comprehensive approach to literature searching was required in the study by Jin et al. (2015).

[Influencing factors of visual hallucinations in patients with Parkinson's disease and its relationship with sleep disorders]

OBJECTIVE

To investigate the prevalence and influencing factors of visual hallucinations in patients with Parkinson's disease(PD), and to analyze the relationship between visual hallucinations and sleep disorders.

METHODS

We recruited 187 patients with PD(H-Y Ⅰ-Ⅲ) from outpatient department in Beijing Hospital. The patients were investigated for general information and the use of medicine. The patients were divided into visual hallucination(VH) group and non-hallucination(non-VH) group. A comparison study was conducted between two groups. We investigated the sleep disorders of PD patients according to Non Motor Symptom Quest(NMSquest) and Parkinson's disease sleep scale(PDSS). Logistic stepwise multiple regression procedures were used to determine the best predictive model of visual hallucinations in patients with PD.

RESULTS

(1) 42 cases(22.5%) of PD patients were accompanied by visual hallucinations; (2) the VH group and non-VH group had no difference in age, sex, duration of illness, the scores of Minimum Mental State Examination(MMSE) and levodopa equivalent doses (LED). The scores of Unified Parkinson's Disease Rating Scale(UPDRS) Ⅰ, the Hamilton Rating Scale for Anxiety(HAMA) and the Hamilton Rating Scale for Depression(HAMD) in VH group were significantly higher than those in non-VH group[3.5(2, 5) vs 2 (1, 3); 10(6.75, 15) vs 8(5, 11); 11(7.75, 17) vs 9(5, 13); P<0.05]; (3) the incidences of vivid dreams and REM sleep behavior disorder(RBD) in VH group were significantly higher than those in non-VH group(61.9% vs 40.7%, 71.4% vs 47.6%, P<0.05). There were no significant differences in incidences of excessive daytime sleepiness and restless legs between two groups(P>0.05). The score of PDSS in VH group was significantly lower than that in non-VH group[111(92.75, 128.25) vs 123(109, 135), P<0.05]; (4) the Logistic stepwise multiple regression revealed that vivid dreams(P=0.045) and the score of PDSS(P=0.006) were the independent influencing factors for VH in PD patients.

CONCLUSIONS

The incidence of VH in PD with H-Y staging Ⅰ-Ⅱ is 22.5%. The presence of vivid dreams and severe sleep disorder are independently associated with VH in PD.

Over-expression of protein kinase C isoforms (α, δ, θ and ζ) in squamous cervical cancer

Protein kinase C was found to be significantly over-expressed in cancer samples compared to adjacent normal cervical tissues by proteomics in our previous study. The aim of this study was to examine protein kinase C expression and to analyze the expression patterns of protein kinase C isoforms in squamous cervical cancer at the protein levels and their associations with clinical and pathologic factors of squamous cervical cancer. First, Western blotting was used to examine protein kinase C expression in the specimens of tumors and matched adjacent normal tissues which were collected from 12 patients with squamous cervical cancer. Protein kinase C isoforms (α, δ, θ and ζ) expression were then detected by immunohistochemistry in other 43 cases of squamous cervical cancer tissues, 32 cases of corresponding adjacent normal cervical squamous epithelial tissue and 31 cases of cervical intraepithelial neoplasia. Western blot analysis revealed that protein kinase C expression was positive in squamous cervical cancer while it was not expressed in normal cervical tissues. On the other hand, immunohistochemical analysis suggested that, protein kinase C isoforms (α, δ, θ and ζ) expression was significantly higher in squamous cervical cancer compared to cervical intraepithelial neoplasia, as well as in cervical intraepithelial neoplasia compared with normal tissues, respectively.High levels of protein kinase C α expression were associated with cellular differentiation(P<0.05). Protein kinase C δ was significantly associated with tumor stage (P<0.05) and protein kinase C ζ was associated with lymphatic metastasis (P < 0.05). These findings indicate that protein kinase C isoforms expression in cervical lesions was associated with carcinogenesis and might play important roles throughout the process of cervical cancer development.

A family with osteoporosis pseudoglioma syndrome due to compound heterozygosity of two novel mutations in the LRP5 gene

Osteoporosis pseudoglioma syndrome (OPPG) is an autosomal recessive disorder due to mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene. Here, we report two novel missense mutations found in a southern Chinese family of a non-consanguineous marriage. Three out of four children had blindness, low bone mineral density (BMD) and multiple fractures in their childhood. Genotyping by DNA sequencing demonstrated 2 new mutations in exon 7 of the LRP5 gene. Tryptophans at amino acid residue positions 478 and 504 were replaced by arginine (W478R) and cysteine (W504C), respectively. While the parents that possessed either heterozygous W478R or W504C were apparently normal, all affected subjects were compound heterozygotes for the W478R and W504C mutations in the LRP5 gene. W478R is located immediately C-terminal to the third YWTD repeat of the second YWTD/EGF domain in LRP5, while W504C is located between the third and the fourth YWTD repeats of the second YWTD/EGF domain in LRP5. Using LRP5-related proteins, such as the low-density lipoprotein receptor (LDLR) and nidogen as reference models, a homology model of LRP5 suggested that the observed mutations may affect the molecular interactions of LRP5 and so lead to the observed OPPG phenotypes.

Effects of cyproheptadine on TXB2 and 6-keto-PGF1 alpha plasma levels in rabbits with hemorrhagic shock

Profound hemorrhagic shock was produced in 26 rabbits by exsanguination via carotid artery until blood pressure (BP) = 5.3 kPa (40 mmHg) for a period of 90 min. Rabbits were equally divided into a cyproheptadine (Cyp) treated group and a control group. The blood samples before and 90 min after shock and 30 min after liquid and blood infusion and administering Cyp (10 mg.kg-1) were collected from the carotid artery. With radioimmunoassay, we measured the thromboxane B2(TXB2) and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) contents in plasma. The results indicated that the TXB2 and 6-keto-PGF1 alpha levels during shock (1024 +/- 924, 30 +/- 32) and after liquid and blood infusion (990 +/- 943, 60 +/- 54) were higher than those (221 +/- 134, 6 +/- 4) in normal rabbits (P < 0.01, P < 0.05). Cyp reduced obviously the TXA2 plasma level in rabbit with shock (304 +/- 299 vs 990 +/- 943, P < 0.05). We conclude that the decrease of TXB2 content is one of the possible mechanisms of cyproheptadine anti-shock effect.