ABSTRACT
Stromal cell-derived growth factor (SDF)-1α acts as a ligand to C-X-C chemokine receptors 4 (CXCR4) and 7 (CXCR7), which are involved in the formation of choroidal neovascularization. Previous studies have demonstrated crosstalk between the platelet-derived growth factor (PDGF)-BB/PDGF receptor (PDGFR)-ß and SDF-1α/CXCR4 axes during tumor neovascularization by increasing the recruitment of pericytes. However, the effects of interactions between these two signaling pathways in retinal microvascular pericytes remain poorly understood. Western blotting and reverse transcription-quantitative PCR were used to measure CXCR4 and CXCR7 expression in PDGF-BB-treated pericytes, whilst Cell Counting Kit-8 and Transwell migration assays were used to investigate cell viability and migration following PDGF-BB pretreatment on SDF-1α-treated pericytes. Exogenous PDGF-BB enhanced CXCR4 and CXCR7 expression through PDGFR-ß in a dose- and time-dependent manners. In addition, PDGF-BB increased cell viability and migration in SDF-1α-treated pericytes, which were inhibited by AMD3100 and niclosamide, inhibitors for CXCR4 and STAT3 respectively. Crosstalk between PDGF-BB/PDGFR-ß and SDF-1α/CXCR4/CXCR7 were involved in the JAK2/STAT3 signaling pathway. PDGF-BB treatment enhanced CXCR4, CXCR7 and PDGFR-ßexpression, which may be associated with the phosphorylation of STAT3. siRNA-PDGFR-ß transfection reduced CXCR4 and CXCR7 expression in pericytes. Therefore, PDGF-BB directly targets PDGFR-ß and serves an important role in regulating CXCR4 and CXCR7 expression, ultimately affecting viability and migration in SDF-1α-treated pericytes. Therefore, targeting CXCR4/CXCR7 may serve as a potential therapeutic strategy for fundus diseases.
ABSTRACT
OBJECTIVE: To analyze the clinical features, risk factors and drug uses of senior hospitalized patients with chronic constipation. METHODS: A total of 162 hospitalized patients aged 85 years and over at our hospital during the period of January-March 2012 conducted a questionnaire survey. There were 137 males and 25 females. And 112 cases of chronic constipation were diagnosed in accordance with the Rome III criteria. The survey included general condition, risk factors of constipation, spectrum of symptoms, associated symptoms, previous medication and medication for constipation after admission. The results were statistically analyzed by Logistic regression. RESULTS: Their average age was (90 ± 4) years old. And the total prevalence of chronic constipation was 69.1% (112/162). Logistic regression analysis showed that less activity (OR = 10.873) and diet (OR = 4.752) were the important risk factors. Defecation effort was the most common symptom (n = 85, 75.9%). A total of 88 cases (78.6%) took lactulose alone or lactulose plus other laxatives. The reasons of using lactulose were as follows: dietary restrictions (n = 31, 35.2%), aspiration prevention (n = 21, 23.9%) and poor efficacy of other laxatives (n = 36, 40.9%). CONCLUSIONS: Prevalence of constipation is high among senior hospitalized patients. Less activity and diet are the main risk factors. And lactulose should be a first-line therapy.
