Human amniotic MSCs-mediated anti-inflammation of CD206hiIL-10hi macrophages alleviates isoproterenol-induced ventricular remodeling in mice

BACKGROUND

Human amniotic mesenchymal stem cells (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammation which makes them suitable for the treatment of various diseases.

OBJECTIVE

This study aimed to explore the therapeutic effect and molecular mechanism of hAMSCs in ventricular remodeling (VR).

METHODS

hAMSCs were characterized by a series of experiments such as flow cytometric analysis, immunofluorescence, differentiative induction and tumorigenicity. Mouse VR model was induced by isoproterenol (ISO) peritoneally, and the therapeutic effects and the potential mechanisms of hAMSCs transplantation were evaluated by echocardiography, carboxy fluorescein diacetate succinimidyl ester (CFSE) labeled cell tracing, histochemistry, qRT-PCR and western blot analysis. The co-culturing experiments were carried out for further exploring the mechanisms of hAMSCs-derived conditioned medium (CM) on macrophage polarization and fibroblast fibrosis in vitro.

RESULTS

hAMSCs transplantation significantly alleviated ISO-induced VR including cardiac hypertrophy and fibrosis with the improvements of cardiac functions. CFSE labeled hAMSCs kept an undifferentiated state in heart, indicating that hAMSCs-mediated the improvement of ISO-induced VR might be related to their paracrine effects. hAMSCs markedly inhibited ISO-induced inflammation and fibrosis, seen as the increase of M2 macrophage infiltration and the expressions of CD206 and IL-10, and the decreases of CD86, iNOS, COL3 and αSMA expressions in heart, suggesting that hAMSCs transplantation promoted the polarization of M2 macrophages and inhibited the polarization of M1 macrophages. Mechanically, hAMSCs-derived CM significantly increased the expressions of CD206, IL-10, Arg-1 and reduced the expressions of iNOS and IL-6 in RAW264.7 macrophages in vitro. Interestingly, RAW264.7-CM remarkably promoted the expressions of anti-inflammatory factors such as IL-10, IDO, and COX2 in hAMSCs. Furthermore, the CM derived from hAMSCs pretreated with RAW264.7-CM markedly inhibited the expressions of fibrogenesis genes such as αSMA and COL3 in 3T3 cells.

CONCLUSION

Our results demonstrated that hAMSCs effectively alleviated ISO-induced cardiac hypertrophy and fibrosis, and improved the cardiac functions in mice, and the underlying mechanisms might be related to inhibiting the inflammation and fibrosis during the ventricular remodeling through promoting the polarization of CD206hiIL-10hi macrophages in heart tissues. Our study strongly suggested that by taking the advantages of the potent immunosuppressive and anti-inflammatory effects, hAMSCs may provide an alternative therapeutic approach for prevention and treatment of VR clinically.

[A case of ocular albinism with an abnormal visual evoked potential]

A 16-year-old male patient had poor binocular vision, alternating exotropia, horizontal nystagmus, and no obvious pigmentation loss in the eyes and other parts of the body. Optical coherence tomographic examination showed no normal central macular depression. The three-channel flash visual evoked potential method was used to examine each eye. The left and right channel reactions were found to be significantly asymmetric, and the clinical diagnosis was ocular albinism.

[Efficacy of fenestrated atrial septal defect occulders on pulmonary hypertension dogs]

Objective: To explore the short-term efficacy of fenestrated atrial septal defect (ASD) occulders in the treatment of pulmonary arterial hypertension (PAH). Methods: Thirty-six healthy dogs were divided into the balloon atrial septostomy (BAS)+fenestrated ASD occulders group (n=12), BAS group (n=12) and non-septostomy group (n=12). PAH was induced by intra-atrial injection of dehydrogenized monocrotaline (1.5 mg/kg) in all dogs. Animals in the BAS+fenestrated ASD occulders group underwent atrial septal puncture and fenestrated ASD occulders implantation. Animals in the BAS group underwent balloon atrial septostomy. The non-septostomy group received no surgical intervention. The hemodynamic indexes and blood N-terminal pro-B-type natriuretic peptide (NT-proBNP) of dogs were measured before modeling, 2 months after modeling, 1, 3, and 6 months after surgery, respectively. Echocardiography was performed to observe the patency of the shunt and atrial septostomy of the dogs in the BAS+fenestrated ASD occulders group and BAS group at 1, 3, and 6 months after surgery. Three dogs were sacrificed in each group at 1, 3, and 6 months after surgery, respectively. Atrial septal tissue and fenestrated ASD occulders were removed to observe the patency and endothelialization of the device. Lung tissues were obtained for hematoxylin-eosin (HE) staining to observe the inflammatory cells infiltration and the thickening and narrowing of the pulmonary arterials. Results: Among 36 dogs, 2 dogs died within 24 hours after modeling, and 34 dogs were assigned to BAS+fenestrated ASD occulders group (n=12), BAS group (n=11), and non-septostomy group (n=11). Compared with BAS group, the average right atrial pressure (mRAP) and NT-proBNP of dogs in the BAS+fenestrated ASD occulders group were significantly reduced at 3 months after surgery (P<0.05), and the cardiac output (CO) was significantly increased at 6 months after surgery, arterial oxygen saturation (SaO₂) was also significantly reduced (P<0.05). Compared with non-septostomy group, dogs in the BAS+fenestrated ASD occulders group had significantly lower mRAP and NT-proBNP at 1, 3, and 6 months after surgery (P<0.05), and higher CO and lower SaO₂ at 6 months after surgery (P<0.05). Compared with the non-septostomy group, the dogs in the BAS group had significantly lower mRAP and NT-proBNP at 1 month after surgery (P<0.05), and there was no significant difference on mRAP and NT-proBNP at 3 and 6 months after surgery (P>0.05). Echocardiography showed that there was a minimal right-to-left shunt in the atrial septum in the BAS group at 1 month after the surgery, and the ostomy was closed in all the dogs in the BAS group at 3 months after the surgery. There was still a clear right-to-left shunt in the dogs of BAS+fenestrated ASD occulders group. The shunt was well formed and satisfactory endothelialization was observed at 1, 3 and 6 months after surgery. The results of HE staining showed that the pulmonary arterials were significantly thickened, stenosis and collapse occurred in the non-septostomy group. Pulmonary microvascular stenosis and inflammatory cell infiltration in the pulmonary arterials were observed in the non-septostomy group. Pulmonary arterial histological results were comparable between BAS+fenestrated ASD occulders group and non-septostomy group at 6 months after surgery. Conclusions: The fenestrated ASD occulder has the advantage of maintaining the open fistula hole for a longer time compared with simple balloon dilation. The fenestrated ASD occulder can improve cardiac function, and it is safe and feasible to treat PAH in this animal model.

[Association between D-dimer levels and clinical events in patients with mechanical heart valve replacement under oral anticoagulation therapy]

Objective: To investigate the association between D-dimer levels and clinical events in patients with mechanical heart valve replacement under oral anticoagulation therapy. Methods: This prospective study included 640 consecutive patients underwent mechanical heart valve replacement in Wuhan Asia Heart Hospital between January 2013 and June 2014.Patients were assigned to abnormal D-dimer group (D-dimer level>cut off value, n=88) and normal D-dimer group (D-dimer level≤cut off value, n=552) according to D-dimer levels measured at 3 months after the initiation of oral anticoagulation therapy.All patients were followed up for 24 months or until the observation of the end points, which included thrombotic events, bleeding events and all-cause deaths.The anticoagulation therapy was monitored once per 1-2 months by the international normalized ratio (INR), and the target value was 1.8-3.0. Results: During a follow-up period of 24 months, rates of total clinical events (19.30%(17/88) vs. 5.8%(32/552), P<0.01), thrombotic events (11.4%(10/88) vs. 2.3%(13/552), P<0.01), and all-cause deaths (8.0%(7/88) vs. 2.0%(11/552), P<0.01) were all significantly higher in abnormal D-dimer group than in normal D-dimer group.There were no significant difference in bleeding events between the two groups (2.3%(2/88) vs. 3.1%(17/552), P=0.77). Multivariate Cox regression analysis showed that high D-dimer level was an independent risk factor of total clinical events (HR=3.86, 95%CI 1.92-7.76, P<0.01), thrombotic events(HR=5.29, 95%CI 2.12-13.10, P<0.01), and all-cause deaths(HR=5.32, 95%CI 1.71-16.60, P<0.01), but which was not correlated with bleeding events(HR=1.36, 95%CI 0.27-6.84, P=0.71). Conclusion: Elevated D-dimer levels are linked with clinical events in patients with mechanical heart valve replacement under oral anticoagulation therapy.

Intracavitary Contrast-Enhanced Ultrasound in the Management of Post-Surgical Gastrointestinal Fistulas

The goal of this study was to investigate intracavitary contrast-enhanced ultrasound (IC-CEUS) measures in the management of post-surgical gastrointestinal (GI) fistula throughout detection, treatment and follow-up. From June 2010 to August 2016, patients who were administered ultrasound contrast agent (UCA) via a drainage tube for IC-CEUS were enrolled and retrospectively analyzed. They were suspected of having GI anastomotic fistulas or had been found to have fluid collections with ultrasound that were accompanied by abdominal pain or fever after surgical procedures. Forty-two patients met the inclusion criteria and were enrolled into this study. Twenty-two were confirmed to have GI fistulas confirmed by standard references. None were detected by conventional ultrasound. Although IC-CEUS successfully detected GI fistulas in 16 patients, it missed GI fistulas in 6 patients. One patient was misdiagnosed with a GI fistula. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the diagnosis of GI fistulas by IC-CEUS were 72.7% (16/22), 95.0% (19/20), 94.1% (16/17), 76.0% (19/25) and 83.3% (35/42), respectively. Twenty peritoneal fluid collections in 14 patients were related to fistulas by IC-CEUS based on the distribution of ultrasound contrast agents. Additional drainage was performed in 14 fistula-related fluid collections. Eight GI fistulas were judged to be cured after IC-CEUS re-evaluation, and the drainage tubes were removed from these patients. In conclusion, IC-CEUS can greatly improve the ability to diagnose post-surgical GI fistulas and may also play an important role in interventional treatment and follow-up.

[Analysis of pulmonary valve function in patients with tetralogy of Fallot after radical surgery]

Objective: To analyze the pulmonary valve function in patients with tetralogy of Fallot after radical surgery. Methods: Clinical data of 263 patients (119 male, mean age (33.2±11.5) years old) with tetralogy of Fallot underwent radical surgery in our hospital from January 2010 to June 2016 were retrospectively analyzed. According to age, patients were divided into 14-17 years old group (14 cases), 18-29 years old group (100 cases), 30-39 years old group (61 cases) and above 40 years old group (87 cases). The patients were divided into pulmonary regurgitation group (87 cases) and control group (176 cases) according to weather they have moderate or severe pulmonary regurgitation. Echocardiographic data were compared among groups. Results: A total of 83 patients received re-operation. The median age of the primary radical operation was 9 (5, 13) years, and the median time from the primary radical operation to echocardiographic follow-up was 5 (1, 13) years. Among the 263 enrolled patients, prevalence of pulmonary regurgitation was 36.1% (95/263), and pulmonary stenosis was evidenced in 28 patients (10.6%). The ratio of moderate to severe tricuspid regurgitation was 14.3% (2/14), 27.0% (27/100), 32.8% (20/61) and 37.9% (33/87) in 14-17 years old group, 18-29 years old group, 30-39 years old group and above 40 years old group, respectively (P=0.029), while prevalence of moderate and severe pulmonary regurgitation, moderate and severe pulmonary valve stenosis, pulmonary valve transvalvular pressure >40 mmHg (1 mmHg=0.133 kPa), right atrial and right ventricular enlargement ratio were similar among groups (all P>0.05). The ratio of moderate and severe tricuspid regurgitation and right ventricular enlargement in the pulmonary regurgitation group was significantly higher than in the control group (40.2% (35/87) vs. 27.3% (48/176) and 96.6% (84/87) vs. 87.5% (154/176), all P<0.05), while left ventricular ejection fraction, right atrial enlargement, and right ventricular wall thickness were similar between the two groups (all P>0.05). Conclusion: Pulmonary regurgitation is a common clinical feature among survivors of tetralogy of Fallot patients after radical surgery, and moderate to severe pulmonary regurgitation increases the risk of tricuspid regurgitation and enlargement of the right ventricle.