Viable Allogeneic Mitochondria Transplantation Improves Gas Exchange and Alveolar-Capillary Permeability in Rats with Endotoxin-Induced Acute Lung Injuries.

Background: Acute lung injuries (ALI) cause disruption of the alveolar-capillary barrier and is the leading cause of death in critically ill patients. This study tested the hypothesis that the administration of freshly isolated viable allogeneic mitochondria can prevent alveolar-capillary barrier injuries at the endothelial level, as mitochondrial dysfunction of the pulmonary endothelium is a critical aspect of ALI progression. Methods: ALI was induced by intratracheal lipopolysaccharide instillation (LPS, 1mg/kg) in anesthetized rats. Mitochondria (100 µg) were isolated from the freshly harvested soleus muscles of naïve rats and stained with a green fluorescence MitoTracker™ dyne. A mitochondria or placebo solution was randomly administered into the jugular veins of the rats at 2 h and 4 h after ALI induction. An arterial blood gas analysis was done 20 h later. The animals were then sacrificed and lung tissues were harvested for analysis. Results: An IVIS Spectrum imaging system was used to obtain ex vivo heart-lung block images and track the enhancement of MitoTracker™ fluorescence in the lungs. Mitochondria transplantation significantly improved arterial oxygen contents (PaO2 and SaO2) and reduced CO2 tension in rats with ALI. Animals with mitochondrial transplants had significantly higher ATP concentrations in their lung tissues. Allogeneic mitochondria transplantation preserved alveolar-capillary barrier function, as shown by a reduction in protein levels in the bronchoalveolar lavage fluid and decreased extravasated Evans blue dyne and hemoglobin content in lung tissues. In addition, relaxation responses to acetylcholine and eNOS expression were potentiated in injured pulmonary arteries and inflammatory cells infiltration into lung tissue was reduced following mitochondrial transplantation. Conclusions: Transplantation of viable mitochondria protects the integrity of endothelial lining of the alveolar-capillary barrier, thereby improving gas exchange during the acute stages of endotoxin-induced ALI. However, the long-term effects of mitochondrial transplantation on pulmonary function recovery after ALI requires further investigation.

Prolonged preoperative fasting induces postoperative insulin resistance by ER-stress mediated Glut4 down-regulation in skeletal muscles.

Preoperative fasting aims to prevent pulmonary aspiration and improve bowel preparation, but it may induce profound systemic catabolic responses that lead to protein breakdown and insulin-resistant hyperglycemia after operation. However, the molecular mechanisms of catabolic reaction induced by prolonged preoperative fasting and surgical stress are undetermined. In this study, anesthetized rats were randomly assigned to receive a sham operation or laparotomy cecectomy. Fasting groups were restricted from food and water for 12 h before operation, while the feeding group had free access to food throughout the study period. Twenty-four hours after operation, the animals were sacrificed to collect blood samples and soleus muscles for analysis. Postoperative blood glucose level was significantly increased in the fasting group with elevated serum insulin and C-peptide. Continuous feeding reduced serum myoglobin and lactate dehydrogenase concentrations. Preoperative fasting activated inositol-requiring transmembrane kinase/endoribonuclease (IRE)-1α and c-Jun N-terminal kinase (JNK) mediated endoplasmic reticulum (ER)-stress, and reduced glucose transporter type 4 (Glut4) expression in the soleus muscle. Phospholamban phosphorylation was reduced and intracellular calcium levels were increased in the isolated skeletal muscle cells. Similar results were found in ER stress-induced C1C12 myoblasts. The expression of Glut4 was suppressed in the stressed C1C12, but was potentiated following inhibition of ER stress and chelation of intracellular free calcium. This study provides evidence demonstrating that prolonged preoperative fasting induces ER stress and generates insulin resistance in the skeletal muscle through suppression of Glut4 and inactivation of Ca2+-ATPase, leading to intracellular calcium homeostasis disruption and peripheral insulin resistance.

Morphine Induces Fibroblast Activation through Up-regulation of Connexin 43 Expression: Implication of Fibrosis in Wound Healing.

Morphine is the most effective drugs for attenuating various types of severe pain, but morphine abuse carries a high risk of systemic fibrosis. Our previous have indicated that systemic administration of morphine hinders angiogenesis and delays wound healing. Here we have explained the pathological mechanism underlying the effect of morphine on wound healing. To determine how morphine affects wound healing, we first created a wound in mice treated them with a combination of a low doses (5 mg/kg/day) and high doses (20 or 30 mg/kg/day) of morphine. An In vivo study revealed that high-dose morphine-induced abnormal myofibroblasts persist after the end of wound healing because of connexin 43 (Cx43) upregulation. High-dose morphine-induced Cx43 increased the expression levels of focal adhesion molecules, namely fibronectin and alpha-smooth muscle actin (α-SMA) through the activation of transforming growth factor (TGF)-ß1 signaling. In addition, we found that Cx43 contributed to TGF-ßRII/ Smad2/3 signaling for regulating the differentiation of fibroblasts into myofibroblasts during high-dose morphine exposure. In conclusion, the abnormal regulation of Cx43 by morphine may induce systemic fibrosis because of abnormal myofibroblast function.

The Role of Community Education in Increasing Knowledge of Breast Health and Cancer: Findings from the Asian Breast Cancer Project in Boston, Massachusetts.

In the past decade, cancer rates have significantly decreased in the USA, but breast cancer survival is lower in Asian American women, likely due to lower rates of screening behaviors in Asian Americans compared to other ethnicities, which could lead to later stage cancer diagnosis and increased mortality. This paper reports on the Asian Breast Cancer (ABC) Project, a three-phase peer-led community program designed to promote cancer prevention by improving breast cancer screening rates among Chinese and Vietnamese women in the Greater Boston area. The three phases of planning and coalition building, community health worker training, and the community workshop intervention are described. The workshop intervention was evaluated by comparing pre- and post-workshop questionnaires evaluating knowledge about breast cancer screening and prevention. Two hundred fifty-two women participated in the program across 14 workshops. Each participant completed questionnaires about demographics, access to health care, and a five-item self-administered questionnaire about breast cancer knowledge. Results showed that the majority of the women had received a clinical breast exam or mammogram in the past 12 months (69 and 59 %, respectively), and older women were more likely to get a mammogram (85 %) or clinical breast exams (74 %) compared to younger women. Eighty-one percent of women were interested in reminder systems. Baseline knowledge was high for three survey questions about mammograms and breast cancer risk (88-97 %). For questions with fewer correct answers at baseline, knowledge about the meaning of lumps in the breast significantly increased (69 to 80 % correct, p < 0.0001), as well as knowledge about frequency of clinical breast exam (48 to 67 % correct, p < 0.0001). This pilot project indicated a partial effectiveness of the community workshop in a population with high baseline knowledge. The education workshop increased knowledge about breast lumps and clinical exam frequency. We also identified that reminder systems and appointment assistance are desired by this population. Our findings inform future cancer screening strategies for Asian Americans.

Mobilization of Endothelial Progenitor Cells Following Creation of Arteriovenous Access in Patients with End-Stage Renal Disease.

BACKGROUND: A patent arteriovenous (AV) fistula induces activation of regional vascular endothelium and vascular shear force. Shear stress is an important physiological force in mobilizing endothelial progenitor cells (EPCs). This study aimed to explore the perioperative changes of circulating EPC levels for patients who require hemodialysis and underwent radiocephalic fistula operation. METHODS: This prospective cohort study included patients who received a radiocephalic fistula surgery when they were between 25 and 65 years of age. The subjects were followed for 90 days postoperatively for any stenotic events or immaturity of the fistula. Blood samples were obtained on the day before surgery and at postoperation day (POD) 3 and 30. CD133+/KDR+ cells, defined as EPCs, were analyzed using flow cytometry. Blood flow of the fistula was followed on POD 3 and 30. RESULTS: A total of 30 patients were enrolled in the study from July 2009 to December 2011. One patient dropped out of the study and seven patients developed a stenotic (or immature) AV fistula (7/29, 24.1%). There were positive linear relationships between EPC numbers and shear rate postoperatively, which were more significant on POD 30. In addition, postoperative mobilization of EPCs was significantly higher in patients who developed a stenotic fistula than those without. CONCLUSIONS: The mobilization of circulating EPCs correlated with a compromised arteriovenous fistula. The biological significance of increased EPC numbers need to be determined in future studies. KEY WORDS: Arteriovenous fistula; Endothelial progenitor cells.

Preconditioning renoprotective effect of isoflurane in a rat model of virtual renal transplant.

BACKGROUND: The development of warm-cold ischemia-reperfusion (IR) injury of the kidney grafts is inevitable during renal transplantation. However, there is currently no definite renoprotective strategy available in the protection of the graft tissue. In the present study, we compared the renal protection of preconditioning isoflurane with N-acetylcysteine (NAC) in a novel rat model of warm-cold renal IR injury. MATERIALS AND METHODS: Adult Sprague-Dawley rats were randomly assigned to receive inhaled isoflurane (1.5% for 2 h), NAC (1 g/kg, intra-arterial injection) or placebo before the induction of brief warm ischemia (10 min) followed by cold ischemia (45 min) periods. Plasma levels of creatinine and tissue inflammatory reaction in the kidney were analyzed 72 h after reperfusion. RESULTS: Elevated plasma level of creatinine and urea indicated the development of acute renal injury secondary to IR injury. The creatinine levels were reduced in animals pretreated with inhaled isoflurane and NAC, and the level was more significantly decreased in the isoflurane-treated group. Preconditioning with volatile isoflurane also significantly suppressed the tissue myeloperoxidase activity and expression of the inducible nitric oxide synthase. Immunostaining confirmed that myeloperoxidase expression was most significantly attenuated in the glomerulus and peritubular capillaries of rats pre-exposed to isoflurane. CONCLUSIONS: We present the first study demonstrating that the administration of volatile isoflurane before induction of experimental warm-cold renal IR injury provides preconditioning renoprotective effect, which is superior to the treatment with NAC. The beneficial renoprotective effect of isoflurane is most likely mediated by attenuation of proinflammatory reaction in the injured kidney.

InGaN blue resonant cavity micro-LED with RGY quantum dot layer for broad gamut, efficient displays.

The technology of RGBY micro resonant cavity light emitting diodes (micro-RCLEDs) based on quantum dots (QDs) is considered one of the most promising approaches for full-color displays. In this work, we propose a novel structure combining a high color conversion efficiency (CCE) QD photoresist (QDPR) color conversion layer (CCL) with blue light micro RCLEDs, incorporating an ultra-thin yellow color filter. The additional TiO2 particles inside the QDPR CCL can scatter light and disperse QDs, thus reducing the self-aggregation phenomenon and enhancing the eventual illumination uniformity. Considering the blue light leakage, the influences of adding different color filters are investigated by illumination design software. Finally, the introduction of low-temperature atomic layer deposition (ALD) passivation protection technology at the top of the CCL can enhance the device's reliability. The introduction of RGBY four-color subpixels provides a viable path for developing low-energy consumption, high uniformity, and efficient color conversion displays.

Innovative Stacked Yellow and Blue Mini-LED Chip for White Lamp Applications.

This study introduces a novel approach for fabricating vertically stacked mini-LED arrays, integrating InGaN yellow and blue epitaxial layers with a stress buffer layer to enhance optoelectronic characteristics and structural stability. This method significantly simplifies the LED design by reducing the need for RGB configurations, thus lowering costs and system complexity. Employing vertical stacking integration technology, the design achieves high-density, efficient white light production suitable for multifunctional applications, including automotive lighting and outdoor signage. Experimental results demonstrate the exceptional performance of the stacked yellow and blue mini-LEDs in terms of luminous efficiency, wavelength precision, and thermal stability. The study also explores the performance of these LEDs under varying temperature conditions and their long-term reliability, indicating that InGaN-based yellow LEDs offer superior performance over traditional AlGaInP yellow LEDs, particularly in high-temperature environments. This technology promises significant advancements in the design and application of lighting systems, with potential implications for both automotive and general illumination markets.

Dual phenotypic characteristics of P-selectin in a mouse model of hemorrhagic shock and hepatectomy.

Background: Membrane-bound P-selectin induces endothelial adhesion of leucocytes and amplifies organ inflammations during major trauma, while soluble P-selectin (sP-sel) mediates survival rescue properties. This study characterized the differential effects of P-selectin in a "2-hit" model of hemorrhagic shock (HS) and partial hepatectomy (PH). Materials and methods: HS was induced by withdrawing blood (0.3 mL) directly from the mouse femoral arteries. 70% or 50% of liver volumes were resected after inducing HS. Time of survival in P-selectin deficient (Selp -/-) mice treated with and without intraperitoneal injections of recombinant P-sel IgG-Fc fusion proteins (rP-sel-Fc, 1.5 mg/kg) were recorded for up to 72h after injury. In addition, liver regeneration at 72h after HS and 50% PH was assessed in wild-type and Selp -/- mice. Results: Compared to wild-types, Selp -/- mice had significantly higher mortality rates post HS and 70% PH, as none of these animals survived up to 48h postoperatively. The survival curve was restored in Selp -/- mice pre-treated with rP-sel-Fc. In the HS followed by 50% PH experimental arm, liver remnant growth ratios were significantly higher in Selp -/- mice (15.7 ± 3.1 vs 11.7 ± 4.9, P = 0.040). The elevated serum concentrations of alanine aminotransferase post-PH were significantly reduced in Selp -/- mice. Hepatocyte proliferation indices (CYP7a1 and PCNA) expression were enhanced and myeloperoxidase activity in the regenerated remnant liver was reduced in the Selp -/- mice. Conclusion: In critical conditions induced by HS and PH, P-selectin mediates two distinct phenotypic characteristics. Soluble-form circulating P-selectin improves survival in the acute stage of HS and extensive loss of liver parenchyma; membrane-bound P-selectin induces regional pro-inflammatory reactions in the remnant liver after the acute stage of two insults, thereby inhibiting hepatic regeneration. The results of this pre-clinical study may provide molecular mechanistic insight and clinical therapeutic applications of P-selectin in the acute and regenerative phases of traumatic hepatic injury.

Intraoperative Enteral Nutrition Feeding in Free-Flap Healing after Reconstruction Surgery for Head and Neck Cancers.

OBJECTIVE: To investigate the beneficial outcomes of intraoperative enteral feeding in free-flap regeneration after extended head and neck cancer resection and flap reconstruction surgery. STUDY DESIGN: A pilot randomized, double-blind, placebo-controlled clinical trial. SETTING: Single tertiary care center. METHODS: Patients with advanced head and neck cancers requiring radical tumor resections and free-flap reconstruction were randomly assigned to receive intraoperative enteral nutrition feeding (100 kcal/100 mL at 10-20 mL/h) via a nasogastric tube during free-flap reconstruction (n = 28) or continue fasting (n = 28). The primary outcome was impaired free-flap regeneration that required surgical reintervention within 90 days after the operation. Participants were enrolled between April 2020 and January 2022; the 90-day follow-up ended in April 2022. RESULTS: The incidence of total or partial flap failure was similar between the 2 groups (14.2% or n = 4 in each group), but the rate of wound dehiscence or edge necrosis was significantly reduced in the feeding group (n = 6 vs 0 for fasting vs feeding; absolute risk reduction, 25.0% [95% confidence interval, 6.9-43.0]%; p = 0.022). Hospital stay length was shorter (p = 0.042) and hand grip strength was better preserved (p = 0.025) in the feeding group. Plasma concentrations of interleukin (IL)-6 and IL-8 after the operation increased significantly more in the fasting group. Perioperative adverse events did not differ between the 2 groups. CONCLUSION: Perioperative enteral feeding is a simple, safe, and effective approach to improve perioperative systemic catabolism and proinflammatory reactions, thereby enhancing early wound regeneration after major operations.

Cultural-Responsiveness of the Mental Health First Aid Training for Asian Immigrant Populations in Greater Boston, Massachusetts.

Background: The COVID-19 pandemic and rise in anti-Asian racism have had adverse mental health impacts in Asian communities. The lack of culturally-responsive and linguistically-accessible mental health trainings hinders access to mental health services for Asian populations. In this study, we assessed the mental health needs of Asian communities in Greater Boston and evaluated cultural responsiveness of the Mental Health First Aid (MHFA), a first-responder training teaching participants skills to recognize signs of mental health and substance use challenges, and how to appropriately respond. Methods: This community-based participatory research with the Boston Chinatown Neighborhood Center (BCNC), Asian Women For Health (AWFH), and the Addressing Disparities in Asian Populations through Translational Research (ADAPT) Coalition employed two phases. In phase 1, we conducted focus groups with BCNC and AWFH staff and peer educators to assess mental health priorities of Asian populations in Boston. Findings informed phase 2, which evaluated cultural responsiveness of the MHFA through pre- and post-training questionnaires and focus groups with community participants. The pre-training questionnaire asked about mental health needs and barriers, help-seeking behaviors, and literacy; and personal and Asian community stigma. The post-training questionnaire and focus group with community participants asked about cultural competence of MHFA training for Asian populations. Paired t-tests were used to evaluate questionnaire responses. Thematic analysis was used to analyze interviews. Results: In total, 10 staff/educators and 8 community members participated in focus groups. They identified common mental health needs and workforce and culturally-responsive community strategies to support persons with mental health issues. Twenty-four community participants completed pre- and post-training questionnaires. They reported the MHFA training reduced mental health care stigma and increased mental health literacy. Recommendations to increase cultural-responsiveness of the MHFA were to include mental health case studies common in Asian populations and provide the training in other languages (e.g., Chinese, Vietnamese). Conclusion: Cultural responsiveness of the MHFA for Asian populations could be improved with the inclusion of case studies specific to the Asian communities and accessibility of the training in other languages. Increasing the cultural relevance and language accessibility of these trainings could help reduce mental health stigma and gaps in mental health awareness and service utilization among Asian populations.

Inhibition of cyclooxygenase-2 modulates phenotypic switching of vascular smooth muscle cells during increased aortic blood flow.

This study investigates the interactions between cyclooxygenase (COX-2) and vascular smooth muscle cell (VSMC) phenotypic switching, the two important coupling mechanisms of the vasculature on arterial remodeling in response to high laminal shear stress. High aortic blood flow was induced by creating a fistula in the abdominal aorta and the adjacent IVC of anesthetized rats. Celecoxib, a selective COX-2 inhibitor (25 mg/kg/day), was fed in the chow, and animals were killed 8 weeks later. Blood flow, vasoreactivity and morphological changes in the aorta proximal to the fistula were measured. Concentrations of collagen, expression of desmin and smooth muscle myosin heavy chain (SM-MHC)-II in the aorta were determined. Celecoxib significantly increased aortic blood flow and reduced the contraction responses of aorta. Decreased medial thickness, presence of intimal thickening and derangement of elastic lamina were found in the aortic section of celecoxib-treated animals. Celecoxib significantly reduced the tissue content of collagen and upregulated expression of SM-MHC-II and desmin in the high-flow aorta. Inhibition of COX-2 enzymatic activity in the aorta exposed to higher blood flow resulted in increased blood flow and vascular remodeling. These functional changes were accomplished by VSMC phenotypic switching and reduced biosynthesis of collagen.

The preconditioning pulmonary protective effect of volatile isoflurane in acute lung injury is mediated by activation of endogenous iNOS.

PURPOSE: There is still a lack of evidence to support the use of specific anesthetic agents during major operations that could affect the development of postoperative acute lung injury (ALI). This study determined the protective effect of inhaled isoflurane in a rat model of endotoxin-induced ALI. METHODS: Rats were exposed to volatile isoflurane (1.5 % in oxygen) or pure oxygen via a facemask for 2 h. After a 3-h recovery period, rats were reanesthetized and ALI was induced by intratracheal instillation of lipopolysaccharide (LPS, 1 mg/kg in 0.5 ml saline). In some animals, a specific inducible nitric oxide synthase (iNOS) inhibitor, 1400W, (10 mg/kg, i.p.) was administered before exposure to isoflurane. Animals were sacrificed 12 h later for analysis. Pulmonary artery vasomotor function and alveolocapillary permeability were assessed. Expression of iNOS and CD11b, and activity of myeloperoxidase in the lung were analyzed. RESULTS: The maximal relaxation response to acetylcholine was significantly potentiated in rats pretreated with isoflurane. Lung wet-to-dry ratio was reduced in the lung of isoflurane-treated animals. Expression of iNOS and CD11b were attenuated in the lung tissue obtained from rats receiving isoflurane. Furthermore, enzymatic activity of myeloperoxidase was also reduced in the lung preexposed to isoflurane. However, these pulmonary protective effects of isoflurane were significantly abolished by pretreatment with 1400W. CONCLUSION: Pretreatment with volatile isoflurane attenuated inflammatory process in the lung tissue of rats with LPS-induced ALI, and this preconditioning pulmonary protective effect was mainly mediated by activation of endogenous iNOS in the lung.

Transplantation of viable mitochondria improves right ventricular performance and pulmonary artery remodeling in rats with pulmonary arterial hypertension.

OBJECTIVE: Because mitochondrial dysfunction is a key factor in the progression of pulmonary hypertension, this study tested the hypothesis that transplantation of exogenous viable mitochondria can reverse pulmonary artery remodeling and restore right ventricular performance in pulmonary hypertension. METHODS: Pulmonary hypertension was induced by parenteral injection of monocrotaline (60 mg/kg) and creation of a left-to-right shunt aortocaval fistula in rats. Three weeks after creation of fistula, the animals were randomly assigned to receive intravenous delivery of placebo solution or allogeneic mitochondria once weekly for 3 consecutive weeks. Mitochondria (100 µg) were isolated from the freshly harvested soleus muscles of naïve rats. Transthoracic echocardiography was performed at 3 weeks after mitochondrial delivery. RESULTS: Ex vivo heart-lung block images acquired by an IVIS Spectrum (PerkinElmer, Waltham, Mass) imaging system confirmed the enhancement of MitoTracker (Invitrogen, Carlsbad, Calif) fluorescence in the pulmonary arteries. Mitochondria transplantation significantly increased lung tissue adenosine triphosphate concentrations and improved right ventricular performance, as evidenced by a reduction in serum levels of B-type natriuretic peptide and ventricular diameter. Right ventricular mass and wall thickness were restored in the mitochondrial group. In the pulmonary arteries of rats that received mitochondrial treatment, vascular smooth muscle cells expressed higher levels of α-smooth muscle actin and smooth muscle myosin heavy chain II, indicating the maintenance of the nonproliferative, contractile phenotype. The hyper-reactivity of isolated pulmonary arteries to α-adrenergic stimulation was also attenuated after mitochondrial transplantation. CONCLUSIONS: Transplantation of viable mitochondria can restore the contractile phenotype and vasoreactivity of the pulmonary artery, thereby reducing the afterload and right ventricular remodeling in rats with established pulmonary hypertension. The improvement in overall right ventricular performance suggests that mitochondrial transplantation can be a revolutionary clinical therapeutic option for the management of pulmonary hypertension.

Distinct phenotypic expression levels of macrophages in neonatal lungs.

Alveolar macrophages are the front-line defense against environmental pathogens. However, to the best of our knowledge, differences in function and phenotypic expression levels of macrophages between neonatal and adult lungs have not previously been determined. The present study investigated lung tissues and analyzed blood samples to find cell markers of M1 and M2 macrophages in neonatal and adult rats. Pulmonary sepsis was induced by intrapleural instillation of lipopolysaccharide (LPS; 20 mg/kg) and survival time after administration of LPS was measured. In certain neonates, a selective inducible nitric oxide synthase (iNOS) inhibitor, 1400w, was administered prior to induction of pulmonary sepsis. Compared with adults, fetal and neonatal lung tissues had significantly higher levels of iNOS and CD86 (M1 markers), whereas the expression levels of CD206 and arginase-1 (M2 markers) were lower in the neonatal lung. The circulating cells that co-expressed CD68 (monocytes and macrophages) and CD86 in the blood were also significantly higher in neonates than in adults (25.9±6.6 vs. 11.6±2.2%; P=0.007. At basal unstimulated conditions, lung tissue concentrations of nitrite and nitrate (NOx) were significantly lower in the neonates than in adults (112.1±55.9 vs. 340.9±124.9 µM/g; P<0.001). However, NOx was increased following administration of LPS. Administration of 1400w suppressed lung tissue levels of NOx and improved the survival time in neonatal rats treated with LPS. The present study demonstrated that M1 is the primary macrophage phenotype in the neonatal lung and that higher iNOS expression levels do not have a protective effect against pulmonary endotoxins in neonates. Overproduction of NO by iNOS in neonatal alveolar macrophages may result in detrimental effects during pulmonary inflammation.

Morphine enhances tissue content of collagen and increases wound tensile strength.

PURPOSE: Morphine is a commonly prescribed analgesic for wound pain. Previous studies have shown that morphine enhances accumulation of collagen in cultured fibroblasts. Because fibroblasts are important for the remodeling of connective tissue in incisional wound, this study investigates the biological effects of morphine on cutaneous collagen content and wound tensile strength. METHODS: A full-thickness incisional wound (2 cm in length) was created on the dorsum of mice followed by treatment with placebo or morphine (5 and 20 mg/kg/day, i.p.). Fourteen days later, tensile strength of the healed incisional wound was measured using a tensiometer. Protein expression of transforming growth factor (TGF)-beta1 and matrix metalloproteinases (MMP)-2 in the incisional wound tissue was analyzed. Degree of tissue remodeling and levels of collagen were determined by histological examination and a dye-binding collagen assay, respectively. RESULTS: Morphine enhanced the breaking strength of incisional wound 14 days after treatment (92 +/- 10, 102 +/- 10 and 134 +/- 12 mg for control, morphine 5 mg/kg/day and morphine 20 mg/kg/day, respectively; P = 0.03, n = 6-7). Protein expression of TGF-beta1 and MMP-2 was significantly enhanced in mice treated with morphine. Histological examination of the wound tissue showed evidence of increased thickness of the cutaneous fibrous layer and deposition of collagen in the high-dose morphine treatment group. Collagen assays also demonstrated that tissue concentrations of collagen were significantly increased in the wound tissue of morphine-treated animals on day 2 of drug treatment. CONCLUSION: The present study demonstrates that systemic administration of morphine enhances tissue collagen deposition in the cutaneous tissue, thereby increasing the tensile strength of the incisional wound.

Autologous transplantation of endothelial progenitor cells attenuates acute lung injury in rabbits.

BACKGROUND: Acute lung injury (ALI) and end-stage acute respiratory distress syndrome (ARDS) are among the most common causes of death in intensive care units. Activation and damage of pulmonary endothelium is the hallmark of ALI/ARDS. Recent studies have demonstrated the importance of circulating endothelial progenitor cells (EPCs) in maintaining normal endothelial function as well as endothelial repairing after vascular injury. Here, the authors present the first study demonstrating the therapeutic potential of EPCs in a rabbit model of ALI/ARDS. METHODS: Circulating EPCs were obtained from rabbits using Ficoll centrifugation. One week after culturing, ALI was induced in rabbits by oleic acid (75 mg/kg, intravenous), and autologous EPCs were transplanted intravenously. Vasomotor function of isolated pulmonary artery and degrees of lung injury were assessed 2 days later. RESULTS: Endothelial dysfunction in the pulmonary artery was significantly attenuated in rabbits treated with EPCs, whereas the endothelium-independent relaxation responses were not different. Expression of inducible nitric oxide synthase was suppressed in the pulmonary artery of EPC-treated animals. Infiltration of leukocytes in the lung parenchyma was significantly reduced after EPC transplantation. EPCs also decreased water content, hyaline membrane formation, and hemorrhage in lungs. CONCLUSION: The authors demonstrated that autologous transplantation of EPCs preserves pulmonary endothelial function and maintains the integrity of pulmonary alveolar-capillary barrier. Transplantation of EPCs can be a novel cell-based, endothelium-targeted therapeutic strategy for prevention and treatment of ALI/ARDS.

Prolonged use of high-dose morphine impairs angiogenesis and mobilization of endothelial progenitor cells in mice.

BACKGROUND: Morphine is one of the most commonly prescribed analgesics for treating wound pain. Using a mouse model of excisional wound injury, we determined the effects of high-dose morphine on angiogenesis and mobilization of endothelial progenitor cells. METHODS: An excisional wound was created on mice treated with placebo or morphine (20 mg/kg, i.p. injection for 14 days). Wound healing was compared by measuring the final-to-initial wound area ratio. Generation of superoxide anions in the wound was determined by luminol-enhanced chemiluminescence. Circulating mononuclear cells were isolated and measured for endothelial progenitor cell (defined as CD34+/CD133+ cell) counts. In vivo and in vitro measurements of angiogenesis after morphine treatment were performed using the Matrigel assay. RESULTS: Mice treated with morphine had reduced wound closure and higher wound superoxide ions concentrations than control mice. Morphine reduced the number of postwound circulating endothelial progenitor cells. Matrigel assay showed impaired angiogenesis in animals and reduced capillary tube formation in cultured endothelial cells treated with morphine. CONCLUSION: High-dose morphine impaired angiogenesis, increased systemic oxidative stress, and impaired mobilization of endothelial progenitor cells. This study emphasizes the potential detrimental effect of high-dose morphine on angiogenesis after systemic administration.

Exendin-4 improves cardiovascular function and survival in flow-induced pulmonary hypertension.

OBJECTIVES: Systemic left-to-right shunting causes pulmonary arteriopathy, leading to progressive cardiopulmonary failure and a poor prognosis. In this study, we examined the extraglycemic effect of a synthetic glucagon-like peptide, exendin-4, on pulmonary arteriopathy regression and cardiopulmonary function in nondiabetic rats. METHODS: Pulmonary hypertension (PH) was induced by monocrotaline (60 mg/kg, subcutaneous) injection followed by the creation of an aortocaval fistula. After 4 weeks, exendin-4 (1 µg/kg/day) was administered intraperitoneally for 3 consecutive weeks, followed by an assessment of cardiopulmonary function, pulmonary artery vasoreactivity, tissue and blood biochemistry, and lung histology. RESULTS: Exendin-4 significantly reduced right ventricle mass and pulmonary artery pressure, which improved right ventricle function and the survival rate in rats with PH. Tissue and blood interleukin-1ß levels decreased, whereas pulmonary artery cyclic adenosine monophosphate levels were restored by exendin-4. Smooth muscle-myosin heavy chain-II and α-smooth muscle actin protein levels increased in the pulmonary arteries of exendin-4-treated rats. Histology showed that exendin-4 decreased the main and intra-acinar pulmonary artery medial thickness. CONCLUSIONS: Exendin-4 treatment improved pulmonary artery function in flow-induced PH via its direct vasoactive properties, anti-inflammatory effects, and vascular smooth muscle cell phenotypic modulation. Mitigation of pulmonary arteriopathy further potentiated right ventricle performance and reduced overall mortality. These responses were associated with suppressed expression and activity of interleukin-1ß and its downstream signaling molecules. Glucagon-like peptide analogs may possess pleiotropic therapeutic potential in flow-induced PH.

Hemodynamic, biological, and right ventricular functional changes following intraatrial shunt repair in patients with flow-induced pulmonary hypertension.

OBJECTIVES: Atrial septal defects may result in pulmonary hypertension and right heart remodeling. We analyzed improvements in patients with flow-induced pulmonary hypertension and the activation of endothelial progenitor cells after flow reduction. DESIGN: This prospective cohort study included 37 patients who were admitted for an occluder implantation. Blood samples were collected before and after the procedure. We determined the number of endothelial progenitor cells in outgrowth colonies and serum Hsp27 concentrations. Daily performance and cardiothoracic ratio were reevaluated later. RESULTS: Closure of the defect significantly reduced the pulmonary pressure and B-type natriuretic peptide levels. The cardiothoracic ratio and daily performance status also improved. The number of endothelial progenitor cell outgrowth colony-forming units significantly increased and was positively correlated with daily performance. In patients with enhanced colony formation, Hsp27 levels were significantly increased. CONCLUSIONS: The implantation of an occluder successfully improved hemodynamic, right ventricular, and daily performance. Qualitative enhancement of colony formation for endothelial progenitor cells was also noted and positively correlated with daily performance. Closure of defects may serve as a valid, reliable model to obtain a deeper understanding of the modulation of endothelial progenitor cell activity and its relationship with pulmonary hypertension prognosis.