The role of mechanosensor Piezo1 in bone homeostasis and mechanobiology.

Bones and articular cartilage are important load-bearing tissues. The fluid flow inside the bone cells and cell interaction with the extracellular matrix serve as the mechanical cues for bones and joints. Piezo1 is an ion channel found on the cell surface of many cell types, including osteocytes and chondrocytes. It is activated in response to mechanical stimulation, which subsequently mediates a variety of signaling pathways in osteoblasts, osteocytes, and chondrocytes. Piezo1 activation in osteoblastic cells positively regulates osteogenesis, while its activation in joints mediates cartilage degradation. This review focuses on the most recent research on Piezo1 in bone development and regeneration.

Acid sphingomyelinase mediates ferroptosis induced by high glucose via autophagic degradation of GPX4 in type 2 diabetic osteoporosis.

BACKGROUND: Ferroptosis has been implicated in the pathological process of type 2 diabetic osteoporosis (T2DOP), although the specific underlying mechanisms remain largely unknown. This study aimed to clarify the role and possible mechanism of acid sphingomyelinase (ASM)-mediated osteoblast ferroptosis in T2DOP. METHODS: We treated hFob1.19 cells with normal glucose (NG) and different concentrations of high glucose (HG, 26.25 mM, 35 mM, or 43.75 mM) for 48 h. We then measured cell viability and osteogenic function, quantified ferroptosis and autophagy levels, and measured the levels of ASM and ceramide in the cells. To further investigate the specific mechanism, we examined these indicators by knocking down ASM expression, hydroxychloroquine (HCQ) treatment, or N-acetylcysteine (NAC) treatment. Moreover, a T2DOP rat model was induced and microcomputed tomography was used to observe the bone microstructure. We also evaluated the serum levels of iron metabolism-associated factors, ceramide and lipid peroxidation (LPO) and measured the expression of ASM, LC3 and GPX4 in bone tissues. RESULTS: HG inhibited the viability and osteogenic function of osteoblasts by inducing ferroptosis in a concentration-dependent manner. Furthermore, the expression of ASM and ceramide and autophagy levels were increased by HG treatment, and these factors were required for the HG-induced reactive oxygen species (ROS) generation and LPO. Similarly, inhibiting intracellular ROS also reduced HG-induced ASM activation and autophagy. ASM-mediated activation of autophagy was crucial for HG-induced degradation of GPX4, and inhibiting ASM improved osteogenic function by decreasing HG-induced autophagy, GPX4 degradation, LPO and subsequent ferroptosis. We also found that inhibiting ASM could alleviated ferroptosis and autophagy and improved osteogenic function in a T2DOP rat model. CONCLUSION: ASM-mediated autophagy activation induces osteoblast ferroptosis under HG conditions through the degradation of GPX4, providing a novel mechanistic insight into the treatment and prevention of T2DOP.

Effect of glucocorticoid for patients with type A aortic dissection undergoing surgical repair with deep hypothermic circulatory arrest: A single-center, retrospective study.

BACKGROUND: Postoperative patients with Type A aortic dissection (TAAD) often experience severe inflammatory responses caused by multiple factors perioperatively. However, the effect of postoperative glucocorticoid (GC) use, which is a potent anti-inflammatory agent, on complications or all-cause mortality is unclear. METHODS: Patients with TAAD who underwent surgical repair requiring deep hypothermic circulatory arrest between January 2020 and December 2021 were included in the study. Characteristics of patients treated with and without GCs were compared. The primary outcome was in-hospital mortality, and a composite secondary outcome was defined as in-hospital death or any major complications. Propensity score matching was used to balance baseline differences between groups. Kaplan-Meier curves were used to compare survival probability. RESULTS: A total of 393 postoperative patients with TAAD were included in the study. Forty of them (10.2%) received GC treatment at a median daily methylprednisolone-equivalent dose of 0.6 mg/kg (0.4-0.7) for a median period of 2 (1-3) days. Patients on GCs had more intraoperative blood transfusions, higher postoperative APACHE II (12 vs 9, p = .004) and SOFA (9 vs 6, p < .001) scores, worse perioperative hepatic, renal and cardiac function. The in-hospital mortality in the matched cohort did not differ between groups [GC n = 11/40 (27.5%) versus Non-GC n = 19/80 (23.8%); p = .661]. CONCLUSIONS: The propensity to use GCs correlated with the critical status of the patient. However, low dose and short-term postoperative GC treatment did not reduce in-hospital mortality rates among patients with TAAD. A more appropriate regimen should be further investigated.

Role of Nrf2 in bone metabolism.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor expressed in many cell types, including osteoblasts, osteocytes, and osteoclasts. Nrf2 has been considered a master regulator of cytoprotective genes against oxidative and chemical insults. The lack of Nrf2 can induce pathologies in multiple organs. Nrf2 deficiency promotes osteoclast differentiation and osteoclast activity, which leads to an increase in bone resorption. The role of Nrf2 in osteoblast differentiation and osteoblast activity is more complex. Nrf2 mediates anabolic effects within an ideal range. Nrf2 deletion suppresses load induced bone formation and delays fracture healing. Overall, Nrf2 plays an important role in the regulation of bone homeostasis in bone cells.

Poly(ADP-ribose) polymerase family member 14 promotes functional recovery after spinal cord injury through regulating microglia M1/M2 polarization via STAT1/6 pathway.

Poly(ADP-ribose)polymerase family member 14 (PARP14), which is an intracellular mono(ADP-ribosyl) transferase, has been reported to promote post-stroke functional recovery, but its role in spinal cord injury (SCI) remains unclear. To investigate this, a T10 spinal cord contusion model was established in C57BL/6 mice, and immediately after the injury PARP14 shRNA-carrying lentivirus was injected 1 mm from the injury site to silence PARP14 expression. We found that PARP14 was up-regulated in the injured spinal cord and that lentivirus-mediated downregulation of PARP14 aggravated functional impairment after injury, accompanied by obvious neuronal apoptosis, severe neuroinflammation, and slight bone loss. Furthermore, PARP14 levels were elevated in microglia after SCI, PARP14 knockdown activated microglia in the spinal cord and promoted a shift from M2-polarized microglia (anti-inflammatory phenotype) to M1-polarized microglia (pro-inflammatory phenotype) that may have been mediated by the signal transducers and activators of transcription (STAT) 1/6 pathway. Next, microglia M1 and M2 polarization were induced in vitro using lipopolysaccharide/interferon-γ and interleukin-4, respectively. The results showed that PARP14 knockdown promoted microglia M1 polarization, accompanied by activation of the STAT1 pathway. In addition, PARP14 overexpression made microglia more prone to M2 polarization and further activated the STAT6 pathway. In conclusion, these findings suggest that PARP14 may improve functional recovery after SCI by regulating the phenotypic transformation of microglia via the STAT1/6 pathway.

Different frequencies of repetitive transcranial magnetic stimulation combined with local injection of botulinum toxin type A for post-stroke lower limb spasticity: study protocol for a prospective, single-center, non-randomized, controlled clinical trial.

No definite consensus has currently been reached regarding the safety and efficacy of low- or high-frequency repetitive transcranial magnetic stimulation in the treatment of post-stroke muscle spasticity. The latest research indicates that when combined with local injections of botulinum toxin type A, it is more effective on post-stroke muscle spasticity than local injections of botulinum toxin type A alone. We designed a prospective, single-center, non-randomized, controlled clinical trial to investigate the safety and efficacy of different frequencies of repetitive transcranial magnetic stimulation combined with local injections of botulinum toxin type A in treating post-stroke lower limb muscle spasticity to determine an optimal therapeutic regimen. This trial will enroll 150 patients with post-stroke muscle spasticity admitted to the Department of Rehabilitation Medicine at the First Affiliated Hospital of China Medical University. All enrolled patients will undergo routine rehabilitation training and will be divided into five groups (n = 30 per group) according to the particular area of cerebral infarction and treatment methods. Group A: Patients with massive cerebral infarction will be given local injections of botulinum toxin type A and low-frequency (1 Hz) repetitive transcranial magnetic stimulation on the contralateral side; Group B: Patients with non-massive cerebral infarction will be given local injections of botulinum toxin type A and high-frequency (10-20 Hz) repetitive transcranial magnetic stimulation on the affected side; Group C: Patients with massive/non-massive cerebral infarction will be given local injections of botulinum toxin type A; Group D: Patients with massive cerebral infarction will be given low-frequency (1 Hz) repetitive transcranial magnetic stimulation on the contralateral side; and Group E: Patients with non-massive cerebral infarction will be given high-frequency (10-20 Hz) repetitive transcranial magnetic stimulation on the affected side. The primary outcome measure of this trial is a modified Ashworth scale score from 1 day before treatment to 12 months after treatment. Secondary outcome measures include Fugl-Meyer Assessment of Lower Extremity, Visual Analogue Scale, modified Barthel index, and Berg Balance Scale scores for the same time as specified for primary outcome measures. The safety indicator is the incidence of adverse events at 3-12 months after treatment. We hope to draw a definite conclusion on whether there are differences in the safety and efficacy of low- or high-frequency repetitive transcranial magnetic stimulation combined with botulinum toxin type A injections in the treatment of patients with post-stroke lower limb spasticity under strict grouping and standardized operation, thereby screening out the optimal therapeutic regimen. The study protocol was approved by the Medical Ethics Committee of the First Affiliated Hospital of China Medical University (approval No. [2021] 2021-333-3) on August 19, 2021. The trial was registered with the Chinese Clinical Trial Registry (Registration No. ChiCTR2100052180) on October 21, 2021. The protocol version is 1.1.

Early postoperative organ dysfunction is highly associated with the mortality risk of patients with type A aortic dissection.

OBJECTIVES: This study assessed the impact of early postoperative organ dysfunction (EPOD) on in-hospital mortality of patients with type A aortic dissection (TAAD) after surgery. METHODS: Patients with TAAD who underwent surgical repair requiring deep hypothermic circulatory arrest from January 2020 to December 2021 were included. The Sequential Organ Failure Assessment (SOFA) score was calculated for 3 days postoperatively to stratify the severity of organ dysfunction. Patients with the SOFA of 0-4, 5-8 or >8 were defined as mild, moderate or severe EPOD. The primary outcome was in-hospital mortality, and a composite secondary outcome was defined as in-hospital death or any major complications. Kaplan-Meier curves were used to compare survival probability. The area under the receiver operating characteristic curve and calibration plots were used to evaluate the predictive power and overall performance of SOFA. RESULTS: Of the 368 patients, 5 patients (3%) with moderate EPOD and 33 patients (23%) with severe EPOD died. No patient died with mild EPOD. The areas under the receiver operating characteristic curve of SOFA for predicting mortality and the composite outcome were 0.85 (0.81-0.88) and 0.81 (0.77-0.85) on postoperative day 1. Each point of postoperative day 1 SOFA score corresponded to an odds ratio of 1.65 (1.42-1.92) for mortality. Of the 6 components of the SOFA system, only coagulation (2.34 [1.32-4.13]), cardiovascular (1.47 [1.04-2.08]), central nervous system (1.96 [1.36-2.82]) and renal (1.67 [1.04-2.70]) functions were associated with the higher risk of mortality. CONCLUSIONS: EPOD stratified by the SOFA score was associated with a higher risk of death and predicted the clinical outcomes of patients with TAAD with good accuracy.

Veno-Arterial Extracorporeal Membrane Oxygenation for Patients Undergoing Acute Type A Aortic Dissection Surgery: A Six-Year Experience.

Objectives: Acute type A aortic dissection (aTAAD) is usually lethal without emergency surgery. Although veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is widely used in patients with cardiogenic shock following cardiac surgery, VA-ECMO support following aTAAD surgery has not been well-described. Based on our 6-year experience, we aimed to retrospectively analyze risk factors, application and timing of VA-ECMO, and outcomes in aTAAD patients. Methods: In this retrospective, single-center study, we enrolled adult patients who underwent aTAAD surgery from January 2014 to December 2019 and were supported with VA-ECMO. Patients were divided into two groups according to whether or not they were successfully weaned from VA-ECMO. Preoperative, intraoperative and postoperative variables were assessed and analyzed. Outcomes of the patients were followed up until discharge. Results: Twenty-seven patients who received aTAAD surgery with VA-ECMO support were included in the study. Nine patients (33.3%) were successfully weaned from VA-ECMO. The median VA-ECMO support time and length of hospital stay in the successfully weaned group were significantly longer than in the group could not be successfully weaned (192 [111-327] vs. 55 [23-95] h, p < 0.01; 29 [18-40] vs. 4 [3-8] days, p < 0.01). Overall in-hospital mortality was 81.5%. The main causes of death were bleeding (37%), neurological complications (15%), and multiple organ dysfunction syndrome (15%). Preoperative levels of creatine kinase-MB (CK-MB) were lower in patients who were successfully weaned from VA-ECMO than in the failed group (14 [6-30] vs. 55 [28-138] U/L, p < 0.01). Postoperative peak levels of CK-MB, cardiac troponin T, lactate dehydrogenase, and lactate were significantly lower in the successful group than in the failed group. Conclusion: Postoperative VA-ECMO support was rarely used in aTAAD patients. Our study showed that VA-ECMO can be considered as a salvage treatment in aTAAD patients, despite the high rate of complications and mortality.

[Microarray analysis of human primary astrocytes activated by beta amyloid peptide and alpha1-antichymotrypsin].

OBJECTIVE: To investigate gene expression of astrocytes under the actions of amyloid peptide Abeta(1-42) and alpha1-antichymotrypsin (ACT) and to explore the characteristics of inflammatory reactions occurring in brain of Alzheimer's patients. METHODS: Human primary astrocytes were cultured to the second passage and then treated with lipopolysaccharide (LPS), Abeta(1-42) (50 micromol/L) and Abeta(1-42)/ACT (50:5 micromol/L) respectively. At 24 h, cells were harvested for total RNA extraction. Gene expression profile was screened by microarray technique. And the function enrichment of differentially expressed genes and the signal transduction pathways involved were analyzed. RESULTS: In comparison with LPS, both Abeta(1-42) and Abeta(1-42)/ACT had demonstrated marked effects on altering the astrocyte gene expression. And the gene up-regulation was predominant. But the gene expression spectrum varied between different groups. Gene ontology analysis showed that Abeta(1-42) up-regulated genes modulated inflammation, oxidative stress and immune response. But Abeta(1-42)/ACT had significant effects on genes related with mitochondrial impairment, apoptosis, oxidative stress, epithelial differentiation and vasculogenesis. The analysis of up-regulated genes, such as interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFalpha), showed that transcriptional factors and downstream genes of signal transduction pathways potentiated further the inflammatory response and cell apoptosis and increased the production of abnormal Abeta. CONCLUSION: Abeta(1-42) induces the inflammation of astrocytes. And the Abeta(1-42)/ACT complex has diverse effects on the gene expression of astrocytes. Thus both proteins play important roles in the activation of astrocytes. In addition, IL-6, TNFalpha and their signal pathways are important in the pathogenic process of Alzheimer's disease.

Research hotspots and effectiveness of repetitive transcranial magnetic stimulation in stroke rehabilitation.

Repetitive transcranial magnetic stimulation, as a relatively new type of rehabilitation treatment, is a painless and non-invasive method for altering brain excitability. Repetitive transcranial magnetic stimulation has been widely used in the neurorehabilitation of stroke patients. Here, we used CiteSpace software to visually analyze 315 studies concerning repetitive transcranial magnetic stimulation for stroke rehabilitation from 1999 to 2019, indexed by Web of Science, to clarify the research hotspots in different periods and characterize the gradual process of discovery in this field. We found that four main points were generally accepted: (1) repetitive transcranial magnetic stimulation has a positive effect on motor function recovery in patients with subcortical stroke; (2) it may be more advantageous for stroke patients to receive low-frequency repetitive transcranial magnetic stimulation in the unaffected hemispheres than to receive high-frequency repetitive transcranial magnetic stimulation in affected hemisphere; (3) low-frequency repetitive transcranial magnetic stimulation has become a potential therapeutic tool for patients with non-fluent aphasia after chronic stroke for neurological rehabilitation and language recovery; and (4) there are some limitations to these classic clinical studies, such as small sample size and low test efficiency. Our assessment indicates that prospective, multi-center, large-sample, randomized controlled clinical trials are still needed to further verify the effectiveness of various repetitive transcranial magnetic stimulation programs for the rehabilitation of stroke patients.

Early risk stratification of acute type A aortic dissection: development and validation of a predictive score.

BACKGROUND: The performance of published preoperative risk scores for acute type A aortic dissection (aTAAD) is suboptimal. So, the predictive power of these scores were externally validated in order to develop and validate a more reliable preoperative score for identification of patients at high risk of mortality. METHODS: Potential preoperative risk variables of consecutively admitted patients with aTAAD were prospectively collected. Seven published risk scores were validated with our dataset. For derivation and internal validation, the original population was divided at a ratio of 7:3. Logistic regression was used to identify variables for the new score. A 50-patient retrospective dataset was used for external validation. The predictive accuracy for post-operative mortality was evaluated using the area under the receiver operating characteristic (AUROC) curve. RESULTS: During the study period, 225 patients with aTAAD were admitted preoperatively. Of these, 209 underwent surgical repair and 29 died postoperatively. The AUROCs of the seven published pre-operative risk scores for post-operative mortality ranged from 0.57 to 0.77. Four variables were derived for the new score system, i.e., Acute myocardial ischemia, Lactate, Iliac arteries involved, and CreatininE (the ALICE score). The AUROCs for post-operative mortality in the derivation, internal and external validation populations were 0.85, 0.88 and 0.83, respectively. At a cutoff value of 3, the ALICE score for post-operative mortality had a sensitivity of 71% to 88% and specificity of 78% to 86%. CONCLUSIONS: The ALICE score comprising four components might help bedside clinicians in early detection of the most severe aTAAD patients.

Effect of Sequential Noninvasive Ventilation on Early Extubation After Acute Type A Aortic Dissection.

BACKGROUND: Acute type A aortic dissection (aTAAD) is associated with a high incidence of prolonged postoperative invasive mechanical ventilation. We aimed to assess whether sequential noninvasive ventilation (NIV) could facilitate early extubation postoperatively after a spontaneous breathing trial (SBT) failure among aTAAD patients. METHODS: Beginning in December 2016, we transitioned our weaning strategy from repeated SBT until success (phase 1) to extubation concomitant with sequential NIV (phase 2) for subjects who failed their first SBT. The primary outcomes were re-intubation rate, duration of invasive ventilation, and total duration of ventilation. RESULTS: During the study period, 78 subjects with aTAAD failed their first postoperative SBT (38 subjects in phase 1 and 40 subjects in phase 2). Subjects extubated with sequential NIV had shorter median (interquartile range [IQR]) duration of invasive ventilation of 39.5 (30.8-57.8) h vs 89.5 (64-112) h (P < .001) and median (IQR) length of ICU stay of 6 (4.0-7.8) d vs 7.5 (5.8-9.0) d (P = .030). There were no significant differences between the 2 phases with regard to rates of re-intubation (7.5% vs 7.89%, P = .95), tracheostomy (2.5% vs 5.26%, P = .53), and in-hospital mortality (2.5% vs 2.63%, P = .97). CONCLUSIONS: Early extubation followed by sequential NIV significantly reduced duration of invasive ventilation and length of ICU stay without increasing re-intubation rate in postoperative subjects with aTAAD who failed their first SBT.

[Clinical efficacy of narrow band ultraviolet bin combined with yuyin recipe in treating psoriasis vulgaris].

OBJECTIVE: To observe the clinical efficacy of narrow band ultraviolet bin (NB-UVB) combined with Yuyin Recipe (YYR) in treating psoriasis vulgaris (PV). METHODS: One hundred and nineteen patients with PV were randomly assigned to 2 groups by envelop method, the 62 patients in the treated group were treated with NB-UVB and YYR bathing, and the 57 in the control group were treated with NB-UVB alone. The course of treatment for both groups was 8 weeks. PASI scoring was performed before treatment and at the 2nd, 4th, 6th and 8th week of treatment respectively, and the treatment effect was evaluated depending on the decreasing rate of PASI score. The accumulated dose and side-effect of NB-UVB applied was observed. RESULTS: The PASI scores in the treated group measured at various time points after treatment were significantly different to that of baseline (P < 0.05). The cure rate in the treated group and the control group was 69.35% and 24.56% while the total effective rate in them 96.77% and 71.93%, respectively, showing significant difference between the two groups (chi2 = 27.755, P <0.01). The difference of PASI decreasing rate between groups showed statistical significant from the 4th week (P <0.01). The total dose of NB-UVB applied in the treated group (9.95 +/- 4.76) was less than that in the control group (12.77 +/- 5.05) with the difference of statistical significance (t = 3.141, P <0.01). The adverse reaction occurrence in them was 4.84% (3/62) and 31.58% (18/57) respectively, also showing significant difference (chi2 = 119, P <0.01). CCONCLUSION: The combined use of TCM medicated bath with NB-UVB can enhance the curative effect, reduce the accumulated dosage and lessen the adverse reactions of ultraviolet radiation.

Exogenous brain-derived neurotrophic factor attenuates cognitive impairment induced by okadaic acid in a rat model of Alzheimer's disease.

Decreased expression of brain-derived neurotrophic factor (BDNF) plays an important role in the pathogenesis of Alzheimer's disease, and a typical pathological change in Alzheimer's disease is neurofibrillary tangles caused by hyperphosphorylation of tau. An in vivo model of Alzheimer's disease was developed by injecting okadaic acid (2 µL) and exogenous BDNF (2 µL) into the hippocampi of adult male Wister rats. Spatial learning and memory abilities were assessed using the Morris water maze. The expression levels of protein phosphatase 2A (PP2A), PP2Ac-Yp307, p-tau (Thr231), and p-tau (Ser396/404) were detected by western blot assay. The expression levels of BDNF, TrkB, and synaptophysin mRNA were measured by quantitative real-time polymerase chain reaction. Our results indicated that BDNF expression was suppressed in the hippocampus of OA-treated rats, which resulted in learning and memory deficits. Intra-hippocampal injection of BDNF attenuated this OA-induced cognitive impairment. Finally, our findings indicated an involvement of the PI3K/GSK-3ß/AKT pathway in the mechanism of BDNF in regulating cognitive function. These results indicate that BDNF has beneficial effect on Alzheimer's disease, and highlight the potential of BDNF as a drug target for treatment of Alzheimer's disease.

Human parathyroid hormone (1-34) accelerates natural fracture healing process in the femoral osteotomy model of cynomolgus monkeys.

Several studies in rats have demonstrated that parathyroid hormone accelerates fracture healing by increasing callus formation or stimulating callus remodeling. However the effect of PTH on fracture healing has not been tested using large animals with Haversian remodeling system. Using cynomolgus monkey that has intracortical remodeling similar to humans, we examined whether intermittent treatment with human parathyroid hormone [hPTH(1-34)] accelerates the fracture healing process, especially callus remodeling, and restores geometrical shapes and mechanical properties of osteotomized bone. Seventeen female cynomolgus monkeys aged 18-19 years were allocated into three groups: control (CNT, n=6), low-dose PTH (0.75 microg/kg; PTH-L, n=6), and high-dose PTH (7.5 microg/kg; PTH-H, n=5) groups. In all animals, twice a week subcutaneous injection was given for 3 weeks. Then fracture was produced surgically by transversely cutting the midshaft of the right femur and fixing with stainless plate. After fracture, intermittent PTH treatment was continued until sacrifice at 26 weeks after surgery. The femora were assessed by soft X-ray, three-point bending mechanical test, histomorphometry, and degree of mineralization in bone (DMB) measurement. Soft X-ray showed that complete bone union occurred in all groups, regardless of treatment. Ultimate stress and elastic modulus in fractured femur were significantly higher in PTH-H than in CNT. Total area and percent bone area of the femur were significantly lower in both PTH-L and PTH-H than in CNT. Callus porosity decreased dose-dependently following PTH treatment. Mean DMB of callus was significantly higher in PTH-H than in CNT or PTH-L. These results suggested that PTH decreased callus size and accelerated callus maturation in the fractured femora. PTH accelerates the natural fracture healing process by shrinking callus size and increasing degree of mineralization of the fracture callus, thereby restoring intrinsic material properties of osteotomized femur shaft in cynomolgus monkeys although there were no significant differences among the groups for structural parameters.

Chitosan-alginate microcapsules for oral delivery of egg yolk immunoglobulin (IgY).

Chitosan-alginate microcapsules were evaluated as a method of oral delivery of IgY antibodies. Physical characteristics, encapsulation efficiency (EE%), the loading capacity for IgY (IgY loading percentage, %, w/w of microcapsules), gastro-resistance, and release characteristics of these microcapsules in vitro under varying pH were investigated. Optimum physical factors were established for preparation of homogeneous, spherical, and smooth microcapsules. IgY loading% was not significantly altered by pH of the encapsulation medium. Encapsulation efficiency was highest (73.93%) at a pH of 3.5, above which EE% decreased significantly (p < 0.05). IgY was released from microcapsules upon exposure to simulated intestinal fluid (SIF, pH 6.8), and decreasing pH increased significantly IgY release (p < 0.05). The stability of IgY in simulated gastric fluid (SGF, pH 1.2) was greatly improved by encapsulation in chitosan-alginate microcapsules, and the residual activity was not affected by pH of the encapsulation medium. Moreover, microencapsulated IgY was significantly resistant to pepsin hydrolysis. This approach may enable intact IgY to reach target microorganisms within the lower digestive tract.

Involvement of N-acylethanolamine-hydrolyzing acid amidase in the degradation of anandamide and other N-acylethanolamines in macrophages.

Bioactive N-acylethanolamines including the endocannabinoid anandamide are known to be hydrolyzed to fatty acids and ethanolamine by fatty acid amide hydrolase (FAAH). In addition, we recently cloned an isozyme termed "N-acylethanolamine-hydrolyzing acid amidase (NAAA)", which is active only at acidic pH [Tsuboi, Sun, Okamoto, Araki, Tonai, Ueda, J. Biol. Chem. 285 (2005) 11082-11092]. However, physiological roles of NAAA remained unclear. Here, we examined a possible contribution of NAAA to the degradation of various N-acylethanolamines in macrophage cells. NAAA mRNA as well as FAAH mRNA was detected in several macrophage-like cells, including RAW264.7, and mouse peritoneal macrophages. The homogenates of RAW264.7 cells showed both the NAAA and FAAH activities which were confirmed with the aid of their respective specific inhibitors, N-cyclohexanecarbonylpentadecylamine (CCP) and URB597. As analyzed with intact cells, RAW264.7 cells and peritoneal macrophages degraded anandamide, N-palmitoylethanolamine, N-oleoylethanolamine, and N-stearoylethanolamine. Pretreatment of the cells with CCP or URB597 partially inhibited the degradation, and a combination of the two compounds caused more profound inhibition. In contrast, the anandamide hydrolysis in mouse brain appeared to be principally attributable to FAAH despite the expression of NAAA in the brain. These results suggested that NAAA and FAAH cooperatively degraded various N-acylethanolamines in macrophages.

Biosynthesis of anandamide and N-palmitoylethanolamine by sequential actions of phospholipase A2 and lysophospholipase D.

Anandamide (an endocannabinoid) and other bioactive long-chain NAEs (N-acylethanolamines) are formed by direct release from N-acyl-PE (N-acyl-phosphatidylethanolamine) by a PLD (phospholipase D). However, the possible presence of a two-step pathway from N-acyl-PE has also been suggested previously, which comprises (1) the hydrolysis of N-acyl-PE to N-acyl-lysoPE by PLA1/PLA2 enzyme(s) and (2) the release of NAEs from N-acyllysoPE by lysoPLD (lysophospholipase D) enzyme(s). In the present study we report for the first time the characterization of enzymes responsible for this pathway. The PLA1/PLA2 activity for N-palmitoyl-PE was found in various rat tissues, with the highest activity in the stomach. This stomach enzyme was identified as group IB sPLA2 (secretory PLA2), and its product was determined as N-acyl-1-acyl-lysoPE. Recombinant group IB, IIA and V of sPLA2s were also active with N-palmitoyl-PE, whereas group X sPLA2 and cytosolic PLA2a were inactive. In addition, we found wide distribution of lysoPLD activity generating N-palmitoylethanolamine from N-palmitoyl-lysoPE in rat tissues, with higher activities in the brain and testis. Based on several lines of enzymological evidence, the lysoPLD enzyme could be distinct from the known N-acyl-PE-hydrolysing PLD. sPLA2-IB dose dependently enhanced the production of N-palmitoylethanolamine from N-palmitoyl-PE in the brain homogenate showing the lysoPLD activity. N-Arachidonoyl-PE and N-arachidonoyl-lysoPE as anandamide precursors were also good substrates of sPLA2-IB and the lysoPLD respectively. These results suggest that the sequential actions of PLA2 and lysoPLD may constitute another biosynthetic pathway for NAEs, including anandamide.

[Upregulating the expression of angiogenesis-related genes by transplanting autologous mononuclear bone marrow cells into myocardial infarction scar and the periphery].

OBJECTIVE: To detect the regulation of angiogenic genes involved in the processes of collateral development. METHODS: Myocardial infarction (MI) scar was induced by cryoinjury in New Zealand rabbits. Four weeks after MI, 24 hours before cell transplantation, bone marrow was aspirated from the right thigh bone and mononuclear bone marrow cells (BMCs) were isolated by Ficoll density gradient centrifugation. Then the mononuclear BMCs (n = 8) or IMDM culture medium (n = 8) were transplanted into infarction scar and the periphery. Four weeks after mononuclear BMCs transplantation, DNA microarray analysis was performed to detect the regulation of angiogenesis-related genes in infarction scar and the periphery. And the differences of angiogenic genes expression were compared among several important growth factors by Western blot. RESULTS: DNA microarray analysis showed the detail regulation of genes involved in the angiogenic processes. There were 15 genes upregulated over 3 times in the infarction scar. In addition, we also found more genes are involved in the process of angiogenesis in its periphery than in the infarction scar (40 genes vs. 15 genes). Western bolt analysis further demonstrated that mononuclear BMCs transplantation was capable of increasing the levels of VEGF, FGF and Angiopoietin-I expression in the infarction scar and its periphery, compared with the control group, P < 0.05. CONCLUSION: These findings indicate that the natural angiogenic processes leading to collateral development are extremely complex, since many kinds of bone marrow-derived growth factors involved in the processes after mononuclear BMCs transplantation into infarction sites.