The emerging roles of irisin in vascular calcification.

Vascular calcification is a common accompanying pathological change in many chronic diseases, which is caused by calcium deposition in the blood vessel wall and leads to abnormal blood vessel function. With the progress of medical technology, the diagnosis rate of vascular calcification has explosively increased. However, due to its mechanism's complexity, no effective drug can relieve or even reverse vascular calcification. Irisin is a myogenic cytokine regulating adipose tissue browning, energy metabolism, glucose metabolism, and other physiological processes. Previous studies have shown that irisin could serve as a predictor for vascular calcification, and protect against hypertension, diabetes, chronic kidney disease, and other risk factors for vascular calcification. In terms of mechanism, it improves vascular endothelial dysfunction and phenotypic transformation of vascular smooth muscle cells. All the above evidence suggests that irisin plays a predictive and protective role in vascular calcification. In this review, we summarize the association of irisin to the related risk factors for vascular calcification and mainly explore the role of irisin in vascular calcification.

Osteoporosis: interferon-gamma-mediated bone remodeling in osteoimmunology.

As the world population ages, osteoporosis, the most common disease of bone metabolism, affects more than 200 million people worldwide. The etiology is an imbalance in bone remodeling process resulting in more significant bone resorption than bone remodeling. With the advent of the osteoimmunology field, the immune system's role in skeletal pathologies is gradually being discovered. The cytokine interferon-gamma (IFN-γ), a member of the interferon family, is an important factor in the etiology and treatment of osteoporosis because it mediates bone remodeling. This review starts with bone remodeling process and includes the cellular and key signaling pathways of bone remodeling. The effects of IFN-γ on osteoblasts, osteoclasts, and bone mass are discussed separately, while the overall effects of IFN-γ on primary and secondary osteoporosis are summarized. The net effect of IFN-γ on bone appears to be highly dependent on the environment, dose, concentration, and stage of cellular differentiation. This review focuses on the mechanisms of bone remodeling and bone immunology, with a comprehensive discussion of the relationship between IFN-γ and osteoporosis. Finding the paradoxical balance of IFN-γ in bone immunology and exploring the potential of its clinical application provide new ideas for the clinical treatment of osteoporosis and drug development.

Poly (Betulinic Acid) Nanoparticles Loaded with bFGF Improve Functional Recovery After Spinal Cord Injury.

Oxidative stress (OS) is one of the crucial molecular events of secondary spinal cord injury (SCI). Basic fibroblast growth factor (bFGF) is a multipotent cell growth factor with an anti-oxidant effect. However, bFGF has a short half-life in vivo, which limits its therapeutic application. Biodegradable polymers with excellent biocompatibility have been recently applied in SCI. The negative aspect is that polymers cannot provide a significant therapeutic effect. Betulinic acid (BA), a natural anti-inflammatory compound, has been polymerized into poly (betulinic acid) (PBA) to serve as a drug carrier for bFGF. This study explores the therapeutic effects and underlying molecular mechanisms of PBA nanoparticles (NPs) loaded with bFGF (PBA-bFGF NPs) in SCI. Results show that PBA-bFGF NPs produce remarkable biocompatibility in vivo and in vitro. The results also demonstrate that local delivery of PBA-bFGF NPs enhances motor function recovery, inhibits OS, mitigates neuroinflammation, and alleviates neuronal apoptosis following SCI. Furthermore, the results indicate that local delivery of PBA-bFGF NPs activates the nuclear factor erythroid 2-related factor 2 (Nrf-2) signaling pathway following SCI. In summary, results suggest that local delivery of PBA-bFGF NPs delivers potential therapeutic advantages in the treatment and management of SCI.

Modified classification and single-stage microsurgical repair of posttraumatic infected massive bone defects in lower extremities.

Posttraumatic infected massive bone defects in lower extremities are difficult to repair because they frequently exhibit massive bone and/or soft tissue defects, serious bone infection, and excessive scar proliferation. This study aimed to determine whether these defects could be classified and repaired at a single stage. A total of 51 cases of posttraumatic infected massive bone defect in lower extremity were included in this study. They were classified into four types on the basis of the conditions of the bone defects, soft tissue defects, and injured limb length, including Type A (without soft tissue defects), Type B (with soft tissue defects of 10 × 20 cm or less), Type C (with soft tissue defects of 10 × 20 cm or more), and Type D (with the limb shortening of 3 cm or more). Four types of single-stage microsurgical repair protocols were planned accordingly and implemented respectively. These protocols included the following: Protocol A, where vascularized fibular graft was implemented for Type A; Protocol B, where vascularized fibular osteoseptocutaneous graft was implemented for Type B; Protocol C, where vascularized fibular graft and anterior lateral thigh flap were used for Type C; and Protocol D, where limb lengthening and Protocols A, B, or C were used for Type D. There were 12, 33, 4, and 2 cases of Types A, B, C, and D, respectively, according to this classification. During the surgery, three cases of planned Protocol B had to be shifted into Protocol C; however, all microsurgical repairs were completed. With reference to Johner-Wruhs evaluation method, the total percentage of excellent and good results was 82.35% after 6 to 41 months of follow-up. It was concluded that posttraumatic massive bone defects could be accurately classified into four types on the basis of the conditions of bone defects, soft tissue coverage, and injured limb length, and successfully repaired with the single-stage repair protocols after thorough debridement.

The synergistic effects of polyphenols and intestinal microbiota on osteoporosis.

Osteoporosis is a common metabolic disease in middle-aged and elderly people. It is characterized by a reduction in bone mass, compromised bone microstructure, heightened bone fragility, and an increased susceptibility to fractures. The dynamic imbalance between osteoblast and osteoclast populations is a decisive factor in the occurrence of osteoporosis. With the increase in the elderly population in society, the incidence of osteoporosis, disability, and mortality have gradually increased. Polyphenols are a fascinating class of compounds that are found in both food and medicine and exhibit a variety of biological activities with significant health benefits. As a component of food, polyphenols not only provide color, flavor, and aroma but also act as potent antioxidants, protecting our cells from oxidative stress and reducing the risk of chronic disease. Moreover, these natural compounds exhibit anti-inflammatory properties, which aid in immune response regulation and potentially alleviate symptoms of diverse ailments. The gut microbiota can degrade polyphenols into more absorbable metabolites, thereby increasing their bioavailability. Polyphenols can also shape the gut microbiota and increase its abundance. Therefore, studying the synergistic effect between gut microbiota and polyphenols may help in the treatment and prevention of osteoporosis. By delving into how gut microbiota can enhance the bioavailability of polyphenols and how polyphenols can shape the gut microbiota and increase its abundance, this review offers valuable information and references for the treatment and prevention of osteoporosis.

Lactobacillus plantarum attenuates glucocorticoid-induced osteoporosis by altering the composition of rat gut microbiota and serum metabolic profile.

Introduction: Osteoporosis, one of the most common non-communicable human diseases worldwide, is one of the most prevalent disease of the adult skeleton. Glucocorticoid-induced osteoporosis(GIOP) is the foremost form of secondary osteoporosis, extensively researched due to its prevalence.Probiotics constitute a primary bioactive component within numerous foods, offering promise as a potential biological intervention for preventing and treating osteoporosis. This study aimed to evaluate the beneficial effects of the probiotic Lactobacillus plantarum on bone health and its underlying mechanisms in a rat model of glucocorticoid dexamethasone-induced osteoporosis, using the osteoporosis treatment drug alendronate as a reference. Methods: We examined the bone microstructure (Micro-CT and HE staining) and analyzed the gut microbiome and serum metabolome in rats. Results and discussion: The results revealed that L. plantarum treatment significantly restored parameters of bone microstructure, with elevated bone density, increased number and thickness of trabeculae, and decreased Tb.Sp. Gut microbiota sequencing results showed that probiotic treatment increased gut microbial diversity and the ratio of Firmicutes to Bacteroidota decreased. Beneficial bacteria abundance was significantly increased (Lachnospiraceae_NK4A136_group, Ruminococcus, UCG_005, Romboutsia, and Christensenellaceae_R_7_group), and harmful bacteria abundance was significantly decreased (Desulfovibrionaceae). According to the results of serum metabolomics, significant changes in serum metabolites occurred in different groups. These differential metabolites were predominantly enriched within the pathways of Pentose and Glucuronate Interconversions, as well as Propanoate Metabolism. Furthermore, treatment of L. plantarum significantly increased serum levels of Pyrazine and gamma-Glutamylcysteine, which were associated with inhibition of osteoclast formation and promoting osteoblast formation. Lactobacillus plantarum can protect rats from DEX-induced GIOP by mediating the "gut microbial-bone axis" promoting the production of beneficial bacteria and metabolites. Therefore L. plantarum is a potential candidate for the treatment of GIOP.

Epigallocatechin gallate alleviates osteoporosis by regulating the gut microbiota and serum metabolites in rats.

Osteoporosis, one of the serious public health problems worldwide, can lead to degeneration of the bone structure and increased risk of fractures. Epigallocatechin gallate (EGCG) is a natural product with potential efficacy in inhibiting bone loss. However, the specific mechanism remains unclear. This study first investigated the role of EGCG in preventing dexamethasone (DEX)-induced osteoporosis by regulating intestinal microbiota and serum metabolites. We detected the bone density, bone microstructure, and changes in intestinal microorganisms and serum metabolites. According to our results, EGCG inhibited the decline of bone density, protected the bone microstructure, increased microbial diversity, promoted the abundance of beneficial bacteria such as Prevotellaceae and Ruminococcus, and inhibited the abundance of pathogenic bacteria such as Peptostreptococcaceae. There were also significant changes in serum metabolites among different treatments. Differential metabolites were mainly involved in sphingolipid metabolism and glycerophospholipid metabolism pathways, especially ceramide (d18:0/16:0(2OH)), phosphatidylserine (P-20:0/20:4(5Z,8Z,11Z,14Z)), phosphatidylserine (18:2(9Z,12Z)/12:0), and phosphatidylethanolamine (O-16:0/0:00), which were increased after EGCG treatment. Notably, most of the above metabolites were positively correlated with bone mineral density, BV/TV and Tb·Th, and negatively correlated with Tb·Sp. In summary, EGCG can prevent bone damage, promote the production of beneficial bacteria and metabolites, and enhance immune function. This study provides a basis and reference for the prevention and treatment of osteoporosis, as well as the application of EGCG in maintaining body health.

The Role of SIRT3 in the Osteoporosis.

SIRT3 is an NAD+-dependent deacetylase in the mitochondria with an extensive ability to regulate mitochondrial morphology and function. It has been reported that SIRT3 participates in the occurrence and development of many aging-related diseases. Osteoporosis is a common aging-related disease characterized by decreased bone mass and fragility fractures, which has caused a huge burden on society. Current research shows that SIRT3 is involved in the physiological processes of senescence of bone marrow mesenchymal stem cells (BMSCs), differentiation of BMSCs and osteoclasts. However, the specific effects and mechanisms of SIRT3 in osteoporosis are not clear. In the current review, we elaborated on the physiological functions of SIRT3, the cell types involved in bone remodeling, and the role of SIRT3 in osteoporosis. Furthermore, it also provided a theoretical basis for SIRT3 as a therapeutic target for osteoporosis.

The Role of Sirtuins in Osteogenic Differentiation of Vascular Smooth Muscle Cells and Vascular Calcification.

Vascular calcification (VC) is a common pathological change in many chronic diseases, such as diabetes and chronic kidney disease. It is mainly deposited in the intima and media of vessels in the form of hydroxyapatite. Recently, a lot of research has been performed to show that VC is associated with various cellular stresses, such as hyperphosphate, hyperglycemia and oxidative stress. Unfortunately, our understanding of the pathogenesis of calcification is far from comprehensive. Sirtuins belong to a family of class III highly conserved deacetylases that are involved in the regulation of biological and cellular processes including mitochondrial biogenesis, metabolism, oxidative stress, inflammatory response, DNA repair, etc. Numerous studies have shown that sirtuins might play protective roles in VC, and restoring the activity of sirtuins may be a potentially effective treatment for VC. However, the exact mechanism of their vascular protection remains unclear. Here, we reviewed the roles of sirtuins in the osteogenic transformation of vascular smooth muscle cells and the development of VC. We also elucidated the applications of sirtuins agonists for the treatment of VC.

Quantitative regression analysis of the cutaneous vascular territories in a rat model.

BACKGROUND: The rat skin flap model has been widely used in experimental flap survival studies; however, most of these have been qualitative studies. The purpose of this study was to investigate the quantitative relationship between the diameter of a cutaneous artery and the area of skin that it supplies, and also to explore the factors that influence this relationship. METHODS: Thirty rats were injected with lead oxide and gelatin and then radiographed. Computer imaging of the diameter and the area of blood supply of the cutaneous artery were made to investigate the mathematical relationship between the arterial diameter and its perfusion area. Angiograms were assembled using Adobe Photoshop and analyzed with Scion Image and SPSS software. RESULTS: The blood vessels had an average diameter of 0.53 ± 0.12 mm, perimeter of 18.74 ± 4.84 cm, vascular density of 391.31 ± 76.58 gray value/pixel cm, vascular territory of 22.32 ± 10.04 cm(2) and supplying volume of 4.88 ± 3.02 cm(3). There was a positive correlation between the diameter and the perimeter of the vascular territory, and the area and volume of the vascular territory. The linear regression equation was y = 32.44x + 1.23 [y: nutrition region perimeter (cm), x: cutaneous artery diameter (mm)], y = 72.70x-15.93 [y: supplying area (cm(2)), x: cutaneous artery diameter (mm)] and y = 20.36x-5.83 [y: supplying volume (cm(3)), x: cutaneous artery diameter (mm)], respectively. CONCLUSIONS: Based on this data, it is postulated that the size of reliable skin flaps can be calculated by the diameter and the distribution patterns of the cutaneous artery. With the same diameter, the area of the flap supplied by branch-style artery is larger than the one supplied by the axial artery.

A mini pig model for visualization of perforator flap by using angiography and MIMICS.

BACKGROUND: Research performed using animal models has assisted in the understanding of flap anatomy and physiology. Pigs' vasculature in the skin is anatomically and physiologically similar to human, making it an ideal model for research. Until now, most vascular imaging studies are of two-dimensions. The aim of this study is to provide a three-dimensional (3D) model that reveals detailed architecture of the vascular network of the porcine, for accurate quantitative assessment. METHODS: Five Guangxi Bama minipigs were anaesthetized intramuscularly and underwent whole body lead oxide-gelatin injection. Spiral computed tomography scanning was performed on the subjects and three-dimensional reconstructions were made. Another minipig was used, and underwent Cardiografin injection. 3D-reconstruction was executed in vivo. All subjects were then dissected by layers to document the individual perforators. RESULTS: Angiography using perfusion with lead oxide-gelatine mixture has the advantage of illustrating distinctively the vessels and their perforating branches. However, it is incapable of displaying other tissues structures. Angiography through perfusion with Cardiografin in vivo has the advantage of demonstrating the relationship between arteries and bones. Yet it could only display coarsely the vascular trunk, and is incapable of displaying the vascular network. By combining these two methods, the 3D structure, source, course, and territories of the arteries were presented distinctively. CONCLUSIONS: 3D modeling in combination with traditional sectional imaging of the pig model enables blood vessels to be displayed more dynamically with greater realism. The procedure described could be useful for future flap research, by offering a better visualization of the vascular structure of the skin flap, allowing for better anatomical understanding.

Preventive and Therapeutic Roles of Berberine in Gastrointestinal Cancers.

Berberine (BBR) is an isoquinoline alkaloid isolated from various types of plants, including those from the Berberidaceae, Ranunculaceae, and Papaveraceae families. It has long been used in traditional Chinese medicine for treating diarrhea and gastrointestinal disorders. The medicinal properties of BBR include antimicrobial, anti-inflammatory, antioxidative, lipid-regulatory, and antidiabetic actions. Importantly, the efficacy of BBR against cancers has been assessed in several experimental studies and clinical trials. Gastrointestinal (GI) cancers are a group of the most prevalent cancers worldwide that are associated with high morbidity and mortality, and their associated mortality has been increasing over the years. Thus, GI cancers have become a burden to the patients and health care systems. This review summarizes the cellular and molecular mechanisms underlying the therapeutic effects of BBR and explores its potential preventive and therapeutic applications against GI cancers.

[Effect of Rhizoma curcumae oil on the learning and memory in rats exposed to chronic hypoxia and the possible mechanisms.].

The effect of Rhizoma curcumae oil on the learning and memory in rats exposed to chronic hypoxia and the possible mechanisms were investigated. The rats were divided randomly into 5 groups (14 animals in each group): control, chronic hypoxia, chronic hypoxia with low (5 mg/kg body weight), middle (10 mg/kg body weight) and high (20 mg/kg body weight) concentrations of Rhizoma curcumae oil injection. The animals undergoing chronic hypoxia were exposed to hypoxia in a hypoxic chamber containing 10% O(2) and 5% CO(2) for 10 h/d, lasting 28 d. Morris water maze (MWM) test was used to obtain the scores of leaning and memory. The superoxide dismutase (SOD) activity and malonaldehyde (MDA) content were determined in the serum and hippocampus as well as [Ca(2+)](i) in the hippocampus. The expression of phosphorylated Ca(2+)/calmodulin-dependent protein kinase II (p-CaMKII) in the hippocampus was evaluated by using immunohistochemistry and Western blot. Compared with the control group, the chronic hypoxia group showed the following changes: (1) The escape latency to the hidden platform was remarkably prolonged (P<0.05); (2) The content of MDA and [Ca(2+)](i) were obviously higher, but the activity of SOD and the expression of p-CaMKII were significantly lower (P<0.05, P<0.01). Compared with the chronic hypoxia group, groups with Rhizoma curcumae oil injection had the following changes: (1) The escape latency to the hidden platform was remarkably shorter in 10, 20 mg/kg body weight groups (P<0.05); (2) The content of MDA and [Ca(2+)](i) were markedly decreased in 5, 10, 20 mg/kg body weight groups (P<0.05, P<0.01), but the activity of SOD in the serum and the expression of p-CaMKII were significantly higher in 10, 20 mg/kg body weight groups (P<0.05, P<0.01). The results showed that the capacity of learning and memory was degraded following chronic hypoxia. The decrease in MDA content and [Ca(2+)](i) and (or) the increase in SOD activity and p-CaMKII expression might participate in the enhancing effect on learning and memory induced by Rhizoma curcumae oil.

The Bioactive Substance Secreted by MSC Retards Mouse Aortic Vascular Smooth Muscle Cells Calcification.

BACKGROUND: Vascular calcification, which is associated with low-level chronic inflammation, is a complication that occurs during aging, atherosclerosis, chronic kidney disease, diabetes mellitus, and hyperlipaemia. In this study, we used conditioned media from mesenchymal stem cells (MSC-CM), a source of autologous cytokines, to test the hypothesis that MSC-CM inhibits vascular smooth muscle cell (VSMC) calcification by suppressing inflammation and apoptosis. METHODS: VSMCs were treated with ß-glycerophosphate (ß-GP) to induce calcification and MSC-CM was used as a treatment. Calcium deposition was evaluated using alizarin red and von Kossa staining after a 7-day induction period. Intracellular calcium contents were measured via the o-cresolphthalein complexone method, and alkaline phosphatase (ALP) activity was determined using the para-nitrophenyl phosphate method. The expressions of specific-osteogenic markers, inflammatory cytokines, and apoptosis-associated genes/proteins were examined by real-time polymerase chain reaction or western blotting. RESULTS: MSC-CM inhibited ß-GP-induced calcium deposition in VSMCs and decreased intracellular calcium content and ALP activity. Additionally, MSC-CM suppressed the ß-GP-induced increases in BMP2, Msx2, Runx2, and osteocalcin expression. Additionally, MSC-CM decreased the expression of TNF-α, IL-1ß, and IL-6 in VSMC. MSC-CM also partly blocked ß-GP-induced VSMC apoptosis, which was associated with an increase in the Bcl-2/Bax expression ratio and a decrease in caspase-3 expression. CONCLUSION: Our study results suggest that MSC-CM can inhibit VSMC calcification. This suggests a potential novel clinical application for MSCs in the treatment of vascular calcification and associated diseases.

Conditioned medium from bone marrow-derived mesenchymal stem cells inhibits vascular calcification through blockade of the BMP2-Smad1/5/8 signaling pathway.

BACKGROUND: Arterial calcification is associated with cardiovascular disease as a complication of advanced atherosclerosis and is a significant contributor to cardiovascular morbidity and mortality. Osteoblastic differentiation of vascular smooth muscle cells (VSMCs) plays an important role in arterial calcification and is characterized by cellular necrosis, inflammation, and lipoprotein and phospholipid complexes, especially in atherosclerotic calcification. The conditioned medium from bone marrow-derived mesenchymal stem cells (MSC-CM) is well known as a rich source of autologous cytokines and is universally used for tissue regeneration in current clinical medicine. Here, we demonstrate that MSC-CM inhibits beta-glycerophosphate (ß-GP)-induced vascular calcification through blockade of the bone morphogenetic protein-2 (BMP2)-Smad1/5/8 signaling pathway. METHODS: VSMC calcification was induced by ß-GP followed by treatment with MSC-CM. Mineral deposition was assessed by Alizarin Red S staining. Intracellular calcium content was determined colorimetrically by the o-cresolphthalein complexone method and alkaline phosphatase (ALP) activity was measured by the para-nitrophenyl phosphate method. Expression of BMP2, BMPR1A, BMPR1B, BMPR2, msh homeobox 2 (Msx2), Runt-related transcription factor 2 (Runx2), and osteocalcin (OC), representative osteoblastic markers, was assessed using real-time polymerase chain reaction analysis while the protein expression of BMP2, Runx2, and phosphorylated Smad1/5/8 was detected by western blot analysis. RESULTS: Our data demonstrated that MSC-CM inhibits osteoblastic differentiation and mineralization of VSMCs as evidenced by decreased calcium content, ALP activity, and decreased expression of BMP-2, Runx2, Msx2, and OC. MSC-CM suppressed the expression of phosphorylated Smad1/5/8 and the ß-GP-induced translocation from the cytoplasm to the nucleus. Further study demonstrated that human recombinant BMP-2 overcame the suppression of VSMC calcification by MSC-CM. CONCLUSION: MSC-CM may act as a novel therapy for VSMC calcification by mediating the BMP2-Smad1/5/8 signaling pathway.

Attenuation of the degenerative effects of endothelin-1 on cartilaginous end plate cells by the endothelin receptor antagonist BQ-123 via the Wnt/ß-catenin signaling pathway.

BACKGROUND CONTEXT: Endothelin-1 (ET-1) is an inflammatory mediator associated with cartilage end plate (CEP) degeneration in the intervertebral disc (IVD). SOX9 is downregulated during CEP degeneration, along with its targets, collagen II and aggrecan. Wnt/ß-catenin signaling is associated with CEP degeneration and a downstream target of SOX9; however, the precise mechanism of CEP degeneration and the role of ET-1 are largely unknown. PURPOSE: The purpose of the study was to evaluate the influence of the endothelin-A receptor antagonist, BQ-123, on ET-1-induced effects on cartilaginous end plate cells (CECs) associated with CEP degeneration via the Wnt/ß-catenin signaling pathway. STUDY DESIGN/SETTING: The influence of ET-1 on the expression levels of collagen II, aggrecan, and SOX9 in CECs and the effect of BQ-123 in this context were investigated. METHODS: To establish a model for CEP degeneration, three lumbar discs (L3-L4, L4-L5, and L5-L6 levels) in New Zealand white rabbits were punctured close to the vertebral end plate using a 14G needle. Intervertebral disc degeneration was evaluated by magnetic resonance imaging 4 weeks after vertebral end plate injury. CECs were then isolated from the degenerated CEPs to allow evaluation of the role of ET-1 and BQ-123 and to investigate their effects on the Wnt/ß-catenin signaling pathway. The expression of ET-1 in CECs from degenerated CEPs was analyzed by immunofluorescent staining. Changes in the levels of collagen II, aggrecan, and SOX9 were evaluated in CECs by real-time polymerase chain reaction and by Western blotting. The Wnt/ß-catenin signaling pathway was also investigated by Western blotting. RESULTS: After 4 weeks, IVDs with vertebral end plate injury exhibited clear signs of disc degeneration. Immunofluorescent staining showed that ET-1 was expressed in the cytoplasm of CECs. Endothelin-1 stimulation significantly inhibited the expression of collagen II, aggrecan, and SOX9 in CECs, whereas BQ-123 increased the levels of these three molecules. In addition, ET-1 stimulation increased the expression of ß-catenin, cyclin D1, and Dvl1 in the Wnt/ß-catenin signaling pathway of CECs from degenerated discs and reduced the expression of GSK-3ß, whereas BQ-123 had the opposite effect. CONCLUSIONS: Endothelin-1 can reduce levels of collagen II, aggrecan, and SOX9 in CECs through activation of the Wnt/ß-catenin signaling pathway, whereas BQ-123 attenuates these negative effects, highlighting a new molecular mechanism with potential for exploitation for treatment of CEP degeneration.

Changes of learning, memory and levels of CaMKII, CaM mRNA, CREB mRNA in the hippocampus of chronic multiple-stressed rats.

BACKGROUND: The effect of chronic stress on cognitive functions has been one of the hot topic in neuroscience. But there has been much controversy over its mechanism. Such single stressor applied in the past could not simulate complicated living circumstances that people confronted with. The aim of this study was to investigate the effects of chronic multiple-stress on learning and memory as well as on the levels of calcium/calmodulin-dependent protein kinase II (CaMKII), calmodulin (CaM) mRNA, and cAMP-response element binding protein (CREB) mRNA in the hippocampus of rats. METHODS: The rats were divided randomly into stressed and control groups. The stressed group was given chronic multiple-stress for 6 weeks to set up a chronic multiple-stressed model. The rats' performance of spatial learning and memory was tested using Morris Water Maze (MWM) and Y-maze. Meanwhile, the expressions of CaMKII, CaM mRNA and CREB mRNA of rats' hippocampus were detected by immunohistochemistry, Western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. In addition, the width of synaptic cleft and the thickness of post-synaptic densities (PSD) were observed in the hippocampal CA3 region of rats by electron microscopy. RESULTS: After exposure to chronic multiple-stress for 6 weeks, the ability of learning and memory of the stressed group was higher than that of the control group (P < 0.05, P < 0.01). The width of synaptic cleft was smaller and the thickness of PSD was larger in the hippocampal CA3 region of the stressed group than in that of the control group (P < 0.01). The CaMK II immunostaining of the stressed group was stronger than that of the control group in the stratum radiatum and oriens of the hippocampal CA1 and CA3, especially in the stratum oriens. Quantitative analysis indicated that the expression of CaMK II, CaM mRNA, and CREB mRNA in the hippocampus of the stressed group was higher than that of the control group (P < 0.05, P < 0.01). CONCLUSIONS: The capacity of learning and memory can be enhanced after chronic multiple-stress. The increased levels of CaMK II, CaM mRNA, and CREB mRNA may contribute to the enhancing effect of chronic multiple-stress on learning and memory.

Mesenchymal Stem Cells Stabilize Atherosclerotic Vulnerable Plaque by Anti-Inflammatory Properties.

BACKGROUND AND OBJECTIVES: Formation and progression of atherosclerotic vulnerable plaque (VP) is the primary cause of many cardio-cerebrovascular diseases such as acute coronary syndrome and stroke. It has been reported that bone marrow mesenchymal stem cells (MSC) exhibit protective effects against many kinds of diseases including myocardial infarction. Here, we examined the effects of intravenous MSC infusion on a VP model and provide novel evidence of its influence as a therapy in this animal disease model. SUBJECTS AND METHODS: Thirty healthy male New Zealand white rabbits were randomly divided into a MSC, VP or stable plaque (SP) group (n = 10/group) and received high fat diet and cold-induced common carotid artery intimal injury with liquid nitrogen to form atherosclerotic plaques. Serum hs-CRP, TNF-α, IL-6 and IL-10 levels were measured by ELISA at 1, 2, 3, 7, 14, 21 and 28 days after MSC transplantation. The animals were sacrificed at 4 weeks after MSC transplantation. Lesions in the right common carotid were observed using H&E and Masson staining, and the fibrous cap/lipid core ratio of atherosclerotic plaques were calculated. The expression of nuclear factor κB (NF-κB) and matrix metalloproteinase 1, 2, 9 (MMP-1,2,9) in the plaque were detected using immunohistochemistry, and apoptotic cells in the plaques were detected by TUNEL. In addition, the level of TNF-α stimulated gene/protein 6 (TSG-6) mRNA and protein were measured by quantitative Real-Time PCR and Western blotting, respectively. RESULTS: Two rabbits in the VP group died of lung infection and cerebral infarction respectively at 1 week after plaque injury by liquid nitrogen. Both H&E and Masson staining revealed that the plaques from the SP and MSC groups had more stable morphological structure and a larger fibrous cap/lipid core ratio than the VP group. Serum hs-CRP, TNF-α and IL-6 were significantly down-regulated, whereas IL-10 was significantly up-regulated in the MSC group compared with the VP group. .Immunohistochemistry analysis revealed that NF-κB and MMP expression was reduced in the MSC and SP groups compared to the VP group. Cell apoptosis decreased significantly in both the MSC and SP groups in comparison to the VP group. TSG-6 mRNA and protein expression were higher in the plaques of the MSC group compared to the VP and SP groups. CONCLUSIONS: Our study results suggest that MSC transplantation can effectively stabilize vulnerable plaques in atherosclerotic rabbits. This may potentially offer a new clinical application of MSC in atherosclerosis.

A novel in vivo technique for observations of choke vessels in a rat skin flap model.

BACKGROUND: Choke vessels are reduced-caliber vessels that link adjacent vascular territories throughout the body. The behavior of choke vessels determines flap survival. Therefore, it is important to develop a reliable technique with which to study these vessels. The purpose of this report is to document a novel in vivo technique for the study of choke anastomotic vessels in a rat skin flap model. METHODS: This study was divided into two parts. In part I, 30 adult Sprague-Dawley rats underwent whole-body lead oxide/gelatin injection and the skin was removed for radiography to analyze the skin vasculature. In part II, a dorsal skin flap was elevated in 12 rats, and a skinfold chamber was installed to observe the choke vessels between the iliolumbar artery perforator and the posterior intercostal artery perforator for 8 days. Evans blue dye was injected through the lateral tail vein. Blood flow velocity was calculated. RESULTS: In part I, three distinct patterns of dorsal cutaneous vasculature were found. A three-territory, 3.5×10-cm flap can be elevated on the dorsum of the rat. In part II, an increase in diameter of the choke arteries and the choke veins was observed, particularly in the fine venules. Blood flow velocity across the arterial segment of the choke zone was found to be 2.5 mm/second. CONCLUSIONS: The observation chamber technique for in vivo study of the choke anastomotic region of the rat dorsal skin flap model is a promising novel method for studying skin microcirculation. The time sequence of microvascular events in the choke anastomotic zone of this rat model was documented.