The role of the microbiota-gut-brain axis and intestinal microbiome dysregulation in Parkinson's disease.

Parkinson's disease (PD) is a complex progressive neurodegenerative disease associated with aging. Its main pathological feature is the degeneration and loss of dopaminergic neurons related to the misfolding and aggregation of α-synuclein. The pathogenesis of PD has not yet been fully elucidated, and its occurrence and development process are closely related to the microbiota-gut-brain axis. Dysregulation of intestinal microbiota may promote the damage of the intestinal epithelial barrier, intestinal inflammation, and the upward diffusion of phosphorylated α-synuclein from the enteric nervous system (ENS) to the brain in susceptible individuals and further lead to gastrointestinal dysfunction, neuroinflammation, and neurodegeneration of the central nervous system (CNS) through the disordered microbiota-gut-brain axis. The present review aimed to summarize recent advancements in studies focusing on the role of the microbiota-gut-brain axis in the pathogenesis of PD, especially the mechanism of intestinal microbiome dysregulation, intestinal inflammation, and gastrointestinal dysfunction in PD. Maintaining or restoring homeostasis in the gut microenvironment by targeting the gut microbiome may provide future direction for the development of new biomarkers for early diagnosis of PD and therapeutic strategies to slow disease progression.

A novel method of augmenting gene expression and angiogenesis in the normal and ischemic canine myocardium.

This study presents a novel method that direct intramyocardial injection of low-dose plasmid DNA and microbubbles combined with insonation could further augment gene expression in normal and ischemic canine myocardium. Plasmids encoding enhanced green fluorescent protein (pEGFP) and hepatocyte growth factor (pHGF) (500 µg) were individually mixed with 0.5 ml of microbubble solution (MB) and injected into the normal or acute ischemic canine myocardium. The dogs in the plasmid + MB/US group underwent insonation (US). Other dogs were randomly divided into three treatment groups: plasmid and insonation, plasmid and MB injection, and plasmid injection only. The EGFP and HGF mRNA expressions were assessed in the myocardium at the injection site and at sites 0.5 and 1 cm remote from the injection site. Compared to plasmid transfer alone, a mean 13.4-fold enhancement of gene expression was achieved in the EGFP + MB/US group at 48 h (p < 0.01). HGF mRNA expression in ischemic zones was markedly elevated after 28 days, with a mean 9.0-fold enhancement in the HGF + MB/US group (p < 0.01). EGFP protein expression was detected in the normal myocardium at 1 cm remote from the injection site in the EGFP + MB/US group. Similarly, HGF protein expression was detected in the ischemic myocardium at 0.5 cm remote from the injection site in the HGF + MB/US group. These findings indicate that the radius of gene expression was partly extended in the two plasmid + MB/US groups. The capillary density increased from 20.9 ± 5.3/mm(2) in control myocardial infarction dogs without treatment to 126.7 ± 38.2/mm(2) in the HGF + MB/US group (p < 0.01). Taken together, the present data demonstrate that direct intramyocardial injection of an angiogenic gene and microbubbles combined with insonation can augment gene expression and angiogenesis. Consequently, this strategy may be a useful tool for gene therapy of ischemic heart disease.

[Relationship between glycated albumin level and pancreatic ß cell function in newly diagnosed type 2 diabetics].

OBJECTIVE: To explore the relationship between glycated albumin (GA) level and pancreatic ß cell function in newly diagnosed type 2 diabetics. METHODS: The subjects sought the confirmation of diabetes diagnosis or underwent diabetes screening tests in high-risk patients from January 2008 to October 2010. All of them underwent 75 g oral glucose tolerance test (OGTT) and insulin releasing test. The levels of GA and hemoglobin A1c (HbA1c) were analyzed by liquid enzymatic method and high performance liquid chromatography respectively. Homeostasis model assessment (HOMA) was used to evaluate the basal insulin resistance (HOMA-IR) and pancreatic ß cell function (HOMA-ß). ΔI30/ΔG30 was used to evaluate early-phase insulin secretion after a glucose load. RESULTS: (1) Among 500 type 2 diabetics according to the diagnostic criteria of WHO (1999), 279 were males and 221 were females. Average age was 56.3 ± 12.3, GA (21.1 ± 5.4)% and HbA1c (7.0 ± 1.3)%. (2) A significantly positive relationship was shown between HbA1c and GA (r = 0.691, P < 0.01). GA was also positively correlated with fasting plasma glucose (FPG), 0.5 hPG, 1 hPG, 2 hPG and 3 hPG after a glucose load of OGTT test (r = 0.511 - 0.627, P < 0.01). (3) GA was negatively correlated with body mass index (BMI) (r = -0.112, P < 0.01), HOMA-ß (r = -0.350, P < 0.01) and ΔI30/ΔG30 (r = -0.263, P < 0.01). (4) Multivariant stepwise regression analysis showed that HbA1c, FPG, 3 hPG and ΔI30/ΔG30 were independent factors of GA level. CONCLUSION: Glycated albumin level is closely correlated with the function of early-phase insulin secretion in newly diagnosed type 2 diabetics.

A visible, targeted high-efficiency gene delivery and transfection strategy.

BACKGROUND: To enhance myocardial angiogenic gene expression, a novel gene delivery strategy was tested. Direct intramyocardial injection of an angiogenic gene with microbubbles and insonation were applied in a dog animal model. Dogs received one of the four different treatments in conjunction with either the enhanced green fluorescence protein (EGFP) gene or the hepatocyte growth factor (HGF) gene: gene with microbubbles (MB) and ultrasound (US); gene with US; gene with MB; or the gene alone. RESULTS: Distribution of MB and the gene in the myocardium was visualized during the experiment. Compared with the EGFP gene group, an average 14.7-fold enhancement in gene expression was achieved in the EGFP+MB/US group (P < 0.01). Compared with the HGF gene group, an average 10.7-fold enhancement in gene expression was achieved in the HGF+MB/US group (P < 0.01). In addition, capillary density increased from 20.8 ± 3.4/mm2 in the HGF gene group to 146.7 ± 31.4/mm2 in HGF+MB/US group (P < 0.01). CONCLUSIONS: Thus, direct intramyocardial injection of an angiogenic gene in conjunction with microbubbles plus insonation synergistically enhances angiogenesis. This method offers an observable gene delivery procedure with enhanced expression efficiency of the delivered gene.

Bacteriological differences between COPD exacerbation and community-acquired pneumonia.

OBJECTIVE: To study the differences in pathogen distribution and antibiotic susceptibility between patients with COPD exacerbation and patients with community-acquired pneumonia, and develop guidance for antibiotic treatment of those conditions. METHODS: We retrospectively analyzed the medical records of 586 COPD-exacerbation patients and 345 community-acquired-pneumonia patients from January 2007 to December 2008, including sputum culture results, antibiotic susceptibilities of the microorganisms, and clinical characteristics. RESULTS: 276 (47%) of the COPD-exacerbation patients, and 183 (53%) of the community-acquired-pneumonia patients had a positive sputum culture. In order, the most common pathogens in the COPD-exacerbation patients were Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Acinetobacter baumannii, and Haemophilus influenzae. The most common pathogens in the community-acquired-pneumonia patients were Streptococcus pneumoniae, H. influenzae, K. pneumoniae, S. aureus, and E. coli. CONCLUSIONS: P. aeruginosa was the most common pathogen in our patients with COPD exacerbation, and S. pneumoniae was the most common in our patients with community-acquired pneumonia. P. aeruginosa is especially common in the patients with serious or extremely serious COPD.

[Combined utility of hemoglobin A1c and glycated albumin in diabetic screening].

OBJECTIVE: To assess the validity of combined detection of hemoglobin A1c (HbA1c) and glycated albumin (GA) in diabetic screening. METHODS: A total of 1480 subjects at our out-patient department from March 2007 to December 2009. Those suspected of diabetes or at a high risk of diabetes were enrolled. The study population included 677 males and 803 females with a mean age of 52.7 years. All subjects received an oral glucose tolerance test (OGTT) after a 10-hour fasting. Glycated albumin (GA) and hemoglobin A1c (HbA1c) were measured with liquid enzyme method and high pressure liquid chromatography respectively. RESULTS: (1) According to World Health Organization diabetes diagnosis criteria, there were 562 subjects with normal glucose tolerance (NGT), 411 subjects with impaired glucose regulation (IGR) and 507 subjects with newly diagnosed diabetes mellitus (DM). The level of HbA1c and GA had a rising tendency among NGT, IGR and DM groups (P < 0.01). (2) Pearson correlation analysis demonstrated that HbA1c had a positive association with GA (r = 0.75, P < 0.01). (3) Using OGTT as golden standard of diabetic diagnosis, receiver operator characteristic (ROC) curve indicated that HbA1c and GA were strong predictors of diabetes. The area under curve (AUC) was 0.882 and 0.881 respectively with no significant difference (P > 0.05). (4) The sensitivity of combined use of HbA1c and GA at optimal cut-off points of 6.1% and 17.1% was significantly higher than that of single use of HbA1c or GA in diabetic screening (94.7% vs 81.1%, 88.4%, P < 0.01). CONCLUSION: A combined detection of HbA1c and GA may improve the efficacy of diabetic screening. The subject with HbA1c ≥ 6.1% or GA ≥ 17.1% is recommended to undergo OGTT for confirming a diagnosis of diabetes.

[Therapeutic angiogenesis induced by hepatocyte growth factor directed by ultrasound-targeted microbubble destruction].

OBJECTIVE: To explore the feasibility of therapeutic angiogenesis in myocardial infarction induced by hepatocyte growth factor (HGF) mediated by ultrasound-targeted microbubble destruction. METHODS: Forty Wistar rats were divided into 4 groups after the models of myocardial infarction were established: HGF + ultrasound + microbubble (HGF + US/MB) groups, HGF and ultrasound (HGF + US) group, HGF and microbubble (HGF + MB) group, and surgery alone (SA) group. Ultrasound-targeted destruction microbubble loaded with HGF gene with ECG trigger was performed in HGF + US group. Microbubble loaded with HGF gene was infused intravenously in HGF + MB group, and normal saline were infused in SA group. All rats were killed 14 days after transfection. The CD34 expression was detected by immunohistochemistry (IHC), and microvessel density (MVD) was counted in high power field. The HGF expression on myocardium was detected by ELISA, and the correlation between the contents of HGF and MVD in myocardium was analyzed. RESULTS: IHC results showed that CD34 expressions, shown as brown granules, were located on the membrane and endochylema of vascular endothelial cells. The MVD in HGF + US/MB group [ (266.9 +/- 39.8) /HPF] were highest among all the groups. The contents of HGF in myocardium were highest in HGF + US/MB group [(5.54 +/- 0.81) ng/g], and the contents of HGF in anterior wall were significantly higher than those in posterior wall (P < 0.05); the difference was also significant when compared with others groups (P < 0.01). The correlation analysis showed the contents of HGF was positively correlated with MVD in myocardium. CONCLUSION: Ultrasound-targeted microbubble destruction can effectively deliver HGF into the infracted myocardium and facilitate angiogenesis, which provides a novel way in the gene therapy of myocardial infarction.

Vitamin D should be supplemented more actively in elderly patients with coronary heart disease combined with COPD.

OBJECTIVE: It is not clear whether vitamin D should be actively supplemented in elderly patients suffering from an acute attack of COPD (AECOPD) and coronary heart disease (CHD). PATIENTS AND METHODS: The patients were divided into three groups according to specific criteria: patients with AECOPD (group A), patients with COPD combined with CHD (group B), and patients with CHD (group C). We measured the levels of vitamin D and analyzed the correlation between vitamin D and important electrolytes, including prealbumin, creatinine, hemoglobin, cystatin C, blood fat, blood calcium, and blood magnesium, and the nutrition state of the whole body. The serum B-type natriuretic peptide (BNP) was measured using an ELISA kit. RESULTS: The vitamin D level in group B was the lowest, followed by group A. When compared with group C, they all had statistical significance (P<0.05), but there was no statistical difference between groups A and B. There was no difference among the three groups when prealbumin, creatinine, hemoglobin, cystatin C, blood fat, blood calcium, and blood magnesium were compared. The level of BNP in the three groups increased, but it had no obvious correlation with the level of vitamin D (P>0.05). CONCLUSION: When elderly patients have coronary artery disease with AECOPD, vitamin D levels were obviously lower and were negatively correlated with the BNP. Low vitamin D levels, as well as poor nutrition, affect cardiopulmonary function and quality of living of elderly patients, especially female patients. Therefore, vitamin D should be supplemented more actively in the female patients suffering from AECOPD and CHD.

Memory dysfunction in type 2 diabetes mellitus correlates with reduced hippocampal CA1 and subiculum volumes.

BACKGROUND: Little attention has been paid to the role of subcortical deep gray matter (SDGM) structures in type 2 diabetes mellitus (T2DM)-induced cognitive impairment, especially hippocampal subfields. Our aims were to assess the in vivo volumes of SDGM structures and hippocampal subfields using magnetic resonance imaging (MRI) and to test their associations with cognitive performance in T2DM. METHODS: A total of 80 T2DM patients and 80 neurologically unimpaired healthy controls matched by age, sex and education level was enrolled in this study. We assessed the volumes of the SDGM structures and seven hippocampal subfields on MRI using a novel technique that enabled automated volumetry. We used Mini-Mental State Examination and Montreal Cognitive Assessment (MoCA) scores as measures of cognitive performance. The association of glycosylated hemoglobin (HbA1c) with SDGM structures and neuropsychological tests and correlations between hippocampal subfields and neuropsychological tests were assessed by partial correlation analysis in T2DM. RESULTS: Bilaterally, the hippocampal volumes were smaller in T2DM patients, mainly in the CA1 and subiculum subfields. Partial correlation analysis showed that the MoCA scores, particularly those regarding delayed memory, were significantly positively correlated with reduced hippocampal CA1 and subiculum volumes in T2DM patients. Additionally, higher HbA1c levels were significantly associated with poor memory performance and hippocampal atrophy among T2DM patients. CONCLUSIONS: These data indicate that the hippocampus might be the main affected region among the SDGM structures in T2DM. These structural changes in the hippocampal CA1 and subiculum areas might be at the core of underlying neurobiological mechanisms of hippocampal dysfunction, suggesting that degeneration in these regions could be responsible for memory impairments in T2DM patients.

An accurate, flexible and small optical fiber sensor: a novel technological breakthrough for real-time analysis of dynamic blood flow data in vivo.

Because of the limitations of existing methods and techniques for directly obtaining real-time blood data, no accurate microflow in vivo real-time analysis method exists. To establish a novel technical platform for real-time in vivo detection and to analyze average blood pressure and other blood flow parameters, a small, accurate, flexible, and nontoxic Fabry-Perot fiber sensor was designed. The carotid sheath was implanted through intubation of the rabbit carotid artery (n = 8), and the blood pressure and other detection data were determined directly through the veins. The fiber detection results were compared with test results obtained using color Doppler ultrasound and a physiological pressure sensor recorder. Pairwise comparisons among the blood pressure results obtained using the three methods indicated that real-time blood pressure information obtained through the fiber sensor technique exhibited better correlation than the data obtained with the other techniques. The highest correlation (correlation coefficient of 0.86) was obtained between the fiber sensor and pressure sensor. The blood pressure values were positively related to the total cholesterol level, low-density lipoprotein level, number of red blood cells, and hemoglobin level, with correlation coefficients of 0.033, 0.129, 0.358, and 0.373, respectively. The blood pressure values had no obvious relationship with the number of white blood cells and high-density lipoprotein and had a negative relationship with triglyceride levels, with a correlation coefficient of -0.031. The average ambulatory blood pressure measured by the fiber sensor exhibited a negative correlation with the quantity of blood platelets (correlation coefficient of -0.839, P<0.05). The novel fiber sensor can thus obtain in vivo blood pressure data accurately, stably, and in real time; the sensor can also determine the content and status of the blood flow to some extent. Therefore, the fiber sensor can obtain partially real-time vascular rheology information and may thus enable the early diagnosis of blood rheology disorders and diseases.

Transendocardial delivery of HGF via microbubbles and ultrasound to treat acute myocardial infarction.

To enhance the safety of transendocardial delivery and the efficacy of intramyocardial angiogenic gene expression, a visible, less invasive, targeted, high-efficiency gene delivery strategy was tested. Progress toward clinical approval of systemic administration of genes and microbubbles (MBs) has been limited. The feasibility of transendocardially delivering MBs as extracellular markers and gene carriers in conjunction with intracardiac ultrasound (US) treatment remains unknown. In a canine acute myocardial infarction (MI) model, a naked plasmid encoding 500 µg human hepatocyte growth factor (HGF) was delivered transendocardially to the myocardium via US/MB (HGF-US/MB), insonation (HGFUS), or alone (HGF alone). Control MI dogs received saline without US/MB (control group). During US/MB, intracardiac insonation was performed for 30 s with a 10-s pause, at 4.3-MHz, 1-W/cm(2), for 60 s at each site. Gene and MB distribution in the myocardium was visualized. Compared to the HGF alone group at 28 days, the HGF-US/MB group had an average 7.1-fold enhancement in gene expression (P < 0.01). Compared to the control group, there were 16% decreases in the ratio of left ventricle (LV) weight/body weight in the HGF-US/MB group and decreases in collagen volume fraction (CVF) of type I (33%) and type III (23%) collagen. Capillary density increased from 22.8 ± 6.3/mm(2) in the control group to 154.3 ± 42.9/mm(2) in the HGF-US/MB group (P < 0.01). This less invasive catheter-based US therapeutic procedure offers observable gene delivery with higher therapeutic efficiency, enhanced angiogenesis, and improved myocardial perfusion and ventricular function following MI.

A transendocardial delivery and intracardiac ultrasound irradiation treatment catheter.

OBJECTIVES: This study introduces the structural design, working principles, performance testing and treatment effects of a newly developed ultrasonic irradiation delivery and treatment catheter system that integrates interventional catheterization technology. BACKGROUND: Systemic administration method needs a high dose of gene and induces side effect of non-target organ delivery. Direct intramyocardial injection of a low-dose angiogenic gene followed by insonation treatment can enhance gene expression. So, a novel transendocardial gene delivery and intracardiac ultrasound irradiation strategy was tested. METHODS: The medical interventional ultrasonic therapeutic apparatus is comprised of an ultrasonic irradiation catheter and a host. The ultrasonic irradiation catheter, which is equipped with an advance-and-retreat convenient miniature syringe needle and a miniature piezoelectric transducer on the tip, was used. Twelve dogs were divided into three groups: (1) EGFP and US (EGFP + US), (2) EGFP alone and (3) control group. In the EGFP + US group, EGFP plasmid DNA (500 µg) was injected and followed by intracardiac insonation. In the EGFP alone group, EGFP plasmid DNA (500 µg) was injected without insonation. In the control group, saline was injected. RESULTS: The catheter can enter the heart through percutaneous intervention to realize intramyocardial injection, directly irradiate cardiac muscular tissues at close range and correctly control the ultrasonic irradiation energy delivered to cardiac muscular tissues. Compared with the EGFP gene group, an average sixfold enhancement in gene expression was achieved in the EGFP EGFP + US group (p < 0.05). CONCLUSIONS: The experimental results confirmed that the treatment catheter was safe and reliable, which can realize transendocardial intramyocardial gene injection in the left ventricular chamber, and the ultrasonic parameter can increase gene expression after intracardiac ultrasonic irradiation. The intracardiac ultrasound irradiation treatment catheter may be a useful delivery and therapy tool in the future.

Induction of oxidative stress by oxidized LDL via meprinα-activated epidermal growth factor receptor in macrophages.

AIMS: The aim of this study was to explore meprinα-mediated transactivation of the epidermal growth factor receptor (EGFR) and reactive oxygen species (ROS) production in macrophages. METHODS AND RESULTS: Accelerated atherosclerotic lesions were established by administration of a high-fat diet in apolipoprotein E-deficient (apoE(-/-)) mice. Lentiviral overexpression of meprinα in the thoracic aortic artery during plaque formation enhanced intra-plaque macrophage induction of ROS as well as formation of atherosclerotic plaques, whereas AG1478 (specific inhibitor of the EGFR) treatment exerted the opposite effect. A meprinα inhibitor abrogated EGFR activation in mice. In cultured J774a.1 macrophages, oxidized low-density lipoprotein (OxLDL) increased ROS formation and EGFR activation through a ligand [heparin-binding epidermal growth factor-like growth factor (HB-EGF)]-dependent pathway. However, a meprinα inhibitor or specific siRNA inhibited ROS production and EGFR activation. Recombinant mouse meprinα enhanced OxLDL-stimulated production of ROS and induced HB-EGF. Inhibition of p38 mitogen-activated protein kinase by SB203580 decreased OxLDL-stimulated production of ROS. Conversely, inhibition of meprinα or PI3K-Rac1 inhibitors also decreased p38 activity in OxLDL-stimulated macrophages. In addition, inhibition of meprinα reversed OxLDL-stimulated activation of PI3K. CONCLUSION: Meprinα promotes OxLDL-induced plaque formation and ROS release by transactivation of the EGFR, followed by activation of the PI3K/Rac1/p38 pathway.

A targeted high-efficiency angiogenesis strategy as therapy for myocardial infarction.

AIMS: The aim of this study was to prove that an intramyocardial injection of a mixture of low-dose human growth factor (HGF) plasmid and microbubbles (MB) in combination with insonation was an effective therapy for myocardial infarction. MAIN METHODS: Twenty dogs with myocardial infarction were divided into 4 groups: (1) HGF, MB and ultrasound (HGF-US/MB), (2) HGF and US (HGF-US), (3) HGF alone and (4) surgery alone (control). In the HGF-US/MB group, HGF plasmid DNA (500 µg) mixed with 0.5 ml of MB solution was injected 5 min after coronary occlusion followed by insonation. With the exception of the control group, the other dogs were divided into two groups, one treated with the HGF gene and insonation and the other with the HGF gene only. KEY FINDINGS: Compared to the HGF group, infarct size decreased from 32%±7% (control) to 23%±5% in the HGF-US/MB group 28 d later (P<0.05). Capillary density increased from 21.7±4.2/mm(2) (control) to 114.3±28.9/mm(2) in the HGF-US/MB group (P<0.01). Compared to the HGF group, there was a 14% decrease in the ratio of left ventricle weight/body weight and a 25% decrease in hydroxyproline content. We also observed a 29% and 20% decrease in collagen volume fraction of type I and type III collagen, respectively in the HGF-US/MB group. SIGNIFICANCE: Intramyocardial injection of HGF and MB in combination with insonation enhances neovascularization and reduces ventricular remodeling and infarct size.