Tau, a primary component of microtubule-associated protein, promotes microtubule assembly and/or disassembly and maintains the stability of the microtubule structure. Although the importance of tau in neurodegenerativ...Tau, a primary component of microtubule-associated protein, promotes microtubule assembly and/or disassembly and maintains the stability of the microtubule structure. Although the importance of tau in neurodegenerative diseases has been well demonstrated, wheth- er tau is involved in peripheral nerve regeneration remains unknown. In the current study, we obtained sciatic nerve tissue from adult rats 0, 1, 4, 7, and 14 days after sciatic nerve crush and examined tau mRNA and protein expression levels and the location of tau in the sciatic nerve following peripheral nerve injury. The results from our quantitative reverse transcription polymerase chain reaction analysis showed that compared with the uninjured control sciatic nerve, mRNA expression levels for both tau and tau tubulin kinase 1, a serine/ threonine kinase that regulates tau phosphorylation, were decreased following peripheral nerve injury. Our western blot assay results suggested that the protein expression levels of tau and phosphorylated tau initially decreased 1 day post nerve injury but then gradually increased. The results of our immunohistochemical labeling showed that the location of tau protein was not altered by nerve injury. Thus, these results showed that the expression of tau was changed following sciatic nerve crush, suggesting that tau may be involved in periph- eral nerve repair and regeneration.展开更多
AIM:To investigate the effects of estradiol (E2) and progesterone on the unstimulated and oxidative stressstimulated production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, and macrophage chemotactic...AIM:To investigate the effects of estradiol (E2) and progesterone on the unstimulated and oxidative stressstimulated production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, and macrophage chemotactic protein (MCP)-1 by peripheral blood mononuclear cells (PBMCs) from patients with chronic hepatitis C and healthy controls. METHODS:The PBMCs were separated from agematched 72 males and 71 females with and without chronic hepatitis C, who were divided into two groups based on a mean menopausal age of 50 years. Oxidative stress was induced by hydrogen peroxide in the cells incubated in serum-free media. Cytokines in the culture supernatant were measured by an enzyme-linked immunosorbent assay. RESULTS:The highest levels of the spontaneous production of TNF-α, IL-1β, IL-8, and MCP-1 by the unstimulated PBMCs were in the older male patients with chronic hepatitis C and the lowest levels were in the premenopausal female healthy controls. E2 inhibited the cytokine production by the unstimulated PBMCs from the older male and post-menopausal female patients, which was further stimulated by progesterone. The exposure to hydrogen peroxide in the PBMCs from the younger male and pre-menopausal female healthy subjects induced the production of cytokines. The change rates of the hydrogen peroxide-stimulated cytokine production were suppressed by E2 and enhanced by progesterone. CONCLUSION:These findings suggest that E2 may play a favorable role in the course of persistent liver injury by preventing the accumulation of monocytes-macrophages and by inhibiting proinflammatory cytokine production, whereas progesterone may counteract the favorable E2 effects.展开更多
The diversity and cold adaptation of endophytic fungi associated with five dominant plant species collected from the Baima Snow Mountain(altitude 4,000–4,300 m),Southwest China,were investigated.A total of 604 cultur...The diversity and cold adaptation of endophytic fungi associated with five dominant plant species collected from the Baima Snow Mountain(altitude 4,000–4,300 m),Southwest China,were investigated.A total of 604 culturable endophytic fungi were isolated from 800 stems and leaf segments.The colonization rate of endophytic fungi in the five plant species ranged from 54%to 91%,and the colonization rate of endophytic fungi in the stems was significantly higher(87%)than that in the leaves(67%)(X∼2045.172,P<0.001,chi-squared test).Based on the morphological characteristics and the ITS sequence analysis,the isolates were identified to 43 taxa,of which Cephalosporium,Sirococcus,Penicillium and Aspergillus were the dominant genera,and their relative frequencies were 14.06%,12.58%,9.44%and 7.95%,respectively.The Shannon-Weiner diversity indices and the Sorenson’s coefficient similarity indices of the endophytic fungi from the five plant species ranged from 1.25 to 2.70 and 0.53 to 0.67,respectively.Growth temperature tests indicated that 75%of the isolates from the Baima Snow Mountain were psychrotrophs and 14%were the transitional type between psychrotrophs and mesophiles,whereas all of the isolates from the Yuanjiang Dry-hot Valley were mesophiles,which suggested that the endophytes from the Baima Snow Mountain possess a remarkable ability to adapt to cold environments.展开更多
Extracellular vesicles from skin-derived precursor Schwann cells(SKP-SC-EVs)promote neurite outgrowth in culture and enhance peripheral nerve regeneration in rats.This study aimed at expanding the application of SKPSC...Extracellular vesicles from skin-derived precursor Schwann cells(SKP-SC-EVs)promote neurite outgrowth in culture and enhance peripheral nerve regeneration in rats.This study aimed at expanding the application of SKPSC-EVs in nerve grafting by creating a chitosan/PLGA-based,SKP-SC-EVs-containing tissue engineered nerve graft(TENG)to bridge a 40-mm long sciatic nerve defect in dogs.SKP-SC-EVs contained in TENGs significantly accelerated the recovery of hind limb motor and electrophysiological functions,supported the outgrowth and myelination of regenerated axons,and alleviated the denervation-induced atrophy of target muscles in dogs.To clarify the underlying molecular mechanism,we observed that SKP-SC-EVs were rich in a variety of miRNAs linked to the axon growth of neurons,and miR-30b-5p was the most important among others.We further noted that miR-30b-5p contained within SKP-SC-EVs exerted nerve regeneration-promoting effects by targeting the Sin3a/HDAC complex and activating the phosphorylation of ERK,STAT3 or CREB.Our findings suggested that SKP-SC-EVs-incorporating TENGs represent a novel type of bioactive material with potential application for peripheral nerve repair in the clinic.展开更多
Background The clinical manifestations of cerebrovascular disease are known to differ between the Chinese and United States(US)populations as do the plaque features on imaging.Objectives The aim of this study was to i...Background The clinical manifestations of cerebrovascular disease are known to differ between the Chinese and United States(US)populations as do the plaque features on imaging.Objectives The aim of this study was to investigate and compare the histological features of excised carotid plaques from Chinese and US patients.Methods Carotid endarterectomy specimens collected from two prospective studies were included.The entire plaque was serially sectioned(10-µm thickness)at 0.5-1 mm intervals.Hematoxylin and eosin staining and Mallory’s trichrome staining were performed.The morphology and components of the plaques were measured and compared between the two groups.Results A total of 1152 histological sections from 75 Chinese patients and 1843 sections from 111 US patients were analyzed.The Chinese group had significantly smaller minimum lumen diameters(median:1.1 vs.1.3 mm,p=0.046)and a larger percent wall volume(median:74%vs.70%,p=0.018)than the US group.After adjusting for confounding factors,carotid plaques in the Chinese population had larger lipid pools(β=10.0%,95%CI:4.9 to 15.9%),more recent intraplaque hemorrhage(IPH;β=8.4%,95%CI:4.5 to 12.7%),less late IPH(β=-8.2%,95%CI:-11.3 to-5.4),and fewer fibrous cap disruptions(45%vs.67%,p=0.061).Chinese plaques were more homogeneous and had a higher percentage of plaques with features of xanthomas than did US plaques(20%vs 2.7%,p<0.001).Conclusions The histology of Chinese plaques differs significantly from that of U.S.plaques,suggesting substantial differences in the pathophysiology of atherosclerotic cerebrovascular disease between Chinese and North American populations,which indicates a need for a different management approach.展开更多
Many endophytes have been found to be resistant to heavy metals and/or capable of degrading organic contaminants,and endophyte-assisted phytoremediation has been documented as a promising technology for in situ remedi...Many endophytes have been found to be resistant to heavy metals and/or capable of degrading organic contaminants,and endophyte-assisted phytoremediation has been documented as a promising technology for in situ remediation of contaminated soils.During the phytoremediation of heavy metals,the heavy-metal-resistant endophytes can enhance plant growth,decrease metal phytotoxicity,and affect metal translocation and accumulation in plants.For the phytoremediation of organic contaminants,endophytes can produce various enzymes to degrade organic contaminants and reduce both the phytotoxicity and evapotranspiration of volatile contaminants.This paper reviews the diversity of contaminant-resistant/degrading endophytes and their role in phytoremediation and discusses some issues that have been raised surrounding this area of research.展开更多
Background and purpose While extracranial carotid artery stenosis is more common among Caucasians and intracranial artery stenosis is more common among Asians,the differences in atherosclerotic plaque characteristics ...Background and purpose While extracranial carotid artery stenosis is more common among Caucasians and intracranial artery stenosis is more common among Asians,the differences in atherosclerotic plaque characteristics have not yet been extensively examined.We sought to investigate plaque location and characteristics within extracranial carotid and intracranial arteries in symptomatic Caucasians and Chinese using vessel wall MRI.Methods Subjects with recent anterior circulation ischaemic stroke were recruited and imaged at two sites in the USA and China using similar protocols.Both extracranial carotid and intracranial arteries were reviewed to determine plaque location and characteristics.Results The prevalence of extracranial carotid plaque in Caucasians and Chinese was 73.1%and 49.1%,respectively(p=0.055).Prevalence of intracranial plaque was 38.5%and 69.1%in Caucasians and Chinese,respectively(p=0.02).Furthermore,42% of Caucasians and 16%of Chinese had high-risk plaque(HRP)features(intraplaque haemorrhage,luminal surface disruption)in the extracranial carotid artery(p=0.03).The prevalence of HRP features in intracranial arteries was not significantly different between the two cohorts(4%vs 11%;p=0.42).Conclusions Differences in the location and characteristics of cerebrovascular atherosclerosis were identified by vessel wall MRI in US Caucasian and Chinese subjects with recent anterior circulation ischaemic stroke.Extracranial carotid plaques with HRP features were more common in Caucasians.Intracranial plaques were more common in Chinese subjects,but no significant difference between the two cohorts in intracranial HRP prevalence was found.Larger studies using vessel wall imaging to investigate racial differences in cerebrovascular disease may inform underlying mechanisms of HRP development and may ultimately help guide appropriate therapy.展开更多
基金supported by the National Natural Science Foundation of China,No.81130080,31300942the National Key Basic Research Program of China(973 Program)+5 种基金No.2014CB542202the Natural Science Foundation of Jiangsu Province,China,No.BK20150409the Natural Science Foundation of Jiangsu Higher Education Institutions of China,No.15KJB180013the Scientific Research Foundation of Nantong University of China,No.14R29the Natural Science Foundation of Nantong City in China,No.MS12015043the Priority Academic Program Development of Jiangsu Higher Education Institutions of China
文摘Tau, a primary component of microtubule-associated protein, promotes microtubule assembly and/or disassembly and maintains the stability of the microtubule structure. Although the importance of tau in neurodegenerative diseases has been well demonstrated, wheth- er tau is involved in peripheral nerve regeneration remains unknown. In the current study, we obtained sciatic nerve tissue from adult rats 0, 1, 4, 7, and 14 days after sciatic nerve crush and examined tau mRNA and protein expression levels and the location of tau in the sciatic nerve following peripheral nerve injury. The results from our quantitative reverse transcription polymerase chain reaction analysis showed that compared with the uninjured control sciatic nerve, mRNA expression levels for both tau and tau tubulin kinase 1, a serine/ threonine kinase that regulates tau phosphorylation, were decreased following peripheral nerve injury. Our western blot assay results suggested that the protein expression levels of tau and phosphorylated tau initially decreased 1 day post nerve injury but then gradually increased. The results of our immunohistochemical labeling showed that the location of tau protein was not altered by nerve injury. Thus, these results showed that the expression of tau was changed following sciatic nerve crush, suggesting that tau may be involved in periph- eral nerve repair and regeneration.
文摘AIM:To investigate the effects of estradiol (E2) and progesterone on the unstimulated and oxidative stressstimulated production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, and macrophage chemotactic protein (MCP)-1 by peripheral blood mononuclear cells (PBMCs) from patients with chronic hepatitis C and healthy controls. METHODS:The PBMCs were separated from agematched 72 males and 71 females with and without chronic hepatitis C, who were divided into two groups based on a mean menopausal age of 50 years. Oxidative stress was induced by hydrogen peroxide in the cells incubated in serum-free media. Cytokines in the culture supernatant were measured by an enzyme-linked immunosorbent assay. RESULTS:The highest levels of the spontaneous production of TNF-α, IL-1β, IL-8, and MCP-1 by the unstimulated PBMCs were in the older male patients with chronic hepatitis C and the lowest levels were in the premenopausal female healthy controls. E2 inhibited the cytokine production by the unstimulated PBMCs from the older male and post-menopausal female patients, which was further stimulated by progesterone. The exposure to hydrogen peroxide in the PBMCs from the younger male and pre-menopausal female healthy subjects induced the production of cytokines. The change rates of the hydrogen peroxide-stimulated cytokine production were suppressed by E2 and enhanced by progesterone. CONCLUSION:These findings suggest that E2 may play a favorable role in the course of persistent liver injury by preventing the accumulation of monocytes-macrophages and by inhibiting proinflammatory cytokine production, whereas progesterone may counteract the favorable E2 effects.
基金supported by the Natural Science Foundation of Yunnan Province and the Science Foundation of Yunnan Educational Committee(2011Y381).
文摘The diversity and cold adaptation of endophytic fungi associated with five dominant plant species collected from the Baima Snow Mountain(altitude 4,000–4,300 m),Southwest China,were investigated.A total of 604 culturable endophytic fungi were isolated from 800 stems and leaf segments.The colonization rate of endophytic fungi in the five plant species ranged from 54%to 91%,and the colonization rate of endophytic fungi in the stems was significantly higher(87%)than that in the leaves(67%)(X∼2045.172,P<0.001,chi-squared test).Based on the morphological characteristics and the ITS sequence analysis,the isolates were identified to 43 taxa,of which Cephalosporium,Sirococcus,Penicillium and Aspergillus were the dominant genera,and their relative frequencies were 14.06%,12.58%,9.44%and 7.95%,respectively.The Shannon-Weiner diversity indices and the Sorenson’s coefficient similarity indices of the endophytic fungi from the five plant species ranged from 1.25 to 2.70 and 0.53 to 0.67,respectively.Growth temperature tests indicated that 75%of the isolates from the Baima Snow Mountain were psychrotrophs and 14%were the transitional type between psychrotrophs and mesophiles,whereas all of the isolates from the Yuanjiang Dry-hot Valley were mesophiles,which suggested that the endophytes from the Baima Snow Mountain possess a remarkable ability to adapt to cold environments.
基金supported by the Major Research Plan of the National Natural Science Foundation of China(92068112)the National Key Research and Development Program of China(2017YFA0104700)+1 种基金the National Natural Science Foundation of China(82201509)the National Major Project of Research and Development(2022YFA1105500).
文摘Extracellular vesicles from skin-derived precursor Schwann cells(SKP-SC-EVs)promote neurite outgrowth in culture and enhance peripheral nerve regeneration in rats.This study aimed at expanding the application of SKPSC-EVs in nerve grafting by creating a chitosan/PLGA-based,SKP-SC-EVs-containing tissue engineered nerve graft(TENG)to bridge a 40-mm long sciatic nerve defect in dogs.SKP-SC-EVs contained in TENGs significantly accelerated the recovery of hind limb motor and electrophysiological functions,supported the outgrowth and myelination of regenerated axons,and alleviated the denervation-induced atrophy of target muscles in dogs.To clarify the underlying molecular mechanism,we observed that SKP-SC-EVs were rich in a variety of miRNAs linked to the axon growth of neurons,and miR-30b-5p was the most important among others.We further noted that miR-30b-5p contained within SKP-SC-EVs exerted nerve regeneration-promoting effects by targeting the Sin3a/HDAC complex and activating the phosphorylation of ERK,STAT3 or CREB.Our findings suggested that SKP-SC-EVs-incorporating TENGs represent a novel type of bioactive material with potential application for peripheral nerve repair in the clinic.
基金funded by the National Institutes of Health(R01 NS083503)the National Natural Science Foundation of China(81361120402 and 62271061)the Beijing Natural Science Foundation(L232130).
文摘Background The clinical manifestations of cerebrovascular disease are known to differ between the Chinese and United States(US)populations as do the plaque features on imaging.Objectives The aim of this study was to investigate and compare the histological features of excised carotid plaques from Chinese and US patients.Methods Carotid endarterectomy specimens collected from two prospective studies were included.The entire plaque was serially sectioned(10-µm thickness)at 0.5-1 mm intervals.Hematoxylin and eosin staining and Mallory’s trichrome staining were performed.The morphology and components of the plaques were measured and compared between the two groups.Results A total of 1152 histological sections from 75 Chinese patients and 1843 sections from 111 US patients were analyzed.The Chinese group had significantly smaller minimum lumen diameters(median:1.1 vs.1.3 mm,p=0.046)and a larger percent wall volume(median:74%vs.70%,p=0.018)than the US group.After adjusting for confounding factors,carotid plaques in the Chinese population had larger lipid pools(β=10.0%,95%CI:4.9 to 15.9%),more recent intraplaque hemorrhage(IPH;β=8.4%,95%CI:4.5 to 12.7%),less late IPH(β=-8.2%,95%CI:-11.3 to-5.4),and fewer fibrous cap disruptions(45%vs.67%,p=0.061).Chinese plaques were more homogeneous and had a higher percentage of plaques with features of xanthomas than did US plaques(20%vs 2.7%,p<0.001).Conclusions The histology of Chinese plaques differs significantly from that of U.S.plaques,suggesting substantial differences in the pathophysiology of atherosclerotic cerebrovascular disease between Chinese and North American populations,which indicates a need for a different management approach.
基金H.-Y.Li thanks the Natural Science Foundation of Yunnan Province(KKS0201126013)the Science Foundation of Yunnan Educational Committee(KKJA201126033)for financial supports.
文摘Many endophytes have been found to be resistant to heavy metals and/or capable of degrading organic contaminants,and endophyte-assisted phytoremediation has been documented as a promising technology for in situ remediation of contaminated soils.During the phytoremediation of heavy metals,the heavy-metal-resistant endophytes can enhance plant growth,decrease metal phytotoxicity,and affect metal translocation and accumulation in plants.For the phytoremediation of organic contaminants,endophytes can produce various enzymes to degrade organic contaminants and reduce both the phytotoxicity and evapotranspiration of volatile contaminants.This paper reviews the diversity of contaminant-resistant/degrading endophytes and their role in phytoremediation and discusses some issues that have been raised surrounding this area of research.
基金This research received the National Institutes of Health(R01 NS083503)the National Natural Science Foundation of China(83161120402)JS received support from the American Heart Association(17MCPRP33671077).
文摘Background and purpose While extracranial carotid artery stenosis is more common among Caucasians and intracranial artery stenosis is more common among Asians,the differences in atherosclerotic plaque characteristics have not yet been extensively examined.We sought to investigate plaque location and characteristics within extracranial carotid and intracranial arteries in symptomatic Caucasians and Chinese using vessel wall MRI.Methods Subjects with recent anterior circulation ischaemic stroke were recruited and imaged at two sites in the USA and China using similar protocols.Both extracranial carotid and intracranial arteries were reviewed to determine plaque location and characteristics.Results The prevalence of extracranial carotid plaque in Caucasians and Chinese was 73.1%and 49.1%,respectively(p=0.055).Prevalence of intracranial plaque was 38.5%and 69.1%in Caucasians and Chinese,respectively(p=0.02).Furthermore,42% of Caucasians and 16%of Chinese had high-risk plaque(HRP)features(intraplaque haemorrhage,luminal surface disruption)in the extracranial carotid artery(p=0.03).The prevalence of HRP features in intracranial arteries was not significantly different between the two cohorts(4%vs 11%;p=0.42).Conclusions Differences in the location and characteristics of cerebrovascular atherosclerosis were identified by vessel wall MRI in US Caucasian and Chinese subjects with recent anterior circulation ischaemic stroke.Extracranial carotid plaques with HRP features were more common in Caucasians.Intracranial plaques were more common in Chinese subjects,but no significant difference between the two cohorts in intracranial HRP prevalence was found.Larger studies using vessel wall imaging to investigate racial differences in cerebrovascular disease may inform underlying mechanisms of HRP development and may ultimately help guide appropriate therapy.
