Microinjection of a growth factor cocktail affects activated microglia in the neocortex of adult rats

Microglia, as the resident immune cells in the central nervous system, play important roles in regulating neuronal processes, such as neural excitability, synaptic activity, and apoptotic cell clearance. Growth factors can activate multiple signaling pathways in central nervous system microglia and can regulate their immune effects, but whether growth factors can affect the morphological characteristics and ultrastructure of microglia has not been reported. After microinjecting 300 nL of a growth factor cocktail, including 10 μg/mL epidermal growth factor, 10 μg/mL basic fibroblast growth factor, 10 μg/mL hepatocyte growth factor and 10 μg/mL insulin-like growth factor into adult rat cortex, we found that the number of IBA1-positive microglia around the injection area increased significantly, indicating local activation of microglia. All CD68-positive labeling co-localized with IBA1 in microglia. Cell bodies and protrusions of CD68-positive cells were strongly attached to or were engulfing neurons. Characteristic huge phagosomes were observed in activated phagocytes by electron microscopy. The phagosomes generally included non-degraded neuronal protrusions and mitochondria, yet they contained no myelin membrane or remnants, which might indicate selective phagocytosis by the phagocytes. The remnant myelin sheath after phagocytosis still had regenerative ability and formed "myelin-like" structures around phagocytes. These results show that microinjection of a growth factor cocktail into the cerebral cortex of rodents can locally activate microglia and induce selective phagocytosis of neural structures by phagocytes. The study was approved by the Institute of Laboratory Animal Science, Beijing Institute of Basic Medical Sciences(approval No. IACUC-AMMS-2014-501) on June 30, 2014.     

Phenotypic spectrum of mutations in IBA57, a candidate gene for cavitating leukoencephalopathy

IBA57 is involved in the biogenesis of mitochondrial [4Fe‐4S] proteins. Eighteen cases with IBA57 mutations have been reported to date. We described a novel phenotype in 11 children with cavitating leukoencephalopathy and summarized the phenotypic spectrum of IBA57 mutations. The median age of onset was 9 months, with an initial presentation of motor regression. Deterioration of neurological function reached its peak within 4 months. The median interval between onset and last follow‐up was 2.9 years (0.4‐10.0). All cases survived and remained stable. Severe motor handicap was observed in 50.0% of the patients, 52.9% to 71.4% had a delay in communication, problem solving or personal‐social skills, and 20.0% had mild symptomatic fluctuations. In the peak phase, magnetic resonance imaging (MRI) lesions were mainly observed in the periventricular/central white matter, and cavitating lesions and patchy high diffusion‐weighted imaging (DWI) signals were observed. The numbers and extent of restricted diffusional lesions were reduced, and atrophy was prominent in the recovery phase. Eight novel mutations in IBA57 were identified in our study. This study provided more information about the natural history and evolution of neuroimaging. Combined with previously reported patient studies, our findings suggest that defects in IBA57 can produce diverse phenotypes. IBA57 should be considered a candidate gene for cavitating leukoencephalopathy.     

A monoclonal immunoglobulin G1 in which some molecules possess glycosylated light chains--I. Site of glycosylation

A human monoclonal IgG1_κ protein (Hom) was found to possess two species of light chain with molecular weights of 23,000 and 28,000 respectively. The difference in mass was due to the presence of a carbohydrate prosthetic group on the 28,000 dalton species. The two species of light chain were separated by chromatography on CM-cellulose. Circular dichroism failed to detect any significant differences in conformation between the glycosylated and non-glycosylated forms and both species recombined with a heavy chain in an identical fashion as judged by difference spectroscopy. An anti-idiotypic antibody raised against the glycosylated Fab-fragment of IgGlHom was unable to distinguish between this species and the non-glycosylated Fab fragment, suggesting that the structure of the combining site is identical or very similar in both molecules. Amino-acid sequence analyses showed that both light chains had an identical sequence up to residue 41. Further studies on the glycosylated light chain, using o-iodosobenzoic acid fragments, localized the carbohydrate attachment site to asparagine 107, the penultimate residue of the J_κ region which links V_κ to C_κ. The sequence around the attachment site was Asn-Arg-Thr which satisfies the requirements for an acceptor sequence. The non-glycosylated light chain was found to have the same sequence in this region indicating that the absence of glycosylation was not due to the lack of an acceptor sequence. A kinetic mechanism has been proposed to account for the incomplete glycosylation of the light chains of IgG1Hom in which there is a competition between the rate of folding of the nascent polypeptide and the rate of attachment of core sugars via the dolichol pyrophosphate pathway.     

物联网在医院垃圾管理中的应用

物联网IOT的应用在医疗行业日益广泛,提出一种适合IOT网络的智慧系统设计架构,把“人”、“物”及所有相关的智能系统都抽象成一个地位完全平等的IOT互联对象,抽象和统一了IOT网络环境中联网对象之间的交互模式。在系统实现中,采用XMPP协议进行消息交换,同时提出基于Pipe＆Filter的agent架构模式,支持多样异构的智能设备,方便Agent的升级和扩充。通过基于该平台的医院医疗垃圾管理系统开发和在医院的成功应用,验证了该IOT应用平台的系统设计,也明显改善了医院在医疗垃圾处理环节的监控和管理力度。提升了医院的信息化水平。     

Transient receptor potential melastatin 2 contributes to neuroinflammation and negatively regulates cognitive outcomes in a pilocarpine-induced mouse model of epilepsy

Neuroinflammation contributes to the generation of epileptic seizures and is associate with neuropathology and comorbidities. Transient receptor potential melastatin 2 (TRPM2) expresses in various cell types in the brain. It plays a pathological role in a wide range of neuroinflammatory diseases, but has yet been studied in epilepsy. Here, a temporal lobe epilepsy model was generated by pilocarpine administration in mice. At 24 h, knockout (KO) TRPM2 alleviated the level of neuroinflammation, showing a reduction of IL-1β, TNF-α, CXCL2 and IL-6 mRNA production, NLRP3, ASC, and Caspase-1 protein expression and glial activation. Moreover, KO TRPM2 alleviated neurodegeneration, concurrent with reduced Beclin-1 and ATG5 protein expression. Later, KO TRPM2 ameliorated the epilepsy-induced psychological disorders, with improved performance in the open-field, Y maze and novel object recognition test. Together, these results suggest that TRPM2 facilitates epilepsy-related brain injury and may shed light on its potential as a therapeutic target for epilepsy-associated neuropathology and comorbidities.     

The Arabidopsis NRT1/PTR FAMILY protein NPF7.3/NRT1.5 is an indole-3-butyric acid transporter involved in root gravitropism

Active membrane transport of plant hormones and their related compounds is an essential process that determines the distribution of the compounds within plant tissues and, hence, regulates various physiological events. Here, we report that the Arabidopsis NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY 7.3 (NPF7.3) protein functions as a transporter of indole-3-butyric acid (IBA), a precursor of the major endogenous auxin indole-3-acetic acid (IAA). When expressed in yeast, NPF7.3 mediated cellular IBA uptake. Loss-of-function npf7.3 mutants showed defective root gravitropism with reduced IBA levels and auxin responses. Nevertheless, the phenotype was restored by exogenous application of IAA but not by IBA treatment. NPF7.3 was expressed in pericycle cells and the root tip region including root cap cells of primary roots where the IBA-to-IAA conversion occurs. Our findings indicate that NPF7.3-mediated IBA uptake into specific cells is required for the generation of appropriate auxin gradients within root tissues.

Plant hormones are vital compounds that function as signaling molecules and control a wide range of physiological responses so that plants can cope with fluctuating environments (1). Often, plant hormones induce physiological responses locally (2–6); thus, the endogenous levels as well as the signal transduction pathways of plant hormones are regulated very precisely. Endogenous concentrations of bioactive plant hormones are primarily determined by the balance between the rates of biosynthesis and degradation (or inactivation). Additionally, specific transport systems for plant hormones and their related compounds are also considered to be critical components for generating appropriate hormone concentrations within cells, since hormone biosynthesis and perception do not necessarily take place in the same cell. In fact, movement of plant hormones and their precursors has been reported (7).Auxin is the best-characterized mobile plant hormone that plays crucial roles in many aspects of plant growth and development by mainly regulating cell division, cell elongation, and cell differentiation (8). Indole-3-acetic acid (IAA) is the major naturally occurring auxin. Measurements of IAA by mass spectrometry as well as visualization of auxin responses by reporter genes have suggested that IAA is differentially distributed within plant tissues (9). Furthermore, appropriate IAA gradients or local IAA maxima/minima are required for proper auxin functions (9). In fact, mutants impaired in IAA transport have been isolated based on their defects in organ development and various physiological responses (9). Evidence for IAA transport in a cell-to-cell manner by combinations of several transmembrane transporters is well documented. The plant-specific PIN-FORMED (PIN) transporters and the AUX1/LAX family of amino acid permease-like proteins are IAA efflux and influx carriers, respectively (10, 11). PINs determine the direction of IAA flow by localizing unevenly in the plasma membrane, whereas polarity is not observed for AUX/LAXs distribution (9). Also, some subfamily B members of the adenosine 5′-triphosphate-binding cassette (ABC) transporter (ABCBs) family act as IAA transporters (9).IAA is mainly synthesized from tryptophan via indole-3-pyruvic acid (12); however, minor routes for IAA biosynthesis have also been suggested (13). Indole-3-butyric acid (IBA) has auxin activity when applied exogenously to plants. Arabidopsis mutants isolated based on their resistance to exogenous IBA are defective in the conversion of IBA to IAA (14). Since IBA has been detected in several plant species (13), the compound is considered to be an endogenous IAA precursor. Possible IBA transporters have been identified (15–17), suggesting that IBA transport is also an important factor that regulates endogenous IAA levels.NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY (NPF) proteins have been characterized as transporters for several plant hormones including auxin, although the family was initially identified as nitrate or di/tripeptide transporters (18, 19). The Arabidopsis NPF6.3 protein (also called as CHL1 or NRT1.1) is a well-characterized dual-affinity nitrate transporter that mediates nitrogen uptake from the rhizosphere (20, 21); however, the same protein also transports IAA (22). More recently, the Arabidopsis NPF5.12 protein, also named TRANSPORTER OF IBA1 (TOB1), was identified as an IBA transporter that localizes to the vacuolar membrane (17). Here, we report that NPF7.3, originally identified as a low-affinity nitrate transporter (NRT1.5) and later shown to be a proton/potassium antiporter in Arabidopsis (23, 24), functions as an IBA transporter. We found that npf7.3 mutant roots were not able to respond properly to gravity. Our transport assays in yeast demonstrated that NPF7.3 efficiently mediated IBA uptake into the cells. Asymmetric distribution of auxin activities in root tips following the reorientation of roots was not observed in the npf7.3 mutants, and the defect was restored by IAA but not by IBA treatment. These results suggest that cellular IBA uptake mediated by NPF7.3 contributes to the production of IAA required to fully induce Arabidopsis root gravitropism.     

Microglia activation during neuroregeneration in the adult vertebrate brain

Brain injury and neuronal loss leads to an inflammatory response, which is initiated by the innate immune system. To what extent this immune response is beneficial or detrimental for neurogenesis and regeneration is unclear. We addressed this question during regeneration of dopamine neurons in the adult salamander brain. In contrast to mammals, ablation of dopamine neurons evokes robust neurogenesis leading to complete histological and functional regeneration within four weeks in salamanders. Here we show that similarly to mammals, ablation of dopamine neurons causes microglia activation and an increase in microglia numbers in the ablated areas. Furthermore, microglia numbers remain elevated compared to the uninjured brain at least six weeks after ablation. Suppression of the microglia response results in enhanced regeneration, concomitant with reduced death of dopamine neurons during the regeneration phase. Thus neuroregeneration is not dependent on the absence of an innate immune response, but the suppression of this response may be a means to promote neurogenesis in the adult vertebrate brain.     

Edaravone attenuates cadmium-induced toxicity by inhibiting oxidative stress and inflammation in ICR mice

The neurotoxicity caused by cadmium (Cd) is well known in humans and experimental animals. However, there is no effective treatment for its toxicity. In this study, we established Cd toxicity models in cultured cells or mice to investigate the detoxification effect of edaravone (Eda). We found that Eda protected GL261 cells from Cd toxicity and prevented the loss of cell viability. In Cd-exposed mice, liver, kidney and testicular damage, as well as cognitive dysfunction were observed. Oxidative stress and inflammatory responses, such as decreased SOD and CAT, increased LDH and MDA, and abnormal changes in the inflammatory factors TNF-α, IL-1β, IL-6 and IL-10 were detected in serum and brain tissue. Eda protected mice from Cd-induced toxicity and abrogated oxidative stress and inflammatory responses. Also, Eda prevented inflammatory activation of microglia and astrocytes and was accompanied by restoration of the neuronal marker protein MAP2, indicating restoration of neuronal function. In addition, the BDNF-TrkB/Akt and Notch/HES-1 signaling axes were involved in the response of Eda to the elimination of Cd toxicity. In conclusion, Eda does contribute to the clearance of Cd-induced toxicity.     

生长素处理对胡豆莲扦插生根效果的初探

<正>胡豆莲Euchresta japonica Hook.f.exRege又名山豆根、日本山豆根、三小叶山豆根,系豆科山豆根属植物。其性味苦寒,有清热、解毒、消肿、镇痛等功效。在我国,胡豆莲零星分布于华