Comparison of Bioactive Compounds and Antioxidant Activities in Differentially Pigmented Cerasus humilis Fruits.

Chinese dwarf cherry (Cerasus humilis) is a wild fruit tree and medicinal plant endemic to China. Its fruits are rich in various bioactive compounds, such as flavonoids and carotenoids, which contribute greatly to their high antioxidant capacity. In this study, the contents of bioactive substances (chlorophyll, carotenoids, ascorbic acid, anthocyanin, total flavonoids, and total phenols), antioxidant capacities, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonicacid) (ABTS+) scavenging ability, and ferric-reducing antioxidant power (FRAP)) in differentially pigmented C. humilis fruits of four varieties were determined and compared. The results revealed that anthocyanin, total flavonoids and total phenols were the three main components responsible for the antioxidant activity of C. humilis fruits. 'Jinou No.1' fruits with dark red peel and red flesh had the highest contents of anthocyanin, total flavonoids, and total phenols, as well as the highest antioxidant capacities; 'Nongda No.5' fruits with yellow-green peel and yellow flesh had the highest contents of carotenoids and chlorophyll, while 'Nongda No.6' fruit had the highest ascorbic acid content. To further reveal the molecular mechanism underlying differences in the accumulation of carotenoids and flavonoids among differentially pigmented C. humilis fruits, the expression patterns of structural genes involved in the biosynthesis of the two compounds were investigated. Correlation analysis results revealed that the content of carotenoids in C. humilis fruits was very significantly positively correlated with the expression of the ChCHYB, ChZEP, ChVDE, ChNSY, ChCCD1, ChCCD4, ChNCED1, and ChNCED5 genes (p < 0.01) and significantly negatively correlated with the expression of ChZDS (p < 0.05). The anthocyanin content was very significantly positively correlated with ChCHS, ChFLS, and ChUFGT expression (p < 0.01). The total flavonoid content was very significantly positively correlated with the expression of ChCHS, ChUFGT, and ChC4H (p < 0.01) and significantly positively correlated with ChFLS expression (p < 0.05). This study can provide a basis for understanding the differences in the accumulation of bioactive substances, and is helpful for clarifying the mechanisms underlying the accumulation of various carotenoids and flavonoids among differentially pigmented C. humilis fruits.

Crosstalk between peripheral and the brain-resident immune components in epilepsy.

Epilepsy is one of the most common neurology diseases. It is characterized by recurrent, spontaneous seizures and accompanied by various comorbidities which can significantly affect a person's life. Accumulating evidence indicates an essential pathophysiological role for neuroinflammation in epilepsy, which involves activation of microglia and astrocytes, recruitment of peripheral leukocytes into the central nervous system, and release of some inflammatory mediators, including pro-inflammatory factors and anti-inflammatory cytokines. There is complex crosstalk between the central nervous system and peripheral immune responses associated with the progression of epilepsy. This review provides an update of current knowledge about the contribution of this crosstalk associated with epilepsy. Additionally, how gut microbiota is involved in epilepsy and its possible influence on crosstalk is also discussed. Such recent advances in understanding suggest innovative methods for targeting the molecules correlated with the crosstalk and may provide a better prognosis for patients diagnosed with epilepsy.

Enhancing microRNA167A expression in seed decreases the α-linolenic acid content and increases seed size in Camelina sativa.

Despite well established roles of microRNAs in plant development, few aspects have been addressed to understand their effects in seeds especially on lipid metabolism. In this study, we showed that overexpressing microRNA167A (miR167OE) in camelina (Camelina sativa) under a seed-specific promoter changed fatty acid composition and increased seed size. Specifically, the miR167OE seeds had a lower α-linolenic acid with a concomitantly higher linoleic acid content than the wild-type. This decreased level of fatty acid desaturation corresponded to a decreased transcriptional expression of the camelina fatty acid desaturase3 (CsFAD3) in developing seeds. MiR167 targeted the transcription factor auxin response factor (CsARF8) in camelina, as had been reported previously in Arabidopsis. Chromatin immunoprecipitation experiments combined with transcriptome analysis indicated that CsARF8 bound to promoters of camelina bZIP67 and ABI3 genes. These transcription factors directly or through the ABI3-bZIP12 pathway regulate CsFAD3 expression and affect α-linolenic acid accumulation. In addition, to decipher the miR167A-CsARF8 mediated transcriptional cascade for CsFAD3 suppression, transcriptome analysis was conducted to implicate mechanisms that regulate seed size in camelina. Expression levels of many genes were altered in miR167OE, including orthologs that have previously been identified to affect seed size in other plants. Most notably, genes for seed coat development such as suberin and lignin biosynthesis were down-regulated. This study provides valuable insights into the regulatory mechanism of fatty acid metabolism and seed size determination, and suggests possible approaches to improve these important traits in camelina.

The Influence of Piriformospora indica Colonization on the Root Development and Growth of Cerasus humilis Cuttings.

Numerous studies have shown that the endophytic fungus Piriformospora indica has a broad range of promoting effects on root development and plant growth in host plants. However, there are currently no reports on the application of this fungus on Cerasus humilis. This study first compared the colonization ability of P. indica on 11 C. humilis varieties and found that the colonization rate of this fungus on these varieties ranged from 90% to 100%, with the colonization rate of the varieties '09-01' and 'Nongda 7' being as high as 100%. Subsequently, the effect of P. indica on root development and plant growth of C. humilis was investigated using cuttings of '09-01' and 'Nongda 7' as materials. P. indica colonization was found to increase the biomass of '09-01' and 'Nongda 7' plants; root activity, POD enzymes, and chlorophyll content were also significantly increased. In addition, indole-3-acetic acid (IAA) content in the roots of C. humilis plants increased after colonization, while jasmonic acid (JA) and 1-aminocyclopropane-1-car- boxylic acid (ACC) content decreased. In conclusion, it has been demonstrated that P. indica can promote the growth of C. humilis plants by accelerating biomass accumulation, promoting rooting, and enhancing the production of photosynthetic pigments, as well as regulating hormone synthesis.

Characterization of Carotenoid Cleavage Oxygenase Genes in Cerasus humilis and Functional Analysis of ChCCD1.

Carotenoid cleavage oxygenases (CCOs) are key enzymes that function in degrading carotenoids into a variety of apocarotenoids and some other compounds. In this study, we performed genome-wide identification and characterization analysis of CCO genes in Cerasus humilis. Totally, nine CCO genes could be classified into six subfamilies, including carotenoid cleavage dioxygenase 1 (CCD1), CCD4, CCD7, CCD8, CCD-like and nine-cis-epoxycarotenoid dioxygenase (NCED), were identified. Results of gene expression analysis showed that ChCCOs exhibited diverse expression patterns in different organs and in fruits at different ripening stages. To investigate the roles of ChCCOs in carotenoids degradation, enzyme assays of the ChCCD1 and ChCCD4 were performed in Escerichia coli BL21(DE3) that can accumulate lycopene, ß-carotene and zeaxanthin. The prokaryotic expressed ChCCD1 resulted in obvious degradation of lycopene, ß-carotene and zeaxanthin, but ChCCD4 did not show similar functions. To further determine the cleaved volatile apocarotenoids of these two proteins, headspace gas chromatography/mass spectrometer analysis was performed. Results showed that ChCCD1 could cleave lycopene at 5, 6 and 5', 6' positions to produce 6-methy-5-hepten-2-one and could catalyze ß-carotene at 9, 10 and 9', 10' positions to generate ß-ionone. Our study will be helpful for clarifying the roles of CCO genes especially ChCCD1 in regulating carotenoid degradation and apocarotenoid production in C. humilis.

Organic acid metabolism in Chinese dwarf cherry [Cerasus humilis (Bge.) Sok.] is controlled by a complex gene regulatory network.

The acidity of Chinese dwarf cherry [Cerasus humilis (Bge.) Sok.] fruits is a key factor affecting the sensory quality of fruits, and it undergoes great changes during development. The molecular mechanisms of these changes are still unclear. In this study, fruits of high-acid 'Nongda4' and low-acid 'DS-1' varieties of Chinese dwarf cherry were used to determine the acid content at different developmental stages. We used transcriptome profiles to identify key genes related to organic acid metabolism and construct their co-expression networks, and we studied the expression patterns of key genes in 36 Chinese dwarf cherry accessions. The titratable acid content of both 'DS-1' and 'Nongda4' fruits first increased and then decreased during fruit development; however, the titratable acid content of 'DS-1' fruits changed to a minor extent. The organic acid content of 'Nongda4' was significantly higher than that of 'DS-1'. The organic acids in mature fruits were mainly malic acid and citric acid. Analysis of the differentially expressed genes related to organic acid metabolism revealed six key genes, including two MDH genes, one tDT gene, one ME gene, one PEPCK gene, and one VHA gene. Weighted gene co-expression network association analysis revealed four modules that were significantly correlated with organic acid content, and 10 key genes with high connectivity among these four modules were screened, including two PK genes, two MDH genes, two ME genes, one PEPCK gene, one VHA gene, one PEPC gene, and one tDT gene. According to the expression patterns of genes in different Chinese dwarf cherry accessions, seven genes were confirmed to represent key genes related to the regulation of organic acids during Chinese dwarf cherry fruit development. These results provide a foundation for further studies on the molecular mechanism of organic acid accumulation in Chinese dwarf cherry fruit.

Integrated metabolic, transcriptomic and chromatin accessibility analyses provide novel insights into the competition for anthocyanins and flavonols biosynthesis during fruit ripening in red apple.

Fruit ripening is accompanied by a wide range of metabolites and global changes in gene expression that are regulated by various factors. In this study, we investigated the molecular differences in red apple 'Hongmantang' fruits at three ripening stages (PS1, PS5 and PS9) through a comprehensive analysis of metabolome, transcriptome and chromatin accessibility. Totally, we identified 341 and 195 differentially accumulated metabolites (DAMs) in comparison I (PS5_vs_PS1) and comparison II (PS9_vs_PS5), including 57 and 23 differentially accumulated flavonoids (DAFs), respectively. Intriguingly, among these DAFs, anthocyanins and flavonols showed opposite patterns of variation, suggesting a possible competition between their biosynthesis. To unveil the underlying mechanisms, RNA-Seq and ATAC-Seq analyses were performed. A total of 852 DEGs significantly enriched in anthocyanin metabolism and 128 differential accessible regions (DARs) significantly enriched by MYB-related motifs were identified as up-regulated in Comparison I but down-regulated in Comparison II. Meanwhile, the 843 DEGs significantly enriched in phenylalanine metabolism and the 364 DARs significantly enriched by bZIP-related motifs showed opposite trends. In addition, four bZIPs and 14 MYBs were identified as possible hub genes regulating the biosynthesis of flavonols and anthocyanins. Our study will contribute to the understanding of anthocyanins and flavonols biosynthesis competition in red apple fruits during ripening.

Changes of bioactive components and antioxidant potential during fruit development of Prunus humilis Bunge.

Dynamic changes in flavonoid, total phenol, and antioxidant potential in different Prunus humilis accessions during fruit development stages were studied in order to provide a reference for the optimum harvest time for flavonoid extraction. 'Nongda 4', 'Nongda 5', 'DS-1' and '02-16' were selected as plant materials to determine the content of flavonoid, total phenol and antioxidant indices during six fruit development stages. Changes in total flavonoid content (TFC) and total phenol content (TPC) in different accessions of P. humilis were slightly different depending on the development stage of P. humilis fruit. TFC and TPC in 'Nongda 5' fruit showed a trend of continuous decline. There was a small increase in TFC and TPC from the young fruit stage to the stone hardening stage, followed by a decreasing trend, and then to the lowest level at the ripening stage of 'Nongda 4', 'DS-1', and '02-16' fruits. The trend of antioxidant capacity (ABTS, FRAP, DPPH) with the TFC and TPC of P. humilis fruit was basically the same, and the correlation analysis results showed that the TFC of P. humilis fruit was positively correlated with the antioxidant indices (P<0.01). Catechin (CC), rutin (RT), and quercetin-7-O-ß-D-glucopyranoside (Q7G) were detected in all the fruit development stages of the four P. humilis fruits. Among them, catechin was the most abundant component, accounting for approximately 10%. Myricetin (MC) and quercetin (QC) were generally detected only in the early fruit development stage, but not in the later fruit development stage. Correlation analysis showed that the flavonoid components with TFC, TPC, and antioxidant indices differed between the different accessions. RT, CC, and liquiritigenin (LR) had a stronger correlation with TFC and antioxidant indices. Cyanidin-3-O-glucoside (C3G) was not detected until the coloring stage in two red P. humilis accessions ('Nongda 4' and 'DS-1'), and so it is better to choose a red P. humilis fruit to extract C3G at the ripening stage. Selecting an early stage of fruit development, especially the stone hardening stage, was important for extracting flavonoids, total phenols and other components. We believe that our results will provide basic information and reference for evaluation of fruit nutrition and health benefits, breeding of functional new varieties, and efficient utilization of P. humilis fruit.

Identification of LecRLK gene family in Cerasus humilis through genomic-transcriptomic data mining and expression analyses.

Lectin receptor-like protein kinases (LecRLKs) have been shown to be involved in plants' responses to various biotic and abiotic stresse factors. Cerasus humilis is an important fruit species widely planted for soil and water conservation in northern China due to its strong tolerance to drought and salinity stresses. In this study, a total of 170 LecRLK family genes (125 G-types, 43 L-types and 2 C-types) were identified in the newly released whole-genome sequences of C. humilis. Furthermore, nine representative LecRLK genes in young plants of C. humilis under varying drought and salinity stresses were selected for qRT-PCR analysis. Our systematic comparative analyses revealed the active participation of these nine LecRLK genes in the salt and drought stress responses of C. humilis. The results from our study have provided a solid foundation for future functional verification of these LecRLK family genes and will likely help facilitate the more rapid and effective development of new stress resistant Cerasus humilis cultivars.

Fruit quality and antioxidant potential of Prunus humilis Bunge accessions.

In this study, we aimed to evaluate the fruit quality of Prunus humilis and identify cultivars that could provide superior human health benefits. We measured the basic characteristics, bioactive compounds, and antioxidant capacities of 137 P. humilis accessions. Flavonoid and phenol content were determined via colorimetry and ultrahigh performance liquid chromatography. Single fruit and stone weights varied widely and were genetically diverse among accessions. The variation in soluble solid content was comparatively narrow. Total flavonoid content (TFC) ranged from 3.90 to 28.37 mg/g FW, with an average of 10.58 mg/g FW in 2019. Significant differences between accessions in terms of TFC, total phenol content, and antioxidant capacity were found. TFC in the accessions was normally distributed and predominantly in the medium range (9.57-15.23 mg/g FW). Red was the predominant peel color over all other phenotypes (i.e., dark red, red, light red, red-orange, and yellow). There was no obvious correlation between peel color and TFC. Catechin was the major flavonoid component in the fruit. Principal component analysis showed that TFC, ABTS, single fruit weight, and vertical and horizontal diameter contributed to the first two principal components for each accession. Accessions 10-02, 3-17-2, 3-17-4, and JD1-6-7-37 were characterized by high TFC, ABTS, and large fruit. We believe that our results will aid in the breeding and functional food processing of Prunus humilis.

Identification of Differentially Expressed Genes and Pathways for Abdominal Fat Deposition in Ovariectomized and Sham-Operated Chickens.

Ovariectomy results in improved meat quality (growth rate, tenderness, and flavor) of broilers. However, some negative effects increased (abdominal fat (AF) deposition, low feed conversion, etc.) have also been reported. In this study, the gene expression profiles of AF tissue in ovariectomized and sham-operated chickens were determined to identify differentially expressed genes (DEGs) and pathways to explore the molecular mechanisms underlying AF accumulation. Comparing the ovariectomized group and the sham-operated group, the abdominal fat weight (AFW) and abdominal fat percentage (AFP) were increased significantly (p < 0.05) at 14 and 19 weeks after ovariectomy. According to the gene expression profiling analysis, 108 DEGs of fat metabolism were screened from 1461 DEGs. Among them, ABCA1, ABCACA, LPL, CREB1, PNPLA2, which are involved in glycerolipid-or steroid-associated biological processes, and the hormone receptor genes, ESR1 and PRLR, were down-regulated significantly in the ovariectomized group compared to the sham-operated group (p < 0.05). Conversely, CETP, DGAT2, DHCR24, HSD17B7 and MSMO1, were significantly up-regulated (p < 0.05) after ovariectomy. Based on the DEGs, the glycerolipid metabolism, steroid biosynthesis, and other signaling pathways (MAPK, TGF-ß, and adhesion pathways, etc.) were enriched, which may also contribute to the regulation of AF deposition. Our data suggest that AF deposition was significantly increased in ovariectomized chickens by the down-regulation of the decomposition genes of glycerolipid metabolism, which inhibits AF degradation, and the up-regulation of steroid biosynthesis genes, which increases fat accumulation. These findings provide new insights into the molecular mechanisms of fat deposition in the ovariectomized chickens.

Mutagenesis of the FAE1 genes significantly changes fatty acid composition in seeds of Camelina sativa.

Camelina sativa is a re-emerging low-input oilseed crop that has great potentials. It is necessary to ameliorate camelina oils for optimized fatty acid composition that can meet different application requirements. Camelina seed contains significant amounts of C20-C24 very long-chain fatty acids (VLCFAs) that may not be desirable. We demonstrated that these VLCFAs can be effectively reduced by deactivating the Fatty Acid Elongase1 (FAE1) in camelina. The allohexaploid camelina contains three alleles of FAE1 genes. Ethyl methanesulfonate (EMS) induced mutation at the FAE1-B gene caused over 60% reduction of VLCFAs in seed. Homozygous knockout mutants were successfully created in a single generation by simultaneously targeting three FAE1 alleles using the CRISPR technology with an egg cell-specific Cas9 expression. VLCFAs were reduced to less than 2% of total fatty acids compared to over 22% in the wild type, and the C18 unsaturated fatty acids were concomitantly increased. The fae1 mutants were indistinguishable from wild type in seed physiology and plant growth. This study demonstrated that the CRISPR/Cas9 technology can be effectively applied to the polyploid crop camelina to rapidly obtain desired traits such as optimal fatty acid composition in its seed oil. Knocking out FAE1 also provides a means to increase the levels of oleic acid or α-linolenic acid in camelina oils that are desirable for industrial or food/feed uses.

The chloroplast genome of Cerasus humilis: Genomic characterization and phylogenetic analysis.

Cerasus humilis is endemic to China and is a new fruit tree species with economic and environmental benefits, with potential developmental and utilization applications. We report the first complete chloroplast genome sequence of C. humilis. Its genome is 158,084 bp in size, and the overall GC content is 36.8%. An inverted repeats (IR) of 52,672 bp in size is separated by a large single-copy (LSC) region of 86,374 bp and a small single-copy (SSC) region of 19,038 bp. The chloroplast genome of C. humilis contains 131 genes including 90 protein-coding genes, 33 transfer RNA genes, and 8 ribosomal RNA genes. The genome has a total 510 simple sequence repeats (SSRs). Of these, 306, 149, and 55 were found in the LSC, IR, and SSC regions, respectively. In addition, a comparison of the boundaries of the LSC, SSC, and IR regions of ten other Prunus species exhibited an overall high degree of sequence similarity, with slight variations in the IR boundary region which included gene deletions, insertions, expansions, and contractions. C. humilis lost the ycf1 gene at the IRA/SSC border and it has the largest ycf1 gene at the IRB/SSC border among these Prunus species, whereas the rps19 gene was inserted at the IRB/LSC junction. Furthermore, phylogenetic reconstruction using 61 conserved coding-protein genes clustered C. humilis with Prunus tomentosa. Thus, the complete chloroplast genome sequence of C. humilis provides a rich source of genetic information for studies on Prunus taxonomy, phylogeny, and evolution, as well as lays the foundation for further development and utilization of C. humilis.

Comparison of fruit organic acids and metabolism-related gene expression between Cerasus humilis (Bge.) Sok and Cerasus glandulosa (Thunb.) Lois.

Cerasus humilis (Bge.) Sok and Cerasus glandulosa (Thunb.) Lois are economically important fruit-producing shrubs. Although these two species have similar looking fruits, their fruit organic acid contents differ drastically. In this study, we focused on comparing the organic acid content, activity of enzymes gene expression involved in organic acid metabolism in both C. humilis and C. glandulosa fruits. To investigate the differences of organic acid metabolism in fruits of these two species, a comparative transcriptome analysis was performed. Our results showed that temporal changes of two main organic acids exhibited different trends in these two species. Transcriptome sequencing of developing C. humilis and C. glandulosa fruits systematically revealed 6,594 differentially expressed genes. Compared with C. humilis, the expression levels of 3,469 and 3,125 genes were up- and down-regulated in C. glandulosa, respectively, including one PEPC gene, 12 malic acid metabolism genes, 25 citric acid cycle genes, and 194 NAD/NADP metabolism genes. The correlation analysis and principal component analysis of gene expression, enzymatic activity and organic acid content showed that differences in the expression of genes encoding the NAD-malate dehydrogenase (NAD-MDH) and NADP-malate enzyme (NADP-ME) contributed substantially to the observed differences in organic acid accumulation of two species. Our results provide a solid foundation for future elucidation of key mechanisms regulating organic acid biosynthesis in C. humilis and C. glandulosa fruits and could lead to efficient and highly targeted generation of more commercially accepted cultivars.

Cloning and characterization of the Cerasus humilis sucrose phosphate synthase gene (ChSPS1).

Sucrose is crucial to the growth and development of plants, and sucrose phosphate synthase (SPS) plays a key role in sucrose synthesis. To understand the genetic and molecular mechanisms of sucrose synthesis in Cerasus humilis, ChSPS1, a homologue of SPS, was cloned using RT-PCR. Sequence analysis showed that the open reading frame (ORF) sequence of ChSPS1 is 3174 bp in length, encoding a predicted protein of 1057 amino acids. The predicted protein showed a high degree of sequence identity with SPS homologues from other species. Real-time RT-PCR analysis showed that ChSPS1 mRNA was detected in all tissues and the transcription level was the highest in mature fruit. There is a significant positive correlation between expression of ChSPS1 and sucrose content. Prokaryotic expression of ChSPS1 indicated that ChSPS1 protein was expressed in E. coli and it had the SPS activity. Overexpression of ChSPS1 in tobacco led to upregulation of enzyme activity and increased sucrose contents in transgenic plants. Real-time RT-PCR analysis showed that the expression of ChSPS1 in transgenic tobacco was significantly higher than in wild type plants. These results suggested that ChSPS1 plays an important role in sucrose synthesis in Cerasus humilis.

The Role of SDF-1/CXCR4/CXCR7 in Neuronal Regeneration after Cerebral Ischemia.

Stromal cell-derived factor-1 is a chemoattractant produced by bone marrow stromal cell lines. It is recognized as a critical factor in the immune and central nervous systems (CNSs) as well as exerting a role in cancer. SDF-1 activates two G protein-coupled receptors, CXCR4 and CXCR7; these are expressed in both developing and mature CNSs and participate in multiple physiological and pathological events, e.g., inflammatory response, neurogenesis, angiogenesis, hematopoiesis, cancer metastasis, and HIV infection. After an ischemic stroke, SDF-1 levels robustly increase in the penumbra regions and participate in adult neural functional repair. Here we will review recent findings about SDF-1 and its receptor, analyse their functions in neurogeneration after brain ischemic injury: i.e., how the system promotes the proliferation, differentiation and migration of neural precursor cells and mediates axonal elongation and branching.

dl-3-n-butylphthalide promotes neuroplasticity and motor recovery in stroke rats.

BACKGROUNDS AND AIMS: Racemic l-3-n-butylphthalide (dl-NBP), is able to achieve a functional recovery in animal models of cerebral ischemia, vascular dementia, and Alzheimer's disease. In this study, we investigated the effect of dl-NBP on axonal growth, neurogenesis and behavioral performances in rats with cerebral ischemia. METHODS: Focal cerebral ischemia in rats was produced by intracerebral injection of endothelin-1. Starting from postoperative day 7, the experimental rats were administered 70mg/kg dl-NBP by oral gavage for two weeks. Biotinylated dextran amine (BDA) was injected into the contralateral sensorimotor cortex on day 14 after ischemia to trace the sprouting of corticospinal tract (CST) fibers into the denervated cervical spinal cord. The expressions of Nogo-A, Nogo-R, Rho-A, and ROCK in the perilesional cortex, the expressions of BDA, PSD-95, and vGlut1 in the denervated spinal cord, 5-bromo-20-deoxyuridine (BrdU)/DCX-positive cells in the subventricular zone (SVZ) of the injured hemisphere were detected by immunofluorescence. The rats' behavioral abilities were measured on postoperative days 30-32 in the beam-walking, cylinder and sticky label tests. RESULTS: dl-NBP treatment significantly increased the number and length of crossing CST fibers, enhanced significantly the expression levels of synapse-associated proteins including PSD95 and VGlut-1 in the denervated cervical spinal cord, elevated the number of BrdU+/DCX+ cells in SVZ, and reduced markedly those of Rho-A+, ROCK+, Nogo-A+ and Nogo-R+ cells in perilesional cortex. In addition, dl-NBP improved the behavioral performance of the ischemic rats. CONCLUSION: dl-NBP enhanced the behavioral recovery after cerebral ischemia in rats, possibly by increasing axonal growth and neurogenesis.

Chloride Co-transporter NKCC1 Inhibitor Bumetanide Enhances Neurogenesis and Behavioral Recovery in Rats After Experimental Stroke.

Bumetanide, a selective Na+-K+-Cl--co-transporter inhibitor, is widely used in clinical practice as a loop diuretic. In addition, bumetanide has been reported to attenuate ischemia-induced cerebral edema and reduce neuronal injury. This study examined whether bumetanide could influence neurogenesis and behavioral recovery in rats after experimentally induced stroke. Adult male Wistar rats were randomly assigned to four groups: sham, sham treated with bumetanide, ischemia, and ischemia treated with bumetanide. Focal cerebral ischemia was induced by injection of endothelin-1. Bumetanide (0.2 mg/kg/day) was infused into the lateral ventricle with drug administration being initiated 1 week after ischemia and continued for 3 weeks. Behavioral impairment and recovery were evaluated by tapered/ledged beam-walking test on post-stroke days 28. Then, the rats were perfused for BrdU/DCX (neuroblast marker), BrdU/NeuN (neuronal marker), BrdU/GFAP (astrocyte marker), and BrdU/Iba-1 (microglia marker) immunohistochemistry. The numbers of neuroblasts in the subventricular zone (SVZ) were significantly increased after the experimentally induced stroke. Bumetanide treatment increased migration of neuroblasts in the SVZ towards the infarct area, enhanced long-term survival of newborn neurons, and improved sensorimotor recovery, but it did not exert any effects on inflammation. In conclusion, our results demonstrated that chronic bumetanide treatment enhances neurogenesis and behavioral recovery after experimentally induced stroke in rats.

CXCR4 antagonist AMD3100 reverses the neurogenesis promoted by enriched environment and suppresses long-term seizure activity in adult rats of temporal lobe epilepsy.

It has been showed that enriched environment (EE) enhances the hippocampal neurogenesis and improves the cognitive impairments, accompanied by the increased expressions of stromal cell-derived factor-1 (SDF-1) in adult rats of temporal lobe epilepsy (TLE). We examined whether the enhanced neurogenesis and improved cognitive functions induced by EE following seizures were mediated by SDF-1/CXCR4 pathway. Therefore, we investigated the effects of the EE combined with CXCR4 antagonist AMD3100 on neurogenesis, cognitive functions and the long-term seizure activity in the TLE model. Adult rats were randomly assigned as control rats, rats treated with EE, rats subjected to status epilepticus (SE), post-SE rats treated with EE, AMD3100 or EE combined with AMD3100 respectively. We used immunofluorescence staining to analyze the hippocampal neurogenesis and Nissl staining to evaluate hippocampal damage. Electroencephalography was used to measure the frequency and mean duration of spontaneous seizures. Cognitive function was evaluated by Morris water maze test. EE treatment significantly, as well as improved cognitive impairments and decreased long-term seizure activity, and that these effects might be mediated through SDF-1/CXCR4 pathway during the chronic stage of TLE. Although AMD3100 reversed the effect of EE on neurogenesis, it did not abolish the cognitive improvement induced by EE following seizures. More importantly, EE combined with AMD3100 treatment significantly suppressed long-term seizure activity, which provided promising evidences to treat TLE.

Bumetanide promotes neural precursor cell regeneration and dendritic development in the hippocampal dentate gyrus in the chronic stage of cerebral ischemia.

Bumetanide has been shown to lessen cerebral edema and reduce the infarct area in the acute stage of cerebral ischemia. Few studies focus on the effects of bumetanide on neuroprotection and neurogenesis in the chronic stage of cerebral ischemia. We established a rat model of cerebral ischemia by injecting endothelin-1 in the left cortical motor area and left corpus striatum. Seven days later, bumetanide 200 µg/kg/day was injected into the lateral ventricle for 21 consecutive days with a mini-osmotic pump. Results demonstrated that the number of neuroblasts cells and the total length of dendrites increased, escape latency reduced, and the number of platform crossings increased in the rat hippocampal dentate gyrus in the chronic stage of cerebral ischemia. These findings suggest that bumetanide promoted neural precursor cell regeneration, dendritic development and the recovery of cognitive function, and protected brain tissue in the chronic stage of ischemia.