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Spiroplasma eriocheiris , the pathogen of Eriocheir sinensis tremor disease (TD), has bring a huge economic loss to China aquaculture. The hemocytes of crab as the first target cells of S. eriocheiris , but the interactive relationship between the E. sinensis and this pathogen not particularly clear. The present study is the first time to analysis the role of protein ubiquitination in the process of E. sinensis hemocytes response S. eriocheiris infection. By applying label-free quantitative liquid chromatography with tandem mass spectrometry proteomics, 950 lysine ubiquitination sites and 803 ubiquitination peptides on 458 proteins were identified, of which 48 ubiquitination sites on 40 proteins were quantified as significantly changed after the S. eriocheiris infection. Bioinformatics analysis of ubiquitination different proteins suggested many biological process and pathways were participated in the interaction between S. eriocheiris and host cell, such as ubiquitin system, endocytosis, prophenoloxidase system (proPO system), cell apoptosis, glycolysis. Our study can enhance our understanding of interaction between the crab and S. eriocheiris , and also provides basis to study the role of protein ubiquitination in other crustacean innate immune system. • The ubiquitin-modified proteome changes of E. sinensis hemocytes after S. eriocheiris infection were obtained. • Forty-eight ubiquitination sites on 40 proteins were quantified as significantly changed after the S. eriocheiris infection. • Ubiquitin system, endocytosis, proPO system, cell apoptosis, glycolysis, etc. were related to the S. eriocheiris infection. [ABSTRACT FROM AUTHOR]

Infection by Hepatospora eriocheir would cause serious disease, hepatopancreatic necrosis disease (HPND), and lead to significant economic losses in Eriocheir sinensis. In this study, the response of E. sinensis during H. eriocheir infection was explored by PCR detection, physiological determination (Masson staining and Calcofluor White staining), electron microscopy, and integrated proteome and metabolome analyses. Pathological and electron microscopy analysis demonstrated that H. eriocheir infection could severely damage the E. sinensis hepatopancreas tissue collagen fibers, muscle fibers, and the cells ultrastructure. Base on the PCR detection and Calcofluor White staining results selected the H. eriocheir positive or negative E. sinensis hepatopancreas used to proteome and metabolome analyses. Using a 2-fold change as a physiologically significant benchmark, total of 370 significantly changed proteins (225 up-regulated proteins and 145 down-regulated proteins) and 386 significantly different metabolites (217 metabolites up-regulated and 169 metabolites down-regulated) in crab hepatopancreas during H. eriocheir infection were identified by proteomic and metabolomic analysis, respectively. Biological analysis of these significantly changed proteins and metabolites showed that the lipid metabolism (for example, glycerophospholipid metabolism, carnitine metabolism, lysolecithin metabolism, biosynthesis of unsaturated fatty acids, sphingolipid metabolism, and linoleic acid metabolism) and energy metabolism (such as tricarboxylic acid cycle (TCA cycle), oxidative phosphorylation, and ATP-binding cassette transporter (ABC transporters)) of E. sinensis hepatopancreas were disproportionally affected by H. eriocheir infection. Meanwhile, several key immune-related processes, proteins or metabolites were activated to against the H. eriocheir infection, for example apoptosis, phagocytosis, oxidative stress, C-type lection, β-1, 3-glucan binding protein, vitellogenin receptor, arginine, leucine, aspartic acid, lysine. This study could provide an insightful view into the response mechanism in E. sinensis hepatopancreas during H. eriocheir infection. • Analyzed the histopathological changes of crab hepatopancreas induced by H. eriocheir. • Proteomic and metabolomics analyses the mechanism of H. eriocheir infection. • Energy metabolism, lipid metabolism and immune related processes were identified. [ABSTRACT FROM AUTHOR]

Spiroplasma eriocheiris , a novel pathogen of Chinese mitten crab Eriocheir sinensis tremor disease, has led into catastrophic economic losses in aquaculture. S. eriocheiris invaded the hemocytes in the early stage, then invaded nerve tissue and caused typically paroxysmal tremors of pereiopod in the late stage of infection. The purpose of this study was to detect the infection mechanism of hemocytes in the early stage and thoracic ganglion in the late stage of S. eriocheiris infection at the protein level. Hemocytes and thoracic ganglion were collected at 24 h and 10 d after injection (the crabs with typical paroxysmal tremors of the pereiopod), respectively. TMT was performed with isobaric markers, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS). In hemocytes, 127 proteins were up-regulated and 85 proteins were down-regulated in 2747 quantified proteins. Many proteins and process including proPO system proteins, hemolymph coagulation system proteins and lectins were differently expressed in hemocytes and involved in the early immune process of E. sinensis against S. eriocheiris infection. Meanwhile, 545 significantly different expression proteins (292 down-regulated and 253 up-regulated protein including a number of immune-associated, nervous system development and signal transmission related proteins) were identified in thoracic ganglion in the late stage of S. eriocheiris infection. The qRT-PCR analysis results shown that the selected significantly changed proteins in hemocytes and thoracic ganglion were consistent with the TMT proteomics. This paper reported for the first time to study the responses of crab hemocyte and thoracic ganglion against the S. eriocheiris infection at different stages. These findings help us understand the infection mechanism of S. eriocheiris at different stage with the different tissue. • Understand the infection mechanism of S. eriocheiris at different stage with the different tissue by proteomic analysis. • 212 and 545 significantly different expression proteins were identified in hemocyte and thoracic ganglion, respectively. • ProPO system, nervous system development proteins etc. were identified when the S. eriocheiris infection. • Some significantly changed proteins were confirmed by qRT-PCR. [ABSTRACT FROM AUTHOR]

Spiroplasma eriocheiris is a novel pathogen similar to the Spiroplasma mirum and also had an ability to infect the newborn mice and caused cataract. Our study was designed to study how S. eriocheiris infects mouse 3T6-Swiss albino cells and to elucidate the cellular molecular pathogenesis of Spiroplasma . FCM analysis and MTT analysis clearly shown that S. eriocheiris could induce 3T6 cell apoptosis and cause cell viability decreased seriously. Immunofluorescence experiments and TEM analysis shown that S. eriocheiris can invade 3T6 cells and form typical inclusion bodies and exhibit vacuolization in vitro . S. eriocheiris -oxytetracycline protection assay show that the infective bacteria already were detected at 1 h post infection, and sharply increased at 12 h after the bacteria infection. To further study the infection mechanism of S. eriocheiris , global mRNA and microRNA (miRNA) expression profiling were analyzed after the cells infected with the bacteria. A total of 619 non-redundant annotated transcripts (183 up-regulated and 436 down-regulated) and 22 miRNAs (8 up-regulated and 14 down-regulated) were differential expression after 6 h S. eriocheiris infection compared to control group. Integrated analysis shown that homologous genes from differential expression miRNA targets and the differential expression genes of the mRNA microarray were major focused on two important pathways focal adhesion and MAPK signaling pathway. To validate the results of microarray, eight focal adhesion (β-Catenin, Parvin, Grb2 and ERK) and MAPK signaling pathway (FGFR, Grb2, ERK, MKK3, p38 and JNK) genes and the housekeeping gene GAPDH were assayed by qPCR and Western blot to confirm the results. Eight miRNAs (miR-143-3p, miR-214-5p, miR-322-3p, miR-328-5p, miR-351-5p, miR-466h-5p, miR-503-5p and miR-30c-1-3p) and the housekeeping gene U6 miRNA were assayed by qPCR to confirm the results of microarray. All the results help us better understand the infection mechanism of S. eriocheiris . [ABSTRACT FROM AUTHOR]

Spiroplasma eriocheiris , as a novel aquaculture pathogen, has led into catastrophic economic losses in aquaculture. The Macrobrachium rosenbergii hemocytes were major target cells in S. eriocheiris infection. Our study was designed to examine the hemocytes' immune response at the protein levels. The differential proteomes of the prawn hemocytes were analyzed immediately prior to injection with the pathogen, and at 192 h post-injection by isobaric tags for relative and absolute quantization (iTRAQ) labeling, followed by liquid chromatogramphytandem mass spectrometry (LC–MS/MS). A total of 69 differentially expressed proteins were identified. Forty-nine proteins were up-regulated and 20 proteins were down-regulated resulting from a S. eriocheiris infection. Up-regulated proteins included vertebrate gliacolin-like protein, vitellogenin, Gram-negative binding protein 1, alpha2 macroglobulin isoform 2 (a2M), etc. Down-regulated proteins, involved with beta-1,3-glucan-binding protein (BGBP), immunoglobulin like, Rab7, lipopolysaccharide and β-1,3-glucan (LGBP), actin-related protein, etc. Selected bioactive factors (tachylectin, α2M and vitellogenin, BGBP, C-type lectin, LGBP and Rab7) were verified by their immune roles in the S. eriocheiris infection using real-time PCR. The present work could serve as a basis for future studies on the proteins implicated in the susceptibility/resistance of M. rosenbergii to S. eriocheiris , as well as contribute to our understanding of disease processes in prawns. Biological significance This is the first time using an iTRAQ approach to analyze proteomes of M. rosenbergii mobilized against S. eriocheiris infection and substantiated the hemocytes' proteomic changes in M. rosenbergii using an infection model. The results reported here can provide a significant step forward toward a more complete elucidation of the immune relationship between M. rosenbergii and the pathogen S. eriocheiris . [ABSTRACT FROM AUTHOR]

To better understand the behavior of photogenerated charges in the composite photocatalyst interface is beneficial to the designing of effective photocatalyst for photocatalytic reaction. In our work, the separation and transfer process of photogenerated charges in NiO/TiO 2 nanotube arrays (NiO/TiO 2 NTAs) has been studied by surface photovoltage (SPV) spectroscopy and transient photovoltage (TPV) measurement. Through the experimental results analysis, we find that an interfacial electric field is formed at NiO/TiO 2 NTAs interface, which is attributed to the work function difference between NiO and TiO 2 NTAs. The photogenerated holes in TiO 2 can transfer to the NiO layer along the interface electric field under the ultraviolet irradiation. A large amount of photogenerated holes can be separated effectively and then prolonged the holes lifetime to participate in the photocatalytic oxidation reaction. The above results show that the favorable hole-collecting process of NiO in the surface of TiO 2 NTAs is the main factor being responsible for the increase the photocatalytic efficiency. [ABSTRACT FROM AUTHOR]

C-type lectins are a family of calcium-dependent carbohydrate-binding proteins which are believed to play important roles in the innate immunity of invertebrates. This study identified two novel C-type lectins, designated as MnCTLDcp2 and MnCTLDcp3, from the oriental river prawn Macrobrachium nipponense . The full-length cDNA of MnCTLDcp2 was of 1582 bp with an open reading frame (ORF) of 972 bp encoding a polypeptide of 323 amino acids. The complete nucleotide sequence of MnCTLDcp3 cDNA was 583 bp, containing a 555 bp ORF encoding a putative protein of 184 deduced amino acids. The deduced MnCTLDcp2 and MnCTLDcp3 proteins both contained a single C-type lectin-like domain (CTLD). Besides, MnCTLDcp2 contains a signal peptide and an low-density lipoprotein receptor class A (LDLa) domain. Reverse transcription PCR showed that MnCTLDcp2 was expressed in the heart, gill, nerve hepatopancreas and intestine; MnCTLDcp3 was expressed in the hepatopancreas, heart, nerve, gill and muscle. Their expression in the heart tissue was regulated following challenge with bacteria. The microbial agglutination assay showed that both MnCTLDcp2 and MnCTLDcp3 could agglutinated bacteria in the presence of calcium. All these results suggested that MnCTLDcp2 and MnCTLDcp3 functioned as pattern recognition receptors in the immune system of M. nipponense. [ABSTRACT FROM AUTHOR]

A pattern recognition protein (PRP), lipopolysaccharide and β-1,3-glucan binding protein (LGBP), cDNA was cloned from the hemocytes of red claw crayfish, Cherax quadricarinatus by the techniques of homology cloning and RACE. Analysis of nucleotide sequence revealed that the full-length cDNA of 1456 bp has an open reading frame of 1095 bp encoding a protein of 364 amino acids including a 15 amino acid signal peptide. The calculated molecular mass of the mature protein (349 aa) was 39.92 kDa with an estimated pI of 4.50. Sequence comparison of the deduced amino acid sequence of C. quadricarinatus LGBP (named as CqLGBP) showed a high identity of 82%, 77%, 76% and 74% with Procambarus clarkii LGBP, Homarus gammanus BGBP, Penaeus monodon BGBP and Litopenaeus stylirostlis LGBP, respectively. The CqLGBP sequence contains: (1) two putative integrin-binding motifs, (2) a glucanase motif, (3) two putative N-glycosylation sites, (4) one protein kinase C phosphorylation site, and (5) a putative recognition motif for β-1,3-linkage of polysaccharides. The recombinant CqLGBP were expressed in Escherichia coli BL21 with pGEX-6P-2 expression vector. The titer of rabbit anti-CqLGBP serum was above 1:12,800. Microorganism binding assay showed CqLGBP binds two kinds of crustacean pathogens Spiroplasma eriocheiris and Aeromonas hydrophila . Quantitative RT-PCR method was used to quantify the variation of mRNA transcription level during artificial infection with S. eriocheiris and A. hydrophila . A significant enhancement of CqLGBP transcriptions was apparent post-injection in response to bacterial infection compared to the control group. These data should be helpful to better understand the function of CqLGBP in the crayfish immune system. [ABSTRACT FROM AUTHOR]

Spiroplasma eriocheiris is as a novel pathogen of Chinese mitten crab Eriocheir sinensis tremor disease. The hemocytes have been shown to be major target cells in S. eriocheiris infection. The aim of this study was to examine the hemocytes' immune response at the protein levels. The differential proteomes of the crab hemocytes were analyzed immediately prior to injection with the pathogen, and at 10 d post-injection by isobaric tags for relative and absolute quantization (iTRAQ) labeling, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 1075 proteins were identified by LC-MS/MS and de novo sequencing data. Using a 1.2-fold change in expression as a physiologically significant benchmark, 76 differentially expressed proteins (7.07%) were reliably quantified by iTRAQ analysis. Thirty-five (3.26%) proteins were up-regulated and 41 (3.81%) proteins were down-regulated resulting from a S. eriocheiris infection. Approximately 20 differential proteins in hemocytes were involved in the stress and immune responses. Up-regulated proteins included alpha-2-macroglobulin (α2M), prostaglandin D synthase (GST), ferritin, and heat shock protein 60. Down-regulated proteins included two lectins (mannose-binding protein and hemocytin), three kinds of serine proteinase inhibitors (two serpins and pacifastin), three different kinds of serine proteases, mitogen-activated protein kinase kinase (MAPKK), and two thioredoxins (Trx), crustin, etc. Selected bioactive factors (α2M, GST, ferritin, tubulin, crustin, thioredoxin, clip domain serine protease and serpin) are verified by their immune roles in the S. eriocheiris infection using Real-time PCR. The variation trend of immune gene's mRNA expression is similar with the result of iTRAQ, except the tubulin. The prophenoloxidase-activating system, antimicrobial action and antioxidant system involved in the immune responses of E. sinensis is believed to be a resistance to S. eriocheiris infection. This is the first report of the proteome response of crab hemocytes against S. eriocheiris infection. These findings contribute to our understanding of tremor disease processes in crabs, and provide the first evidence to promote a search for potential biomarkers of the disease. [ABSTRACT FROM AUTHOR]

Spiroplasma eriocheiris , has been identified as a novel lethal pathogen of Eriocheir sinensis tremor disease (TD, typically paroxysmal tremors of the pereiopod). The thoracic ganglion of E. sinensis infected by S. eriocheiris was the direct reason of the TD. This study was designed to understand of TD processes in crab and the immune response of thoracic ganglion at the transcriptomic levels. The transcriptomic profiles of thoracic ganglion in the experimental group (S. eriocheiris inject, termed SI) and the control group (R2 medium inject, termed RI) were obtained using Illumina HiSeq 2500. In total, there were 60,159,089 and 47,613,445 high-quality clean reads assembled from SI and RI, respectively. In addition, 39,636 unigenes were obtained with an N50 length of 575 bp. Moreover, by RPKM analysis, a total of 8049 differentially expressed genes (SI vs RI) were detected, including 927 up-regulated and 7122 down-regulated genes. The transcription levels of gene in prophenoloxidase-activating system (proPO), Wnt signaling pathway, phagocytosis, Toll-like system, Ca2+ regulation related process, etc. of SI were significantly changed compare with RI. Finally, 12 selected differentially expressed genes (Serpin, TLR, FZ4, SPI2, Tax1, TLSP, AI, CTLR, Rab11A, LAMP-1, Trx1 and PI3K) were verified using qRT-PCR showed similar tendency with the RNA-seq. The results shown that the proPO, Wnt signaling pathway, phagocytosis, Toll-like system, Ca2+ regulation related process, glutamate signal related process, etc. were involved in the process of the S. eriocheiris infection. • RNA-seq help to understand the TD pathogenesis in thoracic ganglion of E. sinensis against S. eriocheiris. • proPO system, Wnt signaling pathway, Ca2+ regulation related process, were identified in E. sinensis against S. eriocheiris. • Some important significantly changed genes were identified and confirmed by qRT-PCR. [ABSTRACT FROM AUTHOR]

Exosomes released from infected cells are thought to play an important role in the dissemination of pathogens, as well as in host‐derived immune molecules during infection. As an intracellular pathogen, Spiroplasma eriocheiris is harmful to multiple crustaceans. However, the immune mechanism of exosomes during Spiroplasma infection has not been investigated. Here, we found exosomes derived from S. eriocheiris‐infected crabs could facilitate phagocytosis and apoptosis of hemocytes, resulting in increased crab survival and suppression of Spiroplasma intracellular replication. Proteomic analysis revealed the altered abundance of EsTetraspanin may confer resistance to S. eriocheiris, possibly by mediating hemocyte phagocytosis in Eriocheir sinensis. Specifically, knockdown of EsTetraspanin in E. sinensis increased susceptibility to S. eriocheiris infection and displayed compromised phagocytic ability, whereas overexpression of EsTetraspanin in Drosophila S2 cells inhibited S. eriocheiris infection. Further, it was confirmed that intramuscular injection of recombinant LEL domain of EsTetraspanin reduced the mortality of S. eriocheiris‐infected crabs. Blockade with anti‐EsTetraspanin serum could exacerbate S. eriocheiris invasion of hemocytes and impair hemocyte phagocytic activity. Taken together, our findings prove for the first time that exosomes modulate phagocytosis to resist pathogenic infection in invertebrates, which is proposed to be mediated by exosomal Tetraspanin, supporting the development of preventative strategies against Spiroplasma infection. [ABSTRACT FROM AUTHOR]

Interleukin (IL)-22 is an IL-10 family cytokine secreted by CD4+ T cells and plays an important role in regulating inflammation and infection elimination. IL-22 homologues have been reported in the teleost, but the functions of IL-22 are still unclear. In this study, we identified two duplicated IL-22 genes in common carp (Cyprinus carpio L.), termed Cc _IL-22A and Cc _IL-22B. Sequence analysis showed that Cc _IL-22A and Cc _IL-22B had four conserved cysteine residues, which could form two intra-chain disulfide bridges. The Cc _ IL-22A and Cc _ IL-22B were constitutively expressed in various tissues, with the highest expression in the gill. The mRNA expression levels of Cc _ IL-22A and Cc _ IL-22B were significantly up-regulated in the gill, intestine, head kidney, and spleen of common carp challenged with Aeromonas. hydrophila. In vivo study showed that the expression levels of pro-inflammatory cytokines were significantly up-regulated in the head kidney and spleen when Cc _IL-22A or Cc _IL-22B were over-expressed. Furthermore, the over-expression of Cc _IL-22A and Cc _IL-22B indicated a protective effect on tissues, with only lymphocytic infiltration observed in comparison to the control and pcN3 groups, without obvious change in tissue morphology. Similar stimulatory effects of rIL-22A and rIL-22B were observed in vitro. When HKLs were stimulated with rIL-22A or rIL-22B, the expression levels of critical signaling molecules in the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathway were significantly induced, including JAK1 , JAK3 , STAT1 , and STAT3 , as well as pro-inflammatory cytokines (IL-1β and TNF-α). Together, these results suggest that Cc _IL-22A and Cc _IL-22B may regulate inflammatory responses through the JAK-STAT signaling pathway and have a significant impact on the immune defense of common carp against bacterial infection. Therefore, our study provides a new perspective on the functions of Cc _IL-22A and Cc _IL-22B in the immune defense mechanism of fish. • Common carp IL-22A and IL-22B (Cc _IL-22A and Cc _IL-22B) were identified and characterized. • Cc_IL-22s widely expressed in all tested tissues and responded to bacterial infection. • In vivo , Cc _IL-22s over-expression affected the expression of inflammatory cytokines. • Recombinant Cc _IL-22s induced the expression of genes in JAK–STAT pathway. [ABSTRACT FROM AUTHOR]

Rab7 is a member of the Rab GTPases protein family, and it plays an essential role in regulating trafficking organelles in higher animals. However, recent studies showed that it also participated in the immune response and cytophagy against pathogens in invertebrates. In the present study, the full-length of Rab7 from Procambarus clarkii (PcRab7) was cloned, and its function during pathogen infection and phagocytosis of haemocytes was also explored. The results showed that the full-length of PcRab7 was 3639 bp, containing a 618 bp open reading frame encoding 155 amino acids. The predicted molecular weight and isoelectric point of PcRab7 were 23.2 kDa and 5.77, respectively. PcRab7 was widely expressed in various tissues including haemocytes, intestine, muscle, gill, and hepatopancreas, and the highest expression level was in haemocytes. The mRNA transcripts of PcRab7 in the main organs (gill, intestine, and hepatopancreas, and haemocytes) were significantly affected by white spot syndrome virus (WSSV) and Aeromonas veronii infection. Subsequently, the prokaryotic and eukaryotic expression vectors were successfully constructed, and polyclonal antibodies, which could specifically recognize the endogenous Rab7 protein, were also obtained. Furthermore, the phagocytosis rate of haemocytes against FITC-labeled A. veronii was significantly decreased when the PcRab7 was silenced, while the over-expression of Rab7 increased the phagocytosis rate of haemocytes. The abnormal expression of Rab7 protein could also affect the survival rate of P. clarkii infected with WSSV or A. veronii. These results could provide a basis for further study on the immunological function of PcRab7. • The cDNA of Rab7 from P. clarkii (PcRab7) was cloned. • PcRab7 was widely expressed in various tissues and could be induced by WSSV and A. veronii. • PcRab7 has a positive relation with phagocytosis of haemocytes. • The abnormal expression of PcRab7 could affect the survival rate of P. clarkii infected with WSSV or A. veronii. [ABSTRACT FROM AUTHOR]

Cationic surfactant (CTAB) and anionic surfactant (sodium oleate) were used to modify CdS nanocrystals with different surface states. The surfactant CTAB led to surface states of hole traps, while sodium oleate induced surface states of electron traps on the surface of CdS. The photodegradation of rhodamine B (RhB) over these modified CdS nanocrystals was investigated under visible light irradiation. An efficient cycloreversion degradation of RhB occurred over the E-CdS nanocrystals. However, for H-CdS nanocrystals, an efficient N-deethylation reaction concomitant with a subsequent slow cycloreversion reaction of RhB was observed. The E-CdS sample showed a first-order kinetic rate for the cycloreversion degradation of RhB. By contrast, H-CdS sample shows a zero-order kinetic rate for the N-deethylation reaction of RhB followed by a first-order kinetic rate for the cycloreversion degradation. It is revealed that the different kinds of surface traps could significantly affect the dynamic properties of photogenerated charge carriers, which leads to different degradation mechanism of RhB. These findings demonstrate an alternative solution towards developing efficient photocatalysts with high selectivity by constructing different surface trap states. [ABSTRACT FROM AUTHOR]

The Rab family of proteins is involved in organelle regulation, trafficking, signal transduction, mitosis, phagocytosis, growth differentiation, cytoskeleton protein depolymerization and other cellular functions and abnormal expression has been associated with many pathologies, including cancer. Previous work has focused on Rab function in higher animals but fish, crustaceans and other aquatic animals also express the Rab proteins. The current review summarizes research progress on Rab proteins, focusing on immune defense against pathogens in aquatic animals. Some differences in Rab protein function between aquatic and higher animals were found and greater involvement in the fish and crustacean immune system than that of higher animals. Novel insights into Rab protein in aquatic animals are offered with implications for the development of aquaculture strategies. [ABSTRACT FROM AUTHOR]

Hemocyanin is a copper-binding protein and plays a crucial role in the physiological processes in crustaceans. However, little is known about the hemocyanin from the Chinese mitten crab, Eriocheir sinensis . In this study, three forms of hemocyanins designated as EsHc1 , EsHc2 and EsHc3 were cloned from E. sinensis by using expressed sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) approach. The open reading frames (ORFs) of EsHc1 , EsHc2 and EsHc3 genes were 2182, 2580 and 2220 bp encoding proteins with 678, 662 and 691 amino acids, respectively, and all contain three tandem hemocyanin domains: 1) hemocyanin N, 2) hemocyanin M or tyrosinase, and 3) hemocyanin C domain. BLASTP and phylogenetic tree analysis showed that EsHc1 was clustered together with cryptocyanin 1 from Portunus pelagicus (PpCc1) and cryptocyanin from Metacarcinus magister (MmCc), EsHc2 and EsHc3 with hemocyanin from Pacifastacus leniusculus (PlHc) and hemocyanin subunit 1 from M. magister (MmHc1) were gathered into one clade. EsHc1 was mainly expressed in hepatopancreas and hemocytes with a lower level of expression in nerves, eyestalk, muscles, intestine, gills and heart; whereas EsHc2 and EsHc3 were mainly expressed in hepatopancreas and were also detected in hemocytes. Quantitative real-time RT-PCR analysis showed that EsHcs mRNA transcription in hepatopancreas was significantly expressed at various time points after infection with Lipopolysaccharide (LPS), peptidoglycan (PGN), Staphylococcus aureus , Vibrio parahaemolyticus and Aeromonas hydrophila . In summary, there is evidence that the three isoforms of hemocyanin genes participate in the innate immune response against bacteria infecting the Chinese mitten crab. [ABSTRACT FROM AUTHOR]

As a member of the small G protein superfamily, ras-related nuclear proteins (Ran) mainly function in regulating nucleocytoplasmic transport and microtubule formation. Ran is reported to have an immune function in invertebrate defense against pathogen invasion. This study obtained the full-length sequence of the Ran cDNA (PcRan) of Procambarus clarkii and investigated changes in its expression after pathogenic infection and its role in the clearance of pathogenic bacteria. Phylogenetic tree analysis revealed that PcRan and Ran of other crustaceans belong to one branch and have a close genetic relationship. Multiple sequence alignment analyses revealed that PcRan has a highly conserved G domain and contains all the G1–G5 motifs. PcRan expression was widely distributed in various tissues in P. clarkii, with the highest expression levels being found in the muscle and gills. The levels of PcRan expression in several major immune organs, including hepatopancreas, gills, hemocytes, and intestines, were significantly increased after infection with white spot syndrome virus or Aeromonas veronii. After PcRan overexpression, the bacterial clearance ability and survival rate of P. clarkii infected with A. veronii was significantly higher than that of the control group. This study showed that PcRan is involved in the innate immune process of P. clarkii. The results of this study provide theoretical significance and application value for understanding the immune function of Ran after crayfish pathogen infection, and provide guidance for the prevention and control of crayfish diseases. [ABSTRACT FROM AUTHOR]

GSDMs could punch holes in cell membrane and participate in the immune response to bacterial infections. In current study, the molecular and structural characteristics of Cc GSDMEa-like were analyzed, and the role of Cc GSDMEa-like in the inflammatory response against Aeromonas hydrophila was studied. The results showed that the Cc GSDMEa-like shared the conserved structural characteristics with GSDMEs of other teleosts. The Cc GSDMEa-like mRNA and protein expression levels were significantly affected by A. hydrophila challenge. When the Cc GSDMEa-like was overexpressed, the expression of Cc IL-1β were significantly increased in fish and EPC cells, and bacterial contents were significantly decreased in fish tissues. While, when the Cc GSDMEa-like was knocked down, the expression and secretion of Cc IL-1β were significantly decreased in vivo and in vitro , and the bacterial contents were increased in vivo after A. hydrophila infection 12 h and 24 h. In brief, Cc GSDMEa-like could regulate the content of bacteria in fish through mediating the expression and secretion of Cc IL-1β. Bactericidal assay and cytotoxicity assay showed that Cc GSDMEa-like had no bactericidal activity to Escherichia coli , and did not disrupt cytomembrane integrity of HEK293T cells. This study suggested that Cc GSDMEa-like could play roles in the antibacterial and inflammatory processes in fish. • The Cc GSDMEa-like gene was cloned and described in common carp. • The mRNA and protein expressions of Cc GSDMEa-like were induced after A. hydrophila infection. • Cc GSDMEa-like participates in the inflammatory response of common carp to A. hydrophila infection. [ABSTRACT FROM AUTHOR]

Though Procambarus clarkii (red swamp crayfish) is a lower invertebrate, it has nonetheless developed a complex innate immune system. The crayfish farming industry has suffered considerable economic losses in recent years as a consequence of bacterial and viral diseases. Hence, perhaps the most effective ways to prevent microbial infections in P. clarkii are to examine and elucidate its innate immunity. The first step in the immune response is to recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs). PRRs are expressed mainly on immune cell surfaces and recognize at least one PAMP. Thence, downstream immune responses are activated and pathogens are phagocytosed. To date, the PRRs identified in P. clarkii include Toll-like receptors (TLRs), lectins, fibrinogen-related proteins (FREPs), and β-1,3-glucan-binding proteins (BGRPs). The present review addresses recent progress in research on PRRs and aims to provide guidance for improving immunity and preventing and treating infectious diseases in P. clarkii. • Disease in crayfishes represent a high negative impact in the aquaculture. • Identification of multiple PRRs families participate in the activation of immune response. • Molecular structure characteristics, pathogen recognition, immune functions, signaling pathway genes was described. [ABSTRACT FROM AUTHOR]

Abstract Trypsin-like serine proteases (TLSPs), are members of the serine protease family and play important roles in innate immune responses. There are no previous studies regarding the role of TLSPs in immune responses to Spiroplasma eriocheiris in Eriocheir sinensis. In this paper, two TLSPs were identified from E. sinensis , namely EsTLSP-I and EsTLSP-II. Phylogenetic analysis showed that EsTLSP-I and EsTLSP-II clustered into two different groups that the crustaceans within each group were specifically. Tissue distribution analysis indicated that both EsTLSP-I and EsTLSP-II were mostly expressed in hemocytes, in the gill and in the intestine. The EsTLSP-I and EsTLSP-II transcription levels in hemocytes significantly increased after infection with S. eriocheiris. After dsRNA interference, the expression of both EsTLSP-I and EsTLSP-II distinctively declined from 48 h to 96 h. The expression of proPO and beta-1,3-glucan binding protein (LGBP) were also notably reduced after silencing. Compared to the control group, the copy number of S. eriocheiris increased significantly in interfering EsTLSP-I and EsTLSP-II groups during S. eriocheiris infection. Meanwhile, the mortality of crabs in the silenced EsTLSP-I and EsTLSP-II groups was higher than in the control group after the S. eriocheiris challenge. The results indicate that EsTLSP-I and EsTLSP-II play important roles in the innate immune system of Eriocheir sinensis, in combating infections of S. eriocheiris. Highlights • EsTLSP-I and EsTLSP-II were involved in the immune responses of E. sinensis to S. eriocheiris challenge. • EsTLSP-I and EsTLSP-II are part of the innate immnue system activating the proPO system. • The copies of S. eriocheiris and crabs' death rate were notably increased in EsTLSP-I and EsTLSP-II RNAi assay. [ABSTRACT FROM AUTHOR]

Abstract Background and aims Familial hypercholesterolemia (FH) is a an autosomal dominant disorder characterized by very high levels of low-density lipoprotein cholesterol (LDL-C). It is estimated that >85% of all FH-causing mutations involve genetic variants in the LDL receptor (LDLR). To date, 795 single amino acid LDLR missense mutations have been reported in the Leiden Open Variation Database (LOVD). However, the functional impact of these variants on the LDLR pathway has received little attention and remains poorly understood. We aim to establish a systematic functional prediction model for LDLR single missense mutations. Methods Using a combined structural modeling and bioinformatics algorithm, we developed an in silico prediction model called "Structure-based Functional Impact Prediction for Mutation Identification" (SFIP-MutID) for FH with LDLR single missense mutations. We compared the pathogenicity and functional impact predictions of our model to those of other conventional tools with experimentally validated variants, as well as in vitro functional test results for patients with LDLR variants. Results Our SFIP-MutID model systematically predicted 13,167 potential LDLR single amino acid missense substitutions with biological effects. The functional impact of 52 out of 54 specific mutations with reported in vitro experimental data was predicted correctly. Further functional tests on LDLR variants from patients were also consistent with the prediction of our model. Conclusions Our LDLR structure-based computational model predicted the pathogenicity of LDLR missense mutations by linking genotypes with LDLR functional phenotypes. Our model complements other prediction tools for variant interpretation and facilitates the precision diagnosis and treatment of FH and atherosclerotic cardiovascular diseases. Graphical abstract Image 1 Highlights • A total of 13,167 single amino acid missense substitutions in LDLR were modeled, in which 10,490 substitutions predicted FH pathogenicity with functional impact predictions. • 52 out of all 54 reported experimentally-tested LDLR variants were consistent with our predictions. • Three newly-identified FH-causing LDLR variants in patients and two novel benign variants validated our model predictions experimentally. • This is the first to systematically predict pathogenic LDLR single amino acid missense substitutions with corresponding functional characteristics. [ABSTRACT FROM AUTHOR]

N-glycosylation, one of the main protein posttranslational modifications (PTMs), plays an important role in the pathogenic process of pathogens through binding and invasion of host cells or regulating the internal environment of host cells to benefit their survival. However, N-glycosylation has remained mostly unexplored in Spiroplasma eriocheiris , a novel type of pathogen which has serious adverse effects on aquaculture. In most cases, N-glycoproteins can be detected and analyzed by lectins dependent on sugar recognition domains. In this study, three Macrobrachium nipponense C-type lectins, namely, MnCTLDcp1, MnCTLDcp2 and MnCTLDcp3, were used to screen S. eriocheiris glycosylated proteins. First, qRT-PCR results showed that the expression levels of the three kinds of lectins were all significantly up-regulated in prawn hearts when the host was against S. eriocheiris infection. A bacterial binding assay showed that purified recombinant MnCTLDcp1, MnCTLDcp2 and MnCTLDcp3 could directly bind to S. eriocheiris in vitro. Second, three S. eriocheiris glycosylated proteins, ATP synthase subunit beta (ATP beta), molecular chaperone Dnak (Dnak) and fructose bisphosphate aldolase (FBPA), were screened and identified using the three kinds of full-length C-type lectins. Far-Western blot and coimmunoprecipitation (CO-IP) further demonstrated that there were interactions between the three lectins with ATP beta, Dnak and FBPA. Furthermore, antibody neutralization assay results showed that pretreatment of S. eriocheiris with ATP beta, Dnak and FBPA antibodies could significantly block this pathogen infection. All the above studies showed that the glycosylated protein played a vital role in the process of S. eriocheiris infection. • For the first time, we used C-type lectins screening and identify the Spiroplasma eriocheiris glycosylated proteins. • Three Spiroplasma eriocheiris glycosylated proteins (ATP beta, FBPA and DnaK) were identified. • The glycosylated proteins (ATP beta, FBPA and DnaK) played an important role in the Spiroplasma eriocheiris infection. [ABSTRACT FROM AUTHOR]

For a long time, it was believed that invertebrates do not possess acquired immunity and mainly rely on innate immunity for protection against pathogens infection. However, an increasing number of studies have suggested that some form of "immune memory" can be initiated in invertebrates after primary exposure to the pathogen, which was defined as "specific immune priming". In the present study, two experiments were carried out to determine whether specific immune priming can be induced in crayfish (Procambarus clarkii) by Aeromonas veronii , if so, to identify the underlying mechanism. Once being "preimmunization" by formalin-killed A. veronii , the survival rate, in vitro antibacterial activity and haemocyte phagocytosis rate of crayfish were enhanced, which indicated that better immune protection was obtained. Furthermore, at some time points, the expression of antimicrobial peptide (AMP) and Down syndrome cell adhesion molecule (Dscam) genes was significantly higher in P. clarkii individuals that underwent stimulation twice than in those that were only stimulated once. Taken together, the results suggest that enhanced specific immune protection can be obtained in primed crayfish and that the Dscam molecule, haemocyte phagocytosis function, and AMPs may be involved in this immune priming. The present study provides a better understanding of the molecular mechanism of immune priming in invertebrates. • Upon A. veronii infection, the survival rate was enhanced in P. clarkii pre-immunized with formalin-killed A. veronii. • Better immune protection was obtained in P. clarkii received twice stimulations with A. veronii. • The Dscam gene, phagocytosis, and AMPs may be involved in the immune priming of P. clarkii. [ABSTRACT FROM AUTHOR]

Fish interleukin (IL)-17A/F is homologous with mammalian IL-17A and IL-17F, which plays a key role in regulating inflammatory responses and autoimmune diseases. In fish, IL-17A/F1, 2, and 3 have been identified and described. However, IL-17A/F3 has received little attention in fish. In this study, a homolog of IL-17A/F3 was identified in common carp (Cyprinus carpio L.), which was termed as Cc_ IL-17A/F3. The deduced amino acid sequence of Cc _IL-17A/F3 has four conserved cysteine residues, which could form two intrachain disulfide bonds. Homology comparison showed that the Cc _IL-17A/F3 was in the range of 31.7–71.9% of sequence similarity with these of other fishes. The Cc _ IL-17A/F3 gene was constitutively expressed in various tissues, with higher expression levels in the skin and gills. After common carp were infected by Aeromonas. hydrophila , the mRNA expression levels of Cc _ IL-17A/F3 were significantly up-regulated in the spleen, head kidney, gills, and intestine. Based on the indirect immunofluorescence assay, Cc _IL-17A/F3 proteins were found to be obviously increased in the intestine and spleen upon A. hydrophila infection at 24 h post-infection. The recombinant protein r Cc _IL-17A/F3 could enhance the gene expression levels of pro-inflammatory cytokines (IL-1β , IL-6 , IFN-γ , and TNF-α) as well as chemokines (CXCL8 and CXCL20) in primary head kidney leukocytes. In vivo and in vitro experiments have similar stimulatory effects. When Cc _IL-17A/F3 was overexpressed in common carp, the expressions of pro-inflammatory cytokines and chemokines were significantly up-regulated in head kidney and spleen. In summary, the results derived from the present study suggested that the Cc _IL-17A/F3 plays an important role in defending against bacterial infections, and probably participates in mucosal immunity of the host. • Cc_IL-17A/F3 widely expressed in all tested tissues and responded to bacterial infection. • Prokaryotic expression Cc _IL-17A/F3 could up-regulate pro-inflammatory cytokines in cells. • In vivo Cc _IL-17A/F3 overexpression affected the expressions of inflammatory cytokines. [ABSTRACT FROM AUTHOR]

Selection of the appropriate strain for particular aquatic animals is necessary for the desirable benefits of probiotics application in aquaculture, however, it is not very clear whether fish-derived probiotics could provide beneficial effects on invertebrates. In the present study, two fish-derived probiotics, Bacillus amyloliquefaciens , and Lactococcus lactis , were administrated as feed additives for crayfish (Procambarus clarkii) at concentrations of 106, 107, and 108 CFU/g for 28 days, respectively. Then their effects on the growth performance, innate immune enzyme activity, immune-related genes expression, haemocyte phagocytic activity, intestinal microbial diversity, and pathogen resistance of crayfish were evaluated. The results showed that the final weight, weight gain (WG), and specific growth rate (SGR) were significantly higher in 108 CFU/g B. coagulans and L. lactis additive groups. Compared to the control group, the activities of immune-related enzymes (acid phosphatase, alkaline phosphatase, glutathione peroxidase, and lysozyme) in the intestine were significantly increased in most of the probiotics added groups. In almost all experimental groups, the mRNA expression of two AMP genes (PcALF3 and PcAst) was enhanced in the intestinal of crayfish, and the expression level was proportional to the amounts of probiotics used. Moreover, the intestinal of crayfish in probiotics groups have better integrity and a thicker mucosal layer, and higher density granules in epithelial cells were also observed. According to the results of next-generation sequencing technologies, the diversity of intestinal microbiota in crayfish was also increased after supplementation with B. coagulans or L. lactis. Finally, the phagocytosis rate of haemocytes and pathogen resistance has also been improved. Taken together, our results suggested that fish-derived probiotics have beneficial effects on crayfish, and they can be treated as potential feed additives in practical applications. • Fish-derived probiotics have beneficial effects on growth performance of crayfish. • The disease resistance of crayfish was enhanced after supplementation with fish-derived probiotics. • The diversity of gut microbiota in probiotics additive groups was increased. • Fish-derived B. coagulans and L. lactis could be used as probiotics for crayfish. [ABSTRACT FROM AUTHOR]

Post-translational modifications such as acetylation are an essential regulatory mechanism of protein function. Spiroplasma eriocheiris , with no cell wall and a helical structure, is a novel pathogen of freshwater crustacean. There is no other evidence of acylation (such as succinylation and propionylation) except acetylation genes in S. eriocheiris concise genome. So the acetylation may play an important role in S. eriocheiris . Here, we conducted the first lysine acetylome in S. eriocheiris . We identified 2567 lysine acetylation sites in 555 proteins, which account for 44.69% of the total proteins in this bacterium. To date, this is the highest ratio of acetylated proteins that have been identified in bacteria. Fifteen types of acetylated peptide sequence motifs were revealed from the acetylome. Forty-five lysine-acetylated proteins showed homology with acetylated proteins previously identified from Escherichia coli , Vibrio parahemolyticus and Mycobacterium tuberculosis . Notably, most proteins in glycolysis and all proteins in the arginine deiminase system were acetylated. Meanwhile, the cell skeleton proteins (Fibril and Mrebs) were all acetylated the observed acetylation also played an important role in cell skeleton formation. The results imply previously unreported hidden layers of post-translational regulation in lysine acetylation that define the functional state of Spiroplasma . Biological significance This is the first time to analyze PTM of Spiroplasma . This is the highest ratio of acetylated proteins that have been identified in bacteria. S. eriocheiris lysine acetylome reveals acetylated proteins related to metabolism and helical structure. These data provide an important resource to elucidate the role of acetylation in Spiroplasma cellular physiology. [ABSTRACT FROM AUTHOR]

Haemorrhagic disease caused by grass carp reovirus (GCRV) in grass carp (Ctenopharyngodon idella) is the main viral disease that diminishes the survival of juvenile grass carp. The usage of vaccines, especially oral vaccines, has been considered an effective and convenient way to protect against this disease. However, oral vaccines are easily degraded and digested by digestive enzymes in the intestinal tract. Therefore, a vaccine delivery system that can protect oral vaccines from degradation is a prerequisite for oral vaccines. In this study, the S11 segment (encoding a 35 kDa protein known as VP35) of GCRV was cloned into a binary vector and then transferred into duckweed (Lemna aequinoctialis) to prepare an oral subunit vaccine. Subsequently, Gus staining, Polymerase chain reaction (PCR), Western blotting, and fluorescence observation were used to verify the expression of the S11 segment. The results showed that duckweed calli were successfully induced and could be used for the transformation of Agrobacterium. Afterwards, a plant binary expression vector (pCAMBIA1303- S11) containing GUS and GFP tags was constructed, after which transgenic duckweed lines were obtained. The results of the PCR analysis using RNA or DNA extracted from transgenic duckweed showed that the expression vector pCAMBIA1303- S11 was successfully transferred and replicated in duckweed. After GUS staining, obvious blue signals appeared at the roots, leaf bases, and frond edges of duckweed, and a strong fluorescent signal could be observed under a fluorescence microscope. A Western blot analysis of the protein samples from the transgenic plants demonstrated the expression of a fusion protein with a molecular mass of approximately 50 kDa. Taken together, the duckweed expression system was successfully constructed, and an oral vaccine based on the S11 segment of GCRV was successfully prepared. These results can provide further information for the development of a duckweed-based expression system to produce an edible vaccine for C. idella against GCRV. • The sterile duckweeds were obtained and cultured in the sterile medium. • The plant binary expression vector was successfully constructed. • The duckweed callus was successfully induced. • the S11 segment could be successfully transcript-ed and translated in the duckweed. [ABSTRACT FROM AUTHOR]

The phagocytic function of peripheral blood leukocytes (PBL) in teleost fish is the bridge between cellular-mediated and humoral immunity and plays a central role in the immune system of the teleost fish. However, the phagocytic ability of PBL from Qihe crucian carp Carassius auratus remains unclear. This study aimed to build a convenient separation method to obtain high purity PBL from Qihe crucian carp and to explore their phagocytic characteristics. The results showed that the PBL of Qihe crucian carp (QPBL) could be obtained effectively by 1.085 g/ml percoll separation liquid. Most isolated QPBL were round or elliptical, with horseshoe-shaped, reniform, or irregular nucleus. Finger-like or filamentous protrusions were present on the cell surface, and some cells had a long pseudopod. According to the results of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and fluorescence microscope, fluoresbrite carboxylate YG microspheres (1 μm) could be effectively phagocytosed by QPBL, and various phagocytic stages could be observed. The phagocytic cells in QPBL have morphology similar to those of "professional" phagocytes (monocyte and granulocyte). Notably, the percentage of cells, which can engulf microspheres, increased to approximately 22% after incubation with microspheres for 90 min, and it showed no obvious changes until 180 min. Furthermore, two important phagocytosis regulatory protein genes, Rab5 and Rab7 , were seriously up-regulated during the phagocytosis in QPBL. Taken together, an efficient and convenient separation method for isolating QPBL was established, and the isolated QPBL had a high phagocytic activity towards the external particles. The results could provide the basic foundation for further study of the immune function of PBL in Qihe crucian carp and other teleost fish. • The PBL of Qihe crucian carp (QPBL) could be separated by 1.085 g/ml percoll separation liquid. • The QPBL had a high phagocytic activity towards the external particles. • The proportion of phagocytes in QPBL was about 22%. • Rab5 and Rab7 were involved in the phagocytic activity of QPBL. [ABSTRACT FROM AUTHOR]

The phagocytic function of peripheral blood leukocytes (PBL) in teleost fish is the bridge between cellular-mediated and humoral immunity and plays a central role in the immune system of the teleost fish. However, the phagocytic ability of PBL from Qihe crucian carp Carassius auratus remains unclear. This study aimed to build a convenient separation method to obtain high purity PBL from Qihe crucian carp and to explore their phagocytic characteristics. The results showed that the PBL of Qihe crucian carp (QPBL) could be obtained effectively by 1.085 g/ml percoll separation liquid. Most isolated QPBL were round or elliptical, with horseshoe-shaped, reniform, or irregular nucleus. Finger-like or filamentous protrusions were present on the cell surface, and some cells had a long pseudopod. According to the results of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and fluorescence microscope, fluoresbrite carboxylate YG microspheres (1 μm) could be effectively phagocytosed by QPBL, and various phagocytic stages could be observed. The phagocytic cells in QPBL have morphology similar to those of "professional" phagocytes (monocyte and granulocyte). Notably, the percentage of cells, which can engulf microspheres, increased to approximately 22% after incubation with microspheres for 90 min, and it showed no obvious changes until 180 min. Furthermore, two important phagocytosis regulatory protein genes, Rab5 and Rab7 , were seriously up-regulated during the phagocytosis in QPBL. Taken together, an efficient and convenient separation method for isolating QPBL was established, and the isolated QPBL had a high phagocytic activity towards the external particles. The results could provide the basic foundation for further study of the immune function of PBL in Qihe crucian carp and other teleost fish. • The PBL of Qihe crucian carp (QPBL) could be separated by 1.085 g/ml percoll separation liquid. • The QPBL had a high phagocytic activity towards the external particles. • The proportion of phagocytes in QPBL was about 22%. • Rab5 and Rab7 were involved in the phagocytic activity of QPBL. [ABSTRACT FROM AUTHOR]

Hematopoietic stem cells (HSCs) are exposed to various insults such as genotoxic stress, inflammation, and infection, which have a direct effect. These insults deplete, cause a functional decline in, and promote HSC aging and transformation. However, the impact of hematopoietic insults on niche cells remains largely unknown. We have reported previously that p53 is activated in blood vessels by various stresses, including hypoxia, inflammation, and aging, and contributes to tissue dysfunction and metabolic abnormalities. We hypothesized that hematopoietic insults also affect the bone marrow (BM) vascular niche. Here, we demonstrate that p53 becomes activated in BM endothelial cells upon hematopoietic stresses such as irradiation and chemotherapeutic treatments. The conditional activation of p53 in VE-cadherin + vascular niche cells by deleting Mdm2 induces the expression of p53 target genes specifically in vascular endothelial cells, resulting in the dilation and collapse of vascular endothelial cells and reductions in perivascular mesenchymal stromal cell numbers. Consequently, hematopoietic stem cells (HSCs) fail to maintain dormancy, mobilize to the periphery, and are depleted significantly. Our results indicate that various hematopoietic insults affect HSCs, not only directly, but also indirectly by altering vascular integrity, which is critical for perivascular niche formation and maintenance of HSCs. [ABSTRACT FROM AUTHOR]