Inducible Sbds deletion impairs bone marrow niche capacity to engraft donor bone marrow after transplantation.

Bone marrow (BM) niche-derived signals are critical for facilitating engraftment after hematopoietic stem cell (HSC) transplantation (HSCT). HSCT is required for restoration of hematopoiesis in patients with inherited BM failure syndromes (iBMFSs). Shwachman-Diamond syndrome (SDS) is a rare iBMFS associated with mutations in SBDS. Previous studies have demonstrated that SBDS deficiency in osteolineage niche cells causes BM dysfunction that promotes leukemia development. However, it is unknown whether BM niche defects caused by SBDS deficiency also impair efficient engraftment of healthy donor HSC after HSCT, a hypothesis that could explain morbidity noted after clinical HSCT for patients with SDS. Here, we report a mouse model with inducible Sbds deletion in hematopoietic and osteolineage cells. Primary and secondary BM transplantation (BMT) studies demonstrated that SBDS deficiency within BM niches caused poor donor hematopoietic recovery and specifically poor HSC engraftment after myeloablative BMT. We have also identified multiple molecular and cellular defects within niche populations that are driven by SBDS deficiency and are accentuated by or develop specifically after myeloablative conditioning. These abnormalities include altered frequencies of multiple niche cell subsets, including mesenchymal lineage cells, macrophages, and endothelial cells; disruption of growth factor signaling, chemokine pathway activation, and adhesion molecule expression; and p53 pathway activation and signals involved in cell cycle arrest. Taken together, this study demonstrates that SBDS deficiency profoundly impacts recipient hematopoietic niche function in the setting of HSCT, suggesting that novel therapeutic strategies targeting host niches could improve clinical HSCT outcomes for patients with SDS.

Effects of potential probiotic Bacillus velezensis K2 on growth, immunity and resistance to Vibrio harveyi infection of hybrid grouper (Epinephelus lanceolatus♂ × E. fuscoguttatus♀).

Nowadays, there is no suitable treatment for vibriosis in groupers. So an eco-efficient and environmentally friendly treatment is necessary for the grouper industry. Probiotic-feeding has been a promising strategy to control the bacterial pathogens in aquaculture. A new Bacillus velezensis strain named K2 was isolated from the intestinal tract of healthy grouper, and exhibited wide antimicrobial spectrum of against fish pathogens, including Vibrio harveyi, Vibrio alginolyticus, Aeromonas hydrophila, Aeromonas veronii, Aeromonas caviae, Enterococcus casseliflavus and Lactococcus garvieae. Moreover, results of the safety of B. velezensis K2 showed that intraperitoneal injection of K2 in healthy grouper did not cause any pathological abnormality or death, indicating this bacteria could be considered as a candidate probiotic in aquaculture. Groupers were fed with the diets containing 1 × 107 cfu/g of B. velezensis K2 for 4 weeks. Various immune parameters were examined at 1, 2, 3, and 4 weeks of post-feeding. Results showed that diets supplemented with K2 significantly increased serum acid phosphatase (ACP) activity (P < 0.05). Results of the mRNA expression of immune-related genes in the head kidney of hybrid grouper showed that the expression of lysozyme gene was significantly upregulated after 1 and 2 weeks of feeding (P < 0.05). A significant up-regulation of the expression of piscidin, IgM and MyD88 were detected at day 21, whereas the TLR3 and TLR5 showed lower expression compared to the controls during 21 days, and a significant decrease of TLR3 gene was found at day 28 (P < 0.05). After challenge with V. harveyi, the survival rate of fish administrated with the strain K2 for 28 days was signifiacantly higher than the controls without this strain (P < 0.05). These results collectively suggest that B. velezensis K2 is a potential probiotic species to improve health status and disease resistance and can be developed as a probiotic agent in grouper industry.

Immunosuppression-induced alterations in fish gut microbiota may increase the susceptibility to pathogens.

Intestinal bacteria play an important role in the health and provide a variety of beneficial effects to host. Immunosuppressant can reduce the immunity of host and increase the susceptibility to pathogens. But it is not clear whether the increased susceptibility caused by immunosuppressant is related to changes of gut microbiota. In this study, we used crucian carp administrated with dexamethasone to explore the effects of immunosuppressants on gut microbial communities and further evaluate the potential association between changes in gut microbiota and susceptibility to pathogens. The results of MANOVA based on the top 10 PCoA axis scores from unweighed/weighted UniFrac distances showed that administration of dexamethasone (P = 0.021) and the administration time (P = 0.027) had a significant impact on the gut microbial composition, regardless of pathogens infection status (P = 0.35). After administration with dexamethasone, the fish had higher abundance of Cetobacterium and lower abundance of Bacillus and Lactococcus, and the abundance of genus Bacillus, Pseudomonas and Lactococcus decreased along with prolong administration time of dexamethasone. The results may help us understand the correlation between the host susceptibility to pathogenic bacteria and gut microbial community shift, and extend our knowledge regarding the role of gut microbiota in keeping the balance between pathogenic and symbiotic bacteria.

HSP-4/BiP expression in secretory cells is regulated by a developmental program and not by the unfolded protein response.

Differentiation of secretory cells leads to sharp increases in protein synthesis, challenging endoplasmic reticulum (ER) proteostasis. Anticipatory activation of the unfolded protein response (UPR) prepares cells for the onset of secretory function by expanding the ER size and folding capacity. How cells ensure that the repertoire of induced chaperones matches their postdifferentiation folding needs is not well understood. We find that during differentiation of stem-like seam cells, a typical UPR target, the Caenorhabditis elegans immunoglobulin heavy chain-binding protein (BiP) homologue Heat-Shock Protein 4 (HSP-4), is selectively induced in alae-secreting daughter cells but is repressed in hypodermal daughter cells. Surprisingly, this lineage-dependent induction bypasses the requirement for UPR signaling. Instead, its induction in alae-secreting cells is controlled by a specific developmental program, while its repression in the hypodermal-fated cells requires a transcriptional regulator B-Lymphocyte-Induced Maturation Protein 1 (BLMP-1/BLIMP1), involved in differentiation of mammalian secretory cells. The HSP-4 induction is anticipatory and is required for the integrity of secreted alae. Thus, differentiation programs can directly control a broad-specificity chaperone that is normally stress dependent to ensure the integrity of secreted proteins.

Carrier frequencies of hearing loss variants in newborns of China: A meta-analysis.

OBJECTIVE: The objective of this study was to review the carrier frequencies of hearing loss gene variants, such as GJB2, SLC26A4, and MT-RNR1 in newborns of China. DESIGN: PubMed, Embase, BioCentral, CNKI, WanFang, and VIP databases were used for searching relevant literature studies published during the period of January 2007 and January 2016. Meta-analysis was performed by using the R software. The estimated rate and its 95% confidence intervals (CI) of the relevant indexes in newborns were collected and calculated using a fixed-effects model or a random-effects model when appropriate. RESULTS: In total, 35 of 958 published literature studies in Chinese and English were selected. The overall results showed that in newborns of China, the carrier frequencies of GJB2 variants (235 delC, 299 delAT) were 1.64% (95% CI 1.52% to 1.77%) and 0.33% (95% CI 0.19% to 0.51%); SLC26A4 variants (IVS7-2 A > G, 2168 A > G) were 1.02% (95% CI 0.91% to 1.15%) and 0.14% (95% CI 0.06% to 0.25%); MT-RNR1 variants (1555 A > G, 1449 C > T) were 0.20% (95% CI 0.17% to 0.23%) and 0.03% (95% CI 0.02% to 0.05%). CONCLUSIONS: There are high carrier frequencies of GJB2 variants among newborns in China, followed by SLC26A4 and MT-RNR1 variants. In order to achieve "early detection, early diagnosis and early treatment" and reduce the incidence of hereditary hearing loss in offspring, a comprehensive combination of neonatal hearing screening and deafness gene detection should be recommended and implemented in China.

Single-walled carbon nanotubes as delivery vehicles enhance the immunoprotective effect of a DNA vaccine against spring viremia of carp virus in common carp.

Spring viremia of carp virus (SVCV) is highly contagious and pathogenic to cyprinid fish, causing enormous economic losses in aquaculture. Efficient and economic prophylactic measure against is the most pressing desired for the common carp farming industry. In this research, single-walled carbon nanotubes (SWCNTs) as a candidate DNA vaccine carrier was administrated via bath (1, 5, 10, 20, 40 mg L-1) or injection (1, 4, 8, 12, 20 µg) in common carp juvenile, and the different immune treatments to induce immunoprotective effect was analyzed. The results showed that higher levels of transcription and expression of G gene could be detected in muscle, spleen and kidney tissues via bath administration or intramuscular injection in SWCNTs-pEGFP-G treatment groups compared with naked pEGFP-G treatment groups. Meanwhile, complement activity, superoxide dismutase activity, alkaline phosphatase activity, immune-related genes (especially the TNF-α) and antibody levels were significantly enhanced in fish immunized with DNA vaccine combined with SWCNTs. The relative percentage survival were significantly enhanced in fish bathed with SWCNTs-pEGFP-G vaccine and the relative percentage survival reached to 57.5% in SWCNTs-pEGFP-G group than that of naked pEGFP-G (40.0%) at the highest vaccine dose (40 mg L-1) after 22 days of post infection, and fish in bath immunization group at a concentration of 40 mg L-1 could reach the similar relative percentage survival in injection group at a dose of 12 µg. This study suggest that ammonium-functionalized SWCNTs is the promising carrier for DNA vaccine and might be used to vaccinate large-scale juvenile fish by bath administration approach in aquaculture.

Ammonia exposure alters the expression of immune-related and antioxidant enzymes-related genes and the gut microbial community of crucian carp (Carassius auratus).

Chronic exposure of ammonia in fish can affect the activities of antioxidant enzymes but few studies investigate the influence of ammonia exposure on the expression of immune-related and antioxidant enzymes-related genes. Also, there is no study demonstrates the effect of ammonia exposure on gut microbial community of fish. In this study, crucian carp (Carassius auratus) were exposed to the ammonia concentrations, 0 (control), 10 mg L-1 (low) or 50 mg L-1 (high) for consecutive 30 days at 25 ± 1 °C temperature, respectively, and after that, the fish from all exposure groups were maintained in control conditions for another 15 days. The results showed that low concentration ammonia increased the expression of immune-related genes and antioxidant enzymes-related genes, but high concentration ammonia inhibited the expression of immune-related genes and antioxidant enzymes-related genes. After a 15-day treatment without ammonia, the expression of antioxidant enzymes-related genes and immune-related genes showed no significant changes compared with control. The results of high-throughput sequencing showed that gut microbial communities were significantly differentiated following ammonia exposure. The abundance of Bacteroides and Cetobacterium (two kinds of potential probiotics) increased while fish exposed to 10 mg L-1 ammonia. The Flavobacterium (a potential fish pathogen) showed increasing trends when the exposure dose reached 50 mg L-1, while the Bacteroides and Cetobacterium showed almost no abundance. The results also revealed that ammonia exposure concentration or time can alter the intestinal microbial community. In conclusion, ammonia exposure could induce the immune response in crucian carp, and alter the gut microbial community. The results may help us understand the correlations of gut microbial community shift and ammonia exposure and extend our knowledge to comprehend the effects of environmental factors on intestinal microbial community.

A Bystander Mechanism Explains the Specific Phenotype of a Broadly Expressed Misfolded Protein.

Misfolded proteins in transgenic models of conformational diseases interfere with proteostasis machinery and compromise the function of many structurally and functionally unrelated metastable proteins. This collateral damage to cellular proteins has been termed 'bystander' mechanism. How a single misfolded protein overwhelms the proteostasis, and how broadly-expressed mutant proteins cause cell type-selective phenotypes in disease are open questions. We tested the gain-of-function mechanism of a R37C folding mutation in an endogenous IGF-like C.elegans protein DAF-28. DAF-28(R37C) is broadly expressed, but only causes dysfunction in one specific neuron, ASI, leading to a distinct developmental phenotype. We find that this phenotype is caused by selective disruption of normal biogenesis of an unrelated endogenous protein, DAF-7/TGF-ß. The combined deficiency of DAF-28 and DAF-7 biogenesis, but not of DAF-28 alone, explains the gain-of-function phenotype-deficient pro-growth signaling by the ASI neuron. Using functional, fluorescently-tagged protein, we find that, in animals with mutant DAF-28/IGF, the wild-type DAF-7/TGF-ß is mislocalized to and accumulates in the proximal axon of the ASI neuron. Activation of two different branches of the unfolded protein response can modulate both the developmental phenotype and DAF-7 mislocalization in DAF-28(R37C) animals, but appear to act through divergent mechanisms. Our finding that bystander targeting of TGF-ß explains the phenotype caused by a folding mutation in an IGF-like protein suggests that, in conformational diseases, bystander misfolding may specify the distinct phenotypes caused by different folding mutations.

Chronic spinal cord injury attenuates influenza virus-specific antiviral immunity.

BACKGROUND: Individuals suffering from spinal cord injury (SCI) are at higher risk for respiratory-related viral infections such as influenza. In a previous study (Zha et al., J Neuroinflammation 11:65, 2014), we demonstrated that chronic spinal cord injury caused impairment in CD8(+)T cell function with increased expression of the immunosuppressive protein, programmed cell death 1 (PD-1). The present study was undertaken to establish whether chronic SCI-induced immune deficits would affect antiviral immunity directed against primary and secondary infections. METHODS: Six to seven weeks following a SCI contusion at thoracic level T9, mice were infected intranasally with influenza virus. Virus-specific immunity was analyzed at various time points post-infection and compared to uninjured controls. RESULTS: We report that chronic thoracic SCI impairs the ability of the animals to mount an adequate antiviral immune response. While all uninjured control mice cleared the virus from their lungs by day 10 post-infection, a significant number (approximately 70 %) of chronic SCI mice did not clear the virus and succumbed to infection-induced mortality. This was attributed to severe deficits in both virus-specific antibody production and CD8(+) T cell response in injured mice after primary infection. We also determined that previously acquired humoral immunity was maintained after spinal cord injury as vaccination against influenza A prior to injury-protected mice from a homologous viral challenge. In contrast, prior immunization did not protect mice from a heterotypic challenge with a different strain of influenza virus. CONCLUSIONS: Taken together, our data demonstrate that chronic SCI attenuates virus-specific humoral and cellular immunity during the establishment of primary response and impairs the development of memory CD8(+) T cells. In contrast, B cell memory acquired through vaccination prior to SCI is preserved after injury which demonstrates that antigen-specific memory cells are refractory following injury. Our study defines important parameters of the deficits of chronic SCI-induced immune depression during a viral respiratory infection. Our objective is to better understand the mechanisms of spinal cord injury-induced immune depression with the goal of developing more effective therapies and reduce mortality due to complications from influenza and other infections.

Chronic thoracic spinal cord injury impairs CD8+ T-cell function by up-regulating programmed cell death-1 expression.

BACKGROUND: Chronic spinal cord injury (SCI) induces immune depression in patients, which contributes to their higher risk of developing infections. While defects in humoral immunity have been reported, complications in T-cell immunity during the chronic phase of SCI have not yet been explored. METHODS: To assess the impact of chronic SCI on peripheral T-cell number and function we used a mouse model of severe spinal cord contusion at thoracic level T9 and performed flow cytometry analysis on the spleen for T-cell markers along with intracellular cytokine staining. Furthermore we identified alterations in sympathetic activity in the spleen of chronic SCI mice by measuring splenic levels of tyrosine hydroxylase (TH) and norepinephrine (NE). To gain insight into the neurogenic mechanism leading to T-cell dysfunction we performed in vitro NE stimulation of T-cells followed by flow cytometry analysis for T-cell exhaustion marker. RESULTS: Chronic SCI impaired both CD4+ and CD8+ T-cell cytokine production. The observed T-cell dysfunction correlated with increased expression of programmed cell death 1 (PD-1) exhaustion marker on these cells. Blocking PD-1 signaling in vitro restored the CD8+ T-cell functional defect. In addition, we showed that chronic SCI mice had higher levels of splenic NE, which contributed to the T-cell exhaustion phenotype, as PD-1 expression on both CD4+ and CD8+ T-cells was up-regulated following sustained exposure to NE in vitro. CONCLUSIONS: These studies indicate that alteration of sympathetic activity following chronic SCI induces CD8+ T-cell exhaustion, which in turn impairs T-cell function and contributes to immune depression. Inhibition of the exhaustion pathway should be considered as a new therapeutic strategy for chronic SCI-induced immune depression.

Genetic ablation of toll-like receptor 2 reduces secondary brain injury caused by cortical contusion in mice.

Previous studies have shown that Toll-like receptor 2 (TLR2) was up-regulated after traumatic brain injury (TBI), but the potential contribution of TLR2 to TBI still remains unclear. The present study investigated the role of TLR2 in modulating TBI-induced secondary brain injury in mice. Wild-type TLR2(+/+) and TLR2(-/-)-deficient mice were subjected to a moderately severe weight-drop impact head injury. Brain samples were extracted at 24 hours after trauma. We measured TLR2 by western blot; motor function by Grip test; brain edema by wet/dry method; cortical apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method; and IL-1ß, TNF-α and IL-6 by enzyme-linked immunosorbent assay (ELISA). We found the absence of TLR2 function in mice resulted in amelio-rating brain injury as shown by the reduced severity of neurological deficit, apoptosis, and brain edema at 24 hours after TBI, which was associated with the decreased expression of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6), compared with their wild-type counterparts after TBI. In combination, these results suggest that TLR2 might play an important aggravating role in the pathogenesis of TBI-induced secondary brain injury, possibly by regulating inflammatory cytokines in the cortex.

[TGF-beta/Smad in prostate cancer: an update].

Tumorigenesis and cancer progression are closely associated with the transforming growth factor-beta (TGF-beta) and its downstream component Smad. The TGF-beta/Smad signaling pathway, which is activated in prostate cancer, has a regulatory effect on cell adhesion, the actin filament system and cell cycle, as well as the expression of specific genes. Meanwhile, other protein signals such as MAPK and PI3K/Akt/mTOR and some genes may act on the expression of the TGF-beta/Smad pathway. This article updates recent researches on the expression, action and regulatory effect of the TGF-beta/Smad signaling pathway in prostate cancer.

Effect of intranigral injection of GDNF and EGF on the survival and possible differentiation fate of progenitors and immature neurons in 6-OHDA-lesioned rats.

We investigated the survival and the possible differentiation fate of the progenitors and immature neurons in the pars compacta of the substantia nigra (SNc) by intranigral injection of a glial cell line-derived neurotropic factor (GDNF) or glial cell line-derived neurotropic factor plus epidermal growth factor (EGF + GDNF) in 6-hydroxydopamine (6-OHDA)-lesioned rats. First, we performed behavioral tests by postural asymmetry and forelimb akinesia on the rats injected with 6-OHDA in striatumat day 7, and selected the qualified model according to the results. Then, intranigral GDNF or EGF + GDNF treatment was administered in the qualified PD model rats. On day 21, behavioral tests were performed with these rats; and then the rats were sacrificed for analyses of ß-tubulin isotype-III (Tuj1), nestin, glial fibrillary acidic protein (GFAP), and tyrosine hydroxylase (TH) by immunohistochemistry and Western blotting. The results indicated that GDNF could promote the survival of the progenitor cells and immature neurons in rat SNc following 6-OHDA lesion. Moreover, EGF is capable of enhancing the survival effect of GDNF on the progenitor cells and immature neurons in SNc. On day 21, rapid functional recovery from the lesion-induced behavioral asymmetries was observed in the GDNF or EGF + GDNF treated rats, and the numbers of TH-positive neurons increased in SNc, suggesting that the rats might generate new dopaminergic neurons. Thus, our study provides the new insight that the progenitors and immature neurons in SNc of 6-OHDA-lesioned rats might be able to differentiate toward the dopaminergic neurons fate subsequent to treatment with GDNF or EGF + GDNF.

[Contents of lead, cadmium, zinc and manganese in the follicular fluid and semen of non-professionally exposed infertile couples].

OBJECTIVE: To investigate the contents of lead, cadmium, zinc and manganese in the follicular fluid and semen of infertile couples that are not professionally exposed to the four heavy metallic elements. METHODS: In vitro fertilization pre-embryo transfer (IVF-ET) was carried out in wives, and follicular fluid collected after routine oocyte retrieval. Semen was obtained from husbands by masturbation. The contents of zinc in the follicular fluid and semen were determined by the flame atom absorption method and those of lead, cadmium and manganese by graphite furnace atomic absorption spectrometry. RESULTS: The average concentrations of lead, cad- mium, zinc and manganese were 151.06 microg/L, 2.02 microg/L, 0.54 mg/L and 28.54 microg/L in the follicular fluid, and 250.23 microg/L, 7.42 microg/L, 189.11 mg/L and 82.15 microg/L in the semen. The follicular fluid samples in which lead, cadmium, zinc or manganese was detected constituted 43.8% (21/48), 22.9% (11/48), 75.0% (36/48) and 50.0% (24/48), and the semen samples accounted for 70.2% (33/47), 31.9% (15/47), 100.0% (47/47) and 46.8% (22/47), respectively. CONCLUSION: The results suggest that the average contents of lead, cadmium, zinc and manganese are higher in the semen than in the follicular fluid in the non-professionally exposed infertile couples, and so is the percentage of the samples containing each of the elements, with the exception of manganese.

[Male antifertility drugs and cell apoptosis].

Male antifertility drugs can induce contraception by interfering with spermatogenesis progression. Their action mechanism is correlated with the apoptosis of spermatogenic cells. This paper summarizes recent researches on the mechanism of male antifertility-drugs, including testosterone, gossypol, tamoxifen and triptolide, reviews their regulating effect on cell apoptosis and the expression of the key genes and proteins involved, and explores the significance of further researches on male antifertility drugs and cell apoptosis.