Role of somatic cells on dairy processes and products: a review

Somatic cells are an important component naturally present in milk, and somatic cell count is used as an indicator of udder health and milk quality. The role of somatic cells in dairy processes and products is ill-defined in most studies because the role of these cells combines also the concomitance of physicochemical modifications of milk, bacterial count, and the udder inflammation in the presence of high somatic cell count. The aim of this review is to focus on the role of somatic cells themselves and of endogenous enzymes from somatic cells in milk, in dairy transformation processes, and in characteristics of final products overcoming biases due to other factors. The immune function of somatic cells in the udder defense and their protective role in milk will be primarily considered. Different characteristics of milk induced by various somatic cell counts, types, and their endogenous enzymes influencing directly the technological properties of milk and the final quality of dairy products will be discussed as well. By comparing methods used in other studies and eliminating biases due to other factors not considered in these studies, a new approach has been suggested to evaluate the effective role of somatic cells on dairy processes and products. In addition, this new approach allows the characterization of somatic cells and their endogenous enzymes and, in future research, will allow the clarification of mechanisms involved in the release of these components from somatic cells during dairy processes, particularly in cheese technologies.

The effects of early life lead exposure on the expression of interleukin (IL) 1β, IL-6, and glial fibrillary acidic protein in the hippocampus of mouse pups

The present study was undertaken to investigate the effects of maternal lead (Pb) exposure on the expression of interleukin (IL) 1β, IL 6, and glial fibrillary acidic protein (GFAP) in hippocampus of mice offspring. Pb exposure initiated from the beginning of gestation to weaning. Lead acetate (PbAc) administered in drinking solutions was dissolved in distilled deionized water at the concentrations of 0.1, 0.5 and 1% groups ,respectively. On the postnatal day 21, the Pb levels in their blood and hippocampus were determined by graphite furnace atomic absorption spectrometry. The expression of IL 1β, IL 6, and GFAP in hippocampus was measured by immunohistochemistry and Western blotting. The Pb levels in blood and hippocampus of all Pb-exposed groups were significantly higher than that of the control group ( p < 0.05). The expression of IL-1β, IL-6, and GFAP was increased in Pb-exposed groups in comparison with the control group ( p < 0.05). The high expression of IL-1β, IL-6, and GFAP in the hippocampus of pups may contribute to the neurotoxicity associated with maternal Pb exposure.

Lung recruitment maneuver during proportional assist ventilation of preterm infants with acute respiratory distress syndrome

OBJECTIVE

To investigate the effect of lung recruitment maneuver (LRM) with positive end-expiratory pressure (PEEP) on oxygenation and outcomes in preterm infants ventilated by proportional assist ventilation (PAV) for respiratory distress syndrome (RDS).

STUDY DESIGN

Preterm infants on PAV for RDS after surfactant randomly received an LRM (group A, n=12) or did not (group B, n=12). LRM entailed increments of 0.2 cm H2O PEEP every 5 min, until fraction of inspired oxygen (FiO2)=0.25. Then PEEP was reduced and the lung volume was set on the deflation limb of the pressure/volume curve. When saturation of peripheral oxygen fell and FiO2 rose, we reincremented PEEP until SpO2 became stable.

RESULT

Group A and B infants were similar: gestational age 29.5 ± 1.0 vs 29.4 ± 0.9 weeks; body weight 1314 ± 96 vs 1296 ± 88 g; Silverman Anderson score for babies at start of ventilation 8.6 ± 0.8 vs 8.2 ± 0.7; initial FiO2 0.56 ± 0.16 vs 0.51 ± 0.14, respectively. The less doses of surfactant administered in group A than that in group B (P<0.05). Groups A and B showed different max PEEP during the first 12 h of life (8.4 ± 0.5 vs 6.7 ± 0.6 cm H2O, P=0.00), time to lowest FiO2 (101 ± 18 versus 342 ± 128 min; P=0.000) and O2 dependency (7.83 ± 2.04 vs 9.92 ± 2.78 days; P=0.04). FiO2 levels progressively decreased (F=43.240, P=0.000) and a/AO2 ratio gradually increased (F=30.594, P=0.000). No adverse events and no differences in the outcomes were observed.

CONCLUSION

LRM led to the earlier lowest FiO2 of the first 12 h of life and a shorter O2 dependency.

Platelets provoke distinct dynamics of immune responses by differentially regulating CD4+ T-cell proliferation

BACKGROUND

Platelets regulate responses of type 1 T helper (Th1), Th17, and regulatory T (Treg) cells. However, little is known about how platelets influence the dynamics of CD4(+) T-cell responses.

OBJECTIVES

To investigate the dynamics of platelet-regulated CD4(+) T-cell activation and cross-talk and their underlying mechanisms.

METHODS AND RESULTS

Human CD3/CD28-challenged CD4(+) T cells were cultured without or with autologous platelets. Th1, Th17, and Treg responses were monitored during 5 days. Platelets simultaneously enhanced activation of Th1, Th17, and Treg cells within 48-h coculture. Thereafter, platelets remained augmentative for Treg but turned suppressive for Th1/Th17 responses. Without platelets, FoxP3 blockade inhibited Treg activation, which subsequently enhanced Th1 activation. In platelet-T-cell cocultures, however, FoxP3 blockade had no effect on Treg or Th1 activation. Neutralization of platelet-derived transforming growth factor β, but not Treg-derived interleukin-10, enhanced Th1 activation. These data suggest that Treg cells have limited impact on, while platelets are the primary regulator for Th1 suppression during the second phase of coculture. Combining carboxyfluorescein succinimidyl ester and FoxP3 staining, platelets were found to enhance Treg response by promoting cell proliferation of FoxP3(+) T cells and to induce the suppression phrase of Th1 responses by inhibiting FoxP3(-) T-cell proliferation. The latter was markedly attenuated by TGFβ neutralization.

CONCLUSIONS

Platelets constantly promote Treg cell response but exert a biphasic regulation on Th1/Th17 activation, namely a transient enhancement followed by a secondary suppression. The distinct regulations are achieved by transforming growth factor β-mediated selective inhibition of FoxP3(-) T-cell proliferation. This represents a novel mechanism of platelet-regulated CD4(+) effector cell responses.

Gingipains from Porphyromonas gingivalis - Complex domain structures confer diverse functions

Gingipains, a group of arginine or lysine specific cysteine proteinases (also known as RgpA, RgpB and Kgp), have been recognized as major virulence factors in Porphyromonas gingivalis. This bacterium is one of a handful of pathogens that cause chronic periodontitis. Gingipains are involved in adherence to and colonization of epithelial cells, haemagglutination and haemolysis of erythrocytes, disruption and manipulation of the inflammatory response, and the degradation of host proteins and tissues. RgpA and Kgp are multi-domain proteins composed of catalytic domains and haemagglutinin/adhesin (HA) regions. The structure of the HA regions have previously been defined by a gingipain domain structure hypothesis which is a set of putative domain boundaries derived from the sequences of fragments of these proteins extracted from the cell surface. However, multiple sequence alignments and hidden Markov models predict an alternative domain architecture for the HA regions of gingipains. In this alternate model, two or three repeats of the so-called "cleaved adhesin" domains (and one other undefined domain in some strains) are the modules which constitute the substructure of the HA regions. Recombinant forms of these putative cleaved adhesin domains are indeed stable folded protein modules and recently determined crystal structures support the hypothesis of a modular organisation of the HA region. Based on the observed K2 and K3 structures as well as multiple sequence alignments, it is proposed that all the cleaved adhesin domains in gingipains will share the same β-sandwich jelly roll fold. The new domain model of the structure for gingipains and the haemagglutinin (HagA) proteins of P. gingivalis will guide future functional studies of these virulence factors.

BMP4 promotes SSEA-1(+) hUC-MSC differentiation into male germ-like cells in vitro

OBJECTIVES

Recent studies have demonstrated that primordial germ cells (PGC) can be differentiated from human umbilical cord mesenchymal stem cells (hUC-MSCs), and embryonic stem cells (ESCs) in vitro. Nevertheless, efficiencies were low and unstable. Here, whether hUC-MSCs can be induced to differentiate into germ-like cells with the aid of bone morphogenetic protein (BMP4) was investigated.

MATERIALS AND METHODS

Human umbilical cord mesenchymal stem cells were freshly isolated and cultured with BMP4. SSEA-1(+/-) cells were purified using magnetic-activated cell sorting (MACS) from the hUC-MSCs, and further induced with BMP4. Quantitative real-time PCR (qRT-PCR) and immunofluorescence analysis were used to determine PGC and germ-like cell-specific markers.

RESULTS

Human umbilical cord mesenchymal stem cells differentiated into SSEA-1(+) spherical PGC-like cells efficiently with 12.5 ng/ml BMP4. qRT-PCR and immunofluorescence analysis demonstrated that SSEA-1(+) cells expressed higher levels of PGC-specific markers than SSEA-1(-) cells. Furthermore, SSEA-1(+) cells were induced with BMP4 to differentiate into STRA8, SCP3, DMRT1 and PLZF-positive male germ-like cells, and some sperm-like cells were obtained by 7-14 days after induction.

CONCLUSION

These results suggest that SSEA-1(+) hUC-MSCs can differentiate into male germ-like cells in the presence of BMP4. This study provides an efficient protocol to study germ-cell development using hUC-MSCs.

CTCF-regulating endocrine function of pancreatic islet cells in transgenic mice

Pancreatic islet endocrine cells play crucial roles in regulation of glucose homeostasis. The differentiation and function of islet cells are regulated by various transcription factors, including Pax6, a member of the homeobox gene family. Pax6 plays a key role in the control of gene expression and islet cell development in the pancreas. Recent studies from our lab demonstrate for the first time that Pax6 transcription is regulated by CCCTC binding factor (CTCF), a nuclear protein and transcription regulator. CTCF downregulates Pax6 transcription through interaction with a repressor element located in Pax6 gene P0 promoter region. To further investigate the effect of CTCF on regulating Pax6 function in pancreatic islet cells, we measured blood glucose, insulin, and glucagons levels in newly established transgenic mice overexpressing CTCF. When compared to wild type mice, CTCF transgenic mice demonstrate an increase in insulin level and decrease in glucagon level resulting in lower blood glucose levels (hypoglycemia). In insulin tolerance test, hypoglycemia occurs quickly in CTCF transgenic mice and takes a recovery time. In the mean time, glucagon levels in CTCF mutant mice were significantly lower compared to its wild type counterpart. Our results indicate that CTCF transgenic mice are disordered in glucose homeostasis and suggest that CTCF is involved in regulating endocrine function of pancreatic islet cells by suppression of Pax6 expression.

Cloning and characterization of the drought-resistance OsRCI2-5 gene in rice (Oryza sativa L.)

The genomic expression profile of the super-hybrid rice Liangyoupeijiu female parent Pei'ai 64S in different tissues at different developmental stages under low temperature, drought, and high temperature stresses were detected using an Affymetrix GeneChip Rice Genome Array to screen upregulated and downregulated genes. In this study, we screened the drought-resistant gene OsRCI2-5, after which a constitutive OsRCI2-5 construct was created and transferred into Nipponbare. After polyethylene glycol-6000 and drought treatment, we found that the OsRCI2-5 gene improved the drought resistance of Nipponbare. Gene expression profiling showed that the OsRCI2-5 gene was expressed in the rice leaves, stems, and flower organs. Subcellular localization revealed that the gene was located in the membranes, and hence, we can deduce that a membrane signal peptide was responsible for signal transduction.

Cardiac hypertrophy is negatively regulated by miR-541

Heart failure is a leading cause of death in aging population. Cardiac hypertrophy is an adaptive reaction of the heart against cardiac overloading, but continuous cardiac hypertrophy is able to induce heart failure. We found that the level of miR-541 was decreased in angiotensin II (Ang-II) treated cardiomyocytes. Enforced expression of miR-541 resulted in a reduced hypertrophic phenotype upon Ang-II treatment in cellular models. In addition, we generated miR-541 transgenic mice that exhibited a reduced hypertrophic response upon Ang-II treatment. Furthermore, we found miR-541 is the target of microphthalmia-associated transcription factor (MITF) in the hypertrophic pathway and MITF can negatively regulate the expression of miR-541 at the transcriptional levels. MITF(ce/ce) mice exhibited a reduced hypertrophic phenotype upon Ang-II treatment. Knockdown of MITF also results in a reduction of hypertrophic responses after Ang-II treatment. Knockdown of miR-541 can block the antihypertrophic effect of MITF knockdown in cardiomyocytes upon Ang-II treatment. This indicates that the effect of MITF on cardiac hypertrophy relies on the regulation of miR-541. Our present study reveals a novel cardiac hypertrophy regulating pathway that was composed of miR-541 and MITF. Modulation of their levels may provide a new approach for tackling cardiac hypertrophy.

Clinical and cytogenomic studies in a case of infertility associated with a nonmosaic dicentric Y chromosome

In this study, a short stature male with infertility is reported. Semen analysis and serum concentrations of FSH, LH, T and PRL were estimated. Chromosome analysis was performed on lymphocytes obtained from both the male and his parents. Cytogenomic studies were performed by fluorescent in situ hybridisation and the CytoScan(™)  HD array analysis to detect Y chromosomal rearrangements and copy number mutations. Semen analysis showed severe oligozoospermia. Numerous spermatogenic cells were observed in the semen, and approximately 60% of the cells examined in semen were primary spermatocytes, showing spermatogenic arrest at the primary spermatocyte level. Cytogenomic studies of blood revealed his karyotype which was 46,X,i(Y) (p11.32) (Yqter→Yp11.32::Yp11.32→Yqter).ish (DYZ3++, SRY++, SHOX-). array (PLCXD1→SHOX) ×1,(SRY →GOLGA2P3Y)×2, (DHRSX→ ASMT, SPRY3 →IL9R)×3. The rearrangement Y chromosome is de novo. This is the first case reported with a nonmosaic 46,X, i (Y) (p11.32), which will be useful to estimate the infertility phenotype-molecular karyotype correlation. Haploinsufficiency of short stature homeobox-containing gene is primarily responsible for the short stature. Aberrations in pseudoautosomal region 1 on the rearranged Y chromosome may result in the deficiency of X-Y pairing or recombination, ultimately lead to the spermatogenic failure.

Notch ligand Delta-like 1 promotes the metastasis of melanoma by enhancing tumor adhesion

Notch signaling plays a vital role in tumorigenicity and tumor progression by regulating proliferation, invasion, and the tumor microenvironment. Previous research by our group indicated that Notch ligand Delta-like 1 (Dll1) is involved in angiogenesis in melanoma, and we noticed that it took a longer time to trypsinize Dll1-expressing B16 melanoma cells than the control cells. In this article, we extended our study to investigate the effects of Dll1 on tumor cell adhesion and metastasis. Dll1 overexpression activated Notch signaling in B16 tumor cells and significantly enhanced the adhering capacity of B16 tumor cells both in vitro and in vivo. B16-Dll1 cells also had a higher metastatic potential than their counterpart in the mouse model of lung metastasis. Along with increased Dll1 expression, N-cadherin, but not E-cadherin, was upregulated in B16-Dll1 cells. These data suggested that Notch ligand Dll1 may enhance the adhesion and metastasis of melanoma cells by upregulation of N-cadherin.

Rapid, high-resolution, whole-brain, susceptibility-based MRI of multiple sclerosis

BACKGROUND

Susceptibility-based MRI offers a unique opportunity to study neurological diseases such as multiple sclerosis (MS). In this work, we assessed a three-dimensional segmented echo-planar-imaging (3D-EPI) sequence to rapidly acquire high-resolution T2 -weighted and phase contrast images of the whole brain. We also assessed if these images could depict important features of MS at clinical field strength, and we tested the effect of a gadolinium-based contrast agent (GBCA) on these images.

MATERIALS AND METHODS

The 3D-EPI acquisition was performed on four healthy volunteers and 15 MS cases on a 3T scanner. The 3D sagittal images of the whole brain were acquired with a voxel size of 0.55 × 0.55 × 0.55 mm(3) in less than 4 minutes. For the MS cases, the 3D-EPI acquisition was performed before, during, and after intravenous GBCA injection.

RESULTS

Both T2-weighted and phase-contrast images from the 3D-EPI acquisition were sensitive to the presence of lesions, parenchymal veins, and tissue iron. Conspicuity of the veins was enhanced when images were obtained during injection of GBCA.

CONCLUSIONS

We propose this rapid imaging sequence for investigating, in a clinical setting, the spatiotemporal relationship between small parenchymal veins, iron deposition, and lesions in MS patient brains.

P2X1-initiated p38 signalling enhances thromboxane A2-induced platelet secretion and aggregation

ATP released by activated platelets can serve as a positive feedback machinery to amplify platelet responses by activating P2X1 receptors. It has, however, not been defined how P2X1 activities influence thromboxane A2 (TXA2)-stimulated platelet functional responses. Our aim was to elaborate the molecular mechanisms of P2X1 engagements in TXA2-induced platelet secretion and aggregation. P2X1 inhibition by 1 µM NF449 inhibited platelet P-selectin expression induced by a low concentration of the TXA2 analogue U46619 (0.3 µM) (32.0 ± 2.0% vs 43.4 ± 3.0%; n=5; p<0.05). p38 inhibition by SB203580, but not ERK inhibition by U0126, elicited a similar inhibition by NF499. The combination of NF449 and SB203580 provided, however, no additive effects. U46619-induced platelet aggregation was similarly decreased by NF449 and SB203580 alone or in combination, and by P2X1 pre-desensitisation with α,β-Me-ATP. U46619 caused rapid and reversible P2X1-dependent p38 phosphorylation. However, the P2X1-p38 pathway mainly enhanced mild platelet activation by U46619, because α,β-Me-ATP supplementation or p38 blockade had no effect on intense platelet activation induced by a higher concentration of U46619 (3 µM). In conclusion, P2X1 activation, via p38 signalling, potentiates platelet activation initiated by low doses of U46619. Hence, the P2X1-induced p38 signalling promotes more robust platelet activation in response to mild platelet stimuli.

Alpha-1-fucosidase as a prognostic indicator for hepatocellular carcinoma following hepatectomy: a large-scale, long-term study

Background:

Preoperative alpha-L-fucosidase (AFU) has been used as a diagnostic biomarker for hepatocellular carcinoma (HCC), but its role as a prognostic predictor after partial hepatectomy has not been well defined. The study aimed to investigate the prognostic significance of preoperative serum AFU for HCC patients after hepatic resection.

Methods:

A retrospective training data set and a prospective validation data set were used to evaluate the prognosis of HCC after partial hepatectomy. A total of 669 patients with histopathologically confirmed HCC were enrolled. Univariate and multivariate analyses were used to identify the prognostic significance of preoperative serum AFU.

Results:

The retrospective training data set showed a preoperative AFU>35 u l⁻¹ should be used. The prospective validation data set showed preoperative AFU was an independent prognostic factor of overall survival (OS) (P=0.008; hazard ratio: 2.333; 95% confidence interval: 1.249–4.369). Patients with a preoperative AFU>35 u l⁻¹ had a lower recurrence-free survival rate and an OS rate than those with AFU⩽35 u l⁻¹, and they have a higher tendency to form macrovascular invasion. Furthermore, the prognostic significance of AFU>35 u l⁻¹ could also be applied to patients with alpha-fetoprotein levels of ⩽400 ng ml⁻¹.

Conclusions:

Preoperative serum AFU is a prognostic predictor of HCC.

Promyelocytic leukaemia zinc finger maintains self-renewal of male germline stem cells (mGSCs) and its expression pattern in dairy goat testis

OBJECTIVES

Previous studies have shown that promyelocytic leukaemia zinc finger (PLZF) is a spermatogonia-specific transcription factor in the testis, required to regulate self-renewal and maintenance of the spermatogonia stem cell. Up to now, expression and function of PLZF in the goat testis has not been known. The objectives of this study were to investigate PLZF expression pattern in the dairy goat and its effect on male goat germline stem cell (mGSC) self-renewal and differentiation.

MATERIALS AND METHODS

Testis development and expression patterns of PLZF in the dairy goat were analysed by haematoxylin and eosin staining, immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, effects of PLZF overexpression on mGSC self-renewal and differentiation were evaluated by quantitative RT-PCR (QRT-PCR), immunofluorescence and BrdU incorporation assay.

RESULTS

Promyelocytic leukaemia zinc finger was essential for dairy goat testis development and expression of several proliferation and pluripotency-associated proteins including OCT4, C-MYC were upregulated by PLZF overexpression. The study demonstrated that PLZF played a key role in maintaining self-renewal of mGSCs and its overexpression enhanced expression of proliferation-associated genes.

CONCLUSIONS

Promyelocytic leukaemia zinc finger could function in the dairy goat as well as in other species in maintaining self-renewal of germline stem cells and this study provides a model to study the mechanism on self-renewal and differentiation of mGSCs in livestock.