Rapid reuptake of granzyme B leads to emperitosis: an apoptotic cell-in-cell death of immune killer cells inside tumor cells

A cell-in-cell process refers to the invasion of one living cell into another homotypic or heterotypic cell. Different from non-apoptotic death processes of internalized cells termed entosis or cannibalism, we previously reported an apoptotic cell-in-cell death occurring during heterotypic cell-in-cell formation. In this study, we further demonstrated that the apoptotic cell-in-cell death occurred only in internalized immune killer cells expressing granzyme B (GzmB). Vacuole wrapping around the internalized cells inside the target cells was the common hallmark during the early stage of all cell-in-cell processes, which resulted in the accumulation of reactive oxygen species and subsequent mitochondrial injury of encapsulated killer or non-cytotoxic immune cells. However, internalized killer cells mediated rapid bubbling of the vacuoles with the subsequent degranulation of GzmB inside the vacuole of the target cells and underwent the reuptake of GzmB by killer cells themselves. The confinement of GzmB inside the vacuole surpassed the lysosome-mediated cell death occurring in heterotypic or homotypic entosis processes, resulting in a GzmB-triggered caspase-dependent apoptotic cell-in-cell death of internalized killer cells. On the contrary, internalized killer cells from GzmB-deficient mice underwent a typical non-apoptotic entotic cell-in-cell death similar to that of non-cytotoxic immune cells or tumor cells. Our results thus demonstrated the critical involvement of immune cells with cytotoxic property in apoptotic cell-in-cell death, which we termed as emperitosis taken from emperipolesis and apoptosis. Whereas entosis or cannibalism may serve as a feed-on mechanism to exacerbate and nourish tumor cells, emperitosis of immune killer cells inside tumor cells may serve as an in-cell danger sensation model to prevent the killing of target cells from inside, implying a unique mechanism for tumor cells to escape from immune surveillance.

Neuroprotective effects of LBP on brain ischemic reperfusion neurodegeneration

AIM

The present study was conducted to investigate whether LBP had a protective effect on cerebral ischemic reperfusion injury and to determine the possible mechanisms.

MATERIALS AND METHODS

Male Kunming (KM) mice were used to make the model cerebral artery occlusion/reperfusion (MCAO/R). The behavioral test was used to measure neurological deficit scores for evaluation of ischemic reperfusion damage of brain. The change of electroencephalograph (EEG) was monitored by Model SMUP-E Bio-electric Signals Processing System. The infarction area of brain was assessed in brain slices with 2% solution of 2,3,5-triphenyl tetrazolium chloride (TTC). Spectrophotometric assay was used to determine the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and lactate dehydrogenase (LDH), contents of malondialdehyde (MDA) and adenosine triphosphate (ATP) of the brain.

RESULTS

The results showed that LBP at doses of 20 and 40 mg/kg markedly decreased the neurological deficit scores and the infarction area in MCAO/R mice. At the same time, LBP significantly decreased MDA content, and increased SOD, GSH-Px, CAT, LDH activities in ischemic reperfusion brain.

CONCLUSIONS

These suggest that LBP might act as a potential neuroprotective agent against the cerebral reperfusion-induced injury in the brain through reducing lipid peroxides, scavenging free radicals, and improving the energy metabolism.

The effect of Shenmai injection on the proliferation of Rat airway smooth muscle cells in asthma and underlying mechanism

BACKGROUND

Over-proliferation of airway smooth muscle cell (ASMC) is one of the important contributors to airway remodeling in asthma. The aim of this study was to investigate the effect of Shenmai injection (SMI) on the proliferation of the rat ASMC in asthma.

METHODS

Rats were randomly divided into three groups: the control group, the asthma group, and the SMI treatment group. Reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemistry staining were used to detect the mRNA and protein expression of transient receptor potential vanilloid 1 (TRPV1) and proliferating cell nuclear antigen (PCNA) in rat ASMC respectively. Intracellular Ca²⁺ concentration ( [Ca²⁺](i)) in rat ASMC were measured with Fluo-3/AM by confocal microscopy. The proliferation was detected by MTT assay.

RESULTS

Compared with the control group, the asthma group showed an increased expression of TRPV1 and [Ca²⁺](i) in rat ASMC. The expression of PCNA and absorbance of MTT assay in asthma rat ASMC was also significantly increased. SMI could significantly decrease the expression of TRPV1 channel and [Ca²⁺](i) in the asthmatic rat ASMC. Furthermore, the expression of PCNA and absorbance of MTT assay in asthmatic rat ASMC was significantly reduced after SMI treatment.

CONCLUSIONS

SMI may prevent asthma-induced ASMC over-proliferation probably by inhibiting the expression of TRPV1 channel, which regulates the intracellular calcium concentration.

Quantifying climate and management effects on regional crop yield and nitrogen leaching in the north china plain

Better water and nitrogen (N) management requires better understanding of soil water and N balances and their effects on crop yield under various climate and soil conditions. In this study, the calibrated Root Zone Water Quality Model (RZWQM2) was used to assess crop yield and N leaching under current and alternative management practices in a double-cropped wheat ( L.) and maize ( L.) system under long-term weather conditions (1970-2009) for dominant soil types at 15 locations in the North China Plain. The results provided quantitative long-term variation of deep seepage and N leaching at these locations, which strengthened the existing qualitative knowledge for site-specific management of water and N. In general, the current management practices showed high residual soil N and N leaching in the region, with the amounts varying between crops and from location to location and from year to year. Seasonal rainfall explained 39 to 84% of the variability in N leaching (1970-2009) in maize across locations, while for wheat, its relationship with N leaching was significant ( < 0.01) only at five locations. When N and/or irrigation inputs were reduced to 40 to 80% of their current levels, N leaching generally responded more to N rate than to irrigation, while the reverse was true for crop yield at most locations. Matching N input with crop requirements under limited water conditions helped achieve lower N leaching without considerable soil N accumulation. Based on the long-term simulation results and water resources availability in the region, it is recommended to irrigate at 60 to 80% of the current water levels and fertilize only at 40 to 60% of the current N rate to minimizing N leaching without compromising crop yield.

Whole-procedural radiological accuracy for delivering multi-session gamma knife radiosurgery with a relocatable frame system

A newly developed Gamma Knife relocatable eXtend frame system has enabled the delivery of multi-session Gamma Knife radiosurgery without the use of skull pin fixation frame system. In this study, we investigate and report for the first time the whole procedural radiological accuracy for administering such treatments. To quantify the radiological alignment, the commonly used Winston-Lutz test was modified and used to determine the device accuracy of the eXtend frame system. Patient setup uncertainties relative to the device were further measured for a series of treatment sessions (n = 58), and then incorporated with the Winston-Lutz test results from individual patient-specific eXtend frame systems. The whole-procedure mean 3D radiological setup uncertainty was determined to be 0.69 ± 0.73 mm (1σ) from all the cases analyzed, and the mean 90% confidence level margins were found to be 0.55, 0.78 and 0.72 mm along the x-, y-, and z-axis, respectively. Our results therefore demonstrated that sub-millimetric radiological accuracy is clinically achievable for multi-session Gamma Knife radiosurgery treatments and a 1 mm margin along the major axes is sufficient for planning multi-session Gamma Knife radiosurgery treatments.

Effect of TRPV1 channel on the proliferation and apoptosis in asthmatic rat airway smooth muscle cells

BACKGROUND

Hyperplasia of airway smooth muscle cells (ASMC) is a major contributor to airway remodeling in asthma. Transient receptor potential vanilloid 1 (TRPV1) is an important channel to mediate Ca(2+) influx. This study explores the expression of TRPV1 channel and its effect on the proliferation and apoptosis in rat ASMC, in order to find a new target to treat airway remodeling in asthma.

METHODS

Rats were sensitized and challenged with ovalbumin to replicate asthmatic models. Proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry. Reverse transcriptase-polymerase chain reaction, immunocytochemistry, and Western blot were used to detect the mRNA and protein expression of TRPV1 channel. Intracellular calcium ([Ca(2+)]i) was detected using confocal fluorescence Ca(2+) imaging. [(3)H] thymidine incorporation and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay were used to observe the DNA synthesis and proliferation. TUNEL assay was used to detect the apoptosis of ASMC.

RESULTS

(1) The expression of PCNA was significantly increased in intact asthmatic rat ASMC. (2) The expression of TRPV1 channel was significantly increased in asthmatic rat ASMC. (3) [Ca(2+)]i in ASMC of the asthmatic group was significantly increased. After treatment with TRPV1 agonist capsaicin (CAP), [Ca(2+)]i was further increased, whereas [Ca(2+)]i was decreased after administration of TRPV1 antagonist capsazepine (CPZ) in ASMC of the asthmatic group. (4) The DNA synthesis and absorbance of MTT were significantly increased, while apoptosis was significantly decreased in asthmatic ASMC. CAP further enhanced proliferation and decreased apoptosis. CPZ significantly inhibited the effect of CAP in asthmatic ASMC.

CONCLUSION

TRPV1 channel was involved in the regulation of proliferation and apoptosis in asthmatic ASMC.

Individual Beam Sharpening Improves Composite Dose Fall-off near a Target for Non-Isocentric Cyberknife Radiosurgery

Stereotactic radiosurgery (SRS) refers to a high dose of radiation delivered to a focal region of interest while maximizing the steep dose gradient to minimize dose to the surrounding normal tissues. Multiple factors can influence the dose fall-off, and the relative importance of such factors have not yet been characterized for non-isocentric Cyberknife SRS. Our aim was to investigate whether the composite dose fall-off near a target may be enhanced via sharpening the lateral beam profile (or penumbra) of each individual beam. Cyberknife beam profiles were fitted and parameterized to obtain a characteristic penumbra function for each collimator size. Simulated beam profiles with progressively sharper penumbras were then generated, and used to perform simulated treatment planning on seven pediatric intracranial arteriovenous malformations (AVMs) cases. Penumbra size was found to significantly influence the peripheral dose fall-off. Peripheral dose volumes were reduced by 5 to 10% with reductions in penumbra size ranging from 40 to 80%. Dose conformality and homogeneity were not significantly changed with decreasing penumbra size. Therefore, individual beam sharpening provides a straightforward way of improving the composite dose fall-off for non-isocentric Cyberknife SRS.

Contamination of bananas with beauvericin and fusaric acid produced by Fusarium oxysporum f. sp. cubense

BACKGROUND

Fusarium wilt, caused by the fungal pathogen Fusarium oxysporum f. sp. cubense (Foc), is one of the most destructive diseases of banana. Toxins produced by Foc have been proposed to play an important role during the pathogenic process. The objectives of this study were to investigate the contamination of banana with toxins produced by Foc, and to elucidate their role in pathogenesis.

METHODOLOGY/PRINCIPAL FINDINGS

Twenty isolates of Foc representing races 1 and 4 were isolated from diseased bananas in five Chinese provinces. Two toxins were consistently associated with Foc, fusaric acid (FA) and beauvericin (BEA). Cytotoxicity of the two toxins on banana protoplast was determined using the Alamar Blue assay. The virulence of 20 Foc isolates was further tested by inoculating tissue culture banana plantlets, and the contents of toxins determined in banana roots, pseudostems and leaves. Virulence of Foc isolates correlated well with toxin deposition in the host plant. To determine the natural occurrence of the two toxins in banana plants with Fusarium wilt symptoms, samples were collected before harvest from the pseudostems, fruit and leaves from 10 Pisang Awak 'Guangfen #1' and 10 Cavendish 'Brazilian' plants. Fusaric acid and BEA were detected in all the tissues, including the fruits.

CONCLUSIONS/SIGNFICANCE

The current study provides the first investigation of toxins produced by Foc in banana. The toxins produced by Foc, and their levels of contamination of banana fruits, however, were too low to be of concern to human and animal health. Rather, these toxins appear to contribute to the pathogenicity of the fungus during infection of banana plants.

Influence of on-farm production practices on sensory and technological quality characteristics of pork loin

Quality of pork from pigs raised either traditionally (outdoor access or bedded settings with no sub-therapeutic antibiotics or growth promotants in feed) or conventionally (commercial indoor) was evaluated. Pork loins (m. longissimus thoracis et lumborum, LTL) from four hundred pigs from either traditional or conventional production systems (n=200) fed commercially formulated diets ad libitum were harvested at slaughter. Intramuscular crude fat content and lean color (L* and b*) values were significantly decreased in conventional pork loins. LTL from conventionally-raised pig carcasses showed increased (P<0.05) mean pH, moisture content and reduced cooking loss and shear force values and had increased tenderness and juiciness scores compared to those from traditionally-raised pig carcasses. Results indicated that pork from conventionally raised pigs was superior to that from traditionally raised pigs in terms of tenderness and juiciness, suggesting that consumers may value pork from traditionally raised pigs on the basis of factors other than eating quality and appearance.

[Macrophage migration inhibitory factor in mud crab Scylla paramamosain: molecular cloning, expression profiles in various tissues and under Vibrio challenge]

As one of the first found cytokines, macrophage migration inhibitory factor (MIF) plays AN important role in several physiological processes in crabs. In this study, a full-length MIF cDNA (GenBank accession number: JX131610) from mud crab Scylla paramamosain (Sp) was cloned based on a sequence of S. paramamosain cDNA library. The full length of SpMIF was 734 bp consisting of a 363 bp open reading frame encoding the SpMIF, a 120 amino acid peptide chain. The molecular weight of SpMIF was 13.46 kDa with the pI of 6.82. The alignment analysis showed that SpMIF appeared to be closely related to the counterpart from crab Eriocheir sinensis (68%). Quantitative real-time PCR analysis revealed that SpMIF was highly expressed in hepatopancreas and hemocytes. In addition, the expression level of SpMIF was increased significantly after a 6-h challenge by Vibrio parahaemolyticus (4.00 x 10(6) CFU/mL), peaked at 8 h, and then declined to the common level in 48 h. This data indicated that SpMIF was cloned successfully, and suggested that it participated in the immune system of mud crabs.

Nitrogen and phosphorus use efficiencies in dairy production in china

Milk production has greatly increased in China recently, with significant impacts on the cycling of nitrogen (N) and phosphorus (P). However, nutrient flows within the changing dairy production system are not well quantified. The aim of this study was to increase the quantitative understanding of N and P cycling and utilization in dairy production through database development and simulation modeling. In 2010, of the entire 1987 and 346 thousand tons (Gg) of N and P input, only 188 Gg N and 31 Gg P ended up in milk. The average N and P use efficiencies were 24 and 25%, respectively, at the whole system level. Efficiencies differed significantly between the four dairy systems. Losses of N from these systems occurred via NH volatilization (33%), discharge (27%), denitrification (24%), NO leaching and runoff (16%), and NO emission (1%). Industrial feedlots use less feed per kg milk produced than traditional systems, and rely more on high-quality feed from fertilized cropland; they have very poor recycling of manure nutrients to cropland. As industrial feedlot systems are booming, overall mean N and P use efficiencies will increase at herd level but will decrease at the whole dairy production system level unless manure N and P are used more efficiently through reconnecting China's feed and dairy production sectors.

Growth factor receptor-bound protein 10-mediated negative regulation of the insulin-like growth factor-1 receptor-activated signalling pathway results in cognitive disorder in diabetic rats

Growth factor receptor-bound protein 10 (Grb10) is a Src homology 2 domain-containing protein and one of the binding partners for several transmembrane tyrosine kinase receptors, including insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1-R). The hippocampus, which is critical for cognitive functions, is one of the main distribution areas of Grb10 in the central nervous system. In recent years, diabetic encephalopathy has been defined as a third type of diabetes and the IGF1-IR pathway was shown to be critical for the neuropathogenic process of cognitive disorder in diabetes. However, the role of endogenous Grb10 in regulating the IGF1-IR pathway and neurobehavioural changes is not explicit. The present study aimed to determine the in vivo function of endogenous Grb10 in diabetic encephalopathy and the underlying mechanisms. Using stereotaxic surgical techniques and lentiviral vectors expressing specific short hairpin RNA, we could steadily knockdown Grb10 expression in the hippocampus. More importantly, we demonstrated that hippocampus-specific modulation of Grb10 protein levels led to a prominent remission of cognitive disorder, including improvements in both ultrastructural pathology and abnormal neurobehavioural changes. Our findings indicate that endogenous overexpression of Grb10 functions as a suppressor of the IGF1-IR pathway, which may represent an important mechanism for regulating cognitive disorder in diabetes.

The driving forces for nitrogen and phosphorus flows in the food chain of china, 1980 to 2010

Nitrogen (N) and phosphorus (P) use and losses in China's food chain have accelerated in the past three decades, driven by population growth, rapid urbanization, dietary transition, and changing nutrient management practice. There has been little detailed quantitative analysis of the relative magnitude of these driving forces throughout this period. Therefore, we analyzed changes in N and P flows and key drivers behind changes in the food (production and consumption) chain at the national scale from 1980 to 2010. Food (N and P) consumption increased by about fivefold in urban settings over this period but has decreased in rural settings since the 1990s. For urban settings, the integrated driving forces for increased food consumption were population growth, which accounted for ∼60%, and changing urban diets toward a greater emphasis on the consumption of animal products. Nutrient inputs and losses in crop and animal productions have continuously increased from 1980 to 2010, but the rates of decadal increase were greatly different. Increased total inputs and losses in crop production were primarily driven by increased crop production for food demand (68-96%) in the 1980s but were likely offset in the 2000s by improved nutrient management practices, as evidenced by decreased total inputs to and losses from cropland for harvesting per nutrient in crop. The contributions of animal production to total N and P losses to waters from the food chain increased by 34 and 60% from 1980 to 2010. These increases were caused mainly by decreased ratios of manure returned to cropland. Our study highlights a larger impact of changing nutrient management practice than population growth on elevated nutrient flows in China's food chain.

An analysis of developments and challenges in nutrient management in china

During the past 50 years, China has successfully realized food self-sufficiency for its rapidly growing population. Currently, it feeds 22% of the global population with 9% of the global area of arable land. However, these achievements were made at high external resource use and environmental costs. The challenge facing China is to further increase food production while drastically decreasing the environmental costs of food production. Here we review the major developments in nutrient management in China over the last 50 years. We briefly analyze the current organizational structure of the "advisory system" in agriculture, the developments in nutrient management for crop production, and the developments in nutrient management in animal production. We then discuss the nutrient management challenges for the next decades, considering nutrient management in the whole chain of crop production-animal production-food processing-food consumption by households. We argue that more coherent national policies and institutional structures are required for research extension education to be able to address the immense challenges ahead. Key actions include nutrient management in the whole food chain concomitant with a shift in objectives from food security only to food security, resource use efficiency, and environmental sustainability; improved animal waste management based on coupled animal production and crop production systems; and much greater emphasis on technology transfer from science to practice through education, training, demonstration, and extension services.

Advances and challenges for nutrient management in china in the 21st century

Managing agricultural nutrients to provide a safe and secure food supply while protecting the environment remains one of the great challenges for the 21st century. The fourth International Nutrient Management Symposium (INMS), held in 2011 at the University of Delaware, addressed these issues via presentations, panel sessions, and field tours focused on latest technologies and policies available to increase nutrient use efficiency. Participants from the United States, Europe, Canada, and China discussed global trends and challenges, balancing food security and the environment in countries with struggling and emerging economics, nutrient management and transport at the catchment scale, new technologies for managing fertilizer and manure nutrients, and adaptive nutrient management practices for farm to watershed scales. A particular area of interest at the fourth INMS was nutrient management progress and challenges in China over the past 40 years. China's food security challenges and rapidly growing economy have led to major advances in agricultural production systems but also created severe nutrient pollution problems. This special collection of papers from the fourth INMS gives an overview of the remarkable progress China has made in nutrient management and highlights major challenges and changes in agri-environmental policies and practices needed today. Lessons learned in China are of value to both developing and developed countries facing the common task of providing adequate food for an expanding world population, while protecting air and water quality and restoring damaged ecosystems.

Investigation of the role of tryptophan residues in cationic antimicrobial peptides to determine the mechanism of antimicrobial action

AIMS

To understand the effects of Trp residues in linear antimicrobial peptides with α-helical conformations on cell permeation ability and membrane transduction efficacy.

METHODS AND RESULTS

A series of L-K6 analogues were designed and synthesized by replacing Ile or Leu with Trp at different positions on the hydrophobic face of L-K6. The antimicrobial and haemolytic activity and secondary structure of the designed Trp-containing peptides were assessed. In addition, the role of Trp in membrane disruption for these designed peptides was investigated. I1W, I4W and L5W demonstrated stronger activity than the other peptides against both Gram-positive and Gram-negative bacteria. All of the tested peptides preferentially interacted with negatively charged vesicles composed of phosphatidylglycerol (PG)/cardiolipin (CL) or PG/CL/phosphatidylethanolamine, and, to a lesser extent, with zwitterionic vesicles. I1W, I4W and L5W caused calcein release at 2·5 μmol l(-1) .

CONCLUSIONS

The position of Trp, rather than the number of Trp residues, in these peptides was an important factor in the antimicrobial activity. Trp residues were deeply inserted into negatively charged membranes but were largely exposed in aqueous buffer solution.

SIGNIFICANCE AND IMPACT OF THE STUDY

These Trp-containing peptides may represent good candidates for new antibiotic agents and for use in new therapeutic approaches.

The applicability of Ki-67 marker for renal epithelioid angiomyolipoma: experience of ten cases from a single center

In order to present our experience with 10 cases of renal epithelioid angiomyolipoma (EAML) and validate the applicability of Ki-67 (proliferation marker) for EAML, we reviewed medical records of 10 consecutive cases diagnosed EAML from January 2005 to February 2012 at our department. Clinical data were collected and analyzed and pathology slides were reviewed. The immunohistochemical reactions for Ki-67 were performed and tumors showed positive expression were estimated. Active follow-up was performed to investigate the association between Ki-67 expression and the prognosis. The mean age and tumor size of the patients was 43.6 years (range 32-56) and 8.2 cm (range 2-15 cm), respectively. Seven were females while three were males. Radical nephrectomy was performed in 6 patients, partial nephrectomy in 3, and renal artery ligation in 1. The immunohistochemical reactions for HMB-45 (Human Melanoma Black), SMA (Smooth Muscle Actin) were positive but for S-100 were negative. The number of patients showing positive/negative Ki-67 expression was 5/5. The survival rate of the positive group was 20% (1/5) while 100% (5/5) of the negative group during the median follow-up time of 26.75 months (range 1-53). Recurrence, metastasis and death due to disease occurred in 1 (10%), 3 (30%) and 4 (40%) patients, respectively. Higher expression (positive) of Ki-67 indicates the presence of EAML and poor prognosis of patients. Surgical excision including radical and partial nephrectomy is a considerable approach to the treatment for its malignant potential.