Imaging Flow Cytometry to Study Biofilm-Associated Microbial Aggregates

The aim of the research was to design an advanced analytical tool for the precise characterization of microbial aggregates from biofilms formed on food-processing surfaces. The approach combined imaging flow cytometry with a machine learning-based interpretation protocol. Biofilm samples were collected from three diagnostic points of the food-processing lines at two independent time points. The samples were investigated for the complexity of microbial aggregates and cellular metabolic activity. Thus, aggregates and singlets of biofilm-associated microbes were simultaneously examined for the percentages of active, mid-active, and nonactive (dead) cells to evaluate the physiology of the microbial cells forming the biofilm structures. The tested diagnostic points demonstrated significant differences in the complexity of microbial aggregates. The significant percentages of the bacterial aggregates were associated with the dominance of active microbial cells, e.g., 75.3% revealed for a mushroom crate. This confirmed the protective role of cellular aggregates for the survival of active microbial cells. Moreover, the approach enabled discriminating small and large aggregates of microbial cells. The developed tool provided more detailed characteristics of bacterial aggregates within a biofilm structure combined with high-throughput screening potential. The designed methodology showed the prospect of facilitating the detection of invasive biofilm forms in the food industry environment.

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P0523PROTECTIVE ROLE OF REGULATORY B CELLS ON THE RENAL TISSUE REPAIRMEN AFTER ISCHEMIA REPERCUSSION INJURY

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p0523 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Yokota Yunosuke ◽

Goh Kodama ◽

Sakuya Itou ◽

Yosuke Nakayama ◽

Nobukazu Komatsu ◽

...

Keyword(s):

Flow Cytometry ◽

Renal Function ◽

B Cells ◽

Interleukin 10 ◽

Renal Tissue ◽

Protective Role ◽

Regulatory B Cells ◽

Tubulointerstitial Injury ◽

Iri Model

Abstract Background and Aims Acute kidney injury (AKI), even if followed by renal recovery, is a risk factor for the future development of chronic kidney disease (CKD) and end- stage renal disease. It has been postulated that interleukin-10 (IL-10)-producing Regulatory B cells (Breg) play an important role for the tissue repairment in several tissues and organs. Basically, protective role of Breg has been reported in inflammatory bowel disease. In the kidney, it has been shown that IL-10 suppresses renal function decline and improves renal prognosis in IRI model, a typical model of AKI. However, the identity of Breg in the kidney and their origin have not been clarified. Further, how the Breg works during the transition from AKI to CKD is not known. Therefore, first we investigated whether Breg existed in renal tissue on the progression from AKI to CKD in IRI model mice. Further, we performed splenectomy, and examined the renal injury, Breg, and plasma IL-10 levels in this model. Method To examine the existence of Breg in the kidney of IRI model, we used 8-10 weeks-old GFP / IL-10 mice based on C57BL / 6J mice. They are reporter mice for IL-10 producing cells, and can visualize IL-10 producing cells under a fluorescence microscope without fluorescent immunostaining. We prepared following three groups, sham, IRI (unilateral), and IRI + SN (splenectomy) groups. Mice were anesthetized with chloral hydrate (4 g/kg,, intraperitoneal). After making a midline incision, exposed a blood vessel of the left renal pedicles and clamped it for 30 min by clips. one day, 7 days, and 14 days after the surgery, mice were sacrificed, and renal function and plasma IL-10 levels as well as tissue damages by PAS and Masson’s Trichrome staining were assessed. Tissue IL-10-producing cells were detected by flow cytometry. Results There was no difference of plasma IL-10 levels and renal tubulointerstitial injury in IRI group and IRI+SN group on day 1 after IRI. However, on day 7 and day 14, plasma IL-10 levels became gradually higher in IRI group, and SN decreased the increase in IL-10 levels. Tubulointerstitial injury was induced by IRI and SN further worsened tubular damages. Serum Cr and BUN levels were not different in three groups due to normal right kidney. On day 1, number of IL-10-producing B cells increased in the spleen and renal medulla in IRI group confirmed by flow cytometry, which was completely diminished by SN, suggesting that origin of the infiltrated Breg might be spleen, thereby being involved in the protective role in IRI injury in the kidney. Conclusion We report for the first time that Breg might be recruited from spleen by AKI, which may be one of the mechanisms to prevent the progression to CKD.

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MicroRNA Quantitation During Dendritic Cell Endocytosis Using Imaging Flow Cytometry: Key Factors and Requirements

Cellular Physiology and Biochemistry ◽

10.1159/000495333 ◽

2018 ◽

Vol 51 (2) ◽

pp. 793-811

Author(s):

Qiang Tong ◽

Ying Zhu ◽

Dandan Zhang ◽

Qing Cai ◽

Wenchun Qu ◽

...

Keyword(s):

Flow Cytometry ◽

Laser Scanning ◽

Laser Scanning Confocal Microscopy ◽

Key Factors ◽

Argonaute 2 ◽

Scanning Confocal Microscopy ◽

Imaging Flow Cytometry ◽

Microscopy Method ◽

Stimulation Of

Background/Aims: MicroRNA (miRNA)-induced suppression of dendritic cells (DCs) has been implicated in many diseases. Therefore, accurate monitoring of miRNA endocytosis by DCs is important for understanding the role of miRNAs in many diseases. Recently, a method for measuring the co-localization of Argonaute 2 (AGO2)-associated miRNAs on laser-scanning confocal microscopy method was proposed to localize the miRNAs. But its definition was limited by the number of observed cells through its accuracy. Methods: In this study, a method based on imaging flow cytometry was developed to localize miR-590-5p with fluorescent probes in DCs. miR-590-5p proven to play an important role in tumor immunity. This method enabled the quantification, visualization and localization of the fluorescence intensity in 30,000 individual cells. Results: Using this method, the DCs with different endocytotic ability were distinguished. The behaviour of miR-590-5p during endocytosis under the stimulation of tumor antigen in DCs was observed, binding to its cognate target mRNA and degradation in DCs. Conclusion: This method based on imaging flow cytometry provide an additional method to study miRNA processing in DCs, which makes it a valuable addition to existing miRNA research techniques.

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The Post-Transfusion Recovery and Survival of Red Blood Cells in Mice Is Affected by the Expression of Cellular Prion Protein.

Blood ◽

10.1182/blood.v108.11.959.959 ◽

2006 ◽

Vol 108 (11) ◽

pp. 959-959

Author(s):

Karel Holada ◽

Jan Simak ◽

Jaroslav G. Vostal

Keyword(s):

Stem Cells ◽

Flow Cytometry ◽

Red Blood Cells ◽

Prion Protein ◽

Blood Cells ◽

Survival Curve ◽

Protective Role ◽

Cellular Prion Protein ◽

Hematopoietic Stem

Abstract Three documented transfusion cases of vCJD underline the need of better insight in blood prion protein biology. Cellular prion protein (PrPc) plays key role in the pathophysiology of prion diseases. Its expression by cells is necessary for amplification of infectious prions and the disease process itself. Physiological function of PrPc remains obscure. Its clarification may provide important clues for the development of urgently needed blood test and effective disease treatment. PrPc is expressed on CD34+ hematopoietic stem cells and its expression is regulated during blood cell differentiation. Recently the importance of PrPc for self-renewal of long-term repopulating hematopoietic stem cells was suggested and other studies reported the protective function of PrPc against oxidative stress and apoptosis in various cell cultures. We previously demonstrated that human as well as mouse red blood cells (RBC) express approximately 200 PrPc molecules / cell (Holada et al., BJH 2000, 110, 472–80). To test if the PrPc expression plays a role in the post-transfusion recovery and survival of RBC we carried out transfusion study in mice. RBC isolated from blood of wild type (WT) and PrP knockout (KO) FVB mice were labeled “in vitro” by different levels of NHS-biotin. The labeling was optimized to allow simultaneous detection of both populations of RBC in mouse blood using flow cytometry. To exclude the influence of different level of cell biotinylation on the experiment outcome two mixtures of RBC were prepared. The first contained KO RBC labeled with high and WT RBC with low level of biotin and the second mixture contained cells labeled “vice versa”. Each mixture was injected via tail vein in a group of WT mice (n=5) and the survival of RBCs was followed. Samples were analyzed on day 1, 2, 3, 6, 9, 15, 21 and 29. The count of biotinylated RBC was measured in comparison to 100 000 nonlabeled recipient RBC. Simultaneously the expression of PrPc on RBC was monitored using flow cytometry with MAb 6H4. KO RBC displayed significantly higher first day post-transfusion recovery compared to WT RBC in both groups of mice (81 ± 3 % vs. 74 ± 3 %, P<0.005 and 90 ± 4 % vs. 80 ± 4 %, P<0.005). The slope of the RBC survival curve in all individual mice during the initial 15 days was steeper for KO RBC (mavg = − 3.44) than for WT RBC (mavg = − 2.37) suggesting the protective role of PrPc in circulating RBC. The difference in the slope diminished during the 15 to 29 day period which was accompanied by a 50% decrease of PrPc surface expression on transfused WT RBC. To confirm our data the identical experiment was carried out in a group of KO mice (n=5) transfused with a mixture containing KO RBC labeled with low and WT RBC with high level of biotin. Again the first day post-transfusion recovery was higher for KO RBC (80 ± 6 % vs. 75 ± 6 %, P<0.05) and the initial slope of the KO RBC survival curve was steeper in all mice in the group. Our data suggest that PrPc expression plays role in the post-transfusion recovery and survival of RBC. The observation that WT RBC disappear from the circulation at lower rate than KO RBC until their level of surface PrPc reaches 50% is compatible with the protective role of PrPc expression on cells. Taken together our study demonstrates that physiological role of PrPc expression on RBC may lay in facilitating their longer survival in circulation. (GACR 310/04/0419, MSMT 0021620806).

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Protective role of peroxiredoxin-4 in heart failure

Clinical Science ◽

10.1042/cs20191072 ◽

2020 ◽

Vol 134 (1) ◽

pp. 71-72

Author(s):

Naseer Ahmed ◽

Masooma Naseem ◽

Javeria Farooq

Keyword(s):

Heart Failure ◽

Cardiac Fibroblasts ◽

Protective Role ◽

Oxidative Stress Markers ◽

Stress Markers ◽

Total Antioxidant ◽

Galectin 3 ◽

Consequent Increase ◽

And Oxidative Stress

Abstract Recently, we have read with great interest the article published by Ibarrola et al. (Clin. Sci. (Lond.) (2018) 132, 1471–1485), which used proteomics and immunodetection methods to show that Galectin-3 (Gal-3) down-regulated the antioxidant peroxiredoxin-4 (Prx-4) in cardiac fibroblasts. Authors concluded that ‘antioxidant activity of Prx-4 had been identified as a protein down-regulated by Gal-3. Moreover, Gal-3 induced a decrease in total antioxidant capacity which resulted in a consequent increase in peroxide levels and oxidative stress markers in cardiac fibroblasts.’ We would like to point out some results stated in the article that need further investigation and more detailed discussion to clarify certain factors involved in the protective role of Prx-4 in heart failure.

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Parenting Behaviors and Anxiety in Young Adults

Journal of Individual Differences ◽

10.1027/1614-0001/a000169 ◽

2015 ◽

Vol 36 (3) ◽

pp. 170-176 ◽

Cited By ~ 5

Author(s):

Erin N. Stevens ◽

Joseph R. Bardeen ◽

Kyle W. Murdock

Keyword(s):

Effortful Control ◽

Parenting Behaviors ◽

Protective Role ◽

Anxiety Symptoms ◽

Interactive Effects ◽

Parental Overprotection ◽

High Control ◽

Development Of Anxiety ◽

The Relationship

Parenting behaviors – specifically behaviors characterized by high control, intrusiveness, rejection, and overprotection – and effortful control have each been implicated in the development of anxiety pathology. However, little research has examined the protective role of effortful control in the relation between parenting and anxiety symptoms, specifically among adults. Thus, we sought to explore the unique and interactive effects of parenting and effortful control on anxiety among adults (N = 162). Results suggest that effortful control uniquely contributes to anxiety symptoms above and beyond that of any parenting behavior. Furthermore, effortful control acted as a moderator of the relationship between parental overprotection and anxiety, such that overprotection is associated with anxiety only in individuals with lower levels of effortful control. Implications for potential prevention and intervention efforts which specifically target effortful control are discussed. These findings underscore the importance of considering individual differences in self-regulatory abilities when examining associations between putative early-life risk factors, such as parenting, and anxiety symptoms.

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