scholarly journals Autolysis and Cell Death Is Affected by pH in L. reuteri DSM 20016 Cells

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1026
Author(s):  
Tahl Zimmerman ◽  
Salam A. Ibrahim

A key obstacle to the successful delivery of a probiotic to the consumer is maintaining viability of the live cells during storage, a challenge for the beneficial Lactibacillus reuteri. Three processes play a role in the reduction of viability: autolysis, cell death, and cell weakening. Using a phosphate induction model of autolysis, the initial aim of this project was to discover novel molecular determinants of autolysis in L. reuteri, with the long -term goal of elucidating new strategies for increasing viability. We employed a 2D Native/SDS-Page method to monitor changes in protein expression over time; however, the result was that excess phosphate did not induce noticeable changes in expression patterns. On the other hand, we found that pH affects both the rate of total viability and autolysis, as seen with other species of LAB. In addition, we found that the phosphate model of autolysis may not be sufficient to explain how autolysis is triggered in L. reuteri. Two parameters appear to modulate the pH in media containing L. reuteri cells: overall buffering capacity and the presence of a carbon source. Ultimately, phosphate sources appear to facilitate autolysis by maintaining pH in the media via a higher buffering capacity. In addition, the alkaline sugar free almond drink appears to be a promising possible preservative for L. reuteri.

Author(s):  
Mohd. Shuhaimi Ishak

 Abstract Generally speaking, media is extensively used as the means to disseminate news and information pertaining to business, social, political and religious concerns. A portion of the time and space of media has now become an important device to generate economic and social activities that include advertising, marketing, recreation and entertainment. The Government regards them as an essential form of relaying news and information to its citizens and at the same time utilizes them as a powerful public relations’ mechanism. The effects of media are many and diverse, which can either be short or long term depending on the news and information. The effects of media can be found on various fronts, ranging from the political, economic and social, to even religious spheres. Some of the negative effects arising from the media are cultural and social influences, crimes and violence, sexual obscenities and pornography as well as liberalistic and extreme ideologies. This paper sheds light on these issues and draws principles from Islam to overcome them. Islam as revealed to humanity contains the necessary guidelines to nurture and mould the personality of individuals and shape them into good servants. Key Words: Media, Negative Effects, Means, Islam and Principles. Abstrak Secara umum, media secara meluas digunakan sebagai sarana untuk menyebarkan berita dan maklumat yang berkaitan dengan perniagaan, kemasyarakatan, pertimbangan politik dan agama. Sebahagian dari ruang dan masa media kini telah menjadi peranti penting untuk menghasilkan kegiatan ekonomi dan sosial yang meliputi pengiklanan, pemasaran, rekreasi dan hiburan. Kerajaan menganggap sarana-sarana ini sebagai wadah penting untuk menyampaikan berita dan maklumat kepada warganya dan pada masa yang sama juga menggunakannya sebagai mekanisme perhubungan awam yang berpengaruh. Pengaruh media sangat banyak dan pelbagai, samada berbentuk jangka pendek atau panjang bergantung kepada berita dan maklumat yang brekenaan. Kesan dari media boleh didapati mempengaruhi pelbagai aspek, bermula dari bidang politik, ekonomi, sosial bahkan juga agama. Beberapa kesan negatif yang timbul dari media ialah pengaruhnya terhadap budaya dan sosial, jenayah dan keganasan, kelucahan seksual dan pornografi serta ideologi yang liberal dan ekstrim. Kertas ini menyoroti isu-isu ini dan cuba mengambil prinsip-prinsip dari ajaran Islam untuk mengatasinya. Tujuan Islam itu sendiri diturunkan kepada umat manusia ialah untuk menjadi pedoman yang diperlukan untuk membina dan membentuk keperibadian individu dan menjadikan manusia hamba yang taat kepada Tuhannya. Kata Kunci: Media, Kesan Negatif, Cara-cara, Islam dan Prinsip-prinsip.


2004 ◽  
Vol 21 (3) ◽  
pp. 70-88 ◽  
Author(s):  
Nancy Gallagher

Public opinion in the United States and elsewhere celebrated the liberation of Afghan women following the defeat of the Taliban government. The United States promised to stay in Afghanistan and foster security, economic development, and human rights for all, especially women. After years of funding various anti- Soviet Mujahidin warlords, the United States had agreed to help reconstruct the country once before in 1992, when the Soviet-backed government fell, but had lost interest when the warlords began to fight among themselves. This time, however, it was going to be different. To date, however, conditions have not improved for most Afghan women and reconstruction has barely begun. How did this happen? This article explores media presentations of Afghan women and then compares them with recent reports from human rights organizations and other eyewitness accounts. It argues that the media depictions were built on earlier conceptions of Muslim societies and allowed us to adopt a romantic view that disguised or covered up the more complex historical context of Afghan history and American involvement in it. We allowed ourselves to believe that Afghans were exotic characters who were modernizing or progressing toward a western way of life, despite the temporary setback imposed by the Taliban government. In Afghanistan, however, there was a new trope: the feminist Afghan woman activist. Images of prominent Afghan women sans burqa were much favored by the mass media and American policymakers. The result, however, was not a new focus on funding feminist political organizations or making women’s rights a foreign policy priority; rather, it was an unwillingness to fulfill obligations incurred during decades of American-funded mujahidin warfare, to face the existence of deteriorating conditions for women, resumed opium cultivation, and a resurgent Taliban, or to commit to a multilateral approach that would bring in the funds and expertise needed to sustain a long-term process of reconstruction.


2021 ◽  
pp. 194016122110252
Author(s):  
Sebastián Valenzuela ◽  
Daniel Halpern ◽  
Felipe Araneda

Despite widespread concern, research on the consequences of misinformation on people's attitudes is surprisingly scant. To fill in this gap, the current study examines the long-term relationship between misinformation and trust in the news media. Based on the reinforcing spirals model, we analyzed data from a three-wave panel survey collected in Chile between 2017 and 2019. We found a weak, over-time relationship between misinformation and media skepticism. Specifically, initial beliefs on factually dubious information were negatively correlated with subsequent levels of trust in the news media. Lower trust in the media, in turn, was related over time to higher levels of misinformation. However, we found no evidence of a reverse, parallel process where media trust shielded users against misinformation, further reinforcing trust in the news media. The lack of evidence of a downward spiral suggests that the corrosive effects of misinformation on attitudes toward the news media are less serious than originally suggested. We close with a discussion of directions for future research.


2021 ◽  
Vol 7 ◽  
pp. 237802312110247
Author(s):  
Alexandrea J. Ravenelle ◽  
Abigail Newell ◽  
Ken Cai Kowalski

The authors explore media distrust among a sample of precarious and gig workers interviewed during the COVID-19 pandemic. Although these left-leaning respondents initially increased their media consumption at the outset of the pandemic, they soon complained of media sensationalism and repurposed a readily available cultural tool: claims of “fake news.” As a result, these unsettled times have resulted in a “diffusion of distrust,” in which an elite conservative discourse of skepticism toward the media has also become a popular form of compensatory control among self-identified liberals. Perceiving “fake news” and media sensationalism as “not good” for their mental health, respondents also reported experiencing media burnout and withdrawing from media consumption. As the pandemic passes its one-year anniversary, this research has implications for long-term media coverage on COVID-19 and ongoing media trust and consumption.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rianne C. Prins ◽  
Sonja Billerbeck

Abstract Background Fungi are premier hosts for the high-yield secretion of proteins for biomedical and industrial applications. The stability and activity of these secreted proteins is often dependent on the culture pH. As yeast acidifies the commonly used synthetic complete drop-out (SD) media that contains ammonium sulfate, the pH of the media needs to be buffered in order to maintain a desired extracellular pH during biomass production. At the same time, many buffering agents affect growth at the concentrations needed to support a stable pH. Although the standard for biotechnological research and development is shaken batch cultures or microtiter plate cultures that cannot be easily automatically pH-adjusted during growth, there is no comparative study that evaluates the buffering capacity and growth effects of different media types across pH-values in order to develop a pH-stable batch culture system. Results We systematically test the buffering capacity and growth effects of a citrate-phosphate buffer (CPB) from acidic to neutral pH across different media types. These media types differ in their nitrogen source (ammonium sulfate, urea or both). We find that the widely used synthetic drop-out media that uses ammonium sulfate as nitrogen source can only be effectively buffered at buffer concentrations that also affect growth. At lower concentrations, yeast biomass production still acidifies the media. When replacing the ammonium sulfate with urea, the media alkalizes. We then develop a medium combining ammonium sulfate and urea which can be buffered at low CPB concentrations that do not affect growth. In addition, we show that a buffer based on Tris/HCl is not effective in maintaining any of our media types at neutral pH even at relatively high concentrations. Conclusion Here we show that the buffering of yeast batch cultures is not straight-forward and addition of a buffering agent to set a desired starting pH does not guarantee pH-maintenance during growth. In response, we present a buffered media system based on an ammonium sulfate/urea medium that enables relatively stable pH-maintenance across a wide pH-range without affecting growth. This buffering system is useful for protein-secretion-screenings, antifungal activity assays, as well as for other pH-dependent basic biology or biotechnology projects.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 28.1-29
Author(s):  
A. Kerstein-Staehle ◽  
C. Alarcin ◽  
J. Luo ◽  
G. Riemekasten ◽  
P. Lamprecht ◽  
...  

Background:The immunomodulatory cytokine IL-16 is increased in several inflammatory and autoimmune diseases1. IL-16 recruits and activates CD4+ immune cells such as T cells, dendritic cells, or monocytes. IL-16 is produced by various immune and non-immune cells, but synthesis and storage of IL-16 is regulated differentially depending on the cell type and stimulation. For its biological activity, IL-16 cleavage by caspase-3 is required1. Necrotizing granulomatous inflammation is a hallmark of granulomatosis with polyangiitis (GPA) with neutrophil dysregulation as a central driver of chronic inflammation and autoimmunity2. Earlier studies showed a correlation between increased serum IL-16 and disease parameters in AAV, including GPA3, but functional evidence for a direct link between IL-16 and neutrophils in granulomatous inflammation is missing so far.Objectives:In this study we aim to identify a functional link between increased IL-16, neutrophils, and the autoantigen proteinase 3 (PR3) with regard to chronic inflammation and autoimmunity in GPA.Methods:IL-16 was measured in sera of GPA patients (n = 40) and healthy controls (HC, n = 50) by ELISA and correlated with clinical features, such as disease activity (BVAS), creatinine, GFR, VDI and PR3-ANCA status. IL-16 protein expression was analyzed in peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMN) from GPA patients and HC (n = 5, each) by SDS-PAGE and western blot. Binding affinity of recombinant pro-IL-16 to native human PR3 was assessed by microscale thermophoresis. Cleavage of pro-IL-16 by active human PR3 was performed at various time points at 37°C. Cleavage products were analyzed by SDS-PAGE and western blot.Results:Circulating IL-16 was significantly increased in GPA patients compared to HC. Elevated IL-16 positively correlated with BVAS, creatinine, VDI and PR3-ANCA status and negatively correlated with GFR. In PMBC and PMN from GPA and HC we identified different expression patters of precursor and active forms of IL-16. In healthy PBMC we found high amounts of precursor (80kD), pro-IL-16 (55kD) and active IL-16 (17kD). In contrast, PBMC from GPA patients had lower amounts of pro-IL-16 and no active IL-16, indicating activation and secretion of IL-16 due to inflammatory stimulation, as shown earlier5. In GPA PMN we detected no precursor IL-16, but pro-IL-16 and its active form, in contrast to very low amounts of all IL-16 forms in healthy PMN. Processing and release of IL-16 in neutrophils has been linked to apoptosis and secondary necrosis5. By interaction studies we demonstrated direct binding of pro-IL-16 to PR3 with a Kd of 10 nM. In a subsequent cleavage assay we confirmed IL-16 processing by PR3 in a time-dependent manner.Conclusion:Correlation of serum IL-16 with clinical features of GPA suggests that IL-16 is associated with markers of disease activity, tissue damage and autoreactivity. We showed that PBMC and PMN represent a source of IL-16 in GPA. By the identification of PR3 as an additional IL-16-activating enzyme we could demonstrate a potential link between excessive PR3 expression, cell death and IL-16-dependent mechanisms, contributing to chronic granulomatous inflammation and autoimmunity in GPA.References:[1]Glass, W. G. et al. Not-so-sweet sixteen: The role of IL-16 in infectious and immune-mediated inflammatory diseases. J. Interf. Cytokine Res. 26, 511–520 (2006).[2]Millet, A. et al. Proteinase 3 on apoptotic cells disrupts immune silencing in autoimmune vasculitis. J. Clin. Invest. 125, 4107–4121 (2015).[3]Yoon, T. et al. Serum interleukin-16 significantly correlates with the Vasculitis Damage Index in antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Res. Ther. 22, 1–6 (2020).[4]Elssner, A. et al. IL-16 Is Constitutively Present in Peripheral Blood Monocytes and Spontaneously Released During Apoptosis. J. Immunol. 172, 7721–7725 (2004).[5]Roth, S. et al. Secondary necrotic neutrophils release interleukin-16C and macrophage migration inhibitory factor from stores in the cytosol. Cell Death Discov. 1, 15056 (2015).Disclosure of Interests:None declared


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yi Wen ◽  
Nazila Salamat-Miller ◽  
Keethkumar Jain ◽  
Katherine Taylor

AbstractDirect delivery of therapeutic enzymes to the Central Nervous System requires stringent formulation design. Not only should the formulation design consider the delicate balance of existing ions, proteins, and osmolality in the cerebrospinal fluid, it must also provide long term efficacy and stability for the enzyme. One fundamental approach to this predicament is designing formulations with no buffering species. In this study, we report a high concentration, saline-based formulation for a human sulfatase for its delivery into the intrathecal space. A high concentration formulation (≤ 40 mg/mL) was developed through a series of systematic studies that demonstrated the feasibility of a self-buffered formulation for this molecule. The self-buffering capacity phenomenon was found to be a product of both the protein itself and potentially the residual phosphates associated with the protein. To date, the self-buffered formulation for this molecule has been stable for up to 4 years when stored at 5 ± 3 °C, with no changes either in the pH values or other quality attributes of the molecule. The high concentration self-buffered protein formulation was also observed to be stable when exposed to multiple freeze–thaw cycles and was robust during in-use and agitation studies.


2021 ◽  
Vol 22 (4) ◽  
pp. 2006
Author(s):  
Mi Jin Kim ◽  
Jinhong Park ◽  
Jinho Kim ◽  
Ji-Young Kim ◽  
Mi-Jin An ◽  
...  

Mercury is one of the detrimental toxicants that can be found in the environment and exists naturally in different forms; inorganic and organic. Human exposure to inorganic mercury, such as mercury chloride, occurs through air pollution, absorption of food or water, and personal care products. This study aimed to investigate the effect of HgCl2 on cell viability, cell cycle, apoptotic pathway, and alters of the transcriptome profiles in human non-small cell lung cancer cells, H1299. Our data show that HgCl2 treatment causes inhibition of cell growth via cell cycle arrest at G0/G1- and S-phase. In addition, HgCl2 induces apoptotic cell death through the caspase-3-independent pathway. Comprehensive transcriptome analysis using RNA-seq indicated that cellular nitrogen compound metabolic process, cellular metabolism, and translation for biological processes-related gene sets were significantly up- and downregulated by HgCl2 treatment. Interestingly, comparative gene expression patterns by RNA-seq indicated that mitochondrial ribosomal proteins were markedly altered by low-dose of HgCl2 treatment. Altogether, these data show that HgCl2 induces apoptotic cell death through the dysfunction of mitochondria.


2021 ◽  
Vol 22 (10) ◽  
pp. 5349
Author(s):  
Mayes Alswady-Hoff ◽  
Johanna Samulin Erdem ◽  
Santosh Phuyal ◽  
Oskar Knittelfelder ◽  
Animesh Sharma ◽  
...  

There is little in vitro data available on long-term effects of TiO2 exposure. Such data are important for improving the understanding of underlying mechanisms of adverse health effects of TiO2. Here, we exposed pulmonary epithelial cells to two doses (0.96 and 1.92 µg/cm2) of TiO2 for 13 weeks and effects on cell cycle and cell death mechanisms, i.e., apoptosis and autophagy were determined after 4, 8 and 13 weeks of exposure. Changes in telomere length, cellular protein levels and lipid classes were also analyzed at 13 weeks of exposure. We observed that the TiO2 exposure increased the fraction of cells in G1-phase and reduced the fraction of cells in G2-phase, which was accompanied by an increase in the fraction of late apoptotic/necrotic cells. This corresponded with an induced expression of key apoptotic proteins i.e., BAD and BAX, and an accumulation of several lipid classes involved in cellular stress and apoptosis. These findings were further supported by quantitative proteome profiling data showing an increase in proteins involved in cell stress and genomic maintenance pathways following TiO2 exposure. Altogether, we suggest that cell stress response and cell death pathways may be important molecular events in long-term health effects of TiO2.


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