Zbyszek Darzynkiewicz | |
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Born | Zbigniew Dierżykraj Darżynkiewicz May 12, 1936 Dzisna (Wilno Voivodeship), Poland |
Died | February 28, 2021 84) | (aged
Citizenship | American (naturalized 1976) |
Alma mater | Medical University of Warsaw, Poland |
Known for | The development of cytometry methods for single-cell analysis; the TUNEL assay |
Spouse | Elizabeth T. Darzynkiewicz |
Children | Richard B. Darzynkiewicz, Robert J. Darzynkiewicz |
Awards | Distinguished Service Award, International Society for Analytical Cytology (ISAC), Officer's Cross of the Order of Merit of the Republic of Poland |
Scientific career | |
Thesis | Studies of the Mechanism of Teratogenic Action of Insulin on Chicken Embryo. (1966) |
Academic advisors | Kazimierz Ostrowski |
Zbigniew (Zbyszek) Darzynkiewicz ( ORCID 0000-0002-2040-7081) (Polish pronunciation: [zbiɡ.ɲɛfdaʐɨŋkʲɛvit͡ʂ] ; born May 12, 1936, in Dzisna, Wilno Voivodeship, Poland [1] – died February 28, 2021) [2] was a Polish-American cell biologist active in cancer research and in developing new methods in histochemistry for flow cytometry. [3] [4] [5] [6]
From 1945 to 1949, Darzynkiewicz attended a primary school in Dzierżoniów, Poland. He spent his high school years (1949–1953) in Skarżysko-Kamienna, Poland. His application to the University of Warsaw's Department of Physics was denied by the communist Social Justice Committee, who viewed him as a "enemy of the people." However, following the intervention of Regina Uszyńska, his high school principal, Darzynkiewicz was permitted to submit an application to the Medical University of Warsaw in the fall of 1953. [7] [8]
He earned his M.D. from the Medical University of Warsaw, Poland (1953–1960). From 1962 to 1965, he was a predoctoral fellow at the Department of Histology, Medical University of Warsaw. From 1965 to 1966, he was a visiting scientist at the Department of Pharmacology, the State University of New York at Buffalo. During and shortly after this period, he published his first manuscripts in Nature [9] [10] [11] [12] and Science [13] journals. In 1966, the Faculty Council of the Medical University of Warsaw granted him the degree of Doctor of Medical Sciences (equivalent to a Ph.D.).
One month after the Soviet Union-led Warsaw Pact troops invaded Czechoslovakia in September 1968, Darzynkiewicz left Poland for Sweden on a tourist visa, refused to return, and soon after applied for an immigration visa to the United States. [7] He arrived in the United States in 1969.
From September 1968 to September 1969, Darzynkiewicz was a visiting scientist at the Laboratory of Cell Research, Karolinska Institute, Stockholm, Sweden, working under the supervision of Nils R. Ringertz. [1] [3] [14] [5] In Ringertz's laboratory, Darzynkiewicz met Endre A. Balazs, who offered him a research position in the United States. [14] From 1969 to 1974, Darzynkiewicz worked as a staff scientist at the Department of Connective Tissue Research, Boston Biomedical Research Institute in Boston, MA. From March 1974 to December 1975, he was Research Associate at Memorial Sloan-Kettering Cancer Center, New York, NY. From January 1976 to March 1978, he was an assistant professor, from June 1978 to June 1988, an associate professor, and finally, from July 1988 to September 1990, a full professor at Cornell University, Graduate School of Medical Sciences, New York, NY. From January 1986 to September 1990, he was the Head of the Laboratory of Experimental Cell Research, Memorial Sloan-Kettering Cancer Center.
In October 1990, Darzynkiewicz became a professor of medicine at New York Medical College – a member of the Touro College and University System, [15] [16] Valhalla, NY, and the director of the Brander Cancer Research Institute, New York Medical College. From 1991 he also served as a professor of Microbiology and Immunology and Professor of Pathology at New York Medical College. [1] [7] [17]
Since 1972, the National Institutes of Health, including the prestigious MERIT award, have provided continuous funding for his research. In addition to receiving a NASA grant to develop cell analysis technologies applicable to the microgravity conditions of the International Space Station, his research was also supported by a number of private cancer research foundations. [17]
Darzynkiewicz has published over 780 peer-reviewed articles, [18] has edited, co-edited, and co-authored 15 books, and was granted eight US patents. [19] [20] [21] [22] [23] [24] [25] [26] As of October 2022, his 1992 manuscript entitled "Features of apoptotic cells measured by flow cytometry," published in Cytometry Part A has been cited over 1800 times. [27] [28]
He served as the president of the Cell Cycle Society (1986-1987) and the president of the International Society for Advancement of Cytometry (1993–1994). [29] He was the Editor-in-Chief of the Open Medicine, [30] a co-founder and an Associate Editor of Cytometry Part A , [31] and an Editor of Current Protocols in Cytometry.
Darzynkiewicz's research centered on cell biology, with an emphasis on cancer cell growth and the regulatory mechanisms associated with cell growth and cell cycle progression. The most significant scientific contribution made by Darzynkiewicz is his discovery that the process of cell death is equally as significant as the cell cycle, thereby connecting conceptually and methodologically apoptosis to cell division. [3] [28] Darzynkiewicz is also recognized for developing the TUNEL assay (terminal deoxynucleotidyl transferase dUTP nick end labeling), which continues to be one of the most popular methods for measuring apoptosis. [32] He also contributed significantly to the investigation of mechanisms of cell death induced by tumor necrosis factor (TNF). [3] The connection between cell death and cell cycle progression has led Darzynkiewicz and his collaborators to further studies on the cell cycle-dependent effect of anticancer drugs and the death of cells during specific phases of the cell cycle caused by topoisomerase inhibitors and lovastatin. [33] [6]
His professional affiliations include member (foreign) of the Polish Academy of Sciences [34] and of the Polish Academy of Learning. [35]
Darzynkiewicz was the recipient of an honorary degree from the Medical University of Warsaw in Poland, [36] [7] the Maria Skłodowska-Curie Award from the Jozef Pilsudski Institute in America, [37] and the Casimir Funk Award from the Polish Institute of Arts and Sciences of America. [38]
In 2002 he received Distinguished Service Award from the International Society for Analytical Cytology (ISAC). In 2009 he became a Fellow of the College of American Institute for Medical and Biological Engineering (AIMBE) in recognition for "developing and applying techniques to assess the cell cycle, cell kinetics, cellular apoptosis, tumor response, and progression." [39]
Darzynkiewicz was a founding member of the Kosciuszko Foundation Collegium of Eminent Scientists of Polish Origin and Ancestry, [40] and a trustee of the Kosciuszko Foundation. [41] From 1986 to 1999, he was an advisory board member of The Alfred Jurzykowski Foundation, which annually awarded the Jurzykowski Prize. [42] In 1995 He was a recipient of the Officer's Cross of the Order of Merit of the Republic of Poland. [43]
Zbigniew Darzynkiewicz publications indexed by Google Scholar.
Zbigniew Darzynkiewicz publications indexed by the Scopus bibliographic database. (subscription required)
Apoptosis is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses 50 to 70 billion cells each day due to apoptosis. For the average human child between 8 and 14 years old, each day the approximate loss is 20 to 30 billion cells.
Flow cytometry (FC) is a technique used to detect and measure the physical and chemical characteristics of a population of cells or particles.
Cell death is the event of a biological cell ceasing to carry out its functions. This may be the result of the natural process of old cells dying and being replaced by new ones, as in programmed cell death, or may result from factors such as diseases, localized injury, or the death of the organism of which the cells are part. Apoptosis or Type I cell-death, and autophagy or Type II cell-death are both forms of programmed cell death, while necrosis is a non-physiological process that occurs as a result of infection or injury.
DNA fragmentation is the separation or breaking of DNA strands into pieces. It can be done intentionally by laboratory personnel or by cells, or can occur spontaneously. Spontaneous or accidental DNA fragmentation is fragmentation that gradually accumulates in a cell. It can be measured by e.g. the Comet assay or by the TUNEL assay.
Propidium iodide is a fluorescent intercalating agent that can be used to stain cells and nucleic acids. PI binds to DNA by intercalating between the bases with little or no sequence preference. When in an aqueous solution, PI has a fluorescent excitation maximum of 493 nm (blue-green), and an emission maximum of 636 nm (red). After binding DNA, the quantum yield of PI is enhanced 20-30 fold, and the excitation/emission maximum of PI is shifted to 535 nm (green) / 617 nm (orange-red). Propidium iodide is used as a DNA stain in flow cytometry to evaluate cell viability or DNA content in cell cycle analysis, or in microscopy to visualize the nucleus and other DNA-containing organelles. Propidium Iodide is not membrane-permeable, making it useful to differentiate necrotic, apoptotic and healthy cells based on membrane integrity. PI also binds to RNA, necessitating treatment with nucleases to distinguish between RNA and DNA staining. PI is widely used in fluorescence staining and visualization of the plant cell wall.
Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) is a method for detecting DNA fragmentation by labeling the 3′- hydroxyl termini in the double-strand DNA breaks generated during apoptosis.
DNA laddering is a feature that can be observed when DNA fragments, resulting from Apoptosis DNA fragmentation are visualized after separation by gel electrophoresis the first described in 1980 by Andrew Wyllie at the University Edinburgh medical school DNA fragments can also be detected in cells that underwent necrosis, but when these DNA fragments after separation are subjected to gel electrophoresis no clear "ladder" pattern is apparent.
Acridine orange is an organic compound that serves as a nucleic acid-selective fluorescent dye with cationic properties useful for cell cycle determination. Acridine orange is cell-permeable, which allows the dye to interact with DNA by intercalation, or RNA via electrostatic attractions. When bound to DNA, acridine orange is very similar spectrally to an organic compound known as fluorescein. Acridine orange and fluorescein have a maximum excitation at 502nm and 525 nm (green). When acridine orange associates with RNA, the fluorescent dye experiences a maximum excitation shift from 525 nm (green) to 460 nm (blue). The shift in maximum excitation also produces a maximum emission of 650 nm (red). Acridine orange is able to withstand low pH environments, allowing the fluorescent dye to penetrate acidic organelles such as lysosomes and phagolysosomes that are membrane-bound organelles essential for acid hydrolysis or for producing products of phagocytosis of apoptotic cells. Acridine orange is used in epifluorescence microscopy and flow cytometry. The ability to penetrate the cell membranes of acidic organelles and cationic properties of acridine orange allows the dye to differentiate between various types of cells. The shift in maximum excitation and emission wavelengths provides a foundation to predict the wavelength at which the cells will stain.
Staurosporine is a natural product originally isolated in 1977 from the bacterium Streptomyces staurosporeus. It was the first of over 50 alkaloids that were discovered to share this type of bis-indole chemical structure. The chemical structure of staurosporine was elucidated by X-ray crystalography in 1994.
DNA damage-inducible transcript 3, also known as C/EBP homologous protein (CHOP), is a pro-apoptotic transcription factor that is encoded by the DDIT3 gene. It is a member of the CCAAT/enhancer-binding protein (C/EBP) family of DNA-binding transcription factors. The protein functions as a dominant-negative inhibitor by forming heterodimers with other C/EBP members, preventing their DNA binding activity. The protein is implicated in adipogenesis and erythropoiesis and has an important role in the cell's stress response.
Apoptotic DNA fragmentation is a key feature of apoptosis, a type of programmed cell death. Apoptosis is characterized by the activation of endogenous endonucleases, particularly the caspase-3 activated DNase (CAD), with subsequent cleavage of nuclear DNA into internucleosomal fragments of roughly 180 base pairs (bp) and multiples thereof (360, 540 etc.). The apoptotic DNA fragmentation is being used as a marker of apoptosis and for identification of apoptotic cells either via the DNA laddering assay, the TUNEL assay, or the by detection of cells with fractional DNA content ("sub G1 cells") on DNA content frequency histograms e.g. as in the Nicoletti assay.
5-Ethynyl-2′-deoxyuridine (EdU) is a thymidine analogue which is incorporated into the DNA of dividing cells. EdU is used to assay DNA synthesis in cell culture and detect cells in embryonic, neonatal and adult animals which have undergone DNA synthesis. Whilst at high doses it can be cytotoxic, this molecule is now widely used to track proliferating cells in multiple biological systems.
Cell cycle analysis by DNA content measurement is a method that most frequently employs flow cytometry to distinguish cells in different phases of the cell cycle. Before analysis, the cells are usually permeabilised and treated with a fluorescent dye that stains DNA quantitatively, such as propidium iodide (PI) or 4,6-diamidino-2-phenylindole (DAPI). The fluorescence intensity of the stained cells correlates with the amount of DNA they contain. As the DNA content doubles during the S phase, the DNA content (and thereby intensity of fluorescence) of cells in the G0 phase and G1 phase (before S), in the S phase, and in the G2 phase and M phase (after S) identifies the cell cycle phase position in the major phases (G0/G1 versus S versus G2/M phase) of the cell cycle. The cellular DNA content of individual cells is often plotted as their frequency histogram to provide information about relative frequency (percentage) of cells in the major phases of the cell cycle.
Lisa Staiano-Coico or Lisa S. Coico is an American academic. Coico was the twelfth president of City College of New York, from August 2010 until October 2016.
Mass cytometry is a mass spectrometry technique based on inductively coupled plasma mass spectrometry and time of flight mass spectrometry used for the determination of the properties of cells (cytometry). In this approach, antibodies are conjugated with isotopically pure elements, and these antibodies are used to label cellular proteins. Cells are nebulized and sent through an argon plasma, which ionizes the metal-conjugated antibodies. The metal signals are then analyzed by a time-of-flight mass spectrometer. The approach overcomes limitations of spectral overlap in flow cytometry by utilizing discrete isotopes as a reporter system instead of traditional fluorophores which have broad emission spectra.
An imaging cycler microscope (ICM) is a fully automated (epi) fluorescence microscope which overcomes the spectral resolution limit resulting in parameter- and dimension-unlimited fluorescence imaging. The principle and robotic device was described by Walter Schubert in 1997 and has been further developed with his co-workers within the human toponome project. The ICM runs robotically controlled repetitive incubation-imaging-bleaching cycles with dye-conjugated probe libraries recognizing target structures in situ (biomolecules in fixed cells or tissue sections). This results in the transmission of a randomly large number of distinct biological informations by re-using the same fluorescence channel after bleaching for the transmission of another biological information using the same dye which is conjugated to another specific probe, a.s.o. Thereby noise-reduced quasi-multichannel fluorescence images with reproducible physical, geometrical, and biophysical stabilities are generated. The resulting power of combinatorial molecular discrimination (PCMD) per data point is given by 65,536k, where 65,536 is the number of grey value levels (output of a 16-bit CCD camera), and k is the number of co-mapped biomolecules and/or subdomains per biomolecule(s). High PCMD has been shown for k = 100, and in principle can be expanded for much higher numbers of k. In contrast to traditional multichannel–few-parameter fluorescence microscopy (panel a in the figure) high PCMDs in an ICM lead to high functional and spatial resolution (panel b in the figure). Systematic ICM analysis of biological systems reveals the supramolecular segregation law that describes the principle of order of large, hierarchically organized biomolecular networks in situ (toponome). The ICM is the core technology for the systematic mapping of the complete protein network code in tissues (human toponome project). The original ICM method includes any modification of the bleaching step. Corresponding modifications have been reported for antibody retrieval and chemical dye-quenching debated recently. The Toponome Imaging Systems (TIS) and multi-epitope-ligand cartographs (MELC) represent different stages of the ICM technological development. Imaging cycler microscopy received the American ISAC best paper award in 2008 for the three symbol code of organized proteomes.
Ellen D. Jorgensen is a New York-based molecular biologist leading the do-it-yourself biology movement. She works to increase scientific literacy in the general population, particularly in the fields of molecular and synthetic biology. She is a co-founder of both Biotech Without Borders and Genspace. In 2017, Ellen Jorgensen was named one of the Most Creative Leaders in Business by Fast Company.
Induced cell cycle arrest is the use of a chemical or genetic manipulation to artificially halt progression through the cell cycle. Cellular processes like genome duplication and cell division stop. It can be temporary or permanent. It is an artificial activation of naturally occurring cell cycle checkpoints, induced by exogenous stimuli controlled by an experimenter.
Tissue image cytometry or tissue cytometry is a method of digital histopathology and combines classical digital pathology and computational pathology into one integrated approach with solutions for all kinds of diseases, tissue and cell types as well as molecular markers and corresponding staining methods to visualize these markers. Tissue cytometry uses virtual slides as they can be generated by multiple, commercially available slide scanners, as well as dedicated image analysis software – preferentially including machine and deep learning algorithms. Tissue cytometry enables cellular analysis within thick tissues, retaining morphological and contextual information, including spatial information on defined cellular subpopulations.
J. Paul Robinson is an Australian/American educator, biologist, biomedical engineer, and expert in the applications of flow cytometry. He is a Distinguished Professor of Cytometry in the Purdue University College of Veterinary Medicine, Department of Basic Medical Sciences, a professor of Biomedical Engineering in the Weldon School of Biomedical Engineering, a professor of Computer and Information Management at Purdue University, an adjunct professor of Microbiology & Immunology at West Lafayette Center for Medical Education, Indiana University School of Medicine, and the Director of Purdue University Cytometry Laboratories.
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: CS1 maint: date and year (link)For developing and applying techniques to assess the cell cycle, cell kinetics, cellular apoptosis, tumor response and progression.