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Doctoral Degrees (Genetics)

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Browsing Doctoral Degrees (Genetics) by Author "Lind, Diane Justine."

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    Quantifying redox signals: a tool to investigate adaptive responses to oxidative stress.
    (2024) Lind, Diane Justine.; Pillay, Che Sobashkar.
    In the context of redox biology's oxidative eustress/distress model, the contrasting roles of ROS, such as hydrogen peroxide, under normoxic and toxic oxidative stress conditions has been more clearly elucidated. However, a fundamental question in the field has been understanding how dynamic redox signalling processes contribute to balancing the cellular response to oxidative eustress/distress.We employed a quantitative approach, evaluating redox signals based on area under the curve (AUC), signal amplitude, time, and duration. These parameters allowed us to investigate how dynamic profiles changed in response to various oxidants across three distinct experimental contexts. First, quantifying the dynamic response of the Tpx1/Pap1 redox-regulated pathway in Schizosaccharoymyces pombe revealed a graded signal and transcriptional response to input peroxide concentrations. Secondly, we applied this method to establish the upper and lower limits of detection for the redox probes HyPer7 and roGFP-TSA2/Tpx1 in Saccharomyces cerevisiae and S. pombe, providing a set of criteria for improved selection and comparison of probes. Thirdly, we quantitatively evaluated the dynamic response of the mammalian NRF2/Keap1 pathway following pre-exposure to DEM and tBHQ. Our findings revealed that, unlike the Tpx1/Pap1 pathway, this pathway showed that the timing of oxidant exposure influenced the NRF2 response. These metrics have therefore provided useful insights to several different pathways in both experimental and analytical contexts. Importantly, these measures allow for further exploratory questions to be asked and provide a fundamental framework for assessing dynamic responses of redoxregulated pathways associated with cell physiology and disease. Iqoqa. Esimweni semodeli i-redox biology's oxidative eustress/distress, izimo ezinokuphikisana ze-ROS, njengehydrogen peroxide, ngaphansi kwezimo zenormoxic kanye netoxic oxidative stress zicaciswe bha. Kepha-ke umbuzo omkhulu esifundweni owokuqonda ukuthi ngabe izinhlobo ezikhombayo zedynamic redox zibamba liphi iqhaza ekubhalansiseni ukuphendula kweselula ku-oxidative eustress/distress. Sasebenzisa indlela yekhwalithethivu, ukuhlola izimpawu zeredox sisusela endaweni engaphansi kwejika (AUC), ukukhombisa, ubukhulu, isikhathi kanye nobude besikhathi. La mapharamitha asivumela ukuba sihlole ukuthi ngabe amaphrofayli edynamic ashintsha kanjani kuma-oxidants ahlukene ezindaweni ezintathu ezahlukene lapho kuhlolwa khona. Okokuqala ukubala iresponse yedynamic ye-Tpx1/Pap1 redox-regulated pathway ku-Schizosaccharoymyces pombe yaveza izinkomba ezihlukanisiwe kanye nokuphendula okutranscriptional kokufakiwe kwe-peroxide concentrations. Okwesibili sasebenzisa le ndlela ukuthola imikhawulo ephezulu nephansi yokuhlola iredox probes HyPer7 kanye ne-roGFP-TSA2/Tpx1 no-Saccharomyces cerevisiae ne-S. pombe, ukuhlinzeka ngesethi yendlela yokukhetha okuthuthukile kanye nokuqhathaniswa kwamaprobes. Okwesithathu sahlola ngokwekhwantithethivu ukuphendula kwe-dynamic ye-mammalian NRF2/Keap1 pathway kulandela ukuvuleleka ngaphambilini ku-DEM kanye ne-tBHQ. Imiphumela yethu yaveza ukuthi kungafani nomgudu i-Tpx1/Pap1, lo mgudu wakhombisa ukuthi isikhathi sokuvuleleka kwe-oxidant sinomthelela ekuphenduleni kwe-NRF2. La mamethrikhsi ahlinzeke ngolwazi lwemigudu eyehlukene ezimweni zokuhlola kanye nokuhlaziya. Okusemqoka, lezi zindlela zivumela eminye imibuzo yokuhlwaya ukuba ibuzwe bese ihlinzeka uhlaka olusemqoka lokuhlola ukuphendula kwedynamic yemigudu ye-redox-regulated eyamaniswa namaseli okusebenza komzimba kanye nezifo.