बुधवार, 11 अक्तूबर 2017

The circadian clock has an impact on many aspects of our physiology( 2017 Nobel Prize in Medicine )

  2017 Nobel Prize in Medicine Goes to 3 Americans for Body Clock Studies(Hindi)II Part (दूसरी क़िस्त)

2017 Nobel Prize in Medicine Goes to 3 Americans for Body Clock Studies(Part ll,Hindi)


अमरीकी विज्ञानियों जेफ्री सी. हाल ,माइकल रोसबाष ,माइकल डबलू योंग को संयुक्त रूप से इस बरस का मेडिसिन  के लिए नोबेल पुरूस्कार दिया गया है। आपने समस्त प्राणियों की जैवघड़ी  की आंतरिक व्यवस्था ,अंदर की बात का पहली मर्तबा खुलासा किया है । यूं जेट लेग ,जीवन शैली से पैदा सोसल जेट ,कॉलसेंटर्स तथा अन्यत्र पालियों में काम करने की व्यवस्था से उत्पन्न वर्क-प्लेस जेटलैग का अनुभव हम सभी ने कभी न कभी किया ही होगा। जो फ़्रिक़ुएन्ट फ्लायर्स हैं वे जानते हैं जितनी अधिक टाइम जोन्स पार करके वे अपने गंतव्य तक पहुंचते हैं जेटलैग भी उसी अनुपात में उग्र होता जाता है। 
जेटलैग का साधरण भाषा में अर्थ है -हमारे अंदर मौजूद सुचारू  रूप पृथ्वी की दैनिक गति (अपने ही अक्ष पे नर्तन और सूर्यके गिर्द भ्रमण  )के अनुरूप चलते रहने वाली हमारी असंख्य सेल -क्लॉक्स (कोशिका घड़ियों )का बाहर के माहौल (सफर के दौरान और बाद की दिन या रात की अवधि और माहौल )से मेल टूट जाता है। सिंक्रो -नाइ -जेशन के स्थान पर मिसमेच होने लगता है आंतरिक शारीरिक व्यवस्था और बाहर के पर्यावरण -पारिस्थितिकी मौसम चक्र में। 

 अब तक चला आया तालमेल ,सिंक्रोनाज़ेशन टूट जाता है। शरीर कहे दिन है तो आसपास का माहौल कहे रात। आँखें देखें रतियाँ। शरीर भोगे दिन का एहसास। 
समझा जाता है कुछ जीवन खंड (जीवन  इकाइयां ,Genes)इस जैव घड़ी  के संचालन में एहम भूमिका निभाती हैं।
जीवन -शास्त्र-विज्ञानों  के माहिर विज्ञानियों की इस तिकड़ी ने फ्रूट फ्लाईज़ (Fruit Flies )से कुछ जींस लेकर उनकी सूक्ष्मतर स्तर पर जांच की। समझा जाता है ये ख़ास जीवन इकाइयां ही रोज़मर्रा के जीवन में हमें समय का बोध करवाती रहतीं हैं। हम खुद भी कयास लगा लेते हैं किसी भी आठ पहर के  समय का बिना घड़ी  देखे। जो तकरीबन -तकरीबन सही ही होता है। 
इस सूक्ष्मतर अध्ययन से इन जींस में झांक कर  देखा गया ,जाना गया कैसे कीटपतंगों प्राणियों की जैव घड़ी पृथ्वी की अपने गिर्द और सूर्य के गिर्द की गति के अनुरूप अपने अंदर   की टिक टिक का अनुकूलन कर लेती है।
आखिर हमारी पृथ्वी भी एक घड़ी ही तो है जो एक आवधिक कालवधि की खबर देती रहती है। एक पेंडुलम  की एक ओसिलेटर  की तरह इसका भरोसा किया जा सकता  शरीर की आंतरिक व्यवस्था कोशिकाओं की धड़कन इसी के अनुरूप  ढ़लती रहती है अहर्निश आपसे आप।  

इस प्रणाली के अनुकूलन (सिंक्रोनाईज़ेशन )को ही इस तिकड़ी ने प्राणियों की अंतर्जात ,इनबिल्ट व्यवस्था या मॉलिक्युलर -मैकेनिज़्म कहा है। इस पर से ही पर्दा हटाया गया है चिलमन के पार देखा गया है। 

विज्ञानियों ने अपने इस अध्ययन यह पता लगाया है कि यही वह जींस हैं  जो   उस प्रोटीन के कूट संकेतों का खुलासा करतीं  हैं  जो इन जीवन इकाइयों में रात्रिकाल में तो एकत्र हो जाती है,और दिन की अवधि में निम्नीकृत हो जाती है डिग्रेड हो रहती है स्वत :स्फूर्त  ही यह प्रोटीन।  
विशेष :इस खोज को इतना एहम क्यों समझा गया है क्या कुछ हासिल हो सकता है क्रोनो -बायलॉजी और क्रोनो -मेडिसिन जैसी नै विधाओं में इस पड़ताल से पढ़िए अगली (और अंतिम )क़िस्त में ,यानी इस आलेख के शेष अंश के रूप में। 

सन्दर्भ -सामिग्री :

(१ )https://www.nytimes.com/2017/10/02/health/nobel-prize-medicine.html 

(२ )Understanding of basic rhythm of human body can enhance health unexpectedly. The science of chronomedicine explores the interaction between biological rhythms, medicine and drugs. ... Endogenously regulated daily cyclic rhythms of body are known as circadian rhythms.
(३ )the scientific study of the effect of time on living systems and of biological rhythms. 
(4 ) http://www.sciencedirect.com/topics/neuroscience/chronobiology
(५  )circadian rhythms are daily rhythms that are approximately 24 h and mimic the geophysical cycles of day and night. 
(६ )https://www.newyorker.com/tech/elements/the-real-message-of-the-2017-nobel-prize-in-physiology-medicine
(७ )Similarly, studies of the circadian rhythm in flies have shed light on the genes and proteins that synchronize our own bodies with the day; they may lead to treatments for a wide range of maladies, from jet lag to obesity to heart disease.
(८ )Circadian biology and human health Chronobiology has an impact on many aspects of our physiology. For example, circadian clocks help to regulate sleep patterns, feeding behavior, hormone release, blood pressure and body temperature (Figure 3). Molecular clocks also play critical roles locally in many tissues. Ablation of clock genes in animal models results in arrhythmic production of hormones, such as corticosterone and insulin (Son et al., 2008). Clock genes also exert a profound influence on metabolism through the control of gluconeogenesis, insulin sensitivity and systemic oscillation of blood glucose (Panda, 2016). Sleep is vital for normal brain function and circadian dysfunction has been linked to sleep disorders, as well as depression, bipolar disorder, cognitive function, memory formation and some neurological diseases (Gerstner and Yin, 2010). Inrare cases, sleep phase disorders are due to mutations in circadian clock genes resulting in advanced or delayed sleep-wake cycles (Patke et al., 2017; Toh et al., 2001). Studies have indicated that chronic misalignment between our lifestyle and the rhythm dictated by our endogenous circadian clock may be associated with increased risk for various diseases including cancer,neurodegenerative diseases, metabolic disorders and inflammation. Efforts are underway to develop approaches in chronobiology and pharmacology to modify the period, phase or amplitude of circadian clocks to improve human health (Hirota and Kay, 2015).

Conclusions The discovery of self-sustained transcription/ translation feedback loops as the central component of the molecular mechanism by which clock genes control circadian oscillations in cells and tissues has led to a new paradigm in our understanding of how organisms anticipate and adapt to the regular daily environmental cues such as light. Since the seminal discoveries by the three laureates, elucidating a fundamental physiological mechanism, circadian biology hasdeveloped into a vast and highly dynamic research field, with important implications for our health and wellbeing.

Figure 3. The circadian clock has an impact on many aspects of our physiology. This clock helps to regulate sleep patterns, feeding behavior, hormone release, blood pressure and body temperature. A large proportion of our genes are regulated by the clock.

सन्दर्भ -सामिग्री :

(१ )https://www.nobelprize.org/nobel_prizes/medicine/laureates/2017/advanced-medicineprize2017.pdf
(२ )https://www.vox.com/science-and-health/2017/10/2/16396486/2017-nobel-prize-award-medicine-physiology-michael-rosbash-jeffrey-hall-michael-you
(३ )

The 2017 Nobel prize in medicine celebrates the tiny clocks in us all ...

https://www.vox.com/...health/.../2017-nobel-prize-award-medicine-physiology-mich...

Oct 2, 2017 - Three American scientists have won the Nobel Prize in physiology or medicine for ... Inhumans, these biological clocks anticipate various activities throughout ... Their findings have had major implications for health research and helped establish what's now a growing field of science called chronobiology.

Three American scientists have won the Nobel Prize in physiology or medicine for their discoveries of the microscopic biological machinery that controls the circadian rhythm, or the 24-hour body clock.

Humans, plants, and animals are all ruled by an internal clock that runs on a 24-hour, light-dark cycle in sync with the sun. And there’s not just one of these clocks inside us: They’re in every single cell of every organism — from a tiny bacterium to a large redwood tree.

In humans, these biological clocks anticipate various activities throughout the day, from waking up to sleeping and eating, by regulating things like hormone levels, temperature, and metabolism. Our circadian rhythm is intimately tied to our health and well-being (which helps explain why jet lag or a late-night shift work can be so draining and harmful).

The three Nobel laureates — Jeffrey C. Hall of the University of Maine, Michael Rosbash of Brandeis University, and Michael W. Young of Rockefeller University — “were able to peek inside our biological clock and elucidate its inner workings,” the Nobel Prize Committee said in a press release. “Their discoveries explain how plants, animals, and humans adapt their biological rhythm so that it is synchronized with the Earth's revolutions.”

In the 1970s, another pair of researchers — Seymour Benzer and his student Ronald Konopka — published their findings of an unknown gene called “period” that controlled the circadian rhythm of fruit flies.

Hall and Rosbash, who were working as collaborators at Brandeis University near Boston, as well as Young, who was (and still is) based at the Rockefeller University in New York, decided to dig deeper. By 1984, they were able to isolate the period gene. Hall and Rosbash also discovered the protein the period gene encoded, which appeared to build up during the night and degrade during the day on a circadian rhythm.
The trio went on to make other discoveries that explained how circadian rhythms are created and sustained. They also found additional proteins that activate the period gene.
“The paradigm-shifting discoveries by the laureates established key mechanistic principles for the biological clock,” the Nobel committee said. “During the following years other molecular components of the clockwork mechanism were elucidated, explaining its stability and function.”

These discoveries were seminal to the field of chronobiology


Long before Hall, Rosbash, and Young were doing their research, scientists suspected we were controlled by a circadian rhythm. But, the Nobel committee said, “Since the seminal discoveries by the three laureates, circadian biology has developed into a vast and highly dynamic research field, with implications for our health and wellbeing.”
Their findings have had major implications for health research and helped establish what’s now a growing field of science called chronobiology.
In recent years, researchers have discovered that each of us has a unique, genetically determined “chronotype,” or clock that programs our ideal sleep time in the 24-hour cycle. This discovery helped clarify why there are true “morning people” and true “night owls,” and why, as Vox’s Brian Resnick has argued, people should be able to set their own work schedules.
Researchers even coined the term “social jet lag” to describe the effects of shifting one’s sleep cycle by even a couple of hours. (Even moving people’s sleep cycle by one hour each day made participants in a study look prediabetic after a three-week trial.)
Researchers studying chronobiology have also found that eating at night can be extra problematic for health, since our bodies aren’t primed to cope with the glucose load from the food in the evening. We usually eat a meal after waking up, so our bodies adapted to produce the most insulin in the morning.
There’s also emerging work that suggests our circadian rhythm can influence how we metabolize medicines: The timing of taking a drug during the day may control its effectiveness.
So we are slaves to our circadian system, and Hall, Rosbash, and Young helped us understand how and why.

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