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University of Oxford Researchers Use Spectroscopy and Artificial Intelligence to Create a Blood Test for Chronic Fatigue Syndrome

Spectroscopic technique was 91% accurate in identifying the notoriously difficult-to-diagnose disease suggesting a clinical diagnostic test for CFS may be possible

Most clinical pathologists know that, despite their best efforts, scientists have failed to come up with a reliable clinical laboratory blood test for diagnosing myalgic encephalomyelitis (ME), the condition commonly known as chronic fatigue syndrome (CFS)—at least not one that’s ready for clinical use.

But now an international team of researchers at the University of Oxford has developed an experimental non-invasive test for CFS using a simple blood draw, artificial intelligence (AI), and a spectroscopic technique known as Raman spectroscopy.

The approach uses a laser to identify unique cellular “fingerprints” associated with the disease, according to an Oxford news release.

“When Raman was added to a panel of potentially diagnostic outputs, we improved the ability of the model to identify the ME/CFS patients and controls,” Karl Morten, PhD, Director of Graduate Studies and Principal Investigator at Oxford University, told Advanced Science News. Morton led the research team along with Wei Huang, PhD, Professor of Biological Engineering at Oxford.

The researchers claim the test is 91% accurate in differentiating between healthy people, disease controls, and ME/CFS patients, and 84% accurate in differentiating between mild, moderate, and severe cases, the new release states.

The researchers published their paper in the journal Advanced Science titled, “Developing a Blood Cell-Based Diagnostic Test for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Using Peripheral Blood Mononuclear Cells.”

Karl Morten, PhD

“This could be a game changer as we are unsure what causes [ME/CFS] and diagnosis occurs perhaps 10 to 20 years after the condition has started to develop,” said Karl Morten, PhD, Director of Graduate Studies and Principal Investigator at Oxford University. “An early diagnosis might allow us to identify what is going wrong with the potential to fix it before the more long-term degenerative changes are observed.” Though this research may not lead to a simple clinical laboratory blood test for CFS, any non-invasive diagnostic test would enable doctors to help many people. (Photo copyright: Oxford University.)

Need for an ME/CFS Test

The federal Centers for Disease Control and Prevention (CDC) describes ME/CFS as “a serious, long-term illness that affects many body systems,” with symptoms that include severe fatigue and sleep difficulties. Citing an Institute of Medicine (IoM) report, the agency estimates that 836,000 to 2.5 million Americans suffer from the condition but notes that most cases have not been diagnosed.

“One of the difficulties is the complexity of the disease,” said Jonas Bergquist, MD, PhD, Director of the ME/CFS Research Center of Uppsala University in Sweden, told Advanced Science News. “Because it’s a multi-organ disorder, you get symptoms from many different regions of the body with different onsets, though it’s common with post viral syndrome to have different overlapping [symptoms] that disguise the diagnosis.” Bergquist was not involved with the Oxford study.

One key to the Oxford researchers’ technique is the use of multiple artificial intelligence models to analyze the spectral profiles. “These signatures are complex and by eye there are not necessarily clear features that separate ME/CFS patients from other groups,” Morten told Advanced Science News.

“The AI looks at this data and attempts to find features which can separate the groups,” he continued. “Different AI methods find different features in the data. Individually, each method is not that successful at assigning an unknown sample to the correct group. However, when we combine the different methods, we produce a model which can assign the subjects to the different groups very accurately.”

Without a reliable test, “diagnosis of the condition is difficult, with most patients relying on self-report, questionnaires, and subjective measures to receive a diagnosis,” the Oxford press release noted.

But developing such a test has been challenging, Advanced Science News noted.

How Oxford’s Raman Technique Works

Raman spectroscopy uses a laser to determine the “vibrational modes of molecules,” according to the Oxford press release.

“When a laser beam is directed at a cell, some of the scattered photons undergo frequency shifts due to energy exchanges with the cell’s molecular components,” the press release stated. “Raman micro-spectroscopy detects these shifted photons, providing a non-invasive method for single cell analysis. The resulting single cell Raman spectra serve as a unique fingerprint, revealing the intrinsic and biochemical properties and indicating the physiological and metabolic state of the cell.”

The researchers employed the technique on blood samples from 98 subjects, including 61 ME/CFS patients, 16 healthy controls, and 21 controls with multiple sclerosis (MS), Advanced Science reported.

The Oxford scientists focused their attention on peripheral blood mononuclear cells (PBMCs), as previous studies found that these cells showed “reduced energetic function” in ME/CFS patients. “With this evidence, the team proposed that single-cell analysis of PBMCs might reveal differences in the structure and morphology in ME/CFS patients compared to healthy controls and other disease groups such as multiple sclerosis,” the press release states.

Clinical Laboratory Blood Processing and the Oxford Raman Technique

Oxford’s Raman spectroscopic technique “only requires a small blood sample which could be developed as a point-of-care test perhaps from one drop of blood,” the researchers wrote. However, Advanced Science News pointed out that required laser microscopy equipment costs more than $250,000.

In their Advanced Science paper, the researchers note that the test could be made more widely available by transferring blood samples collected by local clinical laboratories to diagnostic centers that have the needed hardware.

“Alternatively, a compact system containing portable Raman instruments could be developed, which would be much cheaper than a standard Raman microscope, and [which] incorporated with microfluidic systems to stream cells through a Raman laser for detection, eliminating the need for lengthy blood sample processing,” the researchers wrote.

They noted that the technique could be adapted to test for other chronic conditions as well, such as MS, fibromyalgia, Lyme disease, and long COVID.

“Our paper is very much a starting point for future research,” Morten told Advanced Science News. “Larger cohorts need to be studied, and if Raman proves useful, we need to think carefully about how a test might be developed.”

Bergquist agreed, stating it’s “not necessarily something you would see in a doctor’s office. It requires a lot of advanced data analysis to use—I still see it as a research methodology. But in the long run, it could be developed into a tool that could be used in a more simplistic way.”

Though a useable diagnostic test may be far off, clinical laboratories should consider how they can aid in ME/CFS research.

—Stephen Beale

Related Information:

First Steps Towards Developing a New Diagnostic Test to Accurately Identify Hallmarks of Chronic Fatigue Syndrome in Blood Cells

First Ever Diagnostic Test for Chronic Fatigue Syndrome Sparks Hope

Developing a Blood Cell-Based Diagnostic Test for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Using Peripheral Blood Mononuclear Cells

Blood Test for Chronic Fatigue Syndrome Found to Be 91% Accurate

Scientists Develop Blood Test for Chronic Fatigue Syndrome

Biomarkers for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Systematic Review

Biomarker for Chronic Fatigue Syndrome Identified

University of Athens Researchers Create Wooden Tongue Depressor with Biosensing Capabilities Capable of Identifying Biomarkers

Scientists believe the biodegradable device could someday help detect multiple saliva biomarkers. If true, it might provide a new type of test for clinical laboratories

When it comes to tongue depressors, it turns out you can teach an old dog new tricks. Researchers from National and Kapodistrian University of Athens Greece (NKUA) have taken this simple wooden medical tool and developed a high-tech biosensing device that may someday be useful at the point-of-care in hospitals and as a new type of test for clinical laboratories.

Using diode laser engraving, the researchers developed an “eco-friendly disposable sensor that can measure glucose levels and other biomarkers in saliva,” according to LabMedica.

This proof-of-principle biosensing device demonstrates the feasibility of “simultaneous determination of glucose and nitrite in artificial saliva,” according to the NKUA scientists who hope it will help doctors diagnose a variety of conditions.

The researchers published a paper on the development of their new wooden biosensor in the journal Analytical Chemistry titled, “Wooden Tongue Depressor Multiplex Saliva Biosensor Fabricated via Diode Laser Engraving.”

biosensing tongue depressor

In their published paper, the scientists at the University of Athens wrote that their wooden electrochemical biosensing tongue depressor (above) “is an easy-to-fabricate disposable point-of-care chip with a wide scope of applicability to other bioassays,” and that “it paves the way for the low-cost and straightforward production of wooden electrochemical platforms.” Might this and other similar biosensing devices eventually find their way to clinical laboratories for use in identifying and tracking certain biomarkers for disease? (Photo copyright: University of Athens.)


How to Make a High-Tech Tongue Depressor

Though wood is affordable and accessible, it doesn’t conduct electricity very well. The researchers’ first attempt to solve this problem was to use the wood as “a passive substrate” to which they coated “metals and carbon-based inks,” LabMedica reported. After that they tried using high-powered lasers to “char specific regions on the wood, turning those spots into conductive graphite.” But that process was complicated, expensive, and a fire hazard.

The researchers eventually turned to “low-power diode lasers” which have been used successfully “to make polyimide-based sensors but have not previously been applied to wooden electronics and electrochemical sensors,” LabMedica noted.

In their Analytical Chemistry paper, the researchers wrote, “A low-cost laser engraver, equipped with a low-power (0.5 W) diode laser, programmably irradiates the surface of the WTD [wooden tongue depressor], forming two mini electrochemical cells (e-cells). The two e-cells consist of four graphite electrodes: two working electrodes, a common counter, and a common reference electrode. The two e-cells are spatially separated via programmable pen-plotting, using a commercial hydrophobic marker pen.”

In other words, the researchers “used a portable, low-cost laser engraver to create a pattern of conductive graphite electrodes on a wooden tongue depressor, without the need for special conditions. Those electrodes formed two electrochemical cells separated by lines drawn with a water-repellent permanent marker,” states a press release from the American Chemical Society.

“The biosensor was then used to quickly and simultaneously measure nitrite and glucose concentrations in artificial saliva. Nitrite can indicate oral diseases like periodontitis, while glucose can serve as a diagnostic for diabetes. The researchers suggest that these low-cost devices could be adapted to detect other saliva biomarkers and could be easily and rapidly produced on-site at medical facilities,” LabMedica reported.

Benefits of Using Wood

One of the major benefits of using wood for their biosensing device is how environmentally friendly it is. “Since wood is a renewable, biodegradable naturally occurring material, the development of conductive patterns on wood substrates is a new and innovative chapter in sustainable electronics and sensors,” the researchers wrote in Analytical Chemistry.

Additionally, the tongue depressor features “An easy-to-fabricate disposable point-of-care chip with a wide scope of applicability to other bioassays, while it paves the way for the low-cost and straightforward production of wooden electrochemical platforms,” the researchers added.

This adds to a growing trend of developing bioassay products that keep the health of our planet in mind.

In “University of Pennsylvania Researchers Use Cellulose to Produce Accurate Rapid COVID-19 Test Results Faster and Cheaper than Traditional PCR Tests,” we covered how researchers at the University of Pennsylvania (UPenn) had developed a biodegradable rapid COVID-19 test that uses bacterial cellulose (BC) instead of printed circuit boards (PCBs) as its biosensor.

“This new BC test is non-toxic, naturally biodegradable and both inexpensive and scalable to mass production, currently costing less than $4.00 per test to produce. Its cellulose fibers do not require the chemicals used to manufacture paper, and the test is almost entirely biodegradable,” a UPenn blog post noted.

New Future Tool Use in Clinical Diagnostics

Who could have predicted that the lowly wooden tongue depressor would go high tech with technology that uses lasers to convert it to an electrochemical multiplex biosensing device for oral fluid analysis? This is yet another example of technologies cleverly applied to classic devices that enable them to deliver useful diagnostic information about patients.

And while a biosensing tongue depressor is certainly a diagnostic tool that may be useful for nurses and physicians in clinic and hospital settings, with further technology advancements, it could someday be used to collect specimens that measure more than glucose and nitrites.

—Kristin Althea O’Connor

Related Information:

Wooden Tongue Depressor Multiplex Saliva Biosensor Fabricated via Diode Laser Engraving

Say ‘Ahhh’: This Ecofriendly Tongue Depressor Checks Vitals

Biosensor-Fabricated Wooden Tongue Depressor Measures Glucose and Nitrite in Saliva

Researchers at Stanford University Discover Gene Variant That Appears to Protect Individuals from Both Alzheimer’s and Parkinson’s Disease

Study findings may lead to new clinical laboratory tests, as well as vaccines and immunotherapies for neurodegenerative diseases

Research into the human genome continues to produce useful new insights. This time, a study led by researchers at Stanford University identified a genetic variation that is believed to help “slow or even stall” progression of neurodegenerative diseases, including Alzheimer’s and Parkinson’s, according to a press release. Because these genetic variations are common, it is likely that diagnostic tests can be developed for use by clinical laboratories.

Researchers at Stanford Medicine led the study which discovered that approximately one in five individuals carry the gene variant, a protective allele identified as DR4 (aka, HLA-DR4). It’s one of a large number of alleles found in a gene known as DRB1.

DRB1 is part of a family of genes collectively known as the human lymphocyte antigen complex or HLA. The HLA-DRB1 gene plays a crucial role in the ability of the immune system to see a cell’s inner contents.

The Stanford scientists published their findings in the journal PNAS titled, “Multiancestry Analysis of the HLA Locus in Alzheimer’s and Parkinson’s Diseases Uncovers a Shared Adaptive Immune Response Mediated by HLA-DRB1*04 Subtypes.” Approximately 160 researchers from roughly 25 countries contributed to the work. 

Emmanuel Mignot, MD, PhD

“In an earlier study, we’d found that carrying the DR4 allele seemed to protect against Parkinson’s disease,” said Emmanuel Mignot, MD, PhD (above), Director of the Stanford Center for Narcolepsy, in a Stanford press release. “Now, we’ve found a similar impact of DR4 on Alzheimer’s disease.” Clinical laboratories may soon have new vaccines for both neurodegenerative diseases. (Photo copyright: Stanford University.)


DR4 Found to Impact Both Parkinson’s and Alzheimer’s Diseases

To perform their research, the team examined a large collection of medical and genetic databases from 176,000 people who had either Alzheimer’s or Parkinson’s disease. The people involved in the study were from numerous countries located in East Asia, Europe, the Middle East and South America. Their genomes were then compared with people who did not have the diseases, focusing on the incidence and age of onset.

“In an earlier study we’d found that carrying the DR4 allele seemed to protect against Parkinson’s disease,” said Mignot in the Stanford press release. “Now, we’ve found a similar impact of DR4 on Alzheimer’s disease.”

The team found that about 20% to 30% of people carry DR4, and that they have around a 10% risk reduction for developing the two diseases. 

“That this protective factor for Parkinson’s wound up having the same protective effect with respect to Alzheimer’s floored me,” said Emmanuel Mignot, MD, PhD, the Craig Reynolds Professor of Sleep Medicine in the Department of Psychiatry and Behavioral Sciences at Stanford University and the Director of the Stanford Center for Narcolepsy, in the Stanford Medicine press release. “The night after we found that out, I couldn’t sleep.”

The scientists also analyzed data from autopsied brains of more than 7,000 Alzheimer’s patients and discovered that individuals who carry DR4 had fewer neurofibrillary tangles and that those tangles are composed mainly of modified tau proteins, a common biomarker for Alzheimer’s.

The presence of these tangles corresponds with the severity of Alzheimer’s disease. They are not typically seen in Parkinson’s patients, but the Stanford team found that Parkinson’s patients who did carry DR4 experienced later onset of symptoms.

Mignot stated that tau, which is essential in Alzheimer’s, may also play a role in Parkinson’s, but that further research is required to prove its function.

Both diseases are characterized by the progressive loss of certain nerve cells or neurons in the brain and are linked to an accumulation of abnormal proteins. The Stanford researchers suggested that the DR4 gene variant may help protect individuals from Alzheimer’s and Parkinson’s by preventing the buildup of tau proteins.

“This is a very interesting study, providing additional evidence of the involvement of the immune system in the pathogenesis of Alzheimer’s and Parkinson’s,” neurologist Wassim Elyaman, PhD, Assistant Professor of Neurological Sciences in Neurology, the Taub Institute and the Institute for Genomic Medicine at Columbia University, told Live Science.

New Vaccines and Immunotherapies

According to the Alzheimer’s Association, more than six million Americans are currently living with Alzheimer’s disease and approximately one in three Americans die with Alzheimer’s or another dementia. 

The Parkinson’s Foundation states that nearly one million Americans are currently living with Parkinson’s disease, and that number is expected to rise to 1.2 million by 2030. Parkinson’s is the second-most common neurodegenerative disease after Alzheimer’s disease.

Even though the genetic analysis of the Stanford research is strong, more immune cell and blood-based research is needed to definitively establish how tau is connected to the two diseases.

This research could have implications for clinical laboratories by giving them biomarkers for a useful new diagnostic test, particularly for diagnosing Alzheimer’s and Parkinson’s.

Further, Mignot suggested that an effective vaccine could delay the onset or slow the progression of both diseases. He hopes to test his hypothesis on genetically modified mice and eventually human subjects.

—JP Schlingman

Related Information:

Stanford Medicine-led Study Finds Genetic Factor Fends Off Alzheimer’s and Parkinson’s

Gene Variant Carried by One in Five People May Guard Against Alzheimer’s and Parkinson’s, Massive Study Finds

Multiancestry Analysis of the HLA Locus in Alzheimer’s and Parkinson’s Diseases Uncovers a Shared Adaptive Immune Response Mediated by HLA-DRB1*04 Subtypes

Alzheimer’s Disease: Tau Biology and Pathology

Tau Protein and Alzheimer’s Disease: What’s the Connection?

C₂N Diagnostics Releases PrecivityAD, the First Clinical Laboratory Blood Test for Alzheimer’s Disease

Asian Company Launches World’s First Diagnostic Test for Microbiome of the Mouth

Collected data could give healthcare providers and clinical laboratories a practical view of individuals’ oral microbiota and lead to new diagnostic assays

When people hear about microbiome research, they usually think of the study of gut bacteria which Dark Daily has covered extensively. However, this type of research is now expanding to include more microbiomes within the human body, including the oral microbiome—the microbiota living in the human mouth. 

One example is coming from Genefitletics, a biotech company based in New Delhi, India. It recently launched ORAHYG, the first and only (they claim) at-home oral microbiome functional activity test available in Asia. The company is targeting the direct-to-consumer (DTC) testing market.

According to the Genefitletics website, the ORAHYG test can decode the root causes of:

The test can also aid in the early detection development of:

“Using oral microbial gene expression sequencing technology and its [machine learning] model, [Genefitletics] recently debuted its oral microbiome gene expression solution, which bridges the gap between dentistry and systemic inflammation,” ETHealthworld reported.

“The molecular insights from this test would give an unprecedented view of functions of the oral microbiome, their interaction with gut microbiome and impact on metabolic, cardiovascular, cognitive, skin, and autoimmune health,” BioSpectrum noted.

Sushant Kumar

“Microbes, the planet Earth’s original inhabitants, have coevolved with humanity, carry out vital biological tasks inside the body, and fundamentally alter how we think about nutrition, medicine, cleanliness, and the environment,” Sushant Kumar (above), founder and CEO of Genefitletics, told the Economic Times. “This has sparked additional research over the past few years into the impact of the trillions of microorganisms that inhabit the human body on our health and diverted tons of funding into the microbiome field.” Clinical laboratories may eventually see an interest and demand for testing of the oral microbiome. (Photo copyright: ETHealthworld.)


Imbalanced Oral Microbiome Can Trigger Disease

The term microbiome refers to the tiny microorganisms that reside on and inside our bodies. A high colonization of these microorganisms—including bacteria, fungi, yeast, viruses, and protozoa—live in our mouths.

“Mouth is the second largest and second most diverse colonized site for microbiome with 770 species comprising 100 billion microbes residing there,” said Sushant Kumar, founder and CEO of Genefitletics, BioSpectrum reported. “Each place inside the mouth right from tongue, throat, saliva, and upper surface of mouth have a distinctive and unique microbiome ecosystem. An imbalanced oral microbiome is said to trigger onset and progression of type 2 diabetes, arthritis, heart diseases, and even dementia.”

The direct-to-consumer ORAHYG test uses a saliva sample taken either by a healthcare professional or an individual at home. That sample is then sequenced through Genefitletics’ gene sequencing platform and the resulting biological data set added to an informatics algorithm.

Genefitletics’ machine-learning platform next converts that information into a pre-symptomatic molecular signature that can predict whether an individual will develop a certain disease. Genefitletics then provides that person with therapeutic and nutritional solutions that can suppress the molecules that are causing the disease. 

“The current industrial healthcare system is really a symptom care [system] and adopts a pharmaceutical approach to just make the symptoms more bearable,” Kumar told the Economic Times. “The system cannot decode the root cause to determine what makes people develop diseases.”

Helping People Better Understand their Health

Founded in 2019, Genefitletics was created to pioneer breakthrough discoveries in microbial science to promote better health and increase longevity in humans. The company hopes to unravel the potential of the oral microbiome to help people fend off illness and gain insight into their health. 

“Microorganisms … perform critical biological functions inside the body and transform our approach towards nutrition, medicine, hygiene and environment,” Kumar told CNBC. “It is important to understand that an individual does not develop a chronic disease overnight.

“It starts with chronic inflammation which triggers pro-inflammatory molecular indications. Unfortunately, these molecular signatures are completely invisible and cannot be measured using traditional clinical grade tests or diagnostic investigations,” he added. “These molecular signatures occur due to alteration in gene expression of gut, oral, or vaginal microbiome and/or human genome. We have developed algorithms that help us in understanding these alterations way before the clinical symptoms kick in.” 

Genefitletics plans to utilize individuals’ collected oral microbiome data to determine their specific nutritional shortcomings, and to develop personalized supplements to help people avoid disease.

The company also produces DTC kits that analyze gut and vaginal microbiomes as well as a test that is used to evaluate an infant’s microbiome.

“The startup wants to develop comparable models to forecast conditions like autism, PCOS [polycystic ovarian syndrome], IBD [Inflammatory bowel disease], Parkinson’s, chronic renal [kidney] disease, anxiety, depression, and obesity,” the Economic Times reported.

Time will tell whether the oral microbiome tests offered by this company prove to be clinically useful. Certainly Genefitletics hopes its ORAHYG test can eventually provide healthcare providers—including clinical laboratory professionals—with a useful view of the oral microbiome. The collected data might also help individuals become aware of pre-symptomatic conditions that make it possible for them to seek confirmation of the disease and early treatment by medical professionals.   

—JP Schlingman

Related Information:

Genefitletics Brings Asia’s First Oral Microbiome Test ORAHYG

Let’s Focus on the Role of Microbiomes in Systemic Inflammation and Disease Development: Sushant Kumar, Genefitletics

Genefitletics Can Now Predict and Detect Chronic Diseases and Cancer

Genefitletics Can Now Predict and Detect Chronic Diseases and Cancer

Healthtech Startup Genefitletics Raises Undisclosed Amount in Pre-seed Funding

Understanding Oral Microbiome Testing: What You Need to Know

Stanford Researchers Discover Junk DNA Affects Gene Expression

Research findings could lead to new biomarkers for genetic tests and give clinical laboratories new capabilities to diagnose different health conditions

New insights continue to emerge about “junk DNA” (aka, non-coding DNA). For pathologists and clinical laboratories, these discoveries may have value and eventually lead to new biomarkers for genetic testing.

One recent example comes from researchers at Stanford Medicine in California who recently learned how non-coding DNA—which makes up 98% of the human genome—affects gene expression, the function that leads to observable characteristics in an organism (phenotypes).

The research also could lead to a better understanding of how short tandem repeats (STRs)—the number of times a gene is copied into RNA for protein use—affect gene expression as well, according to Stanford.

Scientists at Stowers Institute for Medical Research and Duke University School of Medicine contributed to the study.

The researchers published their findings in the journal Science titled, “Short Tandem Repeats Bind Transcription Factors to Tune Eukaryotic Gene Expression.”

Polly Fordyce, PhD

“We’ve known for a while that short tandem repeats or STRs, aren’t junk because their presence or absence correlates with changes in gene expression. But we haven’t known how they exert these effects,” said study lead Polly Fordyce, PhD (above), Associate Professor of Bioengineering and Genetics at Stanford University, in a news release. The research could lead to new clinical laboratory biomarkers for genetic testing. (Photo copyright: Stanford University.)


To Bind or Not to Bind

In their Science paper, the Stanford researchers described an opportunity to explore a new angle to transcription factors binding to some sequences, also known as sequence motifs.

“Researchers have spent a lot of time characterizing these transcription factors and figuring out which sequences—called motifs—they like to bind to the most,” said the study lead Polly Fordyce, PhD, Associate Professor of Bioengineering and Genetics at Stanford University, in a Stanford Medicine news release.

“But current models don’t adequately explain where and when transcription factors bind to non-coding DNA to regulate gene expression. Sometimes, no transcription factor is attached to something that looks like a perfect motif. Other times, transcription factors bind to stretches of DNA that aren’t motifs,” the news release explains.

Transcription factors are “like light switches that can turn genes on or off depending on what cells need,” notes a King’s College London EDIT Lab blog post.

But why do transcription factors target some places in the genome and not others?

“To solve the puzzle of why transcription factors go to some places in the genome and not to others, we needed to look beyond the highly preferred motifs,” Fordyce added. “In this study, we’re showing that the STR sequence around the motif can have a really big effect on transcription factor binding, providing clues as to what these repeated sequences might be doing.”

Such information could aid in understanding certain hereditary conditions and diseases. 

“Variations in STR length have been associated with changes in gene expression and implicated in several complex phenotypes such as schizophrenia, cancer, autism, and Crohn’s disease. However, the mechanism by which STRs affect transcription remains unknown,” the researchers wrote in Science.

Special Assays Explore Binding

According to their paper, the research team turned to the Fordyce Lab’s previously developed microfluidic binding assays (MITOMI, kMITOMI, and STAMMP) to analyze the impact of different DNA sequences on transcription factor binding.

“In the experiment we asked, ‘How do these changes impact the strength of transcription factor binding?’ We saw a surprisingly large effect. Varying the STR sequence around a motif can have a 70-fold impact on the binding,” Fordyce wrote.

In an accompanying Science article titled, “Repetitive DNA Regulates Gene Expression,” Thomas Kuhlman, PhD, Assistant Professor, Physics and Astronomy, University of California, Riverside, wrote that the study “demonstrates that STRs exert their effects by directly binding transcription factor proteins, thus explaining how STRs might influence gene expression in both normal and diseased states.”

Junk DNA Affects Blood Pressure

In another study, researchers at The Hospital for Sick Children (SickKids), which is affiliated with the University of Toronto, Ontario, examined the possible effect of non-coding DNA on genes related to blood pressure.

“This research unveils, for the first time, the intricate connection between how variants in the non-coding genome affect genes that are associated with blood pressure and with hypertension. What we’ve created is a kind of functional map of the regulators of blood pressure genes, “said Philipp Maass, PhD, Lead Researcher and Assistant Professor Molecular Genetics, University of Toronto, in a news release.

The research team used massively parallel reporter assay (MPRA) technology to analyze 4,608 genetic variants associated with blood pressure.

In “Systematic Characterization of Regulatory Variants of Blood Pressure Genes,” published in the journal Cell Genomics, the SickKids scientists noted that high throughput technology identified “regulatory variants at blood pressure loci.”

The findings could aid precision medicine for cardiovascular health and may possibly be adopted to other conditions, according to The Hospital for Sick Children.

“The variants we have characterized in the non-coding genome could be used as genomic markers for hypertension, laying the groundwork for future genetic research and potential therapeutic targets for cardiovascular disease,” Maass noted.

Why All the ‘Junk’ DNA?

Clinical laboratory scientists may wonder why genetic research has primarily focused on 20,000 genes within the genome, leaving the “junk” DNA for later investigation. So did researchers at Harvard University.

“After the Human Genome Project, scientists found that there were around 20,000 genes within the genome, a number that some researchers had already predicted. Remarkably, these genes comprise only about 1-2% of the three billion base pairs of DNA. This means that anywhere from 98-99% of our entire genome must be doing something other than coding for proteins,” they wrote in a blog post.

“Imagine being given multiple volumes of encyclopedias that contained a coherent sentence in English every 100 pages, where the rest of the space contained a smattering of uninterpretable random letters and characters. You would probably start to wonder why all those random letters and characters were there in the first place, which is the exact problem that has plagued scientists for decades,” they added.

Not only is junk DNA an interesting study subject, but ongoing research may also produce useful new biomarkers for genetic diagnostics and other clinical laboratory testing. Thus, medical lab professionals may want to keep an eye on new developments involving non-coding DNA.   

—Donna Marie Pocius

Related Information:

Stanford Medicine-led Study Clarifies How “Junk DNA” Influences Gene Expression

Short Tandem Repeats Bind Transcription Factors to Tune Eukaryotic Gene Expression

J for Junk DNA Does Not Exist!

Repetitive DNA Regulates Gene Expression

Illuminating Genetic Dark Matter: How “Junk DNA” Influences Blood Pressure

Systematic Characterization of Regulatory Variants of Blood Pressure Genes

The 99 Percent of the Human Genome

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