Proteins that normally reside inside cell nuclei have never been found in the blood, until now. A new blood test developed at the Johns Hopkins University by Shih-Chin Wang and Chih-Ping Mao—graduate students in Jie Xiao’s lab in the Department of Biophysics and Chien-Fu Hung’s lab in the Department of Pathology—can identify individual molecules in human blood samples with minimal detection errors. Among the molecules that they used their new test to find was a mutated protein thought to be restricted to the inside of cells, mostly within the nucleus. It is the first time that single-molecule imaging has been applied to visualize disease-causing molecules in blood.
Wang and colleagues call their new approach Single-Molecule Augmented Capture (SMAC). They used this new technique to detect molecules commonly screened for in standard blood tests, like prostate-specific antigen. And they were also able to detect rare intracellular proteins, secreted proteins and membrane proteins, including the cancer-associated proteins mutant p53, anti-p53 autoantibodies and programmed death-ligand 1 (PD-L1).
Mutant p53 is a well-known tumour-specific nuclear protein and has never before been detected in the blood, likely because current tests cannot detect its extremely low blood concentrations. Wang and colleagues found mutant p53 or anti-p53 autoantibodies in samples from patients with ovarian cancer, but not in patients without cancer. PD-L1 is also found on the surface of some cancer cells and has recently been effectively targeted with immunotherapy to combat cancer. Knowing whether or not a patient’s tumour expresses PD-L1 is a crucial first step in this treatment—and SMAC may be able to identify cancers that have PD-L1 at low levels that are undetectable by standard blood tests.
“With SMAC, we have brought single-molecule imaging into the clinical arena. By visualizing and examining individual molecules released from diseased cells into the blood, we aim to detect diseases more accurately and gain new insights into their mechanisms,” Mao said.
Biophysics Society https://tinyurl.com/yynccngq

Researchers at the University of Exeter Medical School have developed simple and inexpensive ways to measure C-peptide and have demonstrated that this test can show what treatment will be most effective for people with diabetes. Clinicians at the Western General Hospital in Edinburgh have used the new test on every person thought to have type 1 diabetes for over three years in their clinic and shown that some actually have other types of diabetes and can stop insulin treatment.
C-peptide is produced at the same time and in the same quantities as the insulin that regulates our blood sugar. By measuring C-peptide levels, doctors can now tell how much insulin a person is producing themselves, even if they are taking insulin injections as treatment.
The Exeter team has developed a new urine test for C-peptide, and shown that a simple blood test when a person is seen in clinic can also accurately measure C-peptide, replacing previous methods which were expensive and time-consuming. These tests are now available in nearly every hospital in the UK, and cost as little as £10.
The team demonstrated how urine and blood C-peptide can be used to robustly identify what type of diabetes a person has, and help identify what treatment will work for them. This is crucial to getting the right treatment, education and follow-up care. By offering this test to people thought to have Type 1 diabetes in their clinic, the Edinburgh researchers have shown that many have high C-peptide, raising the possibility of other types of diabetes. Some of these patients have been able to stop insulin and switch to tablet treatment. This testing also revealed that in some of these patients, the diabetes had a genetic cause, which is important both for treatment and for other people in their families.
Professor Mark Strachan, from Western General Hospital, Edinburgh, said: “We have now measured C-peptide in over 750 people with a clinician-diagnosis of Type 1 diabetes, attending our clinic at the Westen General Hospital. So far, we have made a new diagnosis of genetic diabetes in eight people, and changed the diagnosis to Type 2 diabetes in 28 other people. This has allowed us to make changes to treatment in many of these individuals and in 12 people we have actually been able to stop insulin therapy.”
The team’s research also shows that C peptide testing is practical in clinics. They identified optimal storage conditions for the samples, which were previously thought to be unstable, so sample collection is now much easier. They showed that using a specific preservative means that blood C-peptide is stable for more than 24 hours. For the first time, this means it is viable to conduct a test to be measured in primary care and outpatient clinics. This evidence together removed crucial barriers to implementation that had previously blocked widespread adoption of this test in routine clinical care.
University of Exeter www.exeter.ac.uk/news/research/title_707155_en.html

New research on the X chromosome from the School of Veterinary Medicine points to an abnormality in the immune system’s T cells as a possible contributing factor in lupus and other autoimmune diseases.
The autoimmune disease lupus, which can cause fatigue, a facial rash, and joint pain, strikes females far more often than males. Eight-five percent of people with lupus are female, and their second X chromosome seems partly to blame. According to a new study by Penn researchers, females with lupus don’t fully “silence” their second X chromosome in the immune system’s T cells, leading to abnormal expression of genes linked to that chromosome.
The work, led by Montserrat Anguera of the School of Veterinary Medicine is the first to connect disruptions in maintaining X chromosome inactivation in T cells to lupus. It also suggests that changes to the nuclear structure in the inactive X chromosome of T cells may play a part in the genetic missteps that can arise in lupus—the first time that nuclear organization has been noted as a feature of this disease.
“In normal circumstances, the inactive X should be silenced, and what we show is, in lupus, it’s not,” says Anguera, a biologist at Penn Vet. “And it’s ultimately affecting gene expression.”
Anguera’s lab has paid close attention to the link between X chromosome inactivation, an epigenetic process that balances gene expression between males and females, and autoimmune disease. In earlier studies, the team found that, in females, both T cells and B cells have incomplete inactivation of the second X chromosome due to changes in the patterns of Xist, an RNA molecule that is necessary for X inactivation.
In the new work, Anguera and colleagues wanted to more closely examine this process in T cells and specifically in the context of an autoimmune disease, in this case, lupus.
They first tracked the process of X inactivation in T cells from healthy mice. Their observations revealed that, as T cells develop, Xist temporarily diffuses away from the inactive X chromosome. But when a T cell is activated, as it would be upon encountering a potential pathogen, for example, then Xist RNA returns to this chromosome.
To see what happens in autoimmune disease, the researchers used a mouse model that spontaneously develops lupus in a female-biased manner, similar to the human disease. All female mice of this strain develop the disease, while only 40 percent of males do. Examining the animals’ T cells, the researchers discovered that those at early stages of disease resembled healthy controls in their patterns of Xist localization. But those in the later stages of disease had a dramatically different pattern.
The only differences we detected happened at late stages of disease,” Anguera says. “What this means is that abnormal X inactivation is a consequence of the disease; it’s not predisposing the animal to develop the disease.”
Interestingly, when the researchers looked at T cells from paediatric lupus patients, provided by study co-author Edward M. Behrens of the Perelman School of Medicine and Children’s Hospital of Philadelphia, they found the same mislocalization of Xist that they had seen in the mice with lupus, even though the children were in remission from their disease.  
Even stimulating those patients’ cells in vitro wasn’t enough to coax Xist into the normal pattern. “Even though they don’t have active disease, there’s something missing that’s preventing the RNA from staying targeted at that inactive X chromosome,” Anguera says.
University of Pennsylvania https://tinyurl.com/y3nsrssw

Patients with colorectal cancer have the same consistent changes in the gut bacteria across continents, cultures, and diets — a team of international researchers, from University of Copenhagen among others, find in a new study. The hope is the results in the future can be used to develop a new method of diagnosing colorectal cancer.
Cancers have long been known to arise due to environmental exposures such as unhealthy diet or smoking. Lately, the microbes living in and on our body have entered the stage as key players. But the role that gut microbes play in the development of colorectal cancer – the third most common cancer worldwide – is unclear. To determine their influence, association studies have aimed to map how the microbes colonizing the gut of colorectal cancer patients are different from those that inhabit healthy subjects.
Now, researchers from University of Copenhagen, EMBL, the University of Trento, and their international collaborators have analysed multiple existing microbiome association studies of colorectal cancer together with newly generated data. Their meta-analyses establish disease-specific microbiome changes, which are globally robust – consistent across seven countries on three continents – despite differences in environment, diet and life style.
“During disease our microbiome may change. If these changes are consistent in each person getting the same disease then it is a signature of disease. What we show in our study is that the gut microbiome signatures in colorectal cancer seem to be universal. This is despite geography, culture and life style. In the future we hope we can use these signatures as biomarkers and as a diagnostic tool for colorectal cancer,” says Manimozhiyan Arumugam, Associate Professor at the Novo Nordisk Foundation Center for Basic Metabolic Research.
It is the first time a meta-analyses for colorectal cancer has been done on this scale. In the study, the researchers have analyzed and used data from seven cohorts from the countries China, Austria, France, Germany, the US, Italy and Japan.
“We used a rigorous machine learning analysis to identify microbial signatures for colorectal cancer. We validated these signatures in early cancer stages and in multiple studies, so they can serve as the basis for future non-invasive cancer screening,” explains Georg Zeller from the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany.
University of Copenhagen https://tinyurl.com/y4mx25au

The largest genetic study of its kind ever to use accelerometer data to examine how we slumber has uncovered a number of parts of our genetic code that could be responsible for causing poor sleep quality and duration.
The international collaboration, led by the University of Exeter, has found 47 links between our genetic code and the quality, quantity and timing of how we sleep. They include ten new genetic links with sleep duration and 26 with sleep quality.
The Medical Research Council-funded study looked at data from 85,670 participants of UK Biobank and 5,819 individuals from three other studies, who wore accelerometers – wrist-worn devices (similar to a Fitbit) which record activity levels continuously. They wore the accelerometers continuously for seven days, giving more detailed sleep data than previous studies, which have relied on people accurately reporting their own sleep habits.
Among the genomic regions uncovered is a gene called PDE11A. The research team discovered than an uncommon variant of this gene affects not only how long you sleep but your quality of sleep too. The gene has previously been identified as a possible drug target for treatment of people with neuropsychiatric disorders associated with mood stability and social behaviours.
The study also found that among people with the same hip circumference, a higher waist circumference resulted in less time sleeping, although the effect was very small – around 4 seconds less sleep per 1cm waist increase in someone with the average hip circumference of around 100cm.
The team involved colleagues from the Center for Sleep and Circadian Neurobiology in Pennsylvania, Massachusetts General Hospital as well as the Netherlands, France and Switzerland. They found that collectively, the genetic regions linked to sleep quality are also linked to the production of serotonin – a neurotransmitter associated with feelings of happiness and wellbeing. Serotonin is known to play a key role in sleep cycles and is theorised to help promote deeper and more restful sleep.
Senior author Dr Andrew Wood, of the University of Exeter Medical School, said: “We know that getting enough sleep improves our health and wellbeing, yet we still know relatively little about the mechanisms in our bodies that influence how we sleep. Changes in sleep quality, quantity and timing are strongly associated with several human diseases such as diabetes and obesity, and psychiatric disorders.
The group also found further evidence that Restless Leg Syndrome is linked to poorer sleep from the genetic variants they found to be associated with sleep measures derived from the accelerometer data.
University of Exeter https://www.exeter.ac.uk/news/research/title_711082_en.html