Tag: kidney disease

Categories : Metabolic DisordersTags :

Enzyme’s Role in Kidney Disease Could Unlock New Therapies

On By ModernMedia
Anatomic model of a kidney. Photo by Robina Weermeijer on Unsplash

University of South Australia (UniSA) researchers have discovered that a certain enzyme may help to curb chronic kidney disease, which affects nearly 10% of the world’s population.

This enzyme, known as NEDD4-2, is critical for kidney health, said UniSA Centre for Cancer Biology scientist Dr Jantina Manning.

Chronic kidney disease (CKD) is defined as the presence of kidney damage or reduced filtration rate, persisting for three months or more. It is a state of progressive loss of kidney function ultimately resulting in the need for dialysis or transplantation. 

Dr Manning and her colleagues, including Professor Sharad Kumar, Chair of the UniSA Centre for Cancer Biology, have shown in an animal study that there is a link between a high salt diet, low levels of NEDD4-2 and advanced kidney disease.

While a high salt diet can worsen some forms of kidney disease, it was not previously known that NEDD4-2 is involved in promoting this salt-induced kidney damage.

“We now know that both a high sodium diet and low NEDD4-2 levels promote renal disease progression, even in the absence of high blood pressure, which normally goes hand in hand with increased sodium,” says Dr. Manning.

The NEDD4-2 enzyme regulates the pathway required for sodium reabsorption in the kidneys to ensure correct levels of salt are maintained. If this enzyme is reduced or inhibited, increased salt absorption can result in kidney damage.

Even if people are on a low salt diet, they can get kidney damage if their levels of NEDD4-2 are low due to genetic causes.

Prof Kumar said the goal is to eventually to develop a drug that can raise NEDD4-2 levels in people who have CKD.

“We are now testing different strategies to make sure this protein is maintained at a normal level all the time for overall kidney health,” Prof Kumar said. “In diabetic nephropathy—a common cause of kidney disease—levels of NEDD4-2 are severely reduced. This is the case even when salt is not a factor.”

The study also revealed one other unexpected finding: that kidney disease induced by high salt diets is not always the result of high blood pressure.

“In a lot of cases, kidney disease is exacerbated by hypertension, so we wanted to investigate that link in our study. In fact, we found the complete opposite—that a high salt diet caused excessive water loss and low blood pressure. This is significant because it means that kidney disease can also happen in people who don’t have high blood pressure,” Dr Manning said.

A Lancet paper from 2020 estimated that about 700 million people—about 10% of the world’s population—suffer from chronic kidney disease, and has seen a 29% increase in the past 30 years. This massive surge in CKD is mainly due to the global obesity epidemic. Overweight and obesity lead to diabetes, one of the leading causes of CKD, along with high blood pressure. Between 1980 and 2014 there was a 300% increase in diabetes, according to World Health Organization statistics. This makes it one of the top 10 causes of death worldwide.

“Obesity and lifestyle are two main factors driving chronic kidney disease but there are other things at play as well,” said Dr Manning. “Acute kidney injuries, drugs taken for other conditions, high blood pressure and a genetic predisposition can also cause it.”

Source: Medical Xpress

Journal information: Jantina A. Manning et al. The ubiquitin ligase NEDD4-2/NEDD4L regulates both sodium homeostasis and fibrotic signaling to prevent end-stage renal disease, Cell Death & Disease (2021). DOI: 10.1038/s41419-021-03688-7

Categories : AgeingTags :

Telomere Lengthening May Treat Renal Fibrosis

On By ModernMedia

A new study has shown that it may be possible to treat renal fibrosis, an age-related disease, by lengthening telomeres.

Previous research had shown it was that lengthening telomeres successfully treated pulmonary fibrosis and infarctions in mice.

Renal fibrosis is the leading cause of kidney failure, treatable only with dialysis. Moderate renal fibrosis is present in some 11% of people over 65, and is a predictor of the severity of renal failure. Telomeres are proteins at the end of chromosomes that maintain genetic integrity during cellular division. They shorten over time, eventually to the point where they are too short for cells to divide, becoming senescent. Telomere lengthening, eg through hyperbaric oxygen therapy, has been suggested as a way to reverse many age-related declines.

While short telomeres were by themselves not enough to cause renal fibrosis, the researchers found that mice with short telomeres developed it when they were exposed to small amounts of toxin, mimicking the environmental toxins people are exposed to over their lives. Mice that also lacked a certain protein needed for telomere function, Trf1, developed renal fibrosis, showing that telomeres are indeed involved in proper kidney function.

Since genes involved in epithelial-to-mesenchymal transition are overexpressed in patients with kidney failure, the researchers looked for this in mice with short telomeres. And “we found that short telomeres induce changes in the expression of genes involved in EMT.”

As a final demonstration of the importance of telomeres in kidney fibrosis, the authors cultured kidney cells in which they expressed the gene for the telomerase enzyme, which elongates telomeres. In these cells with restored telomeres, the epithelial-to-mesenchymal transition program returned to normal, and the cells regained their healthy, pre-fibrosis appearance.

“As short telomeres accumulate with ageing in the organism, it is tempting to speculate that pathological EMT programmes associated with ageing, such as cancer and different types of tissue fibrosis, may be originated at least in part by the presence of short telomeres,” the authors conclude.

Source: News-Medical.Net

Categories : General Interest TransplantsTags :

Teen Embraces Chance to ‘Live Well’ With Kidney Disease

On By ModernMedia

Thanks to a young organ donor, Bronwen Fredericks has a new kidney that she and her mother Bridget are deeply thankful for.
The 15-year-old was one of two patients at Red Cross War Memorial Children’s Hospital who received their new kidneys last month. With a new chance at their childhoods, they have a chance to embrace the spirit of “Living Well with Kidney Disease”, the 2021 theme for World Kidney Day tomorrow. 

Bronwen said: “I’m really grateful to my donor and excited for my new life. I’m really looking forward to being able to dance again.”

According to her mother, a blood pressure test had alerted them to the problem.

“I would like to encourage everyone, especially parents, to do a regular general check-up with their children at a clinic or GP. A simple blood pressure test could show us that there was a serious problem and we were able to take action that saved my daughter,” she said.

“Irrespective of age, being diagnosed with kidney disease can pose a huge challenge for the patient and their family. It remains draining on those involved, be it emotional, financial, physical or a combination of these – but imagine the impact on a young child,” the Red Cross War Memorial Children’s Hospital said in a statement on Wednesday.  The hospital conducts around 10 to 12 kidney transplants a year.

The Red Cross Hospital said it is aiming to reduce stress factors through education, empowerment and by building a partnership with patients and their families.

“The diagnosis and management, particularly in the advanced stages of kidney disease, impacts severely upon the lives of our young patients by reducing their ability to participate in everyday activities like attending school, participating in extra-curricular activities and socialising, whilst the whole family’s ability to travel and parents ability to work is also affected,” said Dr Deveshni Reddy, ‎paediatric nephrologist at the hospital.

Current management includes dialysis to take the strain off of kidneys, and in more extreme cases, donor transplants.
Professor Mignon McCulloch, the hospital’s head of paediatric nephrology and solid organ transplantation, said: “While we always try our best to treat chronic kidney disease and other kidney disorders through medical intervention, sometimes a surgical intervention, or dialysis and resultant kidney transplant, is the only option.

“The Red Cross War Memorial Children’s Hospital conducts around 10-12 kidney transplants per year, making it one of the most active paediatric transplant services in South Africa, which is only possible due to the close collaboration with the multi-disciplinary role-players from Groote Schuur Hospital and Red Cross.”

Source: IOL News