Stem Cell Therapy: A Panacea or Perturbed Claim!

Stem cell therapy is considered the most promising of all medicines. Many patients with degenerative diseases as well as life-threatening diseases look forward with a pinnacle of hope to stem cell therapy. Is it panacea for all these diseases or merely perturbed claims!


But what actually is stem cell therapy? What are the stem cells?


In layman’s language, stem cells are a type of cells from which potentially all other types of body cell can be derived. They keep dividing and renewing themselves without becoming a specific cell type. Even though stem cells are unspecialized type of cells, they can give rise to all types of specialized cells for example cardiac cells, neural cells, kidney cells and so on which lose the capacity to divide or proliferate. The ‘adult stem cells’ have been identified that exists in our body tissues and circulate in blood. In labs, adult stem cells generally give rise to the type of cell from where they are derived. Now-a-days stem cells are isolated and enriched from tissues and grown in culture dishes in laboratories for the research purposes.

Source: grosovsky.wikispaces.umb.edu

However, initially young embryos were considered to be the sole source of stem cells, called “embryonic stem cells”. In fact an organism’s whole body has been derived from one stem cell that is zygote. After an egg, a female gamete, gets fertilized by a male gamete, a sperm, it forms a zygote which gives rise to the complete organism after several cell divisions and differentiation. The research leading to clinical use of embryonic stem cells has been banned in many countries due to obvious ethical concerns.

Source:www.abpischools.org.uk

The embryonic stem cells derived from early embryo possess the capacity to keep renewing themselves without becoming any specialized type of cells in laboratory as opposed to the adult stem cells, which lose this potential after few division cycles. This could be the limitation of the adult stem cells and may handicap their use in the clinical application.


Before going further to see how scientists found answers to these limitations, let’s see how did scientists thought that stem cells could potentially exit in the adult tissues as well? The concept of their existence in somatic tissue, other than gonads where male and female gametes are produced, came from the fact that to keep the body healthy and repair it from time to time one would require a pool of cells with potential to renew themselves and form different types of cells and tissues in body. The scientists started looking for ‘stem cells like cells’ in the blood and other tissues. Using different stem cells markers, now such cells have been identified in many tissues. In fact, the bone marrow derived stem cells or “hematopoietic stem cells” are the major source of adult stem cells that are actually being utilized to treat some blood disorders.

Source: stemcells.nih.gov

Indeed, unabated growth of cancer and remission of cancers after treatment has been identified to be due to the presence of “cancer stem cells” which are found to be hard to kill by radiotherapy or chemotherapy and bounce back after the treatment regimen is over.


Now let’s come back to our original question about stem cell therapy.


Addressing the road block for isolating adult stem cells and maintaining their “stem-ness” and to coax them to the lineage that one wants, Dr Yamanak, a Nobal Prize Winner of 2012 for physiology or Medicine, identified that normal somatic cells can be induced to become stem cells by modulating a set of at least four transcription factors. Transcription factors are specialized proteins that are formed in cells to regulate the expression of other proteins. These stem cells are called induced pluripotent stem cells (iPS cells).


The iPS cells have ability to divide regularly and can be transformed into any cell type or tissue as regulated by specific set of transcription factors. This discovery removed both the limitations of adult stem cells and has obvious clinical implications. Scientists have successfully tried to coaxed iPS cells from one tissue to transform into another cell type. For example stem cells derived from skin fibroblasts were made into cardiomayocytes by regulating a set of key transcription factors.

Source: stemcells.uct.ac.za

The technological feasibility to make the iPS cells and potentially transform them into organ of choice is complete. Scientists now believe that it will be possible to use the patient’s cells to make iPS cells and transform them into specialized tissue as may be needed. This will also ensure that tissue thus formed may not be rejected by the patient’s immune system.


It appears that stem cell therapy is certainly not a perturbed dream but a potential cure for many diseases and will be a paradigm shift, if not already, in the health care sector.

Does our immunity suffer from forgetfulness?

While studying immunology in college, we had learned that our immune cells, upon infection and subsequent successful immune response create memory cells that persist in the body and through a highly selective process get mature and protect our body from future infections of same pathogen. This is also a basis of vaccination against various illnesses caused by different pathogens.

The common sense says that if there is memory it aught to suffer from forgetfulness. The forgetfulness of immune system came to my mind on several occasions. Whenever, after spending a few years at a stretch in the western countries where high levels of hygiene is practiced, we visit our natives in the India, our first worry is to not consume unfiltered water. Most of the energy, and money too, goes in amassing bottled or filtered water. If it’s not available in the local market, which is the usual scenario because no one buys them there and thus vendors do not sell them, then next best thing is to boil the hand-pump water, tap water being rarity in villages even in twenty first century India.

But if by mistake or in desperation, because water is necessary to live, we consume the normal water, most of our energy, and money too, goes in amassing medicine to combat the aftermath i.e. loose motion or diarrhoea.

What happens that the water we had grown up drinking becomes source of all trouble?

Image source: bigstock.com

The forgetfulness of immune system came to my mind again when a group of scientists recently suggested that in the young children the repeated cause of illness could be that their immune system is forgetful.

World health organization (WHO) says that worldwide one third of total infant mortality is due to infectious diseases! This happens besides the strong vaccination programs being run by the government’s public health department.

As I recalled earlier about memory immune cells created during the immune response or vaccination that get mature by a highly selective process, they also require presence of pathogenic antigen for this selection process. It turns out that in children memory rapidly vanishes in the absence of booster dose of vaccine. The non-compliance of vaccination becomes fatal for these children.

The answer to forgetfulness of adult immune system could be that when we are away in societies where the hygiene level is high, our memory immune cells do not get to see the antigens and they tend to get negatively selected out, a kind of 'out of sight out of mind' thing. Having no specific memory immune cells, these same pathogen becomes “new” and body responds to it as if it is seeing them for the ‘first time’.

Ideally, once a vaccine shot given at birth should be sufficient for long lasting or say life-long protection from disease, but no such vaccine exists. And we do need to follow-up for the vaccination shots to boost-up the child’s immune system and keep it alert and ‘mindful’.

In case of adults, it is probably because immune system is a dynamic process and is shaped by the environment we live in. It's job is to protect us from the pathogens lurking in our surrounding. If, for some reason, we fail to interact with the ‘environment’ our immune memory cells raised against pathogens in that environment get negatively selected out from our body and our immunity become forgetful of those antigens.

Google's Nanobots to diagnose fetal disease early

The search engine and internet giant Google is trying to host a search engine in our bodies by using a magnet based nanopills, which will help diagnose the various disease including cancer and heart diseases. These nanopills will send the signals to the sensors located outside the body which then translate the signals into diagnostic indicators. 

Source: bigthink.com

The pills will be able to identify discrete changes in the cellular biochemistry which will be identified as an early warning to diagnose the diseases such as cancer. This could be a path breaking tool to catch the fetal disease like cancer early.... read more.....  Here

Goodness of Fruits & Vegetables For Health

Ever since the discovery of 'FIRE' our food habit has evolved in such a way that we cook our meals, sometimes char it or overcook it. Overcooking modifies certain food constituents, especially those present in the meat and protienacious foods, and make them toxic. 

The proteins in our food contain amines and aromatic compounds which when heated excessively get converted into various toxic compounds including polycyclic aromatic hydrocarbons, heterocyclic amines, and nitrosamines. A well known polycyclic aromatic hydrocarbons is benzopyrene which is a potential carcinogen. These chemicals are toxic to cells and know to cause damage DNA, the genetic material in our body cells.

The damage to DNA results in various mutations and DNA breaks which may cause cells death or excessive and unregulated cell growth forming tumors. Both of these condition are deleterious to human body.

Further, these chemicals also produce excessive reactive free radicals with induce inflammation in our bodies during damage to the cells and creating a inflammatory condition in body. Inflammation is bad and a starting point to many diseases including aging-related diseases, cardiovascular diseases, various types of cancer and many more. 

Therefore, overcooking and deep frying of food items should be avoided for better benefits of the food that we consume.

Image Source: everydaylife. globalpost. com

In addition including more fruits and vegetables in our diet is always a better option to minimize the risks of developing these complications and diseases. It has been found that some of the fruits and vegetables which include deep colored berries such as blueberries and blackberries, other fruits like cherries, guava, dates, resins, red grapes, apricots, cantaloupe; and vegetables such as green pepper, Olive, Mushrooms, Tomato, Radish, Chicory, cucumber, Spinach, Broccoli and sweet potato contain an potential anti-inflammatory compound salicylic acid. 

Salicylic acid is a know inhibitor of an enzyme in our body called cycloxygenase-2 or Cox-2. Cox-2 produces a pro-inflammatory compound called  prostaglandins which are known to induced and promote inflammation and excessive proliferation of our body cells. Thus, presence of salicylic acid in our diet will suppress the activation of Cox-2 and thereby prevent any onslaught of inflammation on our body.

The take home message is to avoid overcooked meal so that any exposure to toxic chemicals that may damage DNA and thus our health may be prevent; and include appropriate amount of fruits and vegetables in diet so that natural anti-inflammatory compounds present in them could protect the body from any onslaught of oxidants and inflammatory mediators and promote health.

Artificial Sweeteners Cause Metabolic Disorders

For the diabetics, obese and weight conscious individuals artificial sweeteners (AS) are considered safe choice to help regulate the blood glucose level and manage body weight. Use of AS considered good choice to sweeten the drinks and deserts as opposed to the common table sugar mostly due to low amount or lack of calorie in them.  Because of the same reason many food and beverage companies market their “calorie free” “Lite” and “diet” drinks and food items to cater the need of various “calorie conscious” customers.

Image curtsy: huntnewsnu.com

Food and drug administration (FDA) of USA identifies some of these sweeteners as “high-intensity sweeteners” and regulates them as food additive, meaning that they must undergo premarket review and approval by FDA before it can be used in food.  Accordingly nearly six artificial sweeteners have been approved by FDA as food additives in the USA. These are saccharin, aspartame, acesulfame potassium (Ace-K), sucralose, neotame, and advantame. The agency considers these FDA approved AS safe for the general population in certain conditions of use¹.  

The use of AS has become more common in general population due to reported ill effects of common sugar including sudden increase in blood sugar, tooth decay, weight gain, obesity, and an array of life style diseases such as hypertension, cardiovascular diseases, type 2 diabetes and dementia among others. The increased use of AS has propelled the scientists to examine the long-term effects of AS on humans.

In a recent study scientists have observed that use of AS may lead to the development of glucose intolerance (GI). GI is a hyperglycaemic state that is linked to insulin resistance and generally occurs in pre-diabetic individuals. AS induced glucose intolerance, scientists observed, develops due to alteration in the composition and function of the microorganism or microbiota that live in our intestine.

The group of scientists led by Jotham Suez² found that when mice were fed AS, they showed altered GI and also their intestinal microbiota composition changed from that of normal mice not fed AS. Further, when the intestinal microbiota from AS consuming mice was transferred to germ- free mice they also showed altered GI and other metabolic defects. These defective metabolisms were abrogated by the use of antibiotics which is known to kill the intestinal bacteria suggesting that the effects were caused due to the changed intestinal microbiota. 

When scientists compared the bacterial population from glucose-fed verses AS-fed mice by genetic analysis, they found that not only the composition, but the functions of the bacteria also had changed in AS-fed mice. The bacteria from AS-fed mice intestine showed increased carbohydrate degrading mechanisms. This means that they can degrade even complex carbohydrates easily leading to elevated glucose levels that may contribute to GI.

The scientists also examined and compared the intestinal microbiota of AS consuming individuals with those who did not consume AS and found that AS consuming people had different bacterial population in their intestine which correlated with markers of obesity and GI. When they fed AS to the volunteers, they showed increased blood glucose levels as well as altered intestinal bacteria in just four days.

These scientific evidences clearly indicate that consumption of AS is associated with increased GI, risk of obesity related metabolic disorders and these changes are not direct but by altering the bacterial community in the intestine. Thus, a caution regarding the excessive use of AS as food additive needs reassessment and in-depth study before being approved for use by general population

References:

1. http://www.fda.gov/Food/IngredientsPackagingLabeling/FoodAdditivesIngredients/ucm397716.htm

2. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Suez J, Korem T, Zeevi D, Zilberman-Schapira G, Thaiss CA, Maza O, Israeli D, Zmora N, Gilad S, Weinberger A, Kuperman Y, Harmelin A, Kolodkin-Gal I, Shapiro H, Halpern Z, Segal E, Elinav E. Nature. 2014 Sep 17. doi: 10.1038/nature13793