Hair Plucking Could Treat Baldness

Plucking sends out a signal by quorum sensing which leads to a surge of hair re-growth.

Have you ever pulled an annoying grey hair out? You probably noticed lots of grey hair appearing in the same place after a few days. Well, scientists believe this is not only true for grey hair, but also for other hair colors.

Pluck a hair, gain five

Researchers from the University of Southern California (USC) in the US reported this exciting finding in Cell. They found that selectively pulling hair leads to the appearance of dense hair re-growth. Could this make baldness a thing of the past? Maybe.

Researchers carefully extracted 200 hairs, one by one, in a specific configuration and density from the back of a mouse. This triggered five-fold growth, resulting in nearly 1,200 new hairs in the area. When a hair is pulled out, the hair follicles receive a skin injury that leads to an immune response, as the skin follicle releases distress signals via the release of inflammatory proteins such as Tnf-a. This leads to the regeneration of hair follicles as it sends a ‘help’ signal to the scalp which triggers a huge surge of re-growth.

Plucking patterns matter

The regeneration is mainly dependent on the pattern of the pluck. The researchers found that pulling 200 hairs from the back of mouse exceeding a 6 mm wide diameter area wouldn’t lead to a regrowth. However, plucking individuals hairs in circular areas between 3 and 5 mm, leads to a greater amount of hair re-growth: between 450 and 1,300 new hairs. The authors believed this was due to hair follicles communicating amongst themselves, a phenomenon known as Quorum sensing.

Basically, the hair follicles need to be located in close proximity in order to signal collectively as a group. Furthermore, plucking has to be closely packed together and must follow a pattern. Only under these circumstances can the follicles work together to give a stronger immune response and ultimately lots of new hair growth.

Great news for people whose hairlines are doomed!

Reference
Chen CC, Wang L, Plikus MV, Jiang TX, Murray PJ, Ramos R, Guerrero-Juarez CF, Hughes MW, Lee OK, Shi S, Widelitz RB, Lander AD, & Chuong CM (2015). Organ-level quorum sensing directs regeneration in hair stem cell populations. Cell, 161 (2), 277-90 PMID: 25860610

Climate Change: What Rice Can Learn From Maize

What makes plants tough enough to deal with a bad climate?

Most of the staple crops like rice, wheat or barley are C3 plants. C4 plants, like maize, enjoy the biochemical and anatomical (Kranz anatomy) innovations that make them more efficient at water and nitrogen use. Therefore, their yield is generally higher even in hot and dry climates. Due to degradation of arable lands, climate change and increasing population size, the pressure on agricultural production systems is becoming more intense day by day. One strategy to improve the productivity of staple crops is to endow them with C4 photosynthesis traits. According to a new study reported in Nature Biotechnology, a group of scientists have been successful in engineering C4 traits into C3 plant. This makes the C3 plants stronger so they can withstand harsh conditions like drought, heat and nutrient limitations.

What makes a C4 tougher than a C3?
So, for people who don’t know much about the plant physiology, these may just appear as numbers. But what are C3 and C4 plants? C3 photosynthesis uses the three-carbon molecule 3-phosphoglycerate (3-PGA) for carbon fixation whereas C4 photosynthesis utilizes a four-carbon molecule — oxaloacetate (OAA). OAA is transported from the outer mesophyll (ME) cells to inner bundle sheath (BS) cells in the form of malate or aspartate. Rice, wheat or barley is example of a C3 plant whereas maize and sugarcane are C4 plants. Since C3 plants evolved into C4 due to global reduction of CO2 level in the atmosphere, the problem of increasing food crisis globally could be solved if the engineering principles could be used to transform C4 traits into C3.

Improving the machinery of the leaf
According to the findings, scientists have been successful in developing a statistical method to simultaneously examine maize and rice expression profile. By sampling maize and rice leaves at similar points in development, they were able to examine convergent and divergent components of C3 and C4 differentiation. The leaf is the main photosynthetic machinery which drives sugar production and yield; therefore, it serves as a model to understand the process of differentiation of photosynthetic tissues. In the present study, the leaf transcriptomes or expression patterns of C4 plant (maize) and C3 plant (rice) was studied to identify new structural and regulatory components important in photosynthesis. By analyzing the metabolic profiles of the two, a mathematical model was developed to directly compare two related grass species undergoing similar development profile. Using cis-regulatory mining tools some important candidate motifs were identified which were recruited during evolution of C4 photosynthesis.

Small steps towards strong rice
The developed tools and methodology in this study provide a platform for future research, that will help to engineer improvements in carbon fixation and ultimately engineer C4 traits into C3 grasses. In the end, rice is still a C3 plant. These small steps, made by the hard work of scientist, might one day turn the C3 into a strong, climate resistant, C4 plant. Imagine what that might do for rice production and the world’s food problems. Amen!

References
Wang L, Czedik-Eysenberg A, Mertz RA, Si Y, Tohge T, Nunes-Nesi A, Arrivault S, Dedow LK, Bryant DW, Zhou W, Xu J, Weissmann S, Studer A, Li P, Zhang C, LaRue T, Shao Y, Ding Z, Sun Q, Patel RV, Turgeon R, Zhu X, Provart NJ, Mockler TC, Fernie AR, Stitt M, Liu P, & Brutnell TP (2014). Comparative analyses of C4 and C3 photosynthesis in developing leaves of maize and rice. Nature biotechnology, 32 (11), 1158-65 PMID: 25306245

Don’t Try Losing Weight By Just Eating More Fruits And Vegetables

Research shows adding more fruits and vegetables to your diet will not help as such.

 

If you think eating more fruits and veggies helps you have a lean and fit body, you might have to re-think. Of course generally, everyone recommends consuming more fruits and vegetables (F/Vs) as a good compensation to weight loss regime because they are low in calories, high in volume and high in critically important nutrients. They fill you up, without loading you up with fat and calories. So if someone says that is not going to help, would you believe it? Certainly not! Especially when you are planning to shed weight, the common belief of people is that F/Vs are good for you. But a recent finding in the American Journal of Clinical Nutrition shows zero or null effect of fruits or vegetables on weight loss.

A team of investigators performed a systematic review and meta-analysis of more than 1200 participants in seven randomized controlled trials that mainly focused on increasing fruit and vegetable intake to check its effects on weight loss. Their results show that increased F/Vs consumption per se does not reduce body weight. F/Vs are a good source of various micronutrients (including antioxidants) and dietary fiber and help fight deadly diseases like cancer, diabetes etc. Although the current study indicates that increased intake of F/Vs may be a sign of healthier people having minimum health risk, there is no empirical evidence that increasing a person’s intake of F/Vs will have a discernible effect on body weight. People must also combine other methods to reduce intake of other energy sources and not only depend on F/Vs intake as a sole solution to weight loss problem.

This study will help people who are hell-bent on losing weight by following a diet rich in F/Vs. Definitely a multimodal research of a healthy lifestyle is required to understand the factors which may help in losing weight apart from enhanced dietary intake of F/Vs.

 

References:
Kaiser KA, Brown AW, Bohan Brown MM, Shikany JM, Mattes RD, & Allison DB (2014). Increased fruit and vegetable intake has no discernible effect on weight loss: a systematic review and meta-analysis. The American journal of clinical nutrition PMID: 24965308

Bacteria May Give You A Heart Attack!

Bacterial biofilms associated with plaque may cause artery blockage.

It hit me like a heart attack

When you finally left me girl…

Enrique Iglesias might have had a heart attack because of his beloved, in reality the culprit are bacteria. The most common cause of heart attack is Atherosclerosis, a condition where excess deposition of plaque inside arteries occurs. Emerging research published online in mBio®, the online open access journal of  American Society for Microbiology, indicates that stress, fear or over exertion may trigger these bacteria to cause a heart attack in vulnerable people. Hormones released during such events cause bacterial biofilm to disperse and rupture the plaque deposits into the bloodstream. This causes clogging of artery and restriction of blood flow and hence death.

Atherosclerosis is the major underlying cause of restriction of blood flow in the arteries, leading to its obstruction, heart failure, stroke and heart attack in humans. Arteries are blood vessels that carry oxygen-rich blood in our heart and other parts of our body. The main constituents which make up plaque are fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque keeps depositing and ultimately narrows the arteries. The result is such that it limits the flow of oxygen-rich blood to organs in our body leading to nausea and finally death.

Bacterial biofilms are polysaccharides or sugars produced for their own survival from harsh conditions. During stress, fear or over-exertion certain hormones are released in our body which provide a signal that causes dispersion of bacteria from these biofilms or scaffold. These signals or enzymes not only break their own scaffold but also surrounding tissues that prevent the arterial plaque deposit from rupturing into the bloodstream.

In this study, scientists injected norepinephrine, a hormone generally released during stress, fear or over exertion situations, to Pseudomonas aeruginosa biofilms under laboratory conditions. This bacterium is most commonly found to be associated with carotid arteries. Upon addition of this hormone, an in vitro spike in hormone concentration induced biofilm dispersion. Because these bacterial biofilms are bound to arterial plaques, biofilms dispersion could cause sudden release of nearby plaque thus triggering a heart attack.

This study is the first to report ever that biofilm bacteria are bound within a carotid arterial plaque deposit. Therefore, this results paves the way to future research for considering bacterial biofilms as a part in pathology for atherosclerosis.

Reference:

Lanter, B., Sauer, K., & Davies, D. (2014). Bacteria Present in Carotid Arterial Plaques Are Found as Biofilm Deposits Which May Contribute to Enhanced Risk of Plaque Rupture mBio, 5 (3) DOI: 10.1128/mBio.01206-14

Is Sugar Bad For You? Not For Plants And Trees, Study Shows

A new study reveals the role of sugars as initial regulator of apical dominance

Everyone loves to decorate their Christmas tree. Have you noted its particular growth pattern? It is broad at the bottom while narrower at the tip which is at the top. This peculiar growth pattern of certain plants is due to a phenomenon known as Apical dominance. Apical dominance can in simpler words be understood by growth of tips towards sunlight. For almost a century, we believed that the main factor responsible for apical dominance was the plant hormone, Auxin.  But, according to new report published in the Journal PNAS, scientists claim that apical dominance is correlated with sugar availability to the plant and not apical supply of Auxin. They showed that apical dominance was controlled by the intensive demand of sugar by growing terminal tips which indirectly also limits their supply towards lateral or axillary buds. Therefore, this helps several trees to survive by out-competing others in dense forests in their race to sunlight, a vital component for photosynthesis.

Apical dominance is maintained by limiting the distribution of sugars to axillary buds, thereby making most of the sugar available to terminal growing tips. Garden pea plants of more than 150 cm in height were selected for the decapitations experiments. The approximate distance of shoot tip with the second node of plant was approximately 20 cm, a relatively far distance. Auxin content and axillary bud growth was investigated in intact and decapitated plants. It was found that when the shoot tip was cut or decapitation was done, there was strong correlation with the rapid bud outgrowth in the plant. Scientists used digital-time photography to observe bud growth in buds 40 cm below the shoot tip within 2.5 hour of decapitation. It was observed that sugars rapidly accumulate in axillary buds after the loss of shoot tip and the buds are released. Stem girdling experiments also proved that any shoot-tip derived inhibitor (Auxin in this case) was not the only responsible factor for bud release.

Examination of sugar content of axillary buds by mass spectrometry revealed that total sucrose (sugar) level was increased by 44% within 4 hours of decapitation. This study leads to an understanding which rules out Auxin as the sole and master regulator of apical dominance in plants. Rather, it gives an edge to sugars for being necessary as well as sufficient factor for axillary bud release from apical dominance.

Reference: 
Mason MG, Ross JJ, Babst BA, Wienclaw BN, & Beveridge CA (2014). Sugar demand, not auxin, is the initial regulator of apical dominance. Proceedings of the National Academy of Sciences of the United States of America PMID: 24711430

Just A Blood Test Is Enough to Detect Dementia

New effective method to detect future Alzheimer’s patients.

In a recent research published online in the journal Nature Medicine, scientists claim to have developed a technique by which they can forecast if a person is capable of developing dementia in two to three years. This will be very useful to mankind since dementia affects over 35 million people worldwide and is expected to affect 150 million by 2050. Dementia is a neurodegenerative disorder which leads to loss of important structures and functions in the brain. It is not a single disease but a non-specific syndrome which worsens with time. The Alzheimer’s disease is the most common form of dementia and is incurable.

The study comprised of a simple blood test from 525 healthy individuals all aged above seventy. Their blood samples were taken once every year for at least five years. About 74 individuals developed Alzheimer’s disease, enabling scientists to compare blood lipid profiles of 53 individuals who developed mild symptoms of the disease to those that were absolutely healthy.

Upon matching they found there are certain lipids that were strongly linked with Alzheimer disease appearance. More specifically, about ten molecules or biomarkers were identified as potential candidates that were responsible for breaking down the neural cell membranes and thereby leading to the development of Alzheimer’s symptoms. The presence of these ten biomarkers could predict with 90% accuracy that people having these compounds in their blood are likely to get affected with mild cognitive impairment (MCI) or Alzheimer’s disease (AD) in the near future.

The Alzheimer’s disease has no fool proof cure so far and the condition worsens as it progresses, eventually leading to death. Several therapies have been tested in clinical trials in the past few years but none have been successful. This may be because the patients that are brought for trial have already acquired the disease. The need is to develop biomarkers that can identify at large scale the at-risks individuals. This study will help to design and develop a drug that might delay or prevent the onset of disease symptoms in those individuals that are at risk.

References:

Mapstone, M., Cheema, A., Fiandaca, M., Zhong, X., Mhyre, T., MacArthur, L., Hall, W., Fisher, S., Peterson, D., Haley, J., Nazar, M., Rich, S., Berlau, D., Peltz, C., Tan, M., Kawas, C., & Federoff, H. (2014). Plasma phospholipids identify antecedent memory impairment in older adults Nature Medicine DOI: 10.1038/nm.3466

Yogurt Is Good For Type 2 Diabetes

Higher consumption fermented dairy products reduces risk of type-2 diabetes by 28 percent.

The increasing prevalence of diabetes is a cause of concern worldwide. Many breakthroughs in understanding and preventing this chronic disease have taken place but none really significant or foolproof. Recent research published online in Diabetologia shows that higher consumption of yogurt reduces the chance of getting new-onset type-2 diabetes by almost 28 percent as compared to absolutely no consumption.

No one will doubt that dairy products are important sources of high-quality proteins, vitamins (A, D, B12, phylloquinones & menaquinones and riboflavin) and minerals (calcium, magnesium and potassium). However, dairy products are also a source of saturated fats, the intake of which is discouraged in current dietary guidelines. It is often recommended that saturated fat intake be replaced with unsaturated fat intake.

In this new study, researchers at the School of Medicine, University of Cambridge found that dairy product intake was associated with a lower risk of type 2 diabetes in three meta-analyses of large prospective epidemiological studies. About 25,000 men and women living in Norfolk, UK were examined. A daily record of all their food and drink consumption  over a week showed new-onset type-2 diabetes in 753 people over 11 years. The researchers not only examined the risk of diabetes in relation to consumption of total dairy products, but also distinguished between different dairy products.

Surprisingly, factors like high-fat dairy, total dairy, obesity, lifestyles and eating habits were not associated with diabetes risk, whereas higher consumption of low-fat fermented dairy products such as yoghurt, all yoghurt varieties and some low-fat cheeses did reduce the risk of type-2 diabetes. The researchers suggest as a mechanical explanation that fermented dairy products exert beneficial effects against diabetes through probiotic bacteria and a special form of vitamin K (part of the menaquinone family) associated with fermentation.

These findings suggest that the consumption of these specific dairy types are beneficial for the prevention of diabetes.

References:

O’Connor LM, Lentjes MA, Luben RN, Khaw KT, Wareham NJ, & Forouhi NG (2014). Dietary dairy product intake and incident type 2 diabetes: a prospective study using dietary data from a 7-day food diary. Diabetologia PMID: 24510203

Why Mosquitoes Bite Specific People

Mosquitoes are attracted to carbon-dioxide and body odors.

Are you the one that always seems to be the sweet target of mosquito terror? Do you wake up from a night out camping to find your ankles and wrists completely covered with mosquito bites, while your tent mates are untouched? In the peak of mosquito season, some outdoor venturers are lucky, while others get relentlessly assaulted by these bloodsucking creatures. Have you ever wondered why? Scientists at the University of California (Riverside) have identified that mosquitoes are attracted to people that exhale more carbon-dioxide and release skin odors.

Olfactory receptor neurons

Mosquitoes transmit deadly diseases such as malaria and dengue. It is therefore important to find the reason for their selective attractiveness towards some people. Earlier studies found that female mosquitoes detect exhaled CO2 using a class of olfactory receptor neurons (ORNs) known as cpA.  These cpA neurons are located in maxillary palps (sensory organs) and express the CO2 receptors. The identity of olfactory receptor neurons required for attraction to skin odor remained a mystery, until now.  The recent report links both CO2 as skin odor detection to the same receptor neurons.

Foot odor

Researchers developed a novel chemical based strategy to selectively stop the activity of cpA in dengue spreading mosquito (Aedes aegypti) to check the levels of skin odor responses. The role of this neuron was checked to see the mosquito’s behavior on human foot odor which was found to be substantially reduced.

This new information leads to possibilities for practical solutions to prevent mosquito bites. About 0.5 million compounds were screened to identify several CO2 receptor ligands, including an antagonist, ethyl pyruvate, that reduces attraction to skin and an agonist, cyclopentanone, that lures mosquitoes to traps as effectively as CO2. Several of these compounds were safe, pleasant-smelling and affordable enough to use in new generation of mosquito control strategies worldwide.

New strategies

Current findings have wide-reaching implications for control of mosquito-borne disease. Present mosquito control strategies use CO2 traps, but they are costly, as generation of CO2 requires energy input. The new alternatives are affordable to use in surveillance and control traps in countries affected most by mosquito-borne diseases. These approaches will protect large areas and might present an economical and environmentally friendly way to control deadly mosquitoes.

Reference:

Tauxe GM, Macwilliam D, Boyle SM, Guda T, & Ray A (2013). Targeting a Dual Detector of Skin and CO2 to Modify Mosquito Host Seeking. Cell, 155 (6), 1365-79 PMID: 24315103

New Step In Genetic Modification Of Plants

Researchers discover role of cytokinin in agrobacterium-mediated plant modification.

Among various methods to modify the genetic make-up of plants agrobacterium tumifaciens is considered the best. It is a soil borne bacterium directed at gene addition. Plant transformation is insertion of new genetic material to the plant’s body. This used to be difficult because many economically important plants are recalcitrant to it as they lack certain gene elements. But according to a recent report published in Science, researchers now have successfully transformed a model plant, Arabidopsis, through agrobacterium-mediated transformation process.

Scientists at Purdue University in a one-of-its-kind study identified certain genes called MTF1. When inactivated, these increase the attachment of different strains of this same bacteria to the plant roots. Cytokinins from Agrobacterium tumefaciens decrease the expression of MTF1 through activation of the cytokinin response regulator ARR3, but the altered MTF1 produces cell molecules which perform cell attachment or adhesion. This means the bacterium now has improved property of attaching to plant cell walls and injecting their DNA.

Thus, by promoting bacterial attachment and transformation of resistant plants and increasing such processes in susceptible plants, treating roots with cytokinins may help engineer crops with improved features or yield.

References:

Photo: Flickr,  Max Mayorov

Sardesai N, Lee LY, Chen H, Yi H, Olbricht GR, Stirnberg A, Jeffries J, Xiong K, Doerge RW, & Gelvin SB (2013). Cytokinins Secreted by Agrobacterium Promote Transformation by Repressing a Plant Myb Transcription Factor. Science signaling, 6 (302) PMID: 24255177

gene, modification, transformation, plant, cytokinin, agrobacterium, MTF1, DNA, resistance, crops

Discovered Link Between Itch And Pain

Finally: a new relieve for that itchy feeling.

When you have an itch on the skin, what is the first thing you do? Obviously, our first immediate and natural response would be to scratch the spot of the itch with our fingernails. But, do you have any idea what is happening under your skin when you have an itch?

Itchy feelings are caused by a hundred different things. Pruritus or chronic itching is an unpleasant sensation on the skin that generally provokes in us the desire to rub or scratch the area in order to obtain relief. But that is not the only option. New research published in The Journal of Clinical Investigation explains how chronic itching is different from other types.

The main characteristic distinguishing chronic itching from normal itch is that the former incorporates not just the itch neurons but also neurons that are responsible for causing pain. Normal itch, on the other hand, involves a fixed pathway that transmits only the itch signals.

Chronic itch thus causes pain as well as discomfort. The study mentioned above, conducted on mice, revealed that BRAF protein may play a role in turning itch genes on and off. BRAF gene and its protein were already known to be involved in pain response. The new findings suggest that targeting the BRAF pathways could help in treating chronic itch too. Although chronic itch and pain are different, it seems that one pathway does lead to the other.

Scientists at Washington University School of Medicine in St. Louis speculate that the remarkable discovery may help develop efficient treatment strategies to target groups of neurons that play a role in inducing both itch as well as pain. Furthermore, there are many pathways leading from BRAF that could be potential hotspots for developing anti-itch therapies and drug discovery.

Reference

Photo: Flickr

Source: Zhau ZQ, Huo FQ, Jeffry J, Hampton L, Demehri S, Kim S, Liu XY, Barry DM, Wan L, Liu ZC, Li H, Turkoz A, Ma K, Cornelius LA, Kopan R, Battey JF, Zhong J, Chen ZF (2013). Chronic itch development in sensory neurons requires BRAF signaling pathways The Journal of Clinical Investigation DOI: 10.1172/JCI70528