Researchers from Bengaluru have made an important discovery of the mechanism used by TB bacteria to tolerate TB drugs, which necessitates longer treatment of six-nine months. They have also demonstrated that a drug combination that prevents the bacteria from inducing this mechanism leads to almost complete clearance of the bacteria from the mice lungs in just two months of therapy. If further studies and trials show similar results, a shorter treatment regimen might be sufficient to treat drug-sensitive TB.

The common notion is that only the non-replicating or slowly metabolising TB bacteria become tolerant to anti-TB drugs. But the team led by Amit Singh from the Department of Microbiology and Cell Biology, and Centre for Infectious Disease Research at the Indian Institute of Science (IISc) found a fraction of the bacteria inside the macrophages was able to tolerate anti-TB drugs even when actively multiplying.

The researchers found that using an already approved anti-malaria drug chloroquine in combination with a TB drug isoniazid can almost clear all the bacteria from the lungs of mice and guinea pigs in just eight weeks. In addition, the drug combination also reduces the chances of TB relapse. The results were published in the journal Science Translational Medicine.

Reducing the pH to make it acidic is the first-line of defence by macrophages when infected with pathogens. But the researchers found that instead of controlling the TB bacteria, the mildly acidic pH was actually facilitating a fraction of the bacteria to continue multiplying and develop drug tolerance.

We used a biosensor which we had developed a few years ago to see the amount of oxidative stress inside the TB bacteria during infection. We found that anti-TB drugs induce oxidative stress to kill bacteria inside macrophages. However, the drug tolerant bacteria have a remarkable ability to counter oxidative stress, says Prof. Singh. The bacteria used the acidic pH of macrophages as a cue to specifically increase its capacity to deal with oxidative stress. Also, the drug-tolerant bacteria induce efflux pumps to expel antibiotics as an additional mechanism to reduce antibiotic efficacy.

The drug-tolerant bacteria were found in macrophages that were more acidic (pH 5.8) while the drug-sensitive bacteria were seen in macrophages that were less acidic (pH 6.6).

We hypothesised that reverting the pH within macrophages to its normal state could probably make the bacteria sensitive to antibiotics, Prof. Singh says. The chloroquine drug does just that it neutralises the pH within the macrophages. This prevented the bacteria from inducing the mechanism to protect themselves from oxidative stress. So no drug-tolerant TB bacteria emerged. Once the pH is neutralised, the isoniazid drug was able to eradicate TB from animals.

While the two-month treatment was able to completely sterilise mouse lungs, a near-complete eradication was observed from the lungs of guinea pigs. The combination was shown to reduce TB bacteria load in both mice and guinea pigs, says Richa Mishra from IISc and the first author of the paper.

In the case of in vitro studies using cell lines and mice macrophages, the ability of the combination drug therapy to reduce TB load was found to be three- to fivefold higher than when treated only with TB drugs. Reduction in bacteria load was more when we combined chloroquine with isoniazid, says Mishra. We observed threefold reduction when we combined chloroquine with rifampicin and fivefold reduction when we used chloroquine-isoniazid combination.

To determine TB relapse following treatment, mice infected with TB were completely rid of bacteria using the drug combination. Eight weeks later, the immune system of mice was suppressed using a drug. While all the five mice treated with only isoniazid relapsed with high bacterial load, three of the five mice treated with the combination drug showed very little presence of bacteria. This shows that the drug combination reduces the chances of TB relapse, says Mishra.

The work was carried out in collaboration with researchers from Bengalurus National Centre for Biological Sciences and Foundation for Neglected Disease Research.

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Combination therapy using malaria drug quickly clears TB - The Hindu

Cell biology has very particular characteristics. During the last decade, researchers and scientists have astounded us with their discoveries in bioprinting and regenerative medicine, proving that a great deal of what happens at the lab is basically knowing and understanding cells. These microscopic structures are the foundation of most projects where cells are patterned to grow into mature tissues, interacting with other cells and non-cellular components of their local environment, such as the extracellular matrix and nutrient sources.

But there have been a few challenges along the way, basically: how to keep the cells alive, what materials to use for cells to live in, and keeping up with the requirements of micro parts in the production sector as well as in academic and industrial research. And that is a big part of bioprinting. Tissue growth and the behavior of cells can be controlled and investigated particularly well by embedding the cells in a delicate 3D framework, yet some methods are very imprecise or only allow a very short time window in which the cells can be processed without being damaged. Moreover, the materials used must be cell-friendly during and after the process, restricting the variety of possible materials, which includes biocompatible synthetic and natural polymers. Now a new high-resolution bioprinting process developed at Vienna University of Technology (TU Wien), in Austria, ensures living cells can be integrated into fine structures created in a 3D printer extremely fast.

Thanks to a special bioink and 3D printing system, cells can be embedded in a 3D matrix printed with micrometer precision, at a printing speed of one meter per second. This high-resolution bioprinting process with completely new materials allows the fabrication of structures and surface textures mimicking the microenvironment of cells.

The behavior of a cell depends crucially on the mechanical, chemical and geometric properties of its environment, said Aleksandr Ovsianikov, head of the 3D Printing and Biofabrication research group at the Institute of Materials Science and Technology at TU Wien. The structures in which the cells are embedded must be permeable to nutrients so that the cells can survive and multiply. But it is also important whether the structures are stiff or flexible and whether they are stable or degrade over time.

The high-resolution 3D printing technology and the materials are being commercialized by UpNano GmbH, a spin-off company of TU Wien. The ultrafast high-resolution 3D printing system called NanoOne is based on multiphoton lithography and combines the precision of two-photon polymerization. UpNano claims that their patented process enables the batch production of microparts with the highest resolution and complexity in the market, enabling the economic production of polymer parts from micro to mesoscale. The biocompatible process in combination with optimized materials facilitates cell, tissue, and biofabrication. Meaning that the living cells of choice can be mixed into the material and printed directly or seeded on sterile, pre-fabricated scaffold structures.

NanoOne 3D printing system

In order to achieve an extremely high resolution, two-photon polymerization methods have been used at TU Wien for years. This method uses a chemical reaction that is only initiated when a molecule of the material simultaneously absorbs two photons of the laser beam. According to the institute, this is only possible where the laser beam has a particularly high intensity. At these points, the substance hardens, while it remains liquid everywhere else. Therefore, this two-photon method is best suited to produce extremely fine structures with high precision.

However, these high-resolution techniques usually have the disadvantage of being very slowoften in the range of micrometers or a few millimeters per second. At TU Wien, however, cell-friendly materials can be processed at a speed of more than one meter per second, and they claim that only if the entire process can be completed within a few hours there is a good chance of the cells surviving and developing further.

Aleksandr Ovsianikov

According to Ovsianikov, printing microscopically fine 3D objects is no longer a problem today, however, the use of living cells presents science with completely new challenges: until now, there has simply been a lack of suitable chemical substances. You need liquids or gels that solidify precisely where you illuminate them with a focused laser beam. However, these materials must not be harmful to the cells, and the whole process has to happen extremely quickly.

UpNanos high-performance two-photon materials are engineered and optimized to utilize the full potential of the NanoOne printing system. In addition to UpBio, the hydrogel material for biological applications and bioprinting, UpNano offers photopolymers (UpPhoto) and sol-gel hybrid materials (UpSol). Living cells of choice can be mixed into the material and printed directly, and cells embedded in an UpBio matrix can be used for 3D in vitro cell tests, which gain increasing importance in cell culture, tissue regeneration and pharmaceutical research.

Our method provides many possibilities to adapt to the environment of the cells. Depending on how the structure is built, it can be made stiffer or softer. Even fine, continuous gradients are possible. In this way, we can define exactly how the structure should look in order to allow the desired kind of cell growth and cell migration. The laser intensity can also be used to determine how easily the structure will be degraded over time.

Ovsianikov is convinced that this is an important step forward for cell research: Using these 3D scaffolds, it is possible to investigate the behavior of cells with previously unattainable accuracy. It is possible to study the spread of diseases, and if stem cells are used, it is even possible to produce tailor-made tissue in this way.

The research project is an international and interdisciplinary cooperation in which three different institutes of the TU Vienna were involved: Ovsianikovs research group was responsible for the printing technology itself, the Institute of Applied Synthetic Chemistry at TU Wien developed fast and cell-friendly photoinitiators (the substances that initiate the hardening process when illuminated) and TU Wiens Institute of Lightweight Structures and Structural Biomechanics analyzed the mechanical properties of the printed structures.

Cells spreading in a 3D scaffold. From left to right: week 1, week 3 week 5. Top: 3D setup, bottom: one layer only.

The advantages of the NanoOne high-resolution printing system enable the additive manufacturing of polymeric microparts in research, science, and industry, with achievable part sizes, ranging from micro to mesoscale, with structure details in a submicrometer range and throughput of the system that opens up a universe of application possibilities. Considering that UpNano is a very new company, founded in 2018, we can expect researchers to come up with some very interesting solutions in a universe of applications.

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UpNano: Forging Ahead in Microfabrication With Two-Photon Polymerization - 3DPrint.com

An intrinsically photosensitive retinal ganglion cell (ipRGC) as it would appear if you looked at a mouses retina through the pupil. The white arrows point to the many different types of cells it networks with: other subtypes of ipRGC cell (red, blue and green) and retinal cells that are not ipRGCs (red). The white bar is 50 micrometers long, approximately the diameter of a human hair. (Image by Franklin Caval-Holme)

November 30, 2019 - ByRobert Sanders- By the second trimester, long before a babys eyes can see images, they can detect light.

But the light-sensitive cells in the developing retina the thin sheet of brain-like tissue at the back of the eye were thought to be simple on-off switches, presumably there to set up the 24-hour, day-night rhythms parents hope their baby will follow.

University of California, Berkeley, scientists have now found evidence that these simple cells actually talk to one another as part of an interconnected network that gives the retina more light sensitivity than once thought, and that may enhance the influence of light on behavior and brain development in unsuspected ways.

In the developing eye, perhaps 3% of ganglion cells the cells in the retina that send messages through the optic nerve into the brain are sensitive to light and, to date, researchers have found about six different subtypes that communicate with various places in the brain. Some talk to the suprachiasmatic nucleus to tune our internal clock to the day-night cycle. Others send signals to the area that makes our pupils constrict in bright light.

But others connect with surprising areas: the perihabenula, which regulates mood, and the amygdala, which deals with emotions.

In mice and monkeys, recent evidence suggests that these ganglion cells also talk with one another through electrical connections called gap junctions, implying much more complexity in immature rodent and primate eyes than imagined.

Given the variety of these ganglion cells and that they project to many different parts of the brain, it makes me wonder whether they play a role in how the retina connects up to the brain, said Marla Feller, a UC Berkeley professor of molecular and cell biology and senior author of a paper that appeared this month in the journalCurrent Biology. Maybe not for visual circuits, but for non-vision behaviors. Not only the pupillary light reflex and circadian rhythms, but possibly explaining problems like light-induced migraines, or why light therapy works for depression.

The cells, called intrinsically photosensitive retinal ganglion cells (ipRGCs), were discovered only 10 years ago, surprising those like Feller who had been studying the developing retina for nearly 20 years. She played a major role, along with her mentor, Carla Shatz of Stanford University, in showing that spontaneous electrical activity in the eye during development so-called retinal waves is critical for setting up the correct brain networks to process images later on.

Hence her interest in the ipRGCs that seemed to function in parallel with spontaneous retinal waves in the developing retina.

We thought they (mouse pups and the human fetus) were blind at this point in development, said Feller, the Paul Licht Distinguished Professor in Biological Sciences and a member of UC Berkeleys Helen Wills Neuroscience Institute. We thought that the ganglion cells were there in the developing eye, that they are connected to the brain, but that they were not really connected to much of the rest of the retina, at that point. Now, it turns out they are connected to each other, which was a surprising thing.

UC Berkeley graduate student Franklin Caval-Holme combined two-photon calcium imaging, whole-cell electrical recording, pharmacology and anatomical techniques to show that the six types of ipRGCs in the newborn mouse retina link up electrically, via gap junctions, to form a retinal network that the researchers found not only detects light, but responds to the intensity of the light, which can vary nearly a billionfold.

Gap junction circuits were critical for light sensitivity in some ipRGC subtypes, but not others, providing a potential avenue to determine which ipRGC subtypes provide the signal for specific non-visual behaviors that light evokes.

Aversion to light, which pups develop very early, is intensity-dependent, suggesting that these neural circuits could be involved in light-aversion behavior, Caval-Holme said. We dont know which of these ipRGC subtypes in the neonatal retina actually contributes to the behavior, so it will be very interesting to see what role all these different subtypes have.

The researchers also found evidence that the circuit tunes itself in a way that could adapt to the intensity of light, which probably has an important role in development, Feller said.

In the past, people demonstrated that these light-sensitive cells are important for things like the development of the blood vessels in the retina and light entrainment of circadian rhythms, but those were kind of a light on/light off response, where you need some light or no light, she said. This seems to argue that they are actually trying to code for many different intensities of light, encoding much more information than people had previously thought.

The research was supported by the National Institutes of Health.

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UC Scientists Say Babies In The Womb May See More Than We Thought - Sierra Sun Times

This picture shows a spirited flying Taiwan Blue Magpie displaying a full array of flight feathers in action. Credit: Shao Huan Lang

If you took a careful look at the feathers on a chicken, youd find many different forms within the same birdeven within a single feather. The diversity of feather shapes and functions expands vastly when you consider the feathers of birds ranging from ostriches to penguins to hummingbirds. Now, researchers reporting in the journal Cell on November 27, 2019, have taken a multidisciplinary approach to understanding how all those feathers get made.

We always wonder how birds can fly and in different ways, says corresponding author Cheng-Ming Chuong of the University of Southern California, Los Angeles. Some soar like eagles, while others require rapid flapping of wings like hummingbirds. Some birds, including ostriches and penguins, dont fly at all.

This picture shows a the asymmetric vane and tapering main shaft of a single flight feather from a goshawk. Credit: Hao Howard Wu and Wen Tau Juan

Such differences in flight styles are largely due to the characteristics of their flight feathers, Chuong adds. We wanted to learn how flight feathers are made so we can understand nature better and learn principles of bioinspired architecture.

In the new study, the researchers put together a multidisciplinary team to look at feathers in many different ways, from their biophysical properties to the underlying molecular biology that allows their formation from stem cells in the skin. They examined the feathers of flightless ostriches, short-distance flying chickens, soaring ducks and eagles, and high-frequency flying sparrows. They studied the extremes by including hummingbirds and penguins. To better understand how feathers have evolved and changed over evolutionary time, the team also looked to feathers that are nearly 100 million years old, found embedded and preserved in amber in Myanmar.

Based on their findings, the researchers explain that feathers modular structure allowed birds to adapt over evolutionary time, helping them to succeed in the many different environments in which birds live today. Their structure also allows for the specialization of feathers in different parts of an individual birds body.

The flight feather is made of two highly adaptable architectural modules: the central shaft, or rachis, and the peripheral vane. The rachis is a composite beam made of a porous medulla that keeps feathers light surrounded by a rigid cortex that adds strength. Their studies show that these two components of the rachis allow for highly flexible designs that enabled to fly or otherwise get around in different ways. The researchers also revealed the underlying molecular signals, including Bmp and Ski, that guide the development of those design features.

Attached to the rachis is the feather vane. The vane is the part of the feather made up of many soft barbs that zip together. The researchers report that the vane develops using principles akin to paper cutting. As such, a single epithelial sheet produces a series of diverse, branched designs with individual barbs, each bearing many tiny hooklets that hold the vane together into a plane using a Velcro-like mechanism. Their studies show that gradients in another signaling pathway (Wnt2b) play an important role in the formation of those barbs.

To look back in time, the researchers studied recently discovered amber fossils, allowing them to explore delicate, three-dimensional feather structures. Their studies show that ancient feathers had the same basic architecture but with more primitive characteristics. For instance, adjacent barbs formed the vane with overlapping barbules, without the Velcro-like, hooklet mechanism found in living birds.

Weve learned how a simple skin can be transformed into a feather, how a prototypic feather structure can be transformed into downy, contour, or flight feathers, and how a flight feather can be modulated to adapt to different flight modes required for different living environments, Chuong says. In every corner and at different morphological scales, we were amazed at how the elegant adaption of the prototype architecture can help different birds to adapt to different new environments.

The researchers say that, in addition to helping to understand how birds have adapted over time, they hope these bioinspired architectural principles theyve uncovered can be useful in future technology design. They note that composite materials of the future could contribute toward the construction of light but robust flying drones, durable and resilient wind turbines, or better medical implants and prosthetic devices.

Team co-leader and biophysicist Wen Tau Juan of the Integrative Stem Cell Center of China Medical University Hospital, Taiwan, has already begun to explore the application of feather-inspired architectural principles in bio-material design. The team also hopes to learn even more about the molecular signals that allow the formation of such complex feather structures from epidermal stem cells that all start out the same.

###

Reference: The Making of a Flight Feather: Bio-architectural Principles and Adaptation by Wei-Ling Chang, Hao Wu, Yu-Kun Chiu, Shuo Wang, Ting-Xin Jiang, Zhong-Lai Luo, Yen-Cheng Lin, Ang Li, Jui-Ting Hsu, Heng-Li Huang, How-Jen Gu, Tse-Yu Lin, Shun-Min Yang, Tsung-Tse Lee, Yung-Chi Lai, Mingxing Lei, Ming-You Shie, Cheng-Te Yao, Yi-Wen Chen, J.C. Tsai, Shyh-Jou Shieh, Yeu-Kuang Hwu, Hsu-Chen Cheng, Pin-Chi Tang, Shih-Chieh Hung, Chih-Feng Chen, Michael Habib, Randall B. Widelitz, Ping Wu, Wen-Tau Juan and Cheng-Ming Chuong, 27 November 2019, Cell.DOI: 10.1016/j.cell.2019.11.008

This work was supported by the ISCC, CMUH, Taiwan, the Drug Development Center, CMU, Higher Education Sprout Project, Ministry of Education (HESP-MOE), and grants from the National Institutes of Health, Ministry of Science and Technology, Taiwan, iEGG/Avian Genetic Resource/ABC supported by HESP-MOE, the Human Frontier Science Program, the National Natural Science Foundation of China, NSFC, Academia Sinica Research Program on Nanoscience and Nanotechnology, Top Notch Project, NCKU, and a University Advancement grant by MOE, Taiwan.

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How Flight Feathers Evolved: Study of Chickens, Ostriches, Penguins, Ducks and Eagles - SciTechDaily

Scientists have cracked a cell mechanism that drives tumor formation in most types of cancer. This finding could lead to much-needed new therapies for cancer, including the hard-to-treat triple-negative breast cancer. Scientists have zoomed in on a cellular mechanism that stabilizes a tumor-driving protein. Disrupting it may lead to new therapies.

The discovery concerns the molecular activity of the suppressor protein p53. This protein sits inside the nucleus of the cell and protects the cells DNA from stress. It has acquired the nickname guardian of the genome for this reason.

However, mutated forms of p53, which are common in cancer, behave differently than regular p53. Instead of protecting the cell, they can take on oncogenic, or tumor-promoting, properties and become active drivers of cancer.

Previous studies had already shown that p53 mutations are more stable than their nonmutant counterparts and can accumulate until they eclipse them in the nucleus. However, the mechanism behind the stability of p53 mutations remained unclear.

Now, researchers from the School of Medicine and Public Health at the University of Wisconsin-Madison have unpicked the stabilizing mechanism, and they suggest that it offers a promising target for new treatments. Their findings in the journal Nature Cell Biology.

The stabilizing process involves two molecules: the enzyme PIPK1-alpha and its lipid messenger PIP2. Between them, they appear to regulate the function of p53.

Although p53 is one of the most commonly mutated genes in cancer, says co-lead researcher and study author Vincent L. Cryns, who is a professor of medicine, we still do not have any drugs that specifically target p53.

The p53 protein protects the genome in several ways. Inside the nucleus, it binds to DNA. When ultraviolet light, radiation, chemicals, or other agents inflict damage on DNA, p53 to repair the damage or instruct the cell to self-destruct.

If the decision is to repair the DNA, p53 triggers other genes to start this process. If the DNA is beyond repair, p53 stops the cell from dividing and sends a signal to begin apoptosis, which is a type of programmed cell death.

In this way, nonmutant p53 prevents cells with damaged DNA from dividing and potentially growing into cancerous tumors.

However, many mutant forms of p53 involve a change to a single building block, or amino acid, in the protein molecule, which prevents it from stopping the replication of cells with damaged DNA.

Using a range of cell cultures, the team behind the new study discovered that the PIPK1-alpha enzyme links up with p53 to make PIP2 when cells become stressed due to DNA damage or another cause.

PIP2 also binds strongly to p53 and causes the protein to associate with small heat shock proteins. It is this association with heat shock proteins that stabilizes mutant p53 and allows it to promote cancer.

Small heat shock proteins are really good at stabilizing proteins, Prof. Cryns explains.

In our case, their binding to mutant p53 likely facilitates its cancer-promoting actions, something we are actively exploring, he adds.

The scientists were surprised to find PIPK1-alpha and PIP2 in the nucleus of cells, as these two molecules tend to occur only in cell walls.

They also found that disrupting the PIP2 pathway prevented the accumulation of mutant p53, effectively stopping it from promoting tumor development.

The team suggests that getting rid of mutant p53 could be a powerful way to fight cancers in which it is the key driver.

This could be a promising route for discovering drugs to treat triple negative , an aggressive type which, by its nature, for drugs to target.

The researchers are already trawling for compounds that block PIPK1-alpha and could become candidate drugs for the treatment of tumors with mutant p53.

Our discovery of this new molecular complex points to several different ways to target p53 for destruction, including blocking [PIPK1-alpha] or other molecules that bind to p53.

Prof. Vincent L. Cryns

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Medical News Today: How destroying a tumor promoter could lead to new cancer treatments - Stock Daily Dish