This ultrasound treatment may help stop arthritis before it starts

Researchers at The University of Alabama in Huntsville (UAH), part of The University of Alabama System, have identified a promising new use for continuous low-intensity ultrasound that could one day help treat joint injuries and reduce the risk of post-traumatic osteoarthritis. Their findings suggest the non-invasive approach may shift the body's immune response away from long-lasting inflammation and toward tissue repair, offering a potential drug-free strategy for improving healing.

The study, published in the Nature journal Scientific Reports, was led by Dr. Anuradha Subramanian, professor of chemical and materials engineering. It combined biological research conducted by Dr. Shahid Khan during his doctoral studies with computational and statistical analysis developed by Dr. Satyaki Roy, professor of mathematical sciences, along with contributions from graduate student Owen Trippany. The research was funded by the National Institutes of Health through an R01 grant awarded to Subramanian.

How Ultrasound Influences Immune Cells

The team focused on macrophages, specialized immune cells that play a key role in both inflammation and tissue repair, to understand how they respond to continuous low-intensity ultrasound.

"Following injury, the body recruits inflammatory 'defender' macrophages (M1) to clear damaged tissue and healer macrophages (M2) to support repair and recovery," Subramanian explains. "Persistent dominance of defender macrophages can create a prolonged inflammatory environment that contributes to post-traumatic osteoarthritis."

The researchers wanted to determine whether ultrasound could encourage these immune cells to transition from an inflammatory state to one that promotes healing.

"In an 'M1' state, microphages promote inflammation to fight damage or infection, but prolonged M1 activity can also harm healthy tissue," Subramanian notes. "In contrast, 'M2-like' macrophages support tissue repair and recovery. Shifting macrophages toward an M2-like state is important, because it may help reduce chronic inflammation while encouraging healing in damaged joints. Our findings suggest that continuous low-intensity ultrasound may help restore this balance by promoting a more reparative macrophage response."

Roy says chronic inflammation is a major factor in the development of post-traumatic osteoarthritis.

"Post-traumatic osteoarthritis is driven in part by persistent inflammation that limits tissue repair and accelerates joint degeneration," Roy adds. "Our team is interested in continuous low-intensity ultrasound because it offers a non-pharmacological, non-invasive approach that may help regulate immune cell behavior and promote a more reparative healing environment in injured joints."

A More Realistic Model of Joint Injury

To better recreate the conditions inside an injured joint, the researchers relied on fibronectin fragments, molecules generated as damaged tissue breaks down, instead of using only conventional laboratory methods to trigger inflammation. This approach produced a model that more closely reflects the biological environment that develops after a joint injury.

The team also combined transcriptomics, the large-scale study of gene activity, with an advanced computational method known as differential clustering. Rather than analyzing genes one by one, this technique identifies groups of genes whose behavior changes together, providing a broader picture of how immune cells respond to ultrasound treatment.

"This allowed us to study not only which genes changed, but also how groups of genes changed their coordinated behavior in response to ultrasound stimulation," Roy says.

Early Results Show Reduced Inflammation

The researchers found that continuous low-intensity ultrasound lowered biological markers linked to inflammation while increasing markers associated with a more reparative, M2-like macrophage state.

Although the research is still limited to laboratory experiments, the findings suggest that non-drug, non-invasive technologies could eventually be used to influence immune cell behavior and improve healing after joint injuries. The researchers believe the technique could become part of future treatments designed to slow the progression of osteoarthritis and improve recovery after joint trauma.

"The next steps will involve validating these findings in animal models of early post-traumatic osteoarthritis and studying how ultrasound-based modulation affects long-term tissue repair in joint injury settings," Subramanian says.

Journal Reference:

1. Shahid Khan, Owen Trippany, Anuradha Subramanian, Satyaki Roy. Continuous low-intensity ultrasound influences the transcriptomic profile in M1 macrophages by downregulating inflammation and promoting M2-like markers. Scientific Reports, 2026; DOI: 10.1038/s41598-026-53228-6

Courtesy:

The University of Alabama in Hunstville. "This ultrasound treatment may help stop arthritis before it starts." ScienceDaily. ScienceDaily, 12 July 2026. <www.sciencedaily.com/releases/2026/07/260710003521.htm>. 

 

 

Scientists finally crack nature's secret for building better cancer drugs

Scientists have uncovered how bacteria naturally manufacture multiple versions of powerful cancer drugs, solving a mystery that has puzzled researchers for decades. The discovery could help speed the development of new treatments for cancers that are still difficult to treat.

For years, scientists have hoped to harness bacterial enzymes to create new drug variants through a process known as combinatorial biosynthesis. However, progress has been limited because researchers did not fully understand how the enzymes coordinate their work.

Published in Nature Communications, the new study reveals how bacterial enzymes communicate with one another to assemble a family of closely related anti-cancer compounds. That family includes Romidepsin (Istodax), an FDA-approved treatment for certain blood cancers. By uncovering this natural "mix and match" system and reproducing its underlying principles in the laboratory, the researchers have established a new strategy for designing future cancer therapies.

"For decades, we've known that bacteria can naturally produce multiple versions of powerful anti-cancer drugs, yet we had no idea how they achieved this," said first author Dr. Munro Passmore, Research Fellow, Department of Chemistry, University of Warwick. "This work finally cracks that code. We've identified how the different enzymes communicate and cooperate to produce these drug variants, something that has eluded researchers because the system is so elegantly economical. It's the breakthrough we needed to actually engineer these drugs ourselves."

Tiny Molecular Connectors Reveal Nature's Drug-Making Strategy

The researchers discovered that small molecular regions known as 'docking domains' serve as connectors between the core drug-building machinery and the enzymes responsible for adding different components. These docking domains share a conserved connection point that allows them to interact with multiple enzyme partners.

This flexible design explains how bacteria can create a variety of related drug molecules while still maintaining the precision needed for the compounds to remain effective.

The study also sheds light on how these natural drug-producing systems evolved. According to the researchers, the newly identified compound most likely developed from a related drug-producing pathway through gene duplication and recombination over time.

Prof. Greg Challis, Monash Warwick Alliance Professor of Sustainable Chemistry, University of Warwick and Monash University concludes: "This research gives us a blueprint to do what nature does, but better and faster. By reverse-engineering nature's evolutionary logic, we can now design synthetic pathways that generate new anti-cancer drug candidates with properties optimized for clinical use, such as superior potency, improved selectivity, fewer side effects. Our immediate goal is to build an expanded library of candidates for various cancers where new treatments are urgently needed. This discovery is moving us from understanding how the systems work to building new ones."

How the Discovery Could Improve Cancer Drug Development

The work focuses on a class of anti-cancer medicines known as HDAC inhibitors. These drugs block histone deacetylases, enzymes that help regulate which genes are switched on or off inside cells. Romidepsin (Istodax) is an FDA-approved HDAC inhibitor used to treat T-cell lymphomas.

A chemically related compound called FR-901375 has been known for decades, but scientists had never identified the biological pathway bacteria use to produce it. This study finally fills in that missing piece.

Like other HDAC inhibitors in its family, FR-901375 belongs to a group of complex cyclic molecules called depsipeptides. These compounds are assembled from amino acid building blocks along with a conserved hydroxy acid pharmacophore, all connected through a combination of peptide and ester bonds.

Inside bacteria, these molecules are built by massive protein complexes called PKS-NRPS hybrids, which combine the activities of polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS). The new research shows that the key to this assembly process is the docking domains, which act like molecular connectors that allow one part of the production line to recognize and pass its product to the next. This mechanism is what enables combinatorial biosynthesis and allows bacteria to naturally generate multiple drug variants.

How the Researchers Solved the Mystery

To uncover how this system works, the team combined structural biology, biochemistry, genetics, and computational modeling.

Their work included:

• Bioinformatic searches of public databases that identified the FR-901375 biosynthetic gene cluster in Pseudomonas chlororaphis subsp. piscium, with the findings confirmed by mass spectrometry analysis of extracted metabolites.
• In vitro reconstitution experiments using purified protein domains that demonstrated productive enzyme-enzyme interactions, verified with intact protein mass spectrometry.
• AlphaFold computational modeling to predict protein complex structures, followed by carbene footprinting mass spectrometry to experimentally map the interaction sites.
• Site-directed mutagenesis experiments that confirmed the importance of the predicted binding residues.
• Gene deletion studies in bacterial strains showing that the docking domains are essential for the system to function in vivo.
• Comparative analysis of biosynthetic gene clusters from multiple HDAC inhibitor-producing bacteria, revealing evolutionarily conserved features shared across these natural drug-making systems.

Journal Reference:

1. Munro Passmore, Xinyun Jian, Xinyi Zhao, Emmanuel L. C. de los Santos, Douglas M. Roberts, Józef R. Lewandowski, Matthew Jenner, Lona M. Alkhalaf, Gregory L. Challis. Molecular basis for depsipeptide HDAC inhibitor combinatorial biosynthesis. Nature Communications, 2026; 17 (1) DOI: 10.1038/s41467-026-74383-4

Courtesy:

University of Warwick. "Scientists finally crack nature's secret for building better cancer drugs." ScienceDaily. ScienceDaily, 8 July 2026. <www.sciencedaily.com/releases/2026/07/260701205001.htm>.