Subject: Biotech and Medical Sciences

Why in the News?

Chinese researchers found that A-to-I mRNA editing, once considered random, plays a key role in development, especially in the wheat pathogen Fusarium graminearum.

About A-to-I mRNA Editing:

• mRNA: Our cells use DNA as a guide to make proteins. First, they copy DNA into messenger RNA (mRNA).
• A-to-I editing: This is a process where the letter adenosine (A) in mRNA is changed to inosine (I) by special enzymes called ADARs. The cell reads inosine as guanine (G), which can change the protein being made.
• Why it matters:
  • It helps the cell make different versions of proteins without changing the DNA.
  • It can remove early stop signals, allowing full proteins to be made.
  • It helps the cell adapt to different conditions or stages of life.

What did scientists discover in the fungus?

• Fungal Discovery: Scientists found that the fungus edits over 26,000 mRNA sites during reproduction, not during normal growth.
• Development Role: This editing fixes early stop signals in key genes, helping the fungus develop and reproduce properly.
• Stress Adaptation: Some genes work better unedited under stress, showing the fungus edits only when needed for survival.

Does this happen in humans?

Yes, A-to-I editing is common in humans:

• In the brain: It helps with brain growth, memory, and learning.
• In the immune system: It helps fight infections and control inflammation.

Health Implications:

• Health Risks: Faulty editing is linked to epilepsy and certain cancers.
• Therapeutic Potential: Understanding this process can lead to new treatments and improve gene-editing technologies.

Why in the News?

Uterine transplant surgery offers a groundbreaking solution for women with absolute uterine infertility, as seen in the recent birth of the first child in the U.K. born to a mother who received a donated uterus.

About Uterine Transplants:

• Uterine transplantation is a surgical procedure where a woman who lacks a functional uterus receives a donor uterus, enabling her to carry and give birth to a child.
• The transplant is typically temporary, allowing for one or two pregnancies, after which the uterus is usually removed to avoid complications.
• Donor Criteria:
  • Age: Between 30 to 50 years.
  • Health: Must be in good overall health, with a BMI under 30, and no history of diabetes, cancer (within 5 years), or STIs.
  • Exclusions: Women with HIV, Hepatitis B, Hepatitis C, or other complications.
• The procedure requires gynecological transplant surgeons with specific training. A 6-month recovery period is needed before attempting pregnancy.

Indian Scenario:

• India’s first transplant was performed on May 18, 2017, at Galaxy Care Hospital in Pune. The recipient was a 26-year-old woman who received her mother’s uterus.
• In October 2018, India’s first baby was born via Caesarean section, weighing 1.45 kg and healthy.
• This success story reflects India’s growing capabilities in reproductive medicine, providing hope to women with uterine infertility, offering them an opportunity for biological motherhood.

Why in the News?

A recent paper published in Nature by a team from the Chinese Academy of Sciences explored the genetic modification of rice plants to increase Coenzyme CoQ10 production.

What are Coenzymes and CoQ?

• Enzymes are biological catalysts made of proteins that speed up chemical reactions in living organisms without being consumed in the process.
• Coenzymes are organic molecules that assist enzymes in catalyzing biochemical reactions, making cellular metabolism more efficient.
• Coenzyme Q (CoQ) is a lipid-soluble antioxidant that helps stabilize cells under stress. It is crucial for cellular energy production.
• CoQ exists in 10 forms (CoQ1 to CoQ10), all present in the respiratory chain within cells.

Importance of CoQ9 and CoQ10

• CoQ9: It is found in cereal crops (wheat, rice, oats, barley, etc.), bamboo, and flowering plants like cinnamon, avocado, and pepper. It is rich in daily foods, making it an accessible nutrient.
• CoQ10: It is vital for mitochondrial energy production. Concentrated in high-energy organs like the heart. CoQ10 is crucial for health, especially in those with neurological issues or age-related deficiencies.
• Health Benefits of CoQ10:
  • 2008: CoQ10 supplementation helped patients with neurological disorders, improving their health (Montini et al., Milan).
  • 2012: Infants with CoQ10 deficiency benefitted from ubiquinone analogues (Shamima Ahmed, London).
• CoQ10-based supplements are now commonly prescribed by healthcare professionals.

Why in the News?

Betsy Arakawa, wife of Oscar-winning actor Gene Hackman, died from a respiratory illness linked to hantavirus, a rare disease transmitted by infected rodents, officials have confirmed.

What is Hantavirus?

• Hantavirus is a family of viruses carried by rodents that cause severe illnesses in humans. The two primary diseases it causes are:

1. Hantavirus Pulmonary Syndrome (HPS) – A fatal respiratory illness common in the Americas.
2. Hemorrhagic Fever with Renal Syndrome (HFRS) – Affects the kidneys and causes internal bleeding, mostly found in Asia and Europe.

• Hantavirus spreads through contact with infected rodent waste, primarily via:
  • Inhalation (Aerosolization) – Breathing in airborne particles from rodent urine, droppings, or saliva.
  • Direct Contact – Touching contaminated surfaces and then touching the eyes, nose, or mouth.
  • Open Wounds – Virus entering through cuts or scratches.
  • Rodent Bites (Rare).
  • Human-to-Human Transmission – Extremely rare, except for Andes virus in South America.

Is there a Cure or Treatment?

• No specific antiviral treatment or vaccine exists.
• Medical care focuses on symptom management:
  • Oxygen therapy for breathing difficulties.
  • ICU support & mechanical ventilation in severe cases.
• Early detection is crucial – Seek medical help immediately after potential rodent exposure.

Why in the News?

A groundbreaking study at the University of British Columbia, published in Nature Mental Health, reveals that addiction involves a complex neural circuit regulating cravings, emotions, and decision-making, shifting approaches to treatment and recovery.

The Three-Stage Cycle of Addiction

• Binge/Intoxication Stage (Basal Ganglia – Reward Processing)

• • Substance use triggers dopamine release, reinforcing pleasurable behaviors.
  • Over time, the brain associates substance use with intense rewards, increasing dependence.
  • Users experience cravings, leading to compulsive drug-seeking behavior.

• Withdrawal/Negative Affect Stage (Extended Amygdala – Emotional Distress)

• • When substance use stops, individuals experience withdrawal symptoms like stress, anxiety, and depression.
  • The brain craves relief, pushing individuals toward continued substance use to avoid discomfort.
  • This stage makes quitting extremely difficult, reinforcing addiction.

• Preoccupation/Anticipation Stage (Prefrontal Cortex – Impulse Control & Cravings)

• • The prefrontal cortex weakens, impairing decision-making and self-control.
  • Cravings dominate thoughts, leading to obsessive focus on substance use.
  • Despite knowing the negative consequences, individuals struggle to quit due to impaired cognitive function.

This cycle continuously repeats, making addiction a self-reinforcing loop.

Why in the News?

Researchers have discovered a reason why certain segments of the human and mouse genomes (Tra2b gene) have remained unchanged for 80 million years. These segments, known as ultra-conserved elements (UCEs), play a vital role in regulating protein production

What are Ultra-Conserved Elements (UCEs) in DNA?

• Ultra-Conserved Elements (UCEs) are long, highly conserved DNA sequences (200+ base pairs) that have remained unchanged for millions of years across multiple species, including humans, mice, rats, chickens, and even fish.
• Key Characteristics:
  • Found in both coding (gene) and non-coding (regulatory) regions of the genome.
  • Do not tolerate mutations, meaning they remain identical across species for tens of millions of years.
  • Many UCEs do not code for proteins but play crucial roles in gene regulation and cellular function.

• Their importance:

• • Evolutionary Significance: Their extreme conservation suggests they are essential for survival, as any mutation would likely be harmful.
  • Gene Regulation: UCEs may function as enhancers or silencers, controlling when and where genes are activated.
  • Developmental Roles: They are often linked to brain development, fertility, and immune response.
  • Disease Prevention: UCEs may protect against genetic disorders and cancers by stabilizing gene expression.

Why do Human and Mouse Genomes overlap?

• Humans and mice share a common mammalian ancestor that lived around 80 million years ago.
• Genomic Similarity:
  • Around 85% of mouse genes have direct counterparts in humans.
  • Nearly 500 UCEs are identical between humans and mice, despite millions of years of evolution.
• Many fundamental processes like cell division, metabolism, and brain function are similar between species, necessitating high conservation of crucial DNA regions.
• Medical Research:
  • Because of these similarities, mice serve as a model organism for studying human genetics, diseases, and drug responses.
  • UCEs help scientists understand gene function across species, leading to insights into evolution and biomedical advancements.

Why in the News?

In December 2024, Russia announced the development of a new mRNA-based personalized cancer vaccine, with plans to make it available for free to patients by early 2025.

What is an mRNA Cancer Vaccine?

• Unlike traditional vaccines, mRNA vaccines provide genetic instructions to train the immune system to detect and attack cancer cells.
• This technology gained prominence with the COVID-19 vaccines (Pfizer-BioNTech, Moderna) and is now being adapted for cancer treatment.
• These vaccines are therapeutic, designed for patients who already have cancer, not for prevention.

How do mRNA Cancer Vaccines Work?

• Cancer cells evade the immune system by suppressing immune responses.
  • Immunotherapy works by enhancing the body’s natural ability to detect and destroy these cancerous cells.
• Unlike chemotherapy, which kills both healthy and cancerous cells, immunotherapy selectively targets only cancer cells, reducing harmful side effects.
• mRNA cancer vaccines are customized for each patient, targeting specific tumor antigens, making them highly personalized and potentially more effective.
• While traditional infectious disease vaccines prevent illness, mRNA cancer vaccines are therapeutic, meaning they are administered to patients who already have cancer to help their immune system fight the disease.