MicroRNAs in the Eye: A potential breakthrough for diabetic retinopathy.

Unlocking the Secrets: Can Tiny Molecules in Your Blood Predict Diabetic Retinopathy?

Kai Mendoza in Health & Wellness November 2025 • 4 min read.

"Groundbreaking research explores how microRNAs miR-29b and miR-200b could revolutionize early detection and treatment of diabetes-related eye damage."

Diabetic retinopathy (DR) is a serious complication of diabetes, leading to vision loss and blindness among adults. While factors like high blood sugar and blood pressure are known risks, genetics also play a role. Scientists are exploring how epigenetic mechanisms, which affect how our genes work, contribute to DR.

MicroRNAs (miRNAs) are small molecules that regulate gene expression. Recent studies have found that abnormal levels of miRNAs in retinal cells are linked to DR. These circulating miRNAs could serve as biomarkers, helping doctors diagnose and manage diabetes and its complications earlier.

A new study focuses on two specific miRNAs, miR-29b and miR-200b, which have shown promise in influencing retinal cell health. This research aims to determine if the levels of these miRNAs in the blood can be linked to the presence and severity of DR in people with type 2 diabetes.

What's the Connection Between MicroRNAs and Eye Health?

MicroRNAs in the Eye: A potential breakthrough for diabetic retinopathy.

Researchers in Brazil conducted a case-control study involving 186 individuals with type 2 diabetes. The participants were divided into three groups: those without DR, those with non-proliferative DR (NPDR), and those with proliferative DR (PDR). The study also included a control group of 20 healthy blood donors to establish baseline miRNA levels.

The team used a sophisticated technique called reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to precisely measure the levels of miR-29b and miR-200b in the participants' blood plasma. Here's a breakdown of what they were looking for and why:

miR-29b: This miRNA has shown protective effects on retinal cells, preventing cell death and fibrosis (scarring). It also helps maintain healthy blood vessel function in the eye.
miR-200b: This miRNA helps protect against leaky blood vessels and excessive blood vessel growth, both of which are hallmarks of DR.
The Hypothesis: The researchers hypothesized that people with DR would have lower levels of these protective miRNAs in their blood.

The initial results showed that individuals with proliferative DR (the more advanced form) had lower levels of both miR-29b and miR-200b. However, after accounting for other factors like age, gender, and diabetes duration, the link between miRNA levels and DR weakened. Interestingly, people with type 2 diabetes overall had lower levels of miR-200b compared to the healthy blood donors.

The Future of Diabetic Retinopathy Research

This study adds to the growing body of evidence suggesting that miRNAs play a crucial role in the development of DR. While the link between miR-29b and DR needs further investigation, the findings highlight the potential of miR-200b as a marker for diabetes and possibly DR risk. More research is needed to understand how these miRNAs are regulated and how they interact with other factors. Ultimately, this knowledge could lead to new diagnostic tools and therapies for preventing vision loss in people with diabetes.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1111/jcmm.14030, Alternate LINK

Title: Plasma Levels Of Mir-29B And Mir-200B In Type 2 Diabetic Retinopathy

Subject: Cell Biology

Journal: Journal of Cellular and Molecular Medicine

Publisher: Wiley

Authors: Maria Enoia Dantas Da Costa E Silva, Evelise Regina Polina, Daisy Crispim, Renan Cesar Sbruzzi, Daniel Lavinsky, Felipe Mallmann, Nidiane Carla Martinelli, Luis Henrique Canani, Katia Gonçalves Dos Santos

Published: 2018-11-23

Everything You Need To Know

What exactly are microRNAs (miRNAs) and how are they connected to diabetic retinopathy (DR)?

MicroRNAs, or miRNAs, are small molecules that play a critical role in regulating gene expression. In the context of diabetic retinopathy, abnormal levels of miRNAs, particularly in retinal cells, have been linked to the development and progression of DR. These circulating miRNAs, such as miR-29b and miR-200b, could potentially serve as biomarkers for early diagnosis and management of diabetes and its complications, including DR. Further research is needed to fully understand their function and interaction within DR.

How do miR-29b and miR-200b potentially protect against diabetic retinopathy, and what were the initial findings regarding their levels in individuals with DR?

MiR-29b has demonstrated protective effects on retinal cells by preventing cell death and fibrosis, while also maintaining healthy blood vessel function in the eye. MiR-200b helps protect against leaky blood vessels and excessive blood vessel growth, both of which are hallmarks of DR. The initial findings indicated that individuals with proliferative DR had lower levels of both miR-29b and miR-200b. While the initial link between miR-29b and DR weakened after adjusting for factors like age and diabetes duration, lower levels of miR-200b were observed in people with type 2 diabetes compared to healthy individuals, suggesting a potential connection.

What method was used to measure the levels of miR-29b and miR-200b in the blood, and why is this technique important?

The method used to measure the levels of miR-29b and miR-200b in the blood was reverse transcription-quantitative polymerase chain reaction, or RT-qPCR. This sophisticated technique is crucial because it allows for the precise quantification of RNA molecules, like miRNAs, in biological samples. Accurate measurement of these miRNAs is essential for determining their potential as biomarkers for diseases like diabetic retinopathy.

Considering that the link between miR-29b and DR weakened after adjusting for other factors, what are the next steps in researching the role of microRNAs in diabetic retinopathy?

Even though the initial link between miR-29b and DR weakened after adjusting for other factors, there is still a reason to investigate. The observation that people with type 2 diabetes had lower levels of miR-200b indicates its potential as a marker for diabetes and possibly DR risk. Future research is crucial to fully understand how these miRNAs are regulated, how they interact with other factors, and whether they can be effectively targeted for therapeutic interventions to prevent vision loss in people with diabetes.

Besides microRNAs like miR-29b and miR-200b, what other factors contribute to diabetic retinopathy, and how might future research integrate these various elements for a more comprehensive understanding?

Besides microRNAs like miR-29b and miR-200b, other established factors contributing to diabetic retinopathy include high blood sugar, high blood pressure, and genetics. Future research should focus on integrating these various elements to gain a more comprehensive understanding of DR development. This may involve investigating how epigenetic mechanisms and other regulatory molecules interact with miRNAs and known risk factors to influence retinal cell health. A holistic approach is essential for developing effective diagnostic tools and therapies for preventing vision loss in people with diabetes.