How ACE2 biology and AAV vector technology may open new directions for gene therapy research

Introduction

Angiotensin-converting enzyme 2, or ACE2, and adeno-associated virus, or AAV, represent two important areas of biomedical research. ACE2 is a key regulator of the renin-angiotensin system, while AAV is one of the most widely used platforms for in vivo gene delivery. Together, ACE2 biology and AAV-mediated gene transfer offer a promising research direction for diseases in which dysregulated inflammation, vascular injury, cardiac remodeling, or renin-angiotensin system imbalance may play a role.

Although ACE2-AAV approaches remain largely preclinical, animal studies and mechanistic research suggest that targeted ACE2 expression may have therapeutic potential in selected disease settings. At the same time, the field must carefully address safety, tissue specificity, dosing, immune response, and disease-context-dependent effects before such strategies can be translated into clinical application.

The Biological Role of ACE2

ACE2 is a membrane-associated carboxypeptidase that counterbalances the classical renin-angiotensin system. While the ACE/angiotensin II/AT1 receptor axis is commonly associated with vasoconstriction, inflammation, fibrosis, oxidative stress, and pathological remodeling, ACE2 converts angiotensin II into angiotensin-(1–7), a peptide that generally supports vasodilation, anti-inflammatory signaling, anti-fibrotic effects, and cardiovascular protection through the Mas receptor pathway. Experimental evidence from animal models has suggested a beneficial role for the ACE2/angiotensin-(1–7) axis in cardiovascular function.

Because ACE2 is involved in cardiovascular, renal, pulmonary, metabolic, and inflammatory pathways, it has attracted interest as a therapeutic target. In cardiovascular research, ACE2 has been studied in relation to hypertension, heart failure, cardiac remodeling, diabetic complications, and vascular dysfunction. However, human genetic association studies linking ACE2 variants with cardiovascular disease have produced inconsistent results, indicating that ACE2 biology is complex and may vary by disease state, sex, tissue type, and patient population.

Why AAV Is a Suitable Platform for ACE2 Gene Delivery

AAV vectors are widely used for in vivo gene therapy because they can support efficient gene transfer, relatively long-term transgene expression, and tissue-selective delivery depending on the serotype, promoter, and route of administration. For ACE2-based strategies, AAV offers a practical way to deliver an ACE2 expression cassette to target tissues such as the heart, vasculature, brain, retina, kidney, or lung in preclinical disease models.

AAV-mediated ACE2 delivery may be useful when sustained local expression is preferred over repeated protein administration. For example, AAV vectors can be designed to express full-length membrane-bound ACE2, soluble ACE2, or engineered ACE2 variants, depending on the therapeutic objective. Tissue-specific promoters and optimized AAV capsids may further help restrict ACE2 expression to the intended target tissue and reduce off-target activity.

Potential Therapeutic Applications of ACE2-AAV Strategies

ACE2-AAV approaches are being explored primarily as research and preclinical strategies rather than established clinical therapies. Potential areas of investigation include:

• Cardiovascular disease: ACE2 overexpression has been studied in animal models of hypertension, heart failure, and cardiac remodeling. Some studies suggest that ACE2 gene transfer may help modulate autonomic activity, improve baroreflex function, or counteract pathological angiotensin II signaling.
• Diabetic and retinal disease models: AAV-mediated ACE2 overexpression has been investigated in diabetic retinopathy models, where local ACE2 activity may help reduce inflammatory and vascular injury pathways.
• Pulmonary and inflammatory disease: Because ACE2 regulates angiotensin II and angiotensin-(1–7) balance, ACE2-based approaches may be relevant to lung injury, inflammation, and vascular dysfunction. However, careful design is required because ACE2 also functions as the cellular entry receptor for SARS-CoV and SARS-CoV-2.
• Infectious disease research models: AAV has also been used to express human ACE2 in animal models to create systems permissive for SARS-CoV-2 infection. This is mainly a research tool for studying viral pathogenesis, vaccines, and antivirals, rather than a therapeutic ACE2 gene therapy approach.

Scientific and Translational Challenges

Despite its promise, ACE2-AAV gene delivery faces several important challenges. ACE2 has context-dependent biological functions, and increasing ACE2 expression may not be beneficial in every tissue or disease state. In the setting of coronavirus biology, membrane-bound ACE2 can also act as a viral entry receptor, which creates additional safety considerations for some applications.

Key challenges include:

• Tissue specificity: ACE2 expression should ideally be limited to the intended tissue or cell type to reduce systemic or off-target effects.
• Dose control: Excessive or prolonged ACE2 expression may have unintended consequences on blood pressure, vascular tone, immune signaling, or local tissue homeostasis.
• Vector selection: The AAV serotype, promoter, regulatory elements, and route of administration must be selected based on the target disease and tissue.
• Immune response: Pre-existing anti-AAV antibodies, capsid-specific immunity, and immune responses to the transgene product may affect safety and durability.
• Clinical translation: Most ACE2-AAV studies remain preclinical. Robust toxicology, biodistribution, dose-response, durability, and disease-specific efficacy data are needed before clinical development can be justified.

Future Outlook

The combination of ACE2 biology and AAV vector technology provides an intriguing direction for gene therapy research. As AAV capsid engineering, tissue-specific promoters, regulatable expression systems, and improved analytical tools continue to advance, it may become possible to design ACE2 gene delivery approaches with greater precision and safety.

Future ACE2-AAV strategies may focus less on broad systemic ACE2 overexpression and more on controlled, tissue-targeted, and disease-specific modulation of the ACE2/angiotensin-(1–7)/Mas receptor axis. Such approaches could be particularly valuable for diseases involving local inflammation, fibrosis, vascular injury, or maladaptive remodeling.

Conclusion

AAV-mediated ACE2 gene delivery represents a promising but still emerging area of gene therapy research. ACE2 offers a biologically meaningful target because of its role in balancing the renin-angiotensin system and modulating cardiovascular, inflammatory, and tissue-protective pathways. AAV provides a versatile delivery platform capable of supporting sustained and tissue-selective expression.

However, ACE2-AAV strategies require careful optimization and rigorous validation. Safety, specificity, vector dose, immune response, and disease context must all be considered. With continued progress in AAV engineering and gene therapy development, ACE2-AAV approaches may contribute to new therapeutic possibilities for selected cardiovascular, inflammatory, and tissue injury-related diseases.

How PackGene Supports AAV-Based Gene Therapy Research

PackGene provides integrated AAV solutions to support gene therapy research and translational development, including vector design, plasmid construction, AAV production, purification, serotype selection, and analytical testing. For ACE2-related research, PackGene can help researchers design fit-for-purpose AAV vectors with appropriate promoters, capsids, expression cassettes, and quality control strategies for in vitro and in vivo studies.

By combining customized AAV vector design with scalable production and quality-focused analytical workflows, PackGene supports researchers developing AAV-based tools for cardiovascular, metabolic, inflammatory, infectious disease, and other biomedical research applications.