Clinical Scorecard: Investigating the Human Brain: Challenges and Strategies in Post-Mortem Spatial Transcriptomics Analysis

At a Glance

Key Highlights

• Spatial transcriptomics (ST) enables high-resolution mapping of gene expression in intact brain tissue without dissociation.
• Sequencing-based ST captures whole transcriptome spatial data but is limited by capture area size and tissue type compatibility.
• Imaging-based ST uses in situ hybridization for targeted transcript detection, offering high spatial resolution but limited transcript number.

Guideline-Based Recommendations

Diagnosis

• Use spatial transcriptomics to identify spatial gene expression patterns in diverse brain cell types.
• Combine ST with classical histological and RNA sequencing methods for comprehensive brain tissue analysis.

Management

• Select sequencing-based ST platforms for unbiased whole-transcriptome profiling in discovery studies.
• Consider imaging-based ST for high-resolution detection of targeted transcripts when spatial precision is critical.
• Use specialized slides with oligonucleotide arrays for mRNA capture, adapting protocols for tissue type (fresh frozen vs FFPE).

Monitoring & Follow-up

• Perform bioinformatics processing to assign gene labels and spatial coordinates to transcript data.
• Assess quality and sensitivity of mRNA capture, especially in fragmented FFPE tissues.

Risks

• Potential bias in single-cell/nucleus RNA sequencing due to cell dissociation and loss of cytoplasmic mRNA.
• Limitations in spatial resolution and tissue size imposed by capture spot size and slide dimensions.
• Probe-based capture methods may miss transcripts not targeted by probes, introducing detection bias.

Patient & Prescribing Data

Post-mortem human brain tissue samples

Spatial transcriptomics is a research tool rather than a treatment; insights gained can inform understanding of neurological disease mechanisms.

Clinical Best Practices

• Integrate spatial transcriptomics with existing histological and molecular techniques for comprehensive brain analysis.
• Choose appropriate ST platform based on research goals, tissue preservation method, and required spatial resolution.
• Address challenges of post-mortem tissue quality and RNA integrity in experimental design.
• Utilize bioinformatics pipelines tailored to spatial transcriptomics data for accurate spatial gene expression mapping.

References

• Brodmann's brain regional specialization
• Bulk RNA sequencing in human tissues
• Single-cell RNA sequencing challenges
• Spatial transcriptomics technology overview