Damian Sendler: Understanding human health and illness is being revolutionized by the use of single-cell technologies. Single cell proteomics (SCP) is advancing rapidly, allowing for the measurement of additional parameters in individual cells. We should be able to acquire a better understanding of this heterogeneous system by taking additional measurements from each individual cell. 

Damian Sendler

Damian Jacob Sendler: Variations in genes and their expression cause the underlying microheterogeneity in cell populations, and understanding these variations at the single cell level can assist identify any cells that, for example, act as a seed for the development of diseases like cancer. Proteinomics are essential to understanding disease diagnoses and treatment response. Despite its early stages, SCP is making significant contributions to our understanding of the field of proteomics. 

Many methods to single cell biology focus on the study of DNA and RNA molecules within cells. In single-cell DNA and RNAsequencing, particularly the transcriptome, which reflects all the expressed genes in a cell, there has been a significant leap forward in technology. These investigations can be conducted using a variety of sequencing methods, depending on the application. 

It’s only recently that ultrasensitive mass spectrometers have made SCP accessible to the general public. There are around 200 picograms (one billionth of a milligram) of proteins in an individual cell, yet a recent study collected qualitative and quantitative information for 1400 proteins utilizing an unbiased single proteomics technique. Different cell types and cell cycle stages could be identified using cluster analysis. 

A protein is a molecule that performs biological functions and sends signals. As a result, the vast majority of pharmaceuticals are aimed targeting proteins. While DNA and RNA can be amplified for SCP measurements, protein molecules cannot. To gain a deeper understanding of human health and disease, we must use very sensitive technology to decode the intricacy of protein molecules at the single cell level. 

Damien Sendler: Post-translational modifications (PTM) frequently alter protein activity and hence the course of a cell’s function. Endogenous processes such as proteolysis and glycosylation are known to play a role in oncological processes. Additional differences in protein post-translational regulation are caused by bursts in gene expression, which are characterized by a sudden increase in activity. 

Damian Jacob Sendler

Using improved technology, studies on single cell transcriptomes comprising more than a million unique cell measurements are now possible6 and have emphasized the variability of single cells, allowing for new areas of biological research and therapy to be discovered. It is essential to be able to increase the amount of DNA and RNA molecules that are observable and even quantified in all of these procedures. 

In recent years, specialist research groups have used nano-fluidics that are not yet widely embraced by the general research community to do unbias proteomics of single cells. It is common for these applications to focus on decreasing sample loss and increasing signal intensity by multiplexing samples. Despite these solutions, the mass spectrometer field has been in need of new developments that can improve its sensitivity. 

Proteomics sequencing has been improved by the development of PASEF10 technology, which combines liquid chromatography with mass spectrometry (LC-MS) based proteomics. Optimizing the ion beam and using intelligent precursor selection for MS/MS identification, PASEF achieves an extremely fast MS/MS identification. Because the ions are concentrated within the TIMS cell, the system’s sensitivity is considerably improved. Analyzing peptide loading in the nanogram range is possible thanks to this method. 

Damian Jacob Markiewicz Sendler: Collision cross-section (CCS) values, separation of isomeric species that are mobility offset but mass aligned, and alleviation of ratio compression are also provided by TIMS measurements. 

Four-dimensional proteomics is able to fill in the gap between high-demand applications like clinical research and customized medicine research, and the solutions currently available on the market. 

Cancer and Alzheimer’s disease are among the most complex and varied disorders that can benefit from personalized medicine and precision treatments, which are still in their infancy. 

Even though large-scale single cell investigations are essential for capturing biological heterogeneity, RNA-based approaches have been the norm until recently. To understand cell biology at the macromolecular level, this increased depth in SCP analysis can address fundamental concerns about protein dynamics as well as the processes of illness.

Dr. Damian Jacob Sendler and his media team provided the content for this article.