Investigation by imaging mass spectrometry of biomarker candidates for aging in the hair cortex

Recent omics advances in hair aging biology and hair biomarkers analysis

Aging is a complex natural process that leads to a decline in physiological functions, which is visible in signs such as hair graying, thinning, and loss. Although hair graying is characterized by a loss of pigment in the hair shaft, the underlying mechanism of age-associated hair graying is not fully understood. Hair graying and loss can have a significant impact on an individual's self-esteem and self-confidence, potentially leading to mental health problems such as depression and anxiety. Omics technologies, which have applications beyond clinical medicine, have led to the discovery of candidate hair biomarkers and may provide insight into the complex biology of hair aging and identify targets for effective therapies. This review provides an up-to-date overview of recent omics discoveries, including age-associated alterations of proteins and metabolites in the hair shaft and follicle, and highlights the significance of hair aging and graying biomarker discoveries. The decline in hair follicle stem cell activity with aging decreased the regeneration capacity of hair follicles. Cellular senescence, oxidative damage and altered extracellular matrix of hair follicle constituents characterized hair follicle and hair shaft aging and graying. The review attempts to correlate the impact of endogenous and exogenous factors on hair aging. We close by discussing the main challenges and limitations of the field, defining major open questions and offering an outlook for future research.

Mapping the Chemistry of Hair Strands by Mass Spectrometry Imaging-A Review

Hair can record chemical information reflecting our living conditions, and, therefore, strands of hair have become a potent analytical target within the biological and forensic sciences. While early efforts focused on analyzing complete hair strands in bulk, high spatial resolution mass spectrometry imaging (MSI) has recently come to the forefront of chemical hair-strand analysis. MSI techniques offer a localized analysis, requiring fewer de-contamination procedures per default and making it possible to map the distribution of analytes on and within individual hair strands. Applying the techniques to hair samples has proven particularly useful in investigations quantifying the exposure to, and uptake of, toxins or drugs. Overall, MSI, combined with optimized sample preparation protocols, has improved precision and accuracy for identifying several elemental and molecular species in single strands of hair. Here, we review different sample preparation protocols and use cases with a view to make the methodology more accessible to researchers outside of the field of forensic science. We conclude that—although some challenges remain, including contamination issues and matrix effects—MSI offers unique opportunities for obtaining highly resolved spatial information of several compounds simultaneously across hair surfaces.

Hair analysis to monitor adherence to prescribed chronic inhaler drug therapy in patients with asthma or COPD

BACKGROUND

Poor adherence to inhaled drug therapy in individuals with asthma and/or chronic obstructive pulmonary disease (COPD) may be associated with suboptimal therapeutic outcomes. Measurement of drug residues in hair samples has been employed to assess oral medication use over time. Here, we test the feasibility of analyzing hair samples from patients with asthma and/or COPD for assessing adherence to prescribed inhaled medication.

METHODS

In total, 200 male and female subjects, ≥ 18 years of age, with stable asthma and/or COPD who were receiving an acceptable standard of care daily inhaled product consistently, were recruited. Head hair samples were taken during a single visit to the clinical site and grouped by hair color according to the Fischer-Saller scale. Drug residues were extracted from milled hair samples using solid-phase extraction and analyzed using liquid chromatography-tandem mass spectrometry.

RESULTS

Inhaled drugs were detected in hair for 72% of subjects from whom it was possible to analyze hair samples (n = 157/200). Most hair samples obtained from subjects receiving formoterol or vilanterol had amounts of drug present that allowed determination of a quantifiable concentration, and demonstrated a dose response. Drugs were detected in all hair colors, with higher concentrations of formoterol observed in dark-haired versus light-haired individuals.

CONCLUSIONS

This is the first study to demonstrate that inhaled medication can be measured in hair samples from subjects with asthma and/or COPD. The results show that hair drug concentration data could potentially provide a record of historical adherence to inhaled therapeutics.

Recurrent triple-negative breast cancer (TNBC) tissues contain a higher amount of phosphatidylcholine (32:1) than non-recurrent TNBC tissues

Triple-negative breast cancer (TNBC) is one of the breast cancer subtype that displays a high risk of early recurrence and short overall survival. Improvement of the prognosis of patients with TNBC requires identifying a predictive factor of recurrence, which would make it possible to provide beneficial personalized treatment. However, no clinically reliable predictive factor is currently known. In this study, we investigated the predictive factor of recurrence in TNBC using matrix-assisted laser desorption/ionization-imaging mass spectrometry for lipid profiling of breast cancer specimens obtained from three and six patients with recurrent and non-recurrent TNBC, respectively. The signal for phosphatidylcholine (PC) (32:1) at m/z 732.5 was significantly higher in the recurrence group compared to the non-recurrence group (P = 0.024). PC (32:1) was more abundant in the cancer epithelial area than it was in the surrounding stroma, suggesting that abnormal lipid metabolism was associated with malignant transformation. Our results indicate PC (32:1) as a candidate predictive factor of TNBC recurrence. A future prospective study investigating whether personalized therapy based on PC (32:1) intensity improves the prognosis of patients with TNBC is recommended.

Matrix-assisted laser desorption/ionization mass spectrometric imaging for the rapid segmental analysis of methamphetamine in a single hair using umbelliferone as a matrix

Segmental hair analysis offers a longer period for retrospective drug detection than blood or urine. Hair is a keratinous fiber and is strongly hydrophobic. The embedding of drugs in hydrophobic hair at low concentrations makes it difficult for extraction and detection with matrix-assisted laser desorption/ionization (MALDI) coupled with mass spectrometric imaging (MSI). In this study, a single scalp hair was longitudinally cut with a cryostat section to a length of 4 mm and fixed onto a stainless steel MALDI plate. Umbelliferone was used as a new hydrophobic matrix to enrich and assist the ionization efficiency of methamphetamine in the hair sample. MALDI-Fourier transform ion cyclotron resonance (FTICR)-MS profiling and imaging were performed for direct detection and mapping of methamphetamine on the longitudinal sections of the single hair sample in positive ion mode. Using MALDI-MSI, the distribution of methamphetamine was observed throughout five longitudinally sectioned hair samples from a drug abuser. The changes of methamphetamine were also semi-quantified by comparing the ratios of methamphetamine/internal standard (I.S). This method improves the detection sensitivity of target drugs embedded in a hair matrix for imaging with mass spectrometry. The method could provide a detection level of methamphetamine down to a nanogram per milligram incorporated into hair. The results were also compared with the conventional high performance liquid chromatography -tandem mass spectrometry (HPLC-MS/MS) method. Changes in the imaging results over time by the MSI method showed good semi-quantitative correlation to the results from the HPLC-MS/MS method. This study provides a powerful tool for drug abuse control and forensic medicine analysis in a narrow time frame, and a reduction in the sample amount required.

Analysis of Antiretrovirals in Single Hair Strands for Evaluation of Drug Adherence with Infrared-Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry Imaging

Adherence to a drug regimen can be a strong predictor of health outcomes, and validated measures of adherence are necessary at all stages of therapy from drug development to prescription. Many of the existing metrics of drug adherence (e.g., self-report, pill counts, blood monitoring) have limitations, and analysis of hair strands has recently emerged as an objective alternative. Traditional methods of hair analysis based on LC-MS/MS (segmenting strands at ≥1 cm length) are not capable of preserving a temporal record of drug intake at higher resolution than approximately 1 month. Here, we evaluated the detectability of HIV antiretrovirals (ARVs) in hair from a range of drug classes using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI) with 100 μm resolution. Infrared laser desorption of hair strands was shown to penetrate into the strand cortex, allowing direct measurement by MSI without analyte extraction. Using optimized desorption conditions, a linear correlation between IR-MALDESI ion abundance and LC-MS/MS response was observed for six common ARVs with estimated limits of detection less than or equal to 1.6 ng/mg hair. The distribution of efavirenz (EFV) was then monitored in a series of hair strands collected from HIV infected, virologically suppressed patients. Because of the role hair melanin plays in accumulation of basic drugs (like most ARVs), an MSI method to quantify the melanin biomarker pyrrole-2,3,5-tricarboxylic acid (PTCA) was evaluated as a means of normalizing drug response between patients to develop broadly applicable adherence criteria.

Forensic Mass Spectrometry

Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Examples of techniques having forensic potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact in the forensic community unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques.

Human breast cancer tissues contain abundant phosphatidylcholine(36∶1) with high stearoyl-CoA desaturase-1 expression

Breast cancer is the leading cause of cancer and mortality in women worldwide. Recent studies have argued that there is a close relationship between lipid synthesis and cancer progression because some enzymes related to lipid synthesis are overexpressed in breast cancer tissues. However, lipid distribution in breast cancer tissues has not been investigated. We aimed to visualize phosphatidylcholines (PCs) and lysoPCs (LPCs) in human breast cancer tissues by performing matrix assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS), which is a novel technique that enables the visualization of molecules comprehensively. Twenty-nine breast tissue samples were obtained during surgery and subjected to MALDI-IMS analysis. We evaluated the heterogeneity of the distribution of PCs and LPCs on the tissues. Three species [PC(32∶1), PC(34∶1), and PC(36∶1)] of PCs with 1 mono-unsaturated fatty acid chain and 1 saturated fatty acid chain (MUFA-PCs) and one [PC(34∶0)] of PCs with 2 saturated fatty acid chains (SFA-PC) were relatively localized in cancerous areas rather than the rest of the sections (named reference area). In addition, the LPCs did not show any biased distribution. The relative amounts of PC(36∶1) compared to PC(36∶0) and that of PC(36∶1) to LPC(18∶0) were significantly higher in the cancerous areas. The protein expression of stearoyl-CoA desaturase-1 (SCD1), which is a synthetic enzyme of MUFA, showed accumulation in the cancerous areas as observed by the results of immunohistochemical staining. The ratios were further analyzed considering the differences in expressions of the estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2), and Ki67. The ratios of the signal intensity of PC(36∶1) to that of PC(36∶0) was higher in the lesions with positive ER expression. The contribution of SCD1 and other enzymes to the formation of the observed phospholipid composition is discussed.