Higher Accumulation of Docosahexaenoic Acid in the Vermilion of the Human Lip than in the Skin

Human lip vermilion: Physiology and age-related changes

BACKGROUND

The human lip vermilion, also known as the red lip, is important to the quality of life and has long attracted the attention of cosmetic researchers. However, there is limited existing literature on the physiological characteristics and age-related alterations in the human vermilion.

OBJECTIVE

We aim to provide an overview of the physiological characteristics and age-related alterations in the human vermilion.

METHODS

This article is a result of previous research. We conducted a literature search using various academic databases such as Google Scholar, Web of Science, and PubMed. Our findings provided a comprehensive understanding of the physiological characteristics and age-related changes of the human lip vermilion.

RESULTS

The human lip vermilion has a unique structure and physiological characteristics, and during the aging process, a few changes may occur in the human lip vermilion.

CONCLUSION

Understanding the human lip vermilion's physiological characteristics and age-related changes can provide key information for the future innovation of lip vermilion care products. Further investigations are necessary to reach a consensus on the physiological characteristics and age-related alterations in the human vermilion.

Elucidating Gender-Specific Distribution of Imipramine, Chloroquine, and Their Metabolites in Mice Kidney Tissues through AP-MALDI-MSI

Knowledge of gender-specific drug distributions in different organs are of great importance for personalized medicine and reducing toxicity. However, such drug distributions have not been well studied. In this study, we investigated potential differences in the distribution of imipramine and chloroquine, as well as their metabolites, between male and female kidneys. Kidneys were collected from mice treated with imipramine or chloroquine and then subjected to atmospheric pressure matrix-assisted laser desorption ionization-mass spectrometry imaging (AP-MALDI-MSI). We observed differential distributions of the drugs and their metabolites between male and female kidneys. Imipramine showed prominent distributions in the cortex and medulla in male and female kidneys, respectively. Desipramine, one of the metabolites of imipramine, showed significantly higher (*** p < 0.001) distributions in the medulla of the male kidney compared to that of the female kidney. Chloroquine and its metabolites were accumulated in the pelvis of both male and female kidneys. Interestingly, they showed a characteristic distribution in the medulla of the female kidney, while almost no distributions were observed in the same areas of the male kidney. For the first time, our study revealed that the distributions of imipramine, chloroquine, and their metabolites were different in male and female kidneys.

Image-based investigation of lip aging features in a large number of Korean women

BACKGROUND

The lips play a significant role in shaping facial aesthetics. Due to the distinct attributes of lips in contrast to other facial skin, a unique approach is imperative for managing lip aging. We analyzed lip characteristics (morphology, wrinkles, and color) to investigate visual changes and distinctive attributes of aging lips.

METHODS

By utilizing image data processing methods, including facial landmark detection, pattern recognition, and color quantification, we extracted 11 lip characteristic indices (four morphological indices, four wrinkle indices, and three color indices) from high-resolution images of 1000 Korean women aged 20-69. Correlation tests were conducted to assess the relationship between lip characteristic indices and age, and also between lip morphological and wrinkle indices.

RESULTS

Lip height significantly decreased, while lip width and lip ratio (lip width divided by the sum of the upper and lower lip height) significantly increased with aging. Lip wrinkles significantly increased with aging, whereas lip colors (redness and yellowness) decreased. The lip wrinkle indices, which are segmented for the first time in this study, exhibited significant correlations with lip width, and three of them additionally were correlated with lip ratio (p < 0.05). The results imply such morphological changes can be associated with wrinkle formation of human lips.

CONCLUSION

The indices suggested in this study can be used for assessing lip aging characteristics, and the study results can contribute to deeper understanding of lip aging.

Detection of Distinct Distributions of Acetaminophen and Acetaminophen-Cysteine in Kidneys up to 10 μm Resolution and Identification of a Novel Acetaminophen Metabolite Using an AP-MALDI Imaging Mass Microscope

Drug distribution studies in tissue are crucial for understanding the pharmacokinetics and potential toxicity of drugs. Recently, matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) has gained attention for drug distribution studies due to its high sensitivity, label-free nature, and ability to distinguish between parent drugs, their metabolites, and endogenous molecules. Despite these advantages, achieving high spatial resolution in drug imaging is challenging. Importantly, many drugs and metabolites are rarely detectable by conventional vacuum MALDI-MSI because of their poor ionization efficiency. It has been reported that acetaminophen (APAP) and one of its major metabolites, APAP-Cysteine (APAP-CYS), cannot be detected by vacuum MALDI-MSI without derivatization. In this context, we showed the distribution of both APAP and APAP-CYS in kidneys at high spatial resolution (25 and 10 μm) by employing an atmospheric pressure-MALDI imaging mass microscope without derivatization. APAP was highly accumulated in the renal pelvis 1 h after drug administration, while APAP-CYS exhibited characteristic distributions in the outer medulla and renal pelvis at both 30 min and 1 h after administration. Interestingly, cluster-like distributions of APAP and APAP-CYS were observed in the renal pelvis at 10 μm spatial resolution. Additionally, a novel APAP metabolite, tentatively coined as APAP-butyl sulfate (APAP-BS), was identified in the kidney, brain, and liver by combining MSI and tandem MSI. For the first time, our study revealed differential distributions of APAP, APAP-CYS (in kidneys), and APAP-BS (in kidney, brain, and liver) and is believed to enhance the understanding of the pharmacokinetics and potential nephrotoxicity of this drug.

The stability of the metabolic turnover of arachidonic acid in human unruptured intracranial aneurysmal walls is sustained

OBJECTIVE

Intracranial aneurysm (IA) is considered a chronic inflammatory condition that affects intracranial arteries. Cyclooxygenase 2 (COX2) and prostaglandin E2 (PGE2) are considered potential targets of specific medical treatment for IAs. Previous studies have reported the elevated COX2 expression in the IA wall. However, not much has been studied about the upstream regulation of COX2 and PGE2, and the metabolism of arachidonic acid (AA) in human IAs. In this study, we aimed to elucidate the distribution of fatty acids in human IA walls for the first time.

METHODS

Samples from 6 ruptured and 5 unruptured human IAs were surgically resected after the aneurysmal clipping and analyzed using desorption electrospray ionization imaging mass spectrometry.

RESULTS

AA and AA-containing phospholipids were not detected in the unruptured IA walls. On the contrast, significantly larger amounts of AA and AA-containing phospholipids were detected in the ruptured IA walls compared to unruptured IA walls.

CONCLUSIONS

This study showed for the first time that AA was not detected in unruptured human IA walls. Our findings suggest that the stability of the turnover of AA in human unruptured IA walls is sustained. In contrast, this study showed that larger amounts of AA and AA-containing phospholipids were detected in the ruptured IA walls. More cases and further analysis are necessary to interpret our present results.

The human vermilion surface contains a rich amount of cholesterol sulfate than the skin

BACKGROUND

The vermilion of the human lip presents characteristic features and undergoes aging faster than the skin. Therefore, knowledge of the vermilion surface-specific functional molecules is important to understand lip aging and formulate lip care products. Previously, we analyzed the free fatty acids distributions and showed that docosahexaenoic acid highly accumulated in the vermilion's epithelium than in the skin.

OBJECTIVE

We aimed to explore the functional molecules other than the free fatty acids on the vermilion's surface.

METHODS

Human lip tissues from children and tape-stripped samples from smooth and rough lips of adults were measured by desorption electrospray ionization-mass spectrometry imaging (DESI-MSI).

RESULTS

DESI-MSI of children's lip sections revealed a major distribution of five phospholipid species in the viable layer, but not in the superficial area, of both the vermilion and the skin than that in the underlying tissue. Interestingly, a remarkably higher distribution of cholesterol sulfate was observed in the vermilion's superficial area compared to that in the skin in all subjects under this study. Furthermore, theDESI-MSI of tape-stripped lip sample showed an overall higher accumulation of cholesterol sulfate in the stratum corneum of the rough lip than that in the smooth lips showed an overall higher accumulation of cholesterol sulfate in the stratum corneum of the rough lips than that in the smooth lips.

CONCLUSION

Our study concluded that cholesterol sulfate has a characteristic distribution to the vermilion's surface and showed an association with the roughness of the lip.

Desorption ionization using through-hole alumina membrane offers higher reproducibility than 2,5-dihydroxybenzoic acid, a widely used matrix in Fourier transform ion cyclotron resonance mass spectrometry imaging analysis

RATIONALE

DIUTHAME (desorption ionization using through-hole alumina membrane), a recently developed matrix-free ionization-assisting substrate, was examined for reproducibility in terms of mass accuracy and intensity using standard lipid and mouse brain sections. The impregnation property of DIUTHAME significantly improved the reproducibility of mass accuracy and intensity compared with 2,5-dihydroxybenzoic acid (DHB).

METHODS

Frozen tissue sections were mounted on indium tin oxide-coated glass slides. DIUTHAME and DHB were applied to individual sections. Subsequently, a solution of a phosphatidylcholine standard, PC(18:2/18:2), was poured onto the DIUTHAME and matrix. Finally, the samples were subjected to laser desorption ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry. The reproducibility was tested by calculating the mean ± standard deviation values of mass errors and intensities of individual ion species.

RESULTS

Analysis of the PC(18:2/18:2) standard showed significantly (p < 0.01) lower mass error for DIUTHAME-MS than for MALDI-MS. Endogenous PC(36:4) analysis in mouse brain section also showed significantly (p < 0.05) lower mass errors for DIUTHAME-MS. Furthermore, we investigated the mass error of some abundant lipid ions in brain sections and observed similar results. DIUTHAME-MS displayed lower signal intensity in standard PC analysis. Interestingly, it offered higher signal intensities for all the endogenous lipid ions. Lower fluctuations of both mass accuracies and signal intensities were observed in DIUTHAME-MS.

CONCLUSIONS

Our results demonstrated that DIUTHAME-MS offers higher reproducibility for mass accuracies and intensities than MALDI-MS in both standard lipid and mouse brain tissue analyses. It can potentially be used instead of conventional MALDI-MS and mass spectrometry imaging analyses to achieve highly reproducible data for mass accuracy and intensity.

Mass spectrometry in the lipid study of cancer

Introduction: Cancer is a heterogeneous disease that exploits various metabolic pathways to meet the demand for increased energy and structural components. Lipids are biomolecules that play essential roles as high energy sources, mediators, and structural components of biological membranes. Accumulating evidence has established that altered lipid metabolism is a hallmark of cancer.Areas covered: Mass spectrometry (MS) is a label-free analytical tool that can simultaneously identify and quantify hundreds of analytes. To date, comprehensive lipid studies exclusively rely on this technique. Here, we reviewed the use of MS in the study of lipids in various cancers and discuss its instrumental limitations and challenges.Expert opinion: MS and MS imaging have significantly contributed to revealing altered lipid metabolism in a variety of cancers. Currently, a single MS approach cannot profile the entire lipidome because of its lack of sensitivity and specificity for all lipid classes. For the metabolic pathway investigation, lipid study requires the integration of MS with other molecular approaches. Future developments regarding the high spatial resolution, mass resolution, and sensitivity of MS instruments are warranted.

Mass spectrometry-based phospholipid imaging: methods and findings

Introduction: Imaging is a technique used for direct visualization of the internal structure or distribution of biomolecules of a living system in a two-dimensional or three-dimensional fashion. Phospholipids are important structural components of biological membranes and have been reported to be associated with various human diseases. Therefore, the visualization of phospholipids is crucial to understand the underlying mechanism of cellular and molecular processes in normal and diseased conditions. Areas covered: Mass spectrometry imaging (MSI) has enabled the label-free imaging of individual phospholipids in biological tissues and cells. The commonly used MSI techniques include matrix-assisted laser desorption ionization-MSI (MALDI-MSI), desorption electrospray ionization-MSI (DESI-MSI), and secondary ion mass spectrometry (SIMS) imaging. This special report described those methods, summarized the findings, and discussed the future development for the imaging of phospholipids. Expert opinion: Phospholipids imaging in complex biological samples has been significantly benefited from the development of MSI methods. In MALDI-MSI, novel matrix that produces homogenous crystals exclusively with polar lipids is important for phospholipids imaging with greater efficiency and higher spatial resolution. DESI-MSI has the potential of live imaging of the biological surface while SIMS is expected to image at the subcellular level in the near future.