Single Cell Effects of Photobiomodulation on Mitochondrial Membrane Potential and Reactive Oxygen Species Production in Human Adipose Mesenchymal Stem Cells

Impact of photobiomodulation on neural embryoid body formation from immortalized adipose-derived stem cells

BACKGROUND

Embryoid bodies (EBs) are three-dimensional (3D) multicellular cell aggregates that are derived from stem cell and play a pivotal role in regenerative medicine. They recapitulate many crucial aspects of the early stages of embryonic development and is the first step in the generation of various types of stem cells, including neuronal stem cells. Current methodologies for differentiating stem cells into neural embryoid bodies (NEBs) in vitro have advanced significantly, but they still have limitations which necessitate improvement. Photobiomodulation (PBM) a low powered light therapy is a non-invasive technique shown to promote stem cell proliferation and differentiation.

METHODS

This in vitro study elucidated the effects of photobiomodulation (PBM) on the differentiation of immortalized adipose-derived stem cells (iADSCs) into NEBs within a 3D cell culture environment. The study utilized PBM at wavelengths of 825 nm, 525 nm, and a combination of both, with fluences of 5 and 10 J/cm2. Morphology, viability, metabolic activity, and differentiation following PBM treatment was analysed.

RESULTS

The results revealed that the effects of photobiomodulation (PBM) are dose dependent. PBM, at 825 nm with a fluence of 10 J/cm2, significantly enhanced the size of neural embryoid bodies (NEBs), improved cell viability and proliferation, and reduced lactate dehydrogenase (LDH) levels, indicating minimal cell damage. Interestingly, the stem cell marker CD 44 was upregulated at 5 J/cm2 in all treatment groups at 24 and 96 hpi, CD105 increased with 825 nm at 10 J/cm2 at 24 hpi, which may be attributed to a heterogeneous cell population within the NEBs. Pax6 expression showed transient activation. Nestin was upregulated at 825 nm with 10 J/cm2 at 96 hpi, suggesting a promotion of neural precursor populations. GFAP an intermediate filament protein was upregulated at 825 nm at 10 J/cm2 at both 24 and 96 hpi. SOX2, a pluripotency marker, was expressed at 5 J/cm2 across all wavelengths. Neu N a neuronal nuclei marker was expressed at 5 J/cm2 in all treatments at 24 hpi and over time the expression was observed in all treatment groups at 10 J/cm2.

CONCLUSION

In conclusion, the application of PBM at 825 nm with a fluence of 10 J/cm2 during the differentiation of iADSCs into NEBs resulted in optimal differentiation. Notably, the neuronal marker Nestin was significantly upregulated, highlighting the potential of the PBM approach for enhancing neuronal differentiation its promising applications in regenerative medicine.

Lipid analysis of human primary dermal fibroblasts and epidermal keratinocytes after near-infrared exposure using mass spectrometry imaging

Photobiomodulation (PBM) therapy is the application of near-infrared (NIR) exposure to injuries or lesions to (among others) improve wound healing, reduce inflammation, and decreases acute and chronic pain. However, the understanding of the molecular mechanism of PBM, more specifically the effects of NIR on skin cells is still lacking behind. Lipids are essential components of cellular membranes that are integral to skin structure and function. This study aims to elucidate the impact of NIR exposure on the skin's lipidome by investigating the molecular effect of NIR exposure on single skin cells. Primary human dermal fibroblasts (NHDFa) and human epidermal keratinocytes (HEKa) were exposed to NIR (850 nm) with a dose of 6.5 J/cm2 for 5 consecutive days between 09.00 and 12.00 am. A workflow utilizing matrix-assisted laser desorption/ionization mass spectrometry imaging combined with liquid chromatography tandem mass spectrometry for lipidomics analysis was performed. This study provides evidence that adequate exposure of NIR influences lipid metabolism in NHDFa, whereas no alterations were found in HEKa. This work lays the groundwork in explaining the beneficial properties on both skin-related effects and systemic health benefits as seen in clinical studies.

Photobiomodulation associated with alginate-based engineered tissue on promoting chondrocytes-derived biological responses for cartilage regeneration

Articular cartilage is a connective tissue with limited self-healing potential, frequently affected by trauma and degenerative changes, leading to osteoarthritis. Photobiomodulation paired with engineered tissue can improve cartilage's poor intrinsic healing and overcome its restricted self-regeneration. In this study, alginate-based scaffolds were fabricated with varying concentrations of CaCl₂ to achieve optimal mechanical, biocompatible, and biodegradable properties. The fluence-dependence of near-infrared (NIR) laser irradiation (830 nm) on chondrocyte viability and proliferation was investigated in a 2D environment across fluences (2.5-10 J/cm2). Optimal conditions of 3 % w/v CaCl₂ and 5 J/cm2 were identified to construct alginate scaffolds and promote chondrocyte growth in 2D and 3D cultures. Single PBM (830 nm, 5 J/cm2) further exhibited a significant relative intensity of collagen type II immunostaining and stimulation of Col2a1 expression in 2D culture. Multiple PBM sessions (830 nm, 5 J/cm2) significantly enhanced chondrocyte proliferation and glycosaminoglycan production in alginate scaffolds, with a protocol of one session every four days being the most effective. Scanning electron microscopy revealed PBM-induced secretory granule formation, corresponding to a significant increase in extracellular vesicle release. Consequently, integrating PBM and alginate-based scaffolds is a promising technique for accelerating and optimizing cartilage regeneration, with potential application in tissue engineering.

Mitochondrial transplantation: a promising strategy for treating degenerative joint diseases

The prevalence of age-related degenerative joint diseases, particularly intervertebral disc degeneration and osteoarthritis, is increasing, thereby posing significant challenges for the elderly population. Mitochondrial dysfunction is a critical factor in the etiology and progression of these disorders. Therapeutic interventions that incorporate mitochondrial transplantation exhibit considerable promise by increasing mitochondrial numbers and improving their functionality. Existing evidence suggests that exogenous mitochondrial therapy improves clinical outcomes for patients with degenerative joint diseases. This review elucidates the mitochondrial abnormalities associated with degenerative joint diseases and examines the mechanisms of mitochondrial intercellular transfer and artificial mitochondrial transplantation. Furthermore, therapeutic strategies for mitochondrial transplantation in degenerative joint diseases are synthesized, and the concept of engineered mitochondrial transplantation is proposed.

Photobiomodulation improves cell survival and death parameters in cardiomyocytes exposed to hypoxia/reoxygenation

INTRODUCTION

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide. Ischemic heart disease is one of the most harmful conditions to cellular structure and function. After reperfusion treatment, a spectrum of adverse effects becomes evident, encompassing altered cell viability, heightened oxidative stress, activated autophagy, and increased apoptosis. Photobiomodulation (PBM) has been utilized in experimental models of cardiac hypoxia to enhance mitochondrial response and ameliorate biochemical changes in injured tissue. However, the effects of PBM on cultured cardiomyocytes subjected to hypoxia/reoxygenation are not yet well established.

METHOD

H9C2 cardiomyocytes were exposed to hypoxia with concentrations of 300 μM CoCl2 for 24 h, followed by 16 h of reoxygenation through incubation in a normoxic medium. Treatment was conducted using GaAIAs Laser (850 nm) after hypoxia at an intensity of 1 J/cm2. Cells were divided into three groups: Group CT (cells maintained under normoxic conditions), Group HR (cells maintained in hypoxia and reoxygenation conditions without treatment), Group HR + PBM (cells maintained in hypoxia and reoxygenation conditions that underwent PBM treatment). Cell viability was analyzed using MTT, and protein expression was assessed by western blot. One-way ANOVA with the Tukey post hoc test was used for data analysis. Differences were significant when p < 0.05.

RESULTS

PBM at an intensity of 1 J/cm2 mitigated the alterations in cell survival caused by hypoxia/reoxygenation. Additionally, it significantly increased the expression of proteins Nrf2, HSP70, mTOR, LC3II, LC3II/I, and Caspase-9, while reducing the expression of PGC-1α, SOD2, xanthine oxidase, Beclin-1, LC3I, and Bax.

CONCLUSION

PBM at intensities of 1 J/cm2 reverses the changes related to oxidative stress, mitochondrial biogenesis, autophagy, and apoptosis caused by hypoxia and reoxygenation in a culture of cardiomyocytes.

Modifying Alzheimer's disease pathophysiology with photobiomodulation: model, evidence, and future with EEG-guided intervention

This manuscript outlines a model of Alzheimer's Disease (AD) pathophysiology in progressive layers, from its genesis to the development of biomarkers and then to symptom expression. Genetic predispositions are the major factor that leads to mitochondrial dysfunction and subsequent amyloid and tau protein accumulation, which have been identified as hallmarks of AD. Extending beyond these accumulations, we explore a broader spectrum of pathophysiological aspects, including the blood-brain barrier, blood flow, vascular health, gut-brain microbiodata, glymphatic flow, metabolic syndrome, energy deficit, oxidative stress, calcium overload, inflammation, neuronal and synaptic loss, brain matter atrophy, and reduced growth factors. Photobiomodulation (PBM), which delivers near-infrared light to selected brain regions using portable devices, is introduced as a therapeutic approach. PBM has the potential to address each of these pathophysiological aspects, with data provided by various studies. They provide mechanistic support for largely small published clinical studies that demonstrate improvements in memory and cognition. They inform of PBM's potential to treat AD pending validation by large randomized controlled studies. The presentation of brain network and waveform changes on electroencephalography (EEG) provide the opportunity to use these data as a guide for the application of various PBM parameters to improve outcomes. These parameters include wavelength, power density, treatment duration, LED positioning, and pulse frequency. Pulsing at specific frequencies has been found to influence the expression of waveforms and modifications of brain networks. The expression stems from the modulation of cellular and protein structures as revealed in recent studies. These findings provide an EEG-based guide for the use of artificial intelligence to personalize AD treatment through EEG data feedback.

A 5-ALA mediated photodynamic therapy increases natural killer cytotoxicity against oral squamous cell carcinoma cell lines

Oral squamous cell carcinoma (OSCC) constitutes over 90% of oral cancers, known for its aggressiveness and poor prognosis. Photodynamic therapy (PDT) has emerged as a promising adjuvant therapy and is linked to immunogenic cell death, activating innate and adaptive anti-tumor responses. Natural Killer (NK) cells, key players in malignant cell elimination, have not been extensively studied in PDT. This study evaluates whether PDT increases OSCC cell lines' susceptibility to NK cell cytotoxicity. PDT, using 5-aminolevulinic acid (5-ALA) and LED irradiation, was applied to Ca1 and Luc4 cell lines. Results showed a dose-dependent viability decrease post-PDT. Gene expression analysis revealed upregulation of NK cell-activating ligands (ULBP1-4, MICA/B) and decreased MHC class I expression in Ca1, suggesting increased NK cell susceptibility. Enhanced NK cell cytotoxicity was confirmed in Ca1 but not in Luc4 cells. These findings indicate that PDT may enhance NK cell-mediated cytotoxicity in OSCC, offering potential for improved treatment strategies.

Exploring the biphasic dose-response effects of photobiomodulation on the viability, migration, and extracellular vesicle secretion of human adipose mesenchymal stem cells

Photobiomodulation (PBM) is a well-established medical technology that employs diverse light sources like lasers or light-emitting diodes to generate diverse photochemical and photophysical reactions in cells, thereby producing beneficial clinical outcomes. In this study, we introduced an 830 nm near-infrared (NIR) laser irradiation system combined with a microscope objective to precisely and controllably investigate the impact of PBM on the migration and viability of human adipose mesenchymal stem cells (hADSCs). We observed a biphasic dose-response in hADSCs' viability and migration after PBM exposure (0-10 J/cm2), with the 5 J/cm2 group showing significantly higher cell viability and migration ability than other groups. Additionally, at the optimal dose of 5 J/cm2, we used nanoparticle tracking analysis (NTA) and found a 6.25-fold increase in the concentration of extracellular vesicles (EVs) derived from hADSCs (PBM/ADSC-EVs) compared to untreated cells (ADSC-EVs). Both PBM/ADSC-EVs and ADSC-EVs remained the same size, with an average diameter of 56 nm measured by the ExoView R200 system, which falls within the typical size range for exosomes. These findings demonstrate that PBM not only improves the viability and migration of hADSCs but also significantly increases the EV yield.

Brain-gut photobiomodulation restores cognitive alterations in chronically stressed mice through the regulation of Sirt1 and neuroinflammation

BACKGROUND

Chronic stress is an important risk factor for the development of major depressive disorder (MDD). Recent studies have shown microbiome dysbiosis as one of the pathogenic mechanisms associated with MDD. Thus, it is important to find novel non-pharmacological therapeutic strategies that can modulate gut microbiota and brain activity. One such strategy is photobiomodulation (PBM), which involves the non-invasive use of light.

OBJECTIVE/HYPOTHESIS

Brain-gut PBM could have a synergistic beneficial effect on the alterations induced by chronic stress.

METHODS

We employed the chronic unpredictable mild stress (CUMS) protocol to induce a depressive-like state in mice. Subsequently, we administered brain-gut PBM for 6 min per day over a period of 3 weeks. Following PBM treatment, we examined behavioral, structural, molecular, and cellular alterations induced by CUMS.

RESULTS

We observed that the CUMS protocol induces profound behavioral alterations and an increase of sirtuin1 (Sirt1) levels in the hippocampus. We then combined the stress protocol with PBM and found that tissue-combined PBM was able to rescue cognitive alterations induced by CUMS. This rescue was accompanied by a restoration of hippocampal Sirt1 levels, prevention of spine density loss in the CA1 of the hippocampus, and the modulation of the gut microbiome. PBM was also effective in reducing neuroinflammation and modulating the morphology of Iba1-positive microglia.

LIMITATIONS

The molecular mechanisms behind the beneficial effects of tissue-combined PBM are not fully understood.

CONCLUSIONS

Our results suggest that non-invasive photobiomodulation of both the brain and the gut microbiome could be beneficial in the context of stress-induced MDD.

Management of oxidative stress for cell therapy through combinational approaches of stem cells, antioxidants, and photobiomodulation

Over the recent decades, stem cell-based therapies have been considered as a beneficial approach for the treatment of various diseases. In these types of therapies, the stem cells and their products are used as treating agents. Despite the helpful efficacy of stem cell-based therapies, there may be challenges. Oxidative stress (OS) is one of these challenges that can affect the therapeutic properties of stem cells. Therefore, it seems that employing strategies for the reduction of OS in combination with stem cell therapy can lead to better results of these therapies. Based on the available evidence, antioxidant therapy and photobiomodulation (PBM) are strategies that can regulate the OS in the cells. Antioxidant therapy is a method in which various antioxidants are used in the therapeutic processes. PBM is also the clinical application of light that gained importance in medicine. Antioxidants and PBM can regulate OS by the effect on mitochondria as an important source of OS in the cells. Considering the importance of OS in pathologic pathways and its effect on the treatment outcomes of stem cells, in the present review first the stem cell therapy and effects of OS on this type of therapy are summarized. Then, antioxidant therapy and PBM as approaches for reducing OS with a focus on mitochondrial function are discussed. Also, a novel combination treatment with the hope of achieving better and more stable outcomes in the treatment process of diseases is proposed.

Osteoblastic differentiation and changes in the redox state in pulp stem cells by laser treatment

The aim of this study was to determine the effect of low-level laser therapy (LLLT) on cell proliferation, mitochondrial membrane potential changes (∆Ψm), reactive oxygen species (ROS), and osteoblast differentiation of human dental pulp stem cells (hDPSCs). These cells were irradiated with 660- and 940-nm lasers for 5 s, 50 s, and 180 s. Cell proliferation was assessed using the resazurin assay, cell differentiation by RUNX2 and BMP2 expression, and the presence of calcification nodules using alizarin-red S staining. ROS was determined by the dichlorofluorescein-diacetate technique and changes in ∆Ψm by the tetramethylrhodamine-ester assay. Data were analyzed by a Student's t-test and Mann-Whitney U test. The 940-nm wavelength for 5 and 50 s increased proliferation at 4 days postirradiation. After 8 days, a significant decrease in proliferation was observed in all groups. Calcification nodules were evident in all groups, with a greater staining intensity in cells treated with a 940-nm laser for 50 s, an effect that correlated with increased RUNX2 and BMP2 expression. ROS production and Δψm increased independently of irradiation time. In conclusion, photobiomodulation (PBM) with LLLT induced morphological changes and reduced cell proliferation rate, which was associated with osteoblastic differentiation and increased ROS and Δψm, independent of wavelength and time.

Photobiomodulation Therapy Improves Repair of Bone Defects Filled by Inorganic Bone Matrix and Fibrin Heterologous Biopolymer

Biomaterials are used extensively in graft procedures to correct bone defects, interacting with the body without causing adverse reactions. The aim of this pre-clinical study was to analyze the effects of photobiomodulation therapy (PBM) with the use of a low-level laser in the repair process of bone defects filled with inorganic matrix (IM) associated with heterologous fibrin biopolymer (FB). A circular osteotomy of 4 mm in the left tibia was performed in 30 Wistar male adult rats who were randomly divided into three groups: G1 = IM + PBM, G2 = IM + FB and G3 = IM + FB + PBM. PBM was applied at the time of the experimental surgery and three times a week, on alternate days, until euthanasia, with 830 nm wavelength, in two points of the operated site. Five animals from each group were euthanized 14 and 42 days after surgery. In the histomorphometric analysis, the percentage of neoformed bone tissue in G3 (28.4% ± 2.3%) was higher in relation to G1 (24.1% ± 2.91%) and G2 (22.2% ± 3.11%) at 14 days and at 42 days, the percentage in G3 (35.1% ± 2.55%) was also higher in relation to G1 (30.1% ± 2.9%) and G2 (31.8% ± 3.12%). In the analysis of the birefringence of collagen fibers, G3 showed a predominance of birefringence between greenish-yellow in the neoformed bone tissue after 42 days, differing from the other groups with a greater presence of red-orange fibers. Immunohistochemically, in all experimental groups, it was possible to observe immunostaining for osteocalcin (OCN) near the bone surface of the margins of the surgical defect and tartrate-resistant acid phosphatase (TRAP) bordering the newly formed bone tissue. Therefore, laser photobiomodulation therapy contributed to improving the bone repair process in tibial defects filled with bovine biomaterial associated with fibrin biopolymer derived from snake venom.

The effect of adjunctive LASER application on periodontal ligament stem cells

Periodontal regeneration involves the composite action of cell, scaffolds and signaling molecules. There are numerous autologous sources of regenerative cells which are present close to the vicinity of the periodontally debilitated site, the primary one being the periodontal ligament stem cell, which is believed to have a key role in regeneration. Various methods can be harnessed to optimize and enhance the regenerative potential of PDLSCs such as the application of LASERs. In the last few years there have been various studies which have evaluated the effect of different types of LASERs on PDLSCs and the present review summarizes the photo-biomodulative activity of LASERs in general and its beneficial role in the stimulation of PDLSC specifically.

The Remodulation of Actin Bundles during the Stimulation of Mitochondria in Adult Human Fibroblasts in Response to Light

β-actin belongs to cytoskeletal structures that change dynamically in cells according to various stimuli. Human skin can be considered as an organ that is very frequently exposed to various stress factors, of which light plays an important role. The present study focuses on adult human fibroblasts exposed to two types of light stress. Orange light with a wavelength of 590 nm was used here to stimulate the photosensitizer localized in the cells as a residual dose of photodynamic therapy (PDT). On the other hand, near-infrared light with a wavelength of 808 nm was considered for photobiomodulation (PBM), which is often used in healing processes. Confocal fluorescence microscopy was used to observe changes in intercellular communication, mitochondrial structures, and cytoskeletal dynamics defined by the remodulation of β-actin of fibroblasts. The number of β-actin bundles forming spherical structures was detected after light exposure. These structures as β-actin oligomers were confirmed with super-resolution microscopy. While PDT led to the disintegration of actin oligomers, PBM increased their number. The interaction of β-actin with mitochondria was observed. The combination of PDT and PBM treatments is important to minimize the side effects of cancer treatment with PDT on healthy cells, as shown by the cell metabolism assay in this work. In this work, β-actin is presented as an important parameter that changes and is involved in the response of cells to PDT and PBM.

Transcranial photobiomodulation ameliorates midbrain and striatum neurochemical impairments and behavioral deficits in reserpine-induced parkinsonism in rats

Photobiomodulation (PBM) of deep brain structures through transcranial infrared irradiation might be an effective treatment for Parkinson's disease (PD). However, the mechanisms underlying this intervention should be elucidated to optimize the therapeutic outcome and maximize therapeutic efficacy. The present study aimed at investigating the oxidative stress-related parameters of malondialdehyde (MDA), nitric oxide (NO), and reduced glutathione (GSH) and the enzymatic activities of sodium-potassium-ATPase (Na+, K+-ATPase), Acetylcholinesterase (AChE), and monoamine oxidase (MAO) and monoamine levels (dopamine (DA), norepinephrine (NE) and serotonin (5-HT) in the midbrain and striatum of reserpine-induced PD in an animal model treated with PBM. Furthermore, the locomotor behavior of the animals has been determined by the open field test. Animals were divided into three groups; the control group, the PD-induced model group, and the PD-induced model treated with the PBM group. Non-invasive treatment of animals for 14 days with 100 mW, 830 nm laser has demonstrated successful attainment in the recovery of oxidative stress, and enzymatic activities impairments induced by reserpine (0.2 mg/kg) in both midbrain and striatum of adult male Wistar rats. PBM also improved the decrease in DA, NE, and 5-HT in the investigated brain regions. On a behavioral level, animals showed improvement in their locomotion activity. These findings have shed more light on some mechanisms underlying the treatment potential of PBM and displayed the safety, easiness, and efficacy of PBM treatment as an alternative to pharmacological treatment for PD.

Small-molecular cyclic peptide exerts viability suppression effects on HepG2 cells via triggering p53 apoptotic pathways

Cyclic peptides have become an attractive modality for drug development due to their high specificity, metabolic stability and higher cell permeability. In an effort to explore novel antitumor compounds based on natural cyclopeptide from the phakellistatin family, we found an isoindolinone-containing analog (S-PK6) of phakellistatin 6 capable of suppressing the viability and proliferation of HepG2 cells. The aim of the present study is to shed light on the mechanism of action of this novel compound. We have detected differences in gene expression before and after treatment with S-PK6 in human hepatocellular carcinoma HepG2 cell line by transcriptome sequencing. To further investigate biological effects, we have also extensively investigated the tumor cell cycle, mitochondrial membrane potential, and intracellular Ca2+ concentration after S-PK6 treatment. Based on the finding that the apoptosis was associated with the p53 signaling pathway and MAPK signaling pathway, western blotting tests were used to assess the expression level of p53 protein and its degenerative regulator MDM2 protein, which showed that S-PK6 could increase p53 levels efficiently. In summary, our results demonstrate the mechanism of action of a small-molecule cyclopeptide, which could be very useful for examining of the possible mechanisms of natural cyclopeptides.

Photobiomodulation at Defined Wavelengths Regulates Mitochondrial Membrane Potential and Redox Balance in Skin Fibroblasts

Starting from the discovery of phototherapy in the beginning of the last century, photobiomodulation (PBM) has been defined in late 1960s and, since then, widely described in different in vitro models. Robust evidence indicates that the effect of light exposure on the oxidative state of the cells and on mitochondrial dynamics, suggesting a great therapeutic potential. The translational scale-up of PBM, however, has often given contrasting and confusing results, mainly due to light exposure protocols which fail to adequately control or define factors such as emitting device features, emitted light characteristics, exposure time, cell target, and readouts. In this in vitro study, we describe the effects of a strictly controlled light-emitting diode (LED)-based PBM protocol on human fibroblasts, one of the main cells involved in skin care, regeneration, and repair. We used six emitter probes at different wavelengths (440, 525, 645, 660, 780, and 900 nm) with the same irradiance value of 0.1 mW/cm2, evenly distributed over the entire surface of the cell culture well. The PBM was analyzed by three main readouts: (i) mitochondrial potential (MitoTracker Orange staining), (ii) reactive oxygen species (ROS) production (CellROX staining); and (iii) cell death (nuclear morphology). The assay was also implemented by cell-based high-content screening technology, further increasing the reliability of the data. Different exposure protocols were also tested (one, two, or three subsequent 20 s pulsed exposures at 24 hr intervals), and the 645 nm wavelength and single exposure chosen as the most efficient protocol based on the mitochondrial potential readout, further confirmed by mitochondrial fusion quantification. This protocol was then tested for its potential to prevent H2O2-induced oxidative stress, including modulation of the light wave frequency. Finally, we demonstrated that the controlled PBM induced by the LED light exposure generates a preconditioning stimulation of the mitochondrial potential, which protects the cell from oxidative stress damage.

Nicotinamide Riboside Improves Stemness of Human Adipose-Derived Stem Cells and Inhibits Terminal Adipocyte Differentiation

Adipose tissue plays a crucial role in maintaining metabolic homeostasis by serving as a storage site for excess fat and protecting other organs from the detrimental effects of lipotoxicity. However, the aging process is accompanied by a redistribution of fat, characterized by a decrease in insulin-sensitive subcutaneous adipose depot and an increase in insulin-resistant visceral adipose depot. This age-related alteration in adipose tissue distribution has implications for metabolic health. Adipose-derived stem cells (ASCs) play a vital role in the regeneration of adipose tissue. However, aging negatively impacts the stemness and regenerative potential of ASCs. The accumulation of oxidative stress and mitochondrial dysfunction-associated cellular damage contributes to the decline in stemness observed in aged ASCs. Nicotinamide adenine dinucleotide (NAD+) is a crucial metabolite that is involved in maintaining cellular homeostasis and stemness. The dysregulation of NAD+ levels with age has been associated with metabolic disorders and the loss of stemness. In this study, we aimed to investigate the effects of nicotinamide riboside (NR), a precursor of NAD+, on the stemness of human ASCs in cell culture. Our findings reveal that adipogenesis is accompanied by an increase in mitochondrial activity and the production of reactive oxygen species (ROS). However, treatment with NR leads to a reduction in mitochondrial activity and ROS production in ASCs. Furthermore, NR administration improves the stemness-related genes expression in ASCs and mitigates their propensity for adipocyte differentiation. These results suggest that NR treatment holds promise as a potential strategy to rejuvenate the stemness of aged ASCs. Further investigations, including in vivo evaluations using animal models and human studies, will be necessary to validate these findings and establish the clinical potential of this well-established drug for enhancing the stemness of aged stem cells.

Automated analysis of mitochondrial dimensions in mesenchymal stem cells: Current methods and future perspectives

As centre of energy production and key regulators of metabolic and cellular signaling pathways, the integrity of mitochondria is essential for mesenchymal stem cell function in tissue regeneration. Alterations in the size, shape and structural organization of mitochondria are correlated with the physiological state of the cell and its environment and could be used as diagnostic biomarkers. Therefore, high-throughput experimental and computational techniques are crucial to ensure adequate correlations between mitochondrial function and disease phenotypes. The emerge of microfluidic technologies can address the shortcomings of traditional methods to determine mitochondrial dimensions for diagnostic and therapeutic use. This review discusses optical detection methods compatible with microfluidics to measure mitochondrial dynamics and their potential for clinical stem cell research targeting mitochondrial dysfunction.

Single-Cell Analysis 2.0

In 1665, Robert Hooke published his revolutionary book Micrographia [...].