Differences in Cytotoxicity of Lidocaine, Ropivacaine, and Bupivacaine on the Viability and Metabolic Activity of Human Adipose-Derived Mesenchymal Stem Cells

Rapid determination of caine-based anesthetics and their metabolite residues in fish using a modified QuEChERS method coupled with UPLC-MS/MS

Caine-based anesthetics are frequently used in the production and transportation of aquatic products, but residues in fish threaten human health. A rapid, sensitive, and effective method was developed for detecting caine-based anesthetics and their metabolite residues in fish using ultra-high performance liquid chromatography-tandem mass spectrometry coupled with a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method. The sample was extracted with 0.05 % (v/v) formic acid-80 % acetonitrile, 4 g NaCl was added for liquid partitioning, and 50 mg C18 was used for purification. Matrix-matched calibrations showed good correlation coefficients with R2 ≥ 0.9942. The limits of detection were 0.5-4.4 ng/g. The recoveries ranged from 71.4 %-115.8 %, and the relative standard deviation for intra-day and inter-day precision was less than 8.5 % and 9.2 %, respectively. This method effectively analyzed the residues of caine-based anesthetics and their metabolites in fish and could be applied to aquatic product anesthetic regulation.

The Potency of Cytotoxic Mechanisms of Local Anesthetics in Human Chondrocyte Cells

Local anesthetics are commonly used in various clinical settings for both prevention and symptom relief. Numerous clinical studies have demonstrated that intra-articular injections of local anesthetics achieve high success rates in orthopedic practices. However, several widely used local anesthetics, including bupivacaine, lidocaine, and ropivacaine, have been shown to exhibit toxicity to chondrocytes, with the underlying mechanisms of chondrotoxicity remaining poorly understood. In this study, we aimed to investigate the cytotoxic effects of local anesthetics, specifically focusing on the consequences of a single intra-articular injection in human chondrocyte cells. Our results reveal that lidocaine, levobupivacaine, bupivacaine, and ropivacaine induced cell death, characterized by the induction of apoptosis and the suppression of cellular proliferation. These effects were mediated through mechanisms involving oxidative stress, mitochondrial dysfunction, and autophagy pathways. We found that the toxic effects of local anesthetics were concentration-dependent, with lidocaine exhibiting the lowest cytotoxicity among the tested agents in TC28a cells. Notably, bupivacaine and levobupivacaine displayed significant cytotoxic effects related to apoptosis, cellular proliferation, reactive oxygen species generation, mitochondrial membrane potential depolarization, and autophagy in human chondrocyte cells. Our findings not only support existing clinical studies but also highlight potential targets for developing protective agents to mitigate serious side effects associated with their use in orthopedic practices.

Histone and Histone Acetylation-Related Alterations of Gene Expression in Uninvolved Psoriatic Skin and Their Effects on Cell Proliferation, Differentiation, and Immune Responses

Psoriasis is a chronic immune-mediated skin disease in which the symptom-free, uninvolved skin carries alterations in gene expression, serving as a basis for lesion formation. Histones and histone acetylation-related processes are key regulators of gene expression, controlling cell proliferation and immune responses. Dysregulation of these processes is likely to play an important role in the pathogenesis of psoriasis. To gain a complete overview of these potential alterations, we performed a meta-analysis of a psoriatic uninvolved skin dataset containing differentially expressed transcripts from nearly 300 individuals and screened for histones and histone acetylation-related molecules. We identified altered expression of the replication-dependent histones HIST2H2AA3 and HIST2H4A and the replication-independent histones H2AFY, H2AFZ, and H3F3A/B. Eight histone chaperones were also identified. Among the histone acetyltransferases, ELP3 and KAT5 and members of the ATAC, NSL, and SAGA acetyltransferase complexes are affected in uninvolved skin. Histone deacetylation-related alterations were found to affect eight HDACs and members of the NCOR/SMRT, NURD, SIN3, and SHIP HDAC complexes. In this article, we discuss how histone and histone acetylation-related expression changes may affect proliferation and differentiation, as well as innate, macrophage-mediated, and T cell-mediated pro- and anti-inflammatory responses, which are known to play a central role in the development of psoriasis.

Biological and chemical contamination of illegal, uncontrolled refuse storage areas in Poland

This study focused on assessing the microbiological and chemical contamination of air, soil and leachate in uncontrolled refuse storage areas in central Poland. The research included an analysis of the number of microorganisms (culture method), endotoxin concentration (gas chromatography-mass spectrometry), heavy metals level (atomic absorption spectrometry), elemental characteristics (elemental analyser), cytotoxicity assessment against A-549 (human lung) and Caco-2 (human colon adenocarcinoma) cell lines (PrestoBlue™ test) and toxic compound identification (ultra-high-performance liquid chromatography-quadrupole time-of-flight ultrahigh-resolution mass spectrometry). Microbial contamination differed depending on the dump and the group of tested microorganisms. The number of bacteria was: 4.3 × 10² - 1.8 × 10³ CFU m^-3 (air); 1.1 × 10³ - 1.2 × 10⁶ CFU mL^-1 (leachate); 1.0 × 10⁶ - 3.9 × 10⁶ CFU g^-1 (soil). Respectively, for air and soil the number of fungi was: 2.2 × 10² - 4.6 × 10² CFU m^-3; 1.8 × 10² - 3.9 × 10³ CFU g^-1. Metal levels (Fe, Mn, Pb, Zn, Al, Hg, Cd, Cu, Cr) were higher than in the control sample; however, the average concentrations did not exceed the permissible standards. The cytotoxicity of soil and leachate samples depended on the dump, sample and cell line tested. The leachates were more cytotoxic than soil extracts. Compounds belonging to pesticides, surfactants and biocides, chemicals and/or polymer degradation products, medicinal drugs and insect repellents were found. The detection of potential pathogens in the air, soil and leachate, the presence of toxic compounds and the confirmation of the cytotoxic effect of leachate and soil on human cell lines justify the need for further research on the risks posed by illegal dumps. These studies should aim at developing a unified assessment method and a method to minimise the risk of contaminants spreading in the environment, including harmful biological agents.

Hyperkalemic or Low Potassium Cardioplegia Protects against Reduction of Energy Metabolism by Oxidative Stress

Open-heart surgery is often an unavoidable option for the treatment of cardiovascular disease and prevention of cardiomyopathy. Cardiopulmonary bypass surgery requires manipulating cardiac contractile function via the perfusion of a cardioplegic solution. Procedure-associated ischemia and reperfusion (I/R) injury, a major source of oxidative stress, affects postoperative cardiac performance and long-term outcomes. Using large-scale liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolomics, we addressed whether cardioplegic solutions affect the baseline cellular metabolism and prevent metabolic reprogramming by oxidative stress. AC16 cardiomyocytes in culture were treated with commonly used cardioplegic solutions, High K+ (HK), Low K+ (LK), Del Nido (DN), histidine-tryptophan-ketoglutarate (HTK), or Celsior (CS). The overall metabolic profile shown by the principal component analysis (PCA) and heatmap revealed that HK or LK had a minimal impact on the baseline 78 metabolites, whereas HTK or CS significantly repressed the levels of multiple amino acids and sugars. H2O2-induced sublethal mild oxidative stress causes decreases in NAD, nicotinamide, or acetylcarnitine, but increases in glucose derivatives, including glucose 6-P, glucose 1-P, fructose, mannose, and mannose 6-P. Additional increases include metabolites of the pentose phosphate pathway, D-ribose-5-P, L-arabitol, adonitol, and xylitol. Pretreatment with HK or LK cardioplegic solution prevented most metabolic changes and increases of reactive oxygen species (ROS) elicited by H2O2. Our data indicate that HK and LK cardioplegic solutions preserve baseline metabolism and protect against metabolic reprogramming by oxidative stress.

Lidocaine inhibits osteogenic differentiation of human dental pulp stem cells in vitro

OBJECTIVE

Lidocaine is an amide local anaesthetic commonly used for pain control, however, few studies have investigated the effect of lidocaine on the osteogenic differentiation of human dental pulp stem cells (HDPSCs). The present study aimed to determine the effect of lidocaine on HDPSC viability and osteogenic differentiation.

METHODS

HDPSCs were incubated with 0, 0.05, 0.2, 0.5, and 1 mM lidocaine for 24, 48 and 72 h, after which, MTT assays were performed. HDPSCs cultured with the above lidocaine concentrations and osteogenic differentiation medium for 7 and 14 days were stained for alkaline phosphatase (ALP). Protein and mRNA levels of relevant osteogenic factors (bone morphogenetic protein-2 [BMP-2] and runt-related transcription factor 2 [RUNX2]) were examined using western blotting and real-time reverse-transcription polymerase chain reaction, respectively.

RESULTS

Lidocaine did not affect the viability of HDPSCs, however, lidocaine reduced ALP activity in HDPSCs. Levels of ALP, BMP-2, and RUNX2 mRNA were reduced with lidocaine, and levels of BMP-2 and RUNX2 proteins were decreased, versus controls.

CONCLUSIONS

Lidocaine inhibits osteogenic differentiation markers in HDPSCs in vitro, even at low concentrations, without cytotoxicity. This study suggests that lidocaine may inhibit osteogenic differentiation in HDPSC-mediated regenerative medicine, including pulp regeneration and repair.

Quality and Vitality of Autologous Fat Grafts Harvested by Different Techniques: A Clinical Comparison Study

BACKGROUND

Unpredictable outcomes with autologous fat grafting due to reabsorption processes present a major challenge for healthcare providers and patients. A higher number of viable adipocytes is considered to result in a higher volume being retained. Although various adverse factors have been extensively researched, other potential parameters have been less investigated or even neglected.

OBJECTIVE

The aim of this study was to investigate the harvesting process of adipose tissue as the primary cause of cell damage and to determine the risk factors associated with low cell survival.

METHODS

Thirty-nine male and female subjects undergoing planned elective liposuction or abdominoplasty were enrolled. Forty-seven lipoaspirates harvested by different liposuction techniques were analyzed. RNA isolation and real-time polymerase chain reaction was performed to elucidate differences in the expression of various adipocyte markers. Furthermore, scanning electron microscopy was performed on various samples to determine the cell damage caused by the different techniques.

RESULTS

A statistically significant lower expression of peroxisome proliferator-activated receptor γ was detected in subjects with a higher BMI. A trend towards a lower expression of perilipin 1 in lipoaspirates harvested by a super wet + ultrasound technique, compared with dry and super wet techniques, was shown. The lowest level of cell damage determined from scanning electron microscopy images was in lipoaspirates harvested by the super wet + ultrasound technique, and this level was statistically significantly different from those obtained by the 2 other techniques.

CONCLUSIONS

Optimization of the outcome in autologous fat grafting may be feasible by targeting and optimizing the harvesting process as a main risk factor for impaired adipocyte viability. Ultrasound-assisted liposuction might be considered a suitable harvesting technique.

LEVEL OF EVIDENCE: 5

MicroRNA-101a enhances trabecular bone accrual in male mice

High-throughput microRNA sequencing was performed during differentiation of MC3T3-E1 osteoblasts to develop working hypotheses for specific microRNAs that control osteogenesis. The expression data show that miR-101a, which targets the mRNAs for the epigenetic enzyme Ezh2 and many other proteins, is highly upregulated during osteoblast differentiation and robustly expressed in mouse calvaria. Transient elevation of miR-101a suppresses Ezh2 levels, reduces tri-methylation of lysine 27 in histone 3 (H3K27me3; a heterochromatic mark catalyzed by Ezh2), and accelerates mineralization of MC3T3-E1 osteoblasts. We also examined skeletal phenotypes of an inducible miR-101a transgene under direct control of doxycycline administration. Experimental controls and mir-101a over-expressing mice were exposed to doxycycline in utero and postnatally (up to 8 weeks of age) to maximize penetrance of skeletal phenotypes. Male mice that over-express miR-101a have increased total body weight and longer femora. MicroCT analysis indicate that these mice have increased trabecular bone volume fraction, trabecular number and trabecular thickness with reduced trabecular spacing as compared to controls. Histomorphometric analysis demonstrates a significant reduction in osteoid volume to bone volume and osteoid surface to bone surface. Remarkably, while female mice also exhibit a significant increase in bone length, no significant changes were noted by microCT (trabecular bone parameters) and histomorphometry (osteoid parameters). Hence, miR-101a upregulation during osteoblast maturation and the concomitant reduction in Ezh2 mediated H3K27me3 levels may contribute to the enhanced trabecular bone parameters in male mice. However, the sex-specific effect of miR-101a indicates that more intricate epigenetic mechanisms mediate physiological control of bone formation and homeostasis.

Metabolomic Impact of Lidocaine on a Triple Negative Breast Cancer Cell Line

Background: Metabolomics and onco-anesthesia are two emerging research fields in oncology. Metabolomics (metabolites analysis) is a new diagnostic and prognostic tool that can also be used for predicting the therapeutic or toxic responses to anticancer treatments. Onco-anesthesia studies assess the impact of anesthesia on disease-free and overall survival after cancer surgery. It has been shown that local anesthetics (LA), particularly lidocaine (LIDO), exert antitumor properties both in vitro and in vivo and may alter the biologic fingerprints of cancer cells. As LA are known to impair mitochondrial bioenergetics and byproducts, the aim of the present study was to assess the impact of LIDO on metabolomic profile of a breast cancer cell line.

Methods: Breast cancer MDA-MB-231 cells were exposed for 4 h to 0.5 mM LIDO or vehicle (n = 4). The metabolomic fingerprint was characterized by high resolution magic angle spinning NMR spectroscopy (HRMAS). The multivariate technique using the Algorithm to Determine Expected Metabolite Level Alteration (ADEMA) (Cicek et al., PLoS Comput. Biol., 2013, 9, e1002859), based on mutual information to identify expected metabolite level changes with respect to a specific condition, was used to determine the metabolites variations caused by LIDO.

Results: LIDO modulates cell metabolites levels. Several pathways, including glutaminolysis, choline, phosphocholine and total choline syntheses were significantly downregulated in the LIDO group.

Discussion: This is the first study assessing the impact of LIDO on metabolomic fingerprint of breast cancer cells. Among pathways downregulated by LIDO, many metabolites are reported to be associated with adverse prognosis when present at a high titer in breast cancer patients. These results fit with the antitumor properties of LIDO and suggest its impact on metabolomics profile of cancer cells. These effects of LIDO are of clinical significance because it is widely used for local anesthesia with cutaneous infiltration during percutaneous tumor biopsy. Future in vitro and preclinical studies are necessary to assess whether metabolomics analysis requires modification of local anesthetic techniques during tumor biopsy.

Quantitative Analysis of the Membrane Affinity of Local Anesthetics Using a Model Cell Membrane

Local anesthesia is a drug that penetrates the nerve cell membrane and binds to the voltage gate sodium channel, inhibiting the membrane potential and neurotransmission. It is mainly used in clinical uses to address the pain of surgical procedures in the local area. Local anesthetics (LAs), however, can be incorporated into the membrane, reducing the thermal stability of the membrane as well as altering membrane properties such as fluidity, permeability, and lipid packing order. The effects of LAs on the membrane are not yet fully understood, despite a number of previous studies. In particular, it is necessary to analyze which is the more dominant factor, the membrane affinity or the structural perturbation of the membrane. To analyze the effects of LAs on the cell membrane and compare the results with those from model membranes, morphological analysis and 50% inhibitory concentration (IC50) measurement of CCD-1064sk (fibroblast, human skin) membranes were carried out for lidocaine (LDC) and tetracaine (TTC), the most popular LAs in clinical use. Furthermore, the membrane affinity of the LAs was quantitatively analyzed using a colorimetric polydiacetylene assay, where the color shift represents their distribution in the membrane. Further, to confirm the membrane affinity and structural effects of the membranes, we performed an electrophysiological study using a model protein (gramicidin A, gA) and measured the channel lifetime of the model protein on the free-standing lipid bilayer according to the concentration of each LA. Our results show that when LAs interact with cell membranes, membrane affinity is a more dominant factor than steric or conformational effects of the membrane.

Therapeutic Potential of Niche-Specific Mesenchymal Stromal Cells for Spinal Cord Injury Repair

The use of mesenchymal stem/stromal cells (MSCs) for transplant-mediated repair represents an important and promising therapeutic strategy after spinal cord injury (SCI). The appeal of MSCs has been fuelled by their ease of isolation, immunosuppressive properties, and low immunogenicity, alongside the large variety of available tissue sources. However, despite reported similarities in vitro, MSCs sourced from distinct tissues may not have comparable biological properties in vivo. There is accumulating evidence that stemness, plasticity, immunogenicity, and adaptability of stem cells is largely controlled by tissue niche. The extrinsic impact of cellular niche for MSC repair potential is therefore important, not least because of its impact on ex vivo expansion for therapeutic purposes. It is likely certain niche-targeted MSCs are more suited for SCI transplant-mediated repair due to their intrinsic capabilities, such as inherent neurogenic properties. In addition, the various MSC anatomical locations means that differences in harvest and culture procedures can make cross-comparison of pre-clinical data difficult. Since a clinical grade MSC product is inextricably linked with its manufacture, it is imperative that cells can be made relatively easily using appropriate materials. We discuss these issues and highlight the importance of identifying the appropriate niche-specific MSC type for SCI repair.