Search Results (50)

Chlorophylls are the major light-harvesting pigments in photosynthetic organisms. Their biosynthesis requires the coordinated supply of metabolic intermediates from two independent upstream branches: the methylerythritol 4-phosphate (MEP)-derived terpenoid pathway, which supplies the phytyl side chain via geranylgeranyl diphosphate (GGPP), and the tetrapyrrole biosynthesis pathway (TBP), which provides the porphyrin ring. How flux through these two branches is coordinated remains poorly understood. In this study, we report the identification of a direct protein–protein interaction between δ-aminolevulinic acid dehydratase (ALAD), the second enzyme of the TBP, positioned immediately upstream of the first metabolic branch point, and the Type II small subunit of GGPP synthase (SSUII), a key regulator of terpenoid flux toward chlorophyll biosynthesis. ALAD was identified as a candidate SSUII-interacting protein by co-immunoprecipitation coupled with LC-MS analysis of rice leaf tissue, with a sequence coverage of 57.04%. The interactions between OsALAD1 and OsSSUII in rice, and between AtALAD1 and AtSSUII in Arabidopsis thaliana, were validated by yeast two-hybrid assay and bimolecular fluorescence complementation (BiFC) in Arabidopsis protoplasts. BiFC imaging demonstrated that the interaction is localized to the chloroplast. Sequence analysis revealed that plant ALAD proteins are highly conserved, with 92% similarity between OsALAD1 and AtALAD1, and 76.9% similarity between OsALAD1 and the green alga Chlamydomonas reinhardtii CrALAD1, indicating cross-species conservation of the ALAD–SSUII interaction. In vitro enzyme activity assays showed that AtSSUII does not directly alter AtALAD1 catalytic activity, suggesting the interaction operates through post-translational rather than direct catalytic mechanisms. Overexpression of AtALAD1 caused severe chlorosis and seedling lethality, while AtSSUII overexpression produced no distinct phenotype; neither transgene altered the transcript level of the other. Together, our results reveal a conserved cross-pathway protein–protein interaction linking the terpenoid regulatory machinery to the early TBP, suggesting a molecular possibility for the coordinated regulation of chlorophyll biosynthesis. Full article

Genetic polymorphisms can modulate susceptibility to mercury (Hg) toxicity by altering metabolic and detoxification pathways. This review evaluated the association between genetic variants, Hg exposure, and obstetric outcomes. A systematic search of Scopus, PubMed and ScienceDirect through May 2025 identified 12 eligible studies (n = 4995), conducted in accordance with PRISMA guidelines, with methodological quality assessed using the Newcastle–Ottawa Scale. Meta-analysis was selectively performed only for genetically and methodologically comparable studies. The most frequently examined genes were GSTP1, GCLC, GCLM, GPX1, MT1A, ALAD, and APOE. Meta-analysis of GSTP1 rs1695, showed no statistically significant association between the Val105 allele and hair mercury concentrations (MD = −0.08 µg/g; 95% CI: −0.18 to 0.02; p = 0.13), although the direction of effect suggested a potential protective trend. Polymorphisms in other glutathione-related genes (GCLC, GCLM, and GPX1) were consistently associated with increased risks of small-for-gestational-age infants, preeclampsia, and impaired neurodevelopmental outcomes in offspring. In contrast, the APOE ε4 allele appeared to be associated with reduced fetal mercury burden, whereas polymorphisms in ALAD and MT1A were linked to higher mercury levels and adverse pregnancy-related outcomes. By integrating epidemiological evidence with mechanistic insights within a gene–environment interaction framework, this review helps to address important gaps in the existing literature. These findings underscore the importance of incorporating genetic susceptibility into Hg risk assessment and precision-based prenatal interventions. Full article

Adiponectin, an adipokine secreted by adipocytes with anti-inflammatory and insulin-sensitizing properties, circulates in several isoforms, of which total and high-molecular-weight (HMW) adiponectin are the most physiologically relevant. While adiponectin has been inversely associated with obesity and metabolic syndrome (MetS), evidence from Latin American populations remains scarce. To explore its role in this context, we conducted a case–control study in 310 Panamanian adults, including 77 individuals with MetS and 233 controls, diagnosed according to the Latin American Diabetes Association (ALAD) criteria. Serum adiponectin, lipid profile, glucose, HbA1c, and body composition were evaluated, with adiponectin quantified by chemiluminescent immunoassay (CLIA). Correlations with metabolic parameters were analyzed using GraphPad Prism 10.5. Participants with MetS exhibited significantly lower adiponectin concentrations compared with controls (7.75 ± 2.58 µg/mL vs. 9.53 ± 3.31 µg/mL, p = 0.0030). Adiponectin levels were significantly lower in males than in females (p = 0.0083) and showed inverse correlations with visceral fat (r = −0.26, p < 0.001), triglycerides (r = −0.25, p = 0.0062), insulin (r = −0.31, p < 0.0001), and HbA1c (r = −0.11, p = 0.046). Conversely, a positive association was observed with HDL cholesterol (r = 0.37, p < 0.0001). Individuals with HbA1c ≥ 6.5% or insulin ≥ 15 µU/mL exhibited markedly reduced adiponectin concentrations (p = 0.0006 and p < 0.0001, respectively). The ROC analysis yielded an AUC of 0.69, indicating a moderate discriminatory ability of adiponectin for identifying MetS in this population. These findings confirm that adiponectin is inversely associated with several metabolic risk factors, supporting its potential utility as a biomarker for early detection and risk stratification of metabolic syndrome in the Panamanian population. Full article

Osteoarthritis (OA) is now widely recognized not merely as a cartilage-centric disease but as a multifactorial disorder affecting the entire joint as an organ, including the articular cartilage, subchondral bone, synovium, ligaments, menisci, and the innervating neural elements. This review explores the complex pathophysiology of OA with a focus on the emerging mechanisms of pain and inflammation that extend beyond articular cartilage degradation. Joint inflammation driven by immune activation in response to cellular stress signals promotes the release of pro-inflammatory mediators and catabolic enzymes. Key signaling pathways such as NF-κB, MAPKs, and JAK/STAT amplify these responses, and pain is sustained through peripheral and central sensitization, contributing to exacerbating symptoms even in the absence of visible joint damage. This review also integrates molecular and cellular mechanisms to highlight innovative therapies aimed at modifying both the structural damage and neurosensory drivers of pain. These approaches offer the potential to not only alleviate symptoms but also alter disease progression, signaling a move toward personalized, mechanism-based treatments. Given the intricate interactions among joint tissues, immune activation, and sensory processing, a comprehensive strategy that targets both structural degeneration and neuroinflammation is essential for the future of OA management. Emphasizing the joint as an integrated organ, we advocate for translational research linking molecular pathology with clinically meaningful outcomes. Full article

Background/Objectives: In Mexico, there is very little data on the prevalence of metabolic syndrome in people living with human immunodeficiency virus (HIV) receiving antiretroviral therapy (ART), so, determining the number of people with this condition will help to establish measures to treat it promptly. Methods: A descriptive, observational, prospective, cross-sectional study was conducted in a cohort of people living with HIV who signed the informed consent form and were stratified according to the criteria established by the Adult Treatment Panel III (ATP-III) and the Latin American Diabetes Association (ALAD) for the diagnosis of metabolic syndrome. Results: According to the ATP-III and ALAD criteria, 26.5% and 36.3% of people living with HIV receiving ART were diagnosed with metabolic syndrome, respectively. Metabolic syndrome was more prevalent in men than in women, using both classification criteria (ATP-III: 58 men [67.4%] vs. 28 women [32.6%]; ALAD: 84 men [71.2%] vs. 34 women [28.8%]). The median time since HIV diagnosis of the participants with metabolic syndrome was longer than for the participants without metabolic syndrome, using the ALAD criteria (p = 0.023). The time spent on ART among participants with metabolic syndrome was longer than among those without, using the ATP-III criteria (p = 0.011). The CD4+ T-cell count and HIV-RNA detection showed no significant difference between participants with and without metabolic syndrome (p > 0.05). No statistical significance was found concerning ART and metabolic syndrome; it is noteworthy that for participants with dolutegravir/abacavir/lamivudine (DTG/ABC/3TC), the frequency was similar regardless of the criteria used, and different for those who were taking bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) or were in other schemes (etravirine, darunavir/ritonavir, raltegravir). Conclusions: Our results suggested that 26.5% and 36.3% of the people living with HIV receiving ART included in this study had metabolic syndrome according to ATP-III and ALAD criteria, respectively. These results are consistent with results reported in the Latin American population. Interestingly, both criteria showed a higher frequency of metabolic syndrome in men living with HIV compared to women. Full article

Pediatric dentistry continually seeks effective and efficient treatments for young patients, especially within pediatric endodontics, where cooperation can often be challenging. This in vivo study aimed to evaluate the effectiveness of a novel photodynamic therapy (PDT) protocol using a 5-aminolevulinic acid gel (Aladent, ALAD) combined with light irradiation during the endodontic treatment of primary teeth. This study included primary teeth requiring root canal therapy due to carious lesions or trauma, with clinical symptoms suggesting irreversible pulpitis or acute apical periodontitis. Following local anesthesia and isolation with a rubber dam, carious lesions were excavated, and access to the pulp chamber was established. Canal preparation included determining the working length and using a sequence of k-files. Afterward, ALAD gel was applied, and the patients were divided into two groups based on their visit duration (Group A with a single visit, Group B returning after one week). Microbiological analysis was conducted on the samples taken before and after treatment. The findings demonstrated significant antibacterial efficacy of the PDT protocol in reducing root canal bacterial load, suggesting ALAD-based PDT may serve as an alternative to traditional endodontic treatment in cases where retaining primary teeth is essential for orthodontic or strategic reasons. Clinically, improvement in symptoms and fistula resolution were observed. Treatment time, patient compliance, and protocol safety in pediatric applications are also discussed, highlighting the protocol’s potential to enhance clinical outcomes in pediatric endodontics. Full article

Intervertebral disc (IVD) disease is typically characterized by the degradation of IVD tissue, secretion of inflammatory and painful factors, and hyperinnervation of the disc. The pro-inflammatory cytokine interleukin-1β (IL-1β) has been regarded as a principal factor in orchestrating disc degeneration. Link N (LN) is a peptide derived from the link protein that has been shown to promote extracellular disc regeneration even in an inflammatory milieu; however, no mechanism(s) has been described for their behaviour to date. Building on prior studies on LN, we hypothesize that LN directly inhibits IL-1β. IVD degeneration was experimentally induced in New Zealand white rabbits, followed by the injection of either sLN or saline as the vehicle control. To determine the expression of markers of pain, histology was performed. Cultured human Nucleus Pulposus disc cells (hNP) were used to determine the effects of LN on IL-1β-induced changes in gene expression, including the effects on IL-1β, TNFα, and IL6 signalling. Isolated murine dorsal root ganglia (DRG) neurons were used to assess the effect of LN on IL-1β-induced neuronal hyperactivity. LN significantly reduced IL-1β-induced NF-κB activation in a dose-dependent manner in disc cells and was further able to modulate IL-1β-induced gene expression, inflammatory mediators, and neurotrophic factors. Peptide docking simulations revealed that LN could interact with IL-1β. A direct interaction of LN and IL-1β was revealed through co-immunoprecipitation experiments. Although IL-1β was able to hypersensitize DRG neurons following a seven-day exposure, as demonstrated by Ca²⁺ imaging, this effect was significantly blunted when co-treated with LN. LN demonstrates a novel mechanism of action by directly inhibiting IL-1β, in addition to mitigating IL-1β-induced hypersensitivity in DRG neurons. These data suggest a potential role for LN in reducing discogenic pain. Full article

Emerging evidence indicates periostin (POSTN) is upregulated in patients with OA, and studies have shown that it can induce the activation of inflammatory cytokines and catabolic enzymes, making it a potential therapeutic target. Link N (LN) is a peptide fragment derived from the link protein and has been demonstrated as an anabolic-like factor and anti-catabolic and anti-inflammatory factors both in vitro and in vivo. This study aims to determine if LN can regulate POSTN expression and function in OA cartilage. Articular cartilage was recovered from donors undergoing total knee replacements to isolate chondrocytes and prepare osteochondral explants. Cells and explants were treated with POSTN and LN (1 and 100 μg) and measured for changes in POSTN expression and various matrix proteins, catabolic and proinflammatory factors, and signaling. To determine the effects of POSTN expression in vivo, a rabbit OA model was used. Immunoprecipitation and in silico modeling were used to determine peptide/POSTN interactions. Western blotting, PCR, and immunohistochemistry demonstrated that LN decreased POSTN expression both in vitro and in vivo. LN was also able to directly inhibit POSTN signaling in OA chondrocytes. In silico docking suggested the direct interaction of LN with POSTN at residues responsible for its oligomerization. Immunoprecipitation experiments confirmed the direct interaction of LN with POSTN and the destabilization of its oligomerization. This study demonstrates the ability of a peptide, LN, to suppress the overexpression and function of POSTN in OA cartilage. Full article

Intervertebral disc degeneration and pain are associated with the nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing 3 (NLRP3) inflammasome activation and the processing of interleukin-1 beta (IL-1β). Activation of thehm inflammasome is triggered by Toll-like receptor stimulation and requires the cofactor receptor cluster of differentiation 14 (CD14). Short Link N (sLN), a peptide derived from link protein, has been shown to modulate inflammation and pain in discs in vitro and in vivo; however, the underlying mechanisms remain elusive. This study aims to assess whether sLN modulates IL-1β and inflammasome activity through interaction with CD14. Disc cells treated with lipopolysaccharides (LPS) with or without sLN were used to assess changes in Caspase-1, IL-1β, and phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). Peptide docking of sLN to CD14 and immunoprecipitation were performed to determine their interaction. The results indicated that sLN inhibited LPS-induced NFκB and Caspase-1 activation, reducing IL-1β maturation and secretion in disc cells. A significant decrease in inflammasome markers was observed with sLN treatment. Immunoprecipitation studies revealed a direct interaction between sLN and the LPS-binding pocket of CD14. Our results suggest that sLN could be a potential therapeutic agent for discogenic pain by mitigating IL-1β and inflammasome activity within discs. Full article

Oral squamous-cell and pancreatic carcinomas are aggressive cancers with a poor outcome. Photodynamic therapy (PDT) consists of the use of photosensitizer-induced cell and tissue damage that is activated by exposure to visible light. PDT selectively acts on cancer cells, which have an accumulation of photosensitizer superior to that of the normal surrounding tissues. 5-aminolevulinic acid (5-ALA) induces the production of protoporphyrin IX (PpIX), an endogenous photosensitizer activated in PDT. This study aimed to test the effect of a new gel containing 5% v/v 5-ALA (ALAD-PDT) on human oral CAL-27 and pancreatic CAPAN-2 cancer cell lines. The cell lines were incubated in low concentrations of ALAD-PDT (0.05%, 0.10%, 0.20%, 0.40%, 0.75%, 1.0%) for 4 h or 8 h, and then irradiated for 7 min with 630 nm RED light. The cytotoxic effects of ALAD-PDT were measured using the MTS assay. Apoptosis, cell cycle, and ROS assays were performed using flow cytometry. PpIX accumulation was measured using a spectrofluorometer after 10 min and 24 and 48 h of treatment. The viability was extremely reduced at all concentrations, at 4 h for CAPAN-2 and at 8 h for CAL-27. ALAD-PDT induced marked apoptosis rates in both oral and pancreatic cancer cells. Elevated ROS production and appreciable levels of PpIX were detected in both cell lines. The use of ALA-PDT as a topical or intralesional therapy would permit the use of very low doses to achieve effective results and minimize side effects. ALAD-PDT has the potential to play a significant role in complex oral and pancreatic anticancer therapies. Full article

Mercury (Hg) pollution is a global public health concern because of its adverse effects on the environment and health. Single-nucleotide polymorphisms (SNPs) have been associated with Hg levels and outcomes. The aim of this review was to describe the research and discuss the evidence on the genetic susceptibility of Hg-exposed individuals to the development of neurocognitive disorders. A systematic review was performed to identify the genes/SNPs associated with Hg toxicokinetics and that, therefore, affect neurological function in exposed populations. Observational and experimental studies were identified by screening three databases. Thirteen articles were included (quality score 82–100%) and 8124 individuals were evaluated. Hg exposure was mainly fish consumption (77%) and, in 31% of the studies, the Hg levels exceeded the reference limits. Genetic susceptibility to higher Hg levels and neurotoxicity risk in Hg poisoning were associated with eight (ALAD rs1800435, CYP3A4 rs2740574, CYP3A5 rs776746, CYP3A7 rs2257401, GSTP1 rs1695, MT1A rs8052394, MT1M rs2270836, and MT4 rs11643815) and three (MT1A rs8052394, MT1M rs2270837, and MT2A rs10636) SNPs, respectively, and rs8052394 was associated with both outcomes. The MT1A rs8052394 SNP may be used as a susceptibility biomarker to identify individuals at greater risk for higher Hg levels and the development of neurocognitive disorders in metal-exposed populations. Full article

This study aimed to evaluate the ability of photodynamic therapy, based on the use of a gel containing 5% delta aminolaevulinic acid (ALAD) for 45′ followed by irradiation with 630 nm LED (PDT) for 7′, to eradicate Candida albicans strains without damaging the gingiva. C. albicans oral strains and gingival fibroblasts (hGFs) were used to achieve these goals. The potential antifungal effects on a clinical resistant C. albicans S5 strain were evaluated in terms of biofilm biomass, colony forming units (CFU/mL) count, cell viability by live/dead analysis, and fluidity membrane changes. Concerning the hGFs, viability assays, morphological analysis (optical, scanning electronic (SEM), and confocal laser scanning (CLSM) microscopes), and assays for reactive oxygen species (ROS) and collagen production were performed. ALAD-mediated aPDT (ALAD-aPDT) treatment showed significant anti-biofilm activity against C. albicans S5, as confirmed by a reduction in both the biofilm biomass and CFUs/mL. The cell viability was strongly affected by the treatment, while on the contrary, the fluidity of the membrane remained unchanged. The results for the hGFs showed an absence of cytotoxicity and no morphological differences in cells subjected to ALAD-aPDT expected for CLSM results that exhibited an increase in the thickening of actin filaments. ROS production was augmented only at 0 h and 3 h, while the collagen appeared enhanced 7 days after the treatment. Full article

Intensive poultry production may result in substantial emissions of pollutants into the environment, including pharmaceuticals and other chemicals used in poultry farming. The objective of this study was to verify the presence of ciprofloxacin, enrofloxacin, carbamazepine, metoclopramide, trimethoprim, diflufenican, flufenacet, and p,p′-DDE in soil and water in the immediate vicinity of a poultry manure heap. The influence of soil contaminants on the growth and selected physiological parameters of seed peas and common duckweed (as indicator plants) was tested. It has been proven that the cultivation of pea plants on soil coming from the close proximity of a heap of manure results in a deterioration of both morphological parameters (root length, shoot length) and physiological parameters (chlorophyll absorption, aminolevulinic acid dehydrogenase (ALAD) activity, aminolevulinic acid (ALA) content, lipid peroxidation, mitochondrial damage or production of HSP70 proteins). Similarly, water extracts from cultivated soils had a significant effect on duckweed, and it was found that contaminant leachates are indeed detectable in soil, groundwater, and deep water. Special attention should, therefore, be paid to the location, methods of storage, and use of poultry fertilizer. Full article

Undiagnosed and untreated oral precancerous lesions often progress into malignancies. Photodynamic therapy (PDT) might be a minimally invasive alternative to conventional treatments. 5-aminolevulinic acid (5-ALA) is one of the most commonly used photosensitizers in PDT, and it is effective on many cancer types. However, its hydrophilic characteristic limits cell membrane crossing. In the present study, the effect of a newly formulated gel containing 5% 5-ALA in combination with red light (ALAD-PDT) on a premalignant oral mucosa cell line was investigated. The dysplastic oral keratinocyte (DOK) cells were incubated with ALAD at different concentrations (0.1, 0.5, 1, and 2 mM) at two different times, 45 min or 4 h, and then irradiated for 7 min with a 630 nm LED (25 J/cm²). MTT assay, flow cytometry, wound healing assay, and quantitative PCR (qPCR) were performed. ALAD-PDT exerted inhibitory effects on the proliferation and migration of DOK cells by inducing ROS and necrosis. mRNA analysis showed modulation of apoptosis-related genes’ expression (TP53, Bcl-2, survivin, caspase-3, and caspase-9). Furthermore, there was no difference between the shorter and longer incubation times. In conclusion, the inhibitory effect of the ALAD-PDT protocol observed in this study suggests that ALAD-PDT could be a promising novel treatment for oral precancerous lesions. Full article

This study aims to test a photodynamic protocol based on a gel containing aminolevulinic acid followed by red-LED (ALAD-PDT) irradiation on human gingival fibroblasts (hGFs) and osteoblasts (hOBs) cultured on a porcine acellular dermal matrix membrane (PADMM). In the previous literature, ALAD-PDT showed solid antibacterial activity and proliferative induction on HGFs cultured on plates and HOBs cultured on a cortical lamina. PADMMs are used in dentistry and periodontology to treat gingival recessions and to increase the tissue thickness in the case of a thin biotype without the risks or postoperative discomfort associated with connective tissue grafts. However, one of the possible complications in this type of surgery is represented by bacterial invasion and membrane exposition during the healing period. We hypothesized that the addition of ALAD-PDT to PADMMs could enhance more rapid healing and decrease the risks connected with bacterial invasion. In periodontal surgery, PADMMs are inserted after a full-thickness flap elevation between the bone and the flap. Consequently, all procedures were performed in parallel on hOBs and hGFs obtained by dental patients. The group control (CTRL) was represented by the unexposed cells cultured on the membranes, group LED (PDT) were the cells subjected to 7 min of red LED irradiation, and ALAD-PDT were the cells subjected to 45 min of ALAD incubation and then to 7 min of red LED irradiation. After treatments, all groups were analyzed for MTT assay and subjected to histological examination at 3 and 7 days and to the SEM observations at 3, 7, and 14 days. Different bone mineralization assays were performed to quantify the effects of ALAD-PDT on hOBs: ALP activity, ALP gene expression, osteocalcin, and alizarin red. The effects of ALAD-PDT on hGFs were evaluated by quantifying collagen 1, fibronectin, and MMP-8. Results showed that ALAD-PDT promoted cellular induction, forming a dense cellular network on hOBs and hGFs, and the assays performed showed statistically significantly higher values for ALAD-PDT with respect to LED alone and CTRLs. In conclusion, ALAD-PDT could represent a promising aid for enhancing the healing of gingival tissues after PADMM applications. Full article