-
Advances in Experimental Medicine and... 2023One of the most prevalent indications of water-electrolyte imbalance is edema. Aquaporins (AQPs) are a protein family that can function as water channels. Osmoregulation...
One of the most prevalent indications of water-electrolyte imbalance is edema. Aquaporins (AQPs) are a protein family that can function as water channels. Osmoregulation and body water homeostasis are dependent on the regulation of AQPs. Human kidneys contain nine AQPs, five of which have been demonstrated to have a role in body water balance: AQP1, AQP2, AQP3, AQP4, and AQP7. Water imbalance is connected with AQP dysfunction. Hyponatremia with elevated AQP levels can accompany edema, which can be caused by disorders with low effective circulating blood volume and systemic vasodilation, such as congestive heart failure (CHF), hepatic cirrhosis, or the syndrome of incorrect antidiuretic hormone secretion (SIADH). In CHF, upregulation of AQP2 expression and targeting is critical for water retention. AQP2 is also involved in aberrant water retention and the formation of ascites in cirrhosis of the liver. Furthermore, water retention and hyponatremia in SIADH are caused by increased expression of AQP2 in the collecting duct. Fluid restriction, demeclocycline, and vasopressin type-2 receptor antagonists are widely utilized to treat edema. The relationship between AQPs and edema is discussed in this chapter.
Topics: Humans; Aquaporin 2; Inappropriate ADH Syndrome; Hyponatremia; Aquaporins; Edema; Heart Failure; Water
PubMed: 36717501
DOI: 10.1007/978-981-19-7415-1_19 -
Future Medicinal Chemistry Sep 2019Tetracyclines are well established antibiotics but show phototoxicity as a side effect. Antimicrobial photodynamic inactivation uses nontoxic dyes combined with harmless... (Review)
Review
Tetracyclines are well established antibiotics but show phototoxicity as a side effect. Antimicrobial photodynamic inactivation uses nontoxic dyes combined with harmless light to destroy microbial cells by reactive oxygen species. Tetracyclines (demeclocycline and doxycycline) can act as light-activated antibiotics by binding to bacterial cells and killing them only upon illumination. The remaining tetracyclines can prevent bacterial regrowth after illumination has ceased. Antimicrobial photodynamic inactivation can be potentiated by potassium iodide. Azide quenched the formation of iodine, but not hydrogen peroxide. Demeclotetracycline (but not doxycycline) iodinated tyrosine after light activation in the presence of potassium iodide. Bacteria are killed by photoactivation of tetracyclines in the absence of oxygen. Since topical tetracyclines are already used clinically, blue light activation may increase the bactericidal effect.
Topics: Anti-Bacterial Agents; Bacteria; Light; Photochemotherapy; Photosensitizing Agents; Tetracyclines
PubMed: 31544504
DOI: 10.4155/fmc-2018-0513 -
Scientific Reports Aug 2023Tetracyclines exhibit anti-viral, anti-inflammatory, and immunomodulatory activities via various mechanisms. The present study investigated the efficacy and safety of... (Randomized Controlled Trial)
Randomized Controlled Trial
Tetracyclines exhibit anti-viral, anti-inflammatory, and immunomodulatory activities via various mechanisms. The present study investigated the efficacy and safety of demeclocycline in patients hospitalized with mild-to-moderate COVID-19 via an open-label, multicenter, parallel-group, randomized controlled phase 2 trial. Primary and secondary outcomes included changes from baseline (day 1, before the study treatment) in lymphocytes, cytokines, and SARS-CoV-2 RNA on day 8. Seven, seven, and six patients in the control, demeclocycline 150 mg daily, and demeclocycline 300 mg daily groups, respectively, were included in the modified intention-to-treat population that was followed until day 29. A significant change of 191.3/μL in the number of CD4 T cells from day 1 to day 8 was observed in the demeclocycline 150 mg group (95% CI 5.1/μL-377.6/μL) (p = 0.023), whereas that in the control group was 47.8/μL (95% CI - 151.2/μL to 246.8/μL), which was not significant (p = 0.271). The change rates of CD4 T cells negatively correlated with those of IL-6 in the demeclocycline-treated groups (R = - 0.807, p = 0.009). All treatment-emergent adverse events were of mild-to-moderate severity. The present results indicate that the treatment of mild-to-moderate COVID-19 patients with demeclocycline elicits immune responses conducive to recovery from COVID-19 with good tolerability.Trial registration: This study was registered with the Japan Registry of Clinical Trials (Trial registration number: jRCTs051200049; Date of the first registration: 26/08/2020).
Topics: Humans; COVID-19; Demeclocycline; RNA, Viral; SARS-CoV-2
PubMed: 37612352
DOI: 10.1038/s41598-023-41051-2 -
British Dental Journal Mar 2021
Topics: Child; Demeclocycline; Drug Combinations; Humans; Triamcinolone Acetonide
PubMed: 33712760
DOI: 10.1038/s41415-021-2796-3 -
Antioxidants (Basel, Switzerland) Feb 2023Several studies have reported that the tetracycline (TC) class antibiotic doxycycline () is effective against Parkinson's disease (PD) pathomechanisms. The aim of the...
Several studies have reported that the tetracycline (TC) class antibiotic doxycycline () is effective against Parkinson's disease (PD) pathomechanisms. The aim of the present work was three-fold: (i) Establish a model system to better characterize neuroprotection by ; (ii) Compare the rescue effect of to that of other TC antibiotics; (iii) Discover novel neuroprotective TCs having reduced antibiotic activity. For that, we used cultures of mouse midbrain dopamine (DA) neurons and experimental conditions that model iron-mediated oxidative damage, a key mechanism in PD pathobiology. We found that and the other TC antibiotic, demeclocycline (), provided sustained protection to DA neurons enduring iron-mediated insults, whereas chlortetracycline and non-TC class antibiotics did not. Most interestingly, non-antibiotic derivatives of and , i.e., and , respectively, were also robustly protective for DA neurons. Interestingly, , , and remained protective for DA neurons until advanced stages of neurodegeneration, and the rescue effects of TCs were observable regardless of the degree of maturity of midbrain cultures. Live imaging studies with the fluorogenic probes DHR-123 and TMRM revealed that protective TCs operated by preventing intracellular oxidative stress and mitochondrial membrane depolarization, i.e., cellular perturbations occurring in this model system as the ultimate consequence of ferroptosis-mediated lipid peroxidation. If oxidative/mitochondrial insults were generated acutely, , and were no longer neuroprotective, suggesting that these compounds are mostly effective when neuronal damage is chronic and of low-intensity. Overall, our data suggest that TC derivatives, particularly those lacking antibiotic activity, might be of potential therapeutic utility to combat low-level oxidative insults that develop chronically in the course of PD neurodegeneration.
PubMed: 36978822
DOI: 10.3390/antiox12030575 -
Journal of Conservative Dentistry : JCD 2022The aim of this study was to investigate the diffusion of triamcinolone and demeclocycline from an endodontic paste when used unmodified, versus when combined in equal...
AIM
The aim of this study was to investigate the diffusion of triamcinolone and demeclocycline from an endodontic paste when used unmodified, versus when combined in equal parts with a calcium hydroxide paste, in terms of diffusion through the dentinal tubules versus through the apical foramen.
METHODOLOGY
Medicaments were placed in endodontically prepared roots that were kept in vials of Milli-Q water. The five experimental groups in the study were (1) control - no medicament, (2) medicament containing triamcinolone and demeclocycline (T&D) and occluded apex, (3) T&D paste and patent apex, (4) T&D + calcium hydroxide (Ca(OH)) occluded apex, and (5) T&D + Ca(OH) and patent apex. The triamcinolone and demeclocycline concentrations were measured with solid-phase extraction and ultra-high performance liquid chromatography-mass spectrometry, after 1, 3, 8, and 24 h, and after 1 week.
RESULTS
Most of the triamcinolone and demeclocycline diffused through the apical foramen, with sparse diffusion through the dentinal tubules. The T&D paste mixed with Ca(OH) in equal amounts showed greater than the expected 50% reduction in the diffusion of triamcinolone and demeclocycline from mass dilution alone (89% and 80%, respectively).
CONCLUSIONS
These results stress the importance of maintaining apical patency, for allowing diffusion of active components of the drugs to target tissues in the periapical environment.
PubMed: 36187869
DOI: 10.4103/jcd.jcd_206_22 -
Frontiers in Immunology 2020Myeloid cells that infiltrate into brain tumors are deactivated or exploited by the tumor cells. We previously demonstrated that compromised microglia, monocytes, and...
Myeloid cells that infiltrate into brain tumors are deactivated or exploited by the tumor cells. We previously demonstrated that compromised microglia, monocytes, and macrophages in malignant gliomas could be reactivated by amphotericin-B to contain the growth of brain tumorinitiating cells (BTICs). We identified meclocycline as another activator of microglia, so we sought to test whether its better-tolerated derivative, demeclocycline, also stimulates monocytes to restrict BTIC growth. Monocytes were selected for study as they would be exposed to demeclocycline in the circulation prior to entry into brain tumors to become macrophages. We found that demeclocycline increased the activity of monocytes in culture, as determined by tumor necrosis factor-α production and chemotactic capacity. The conditioned medium of demeclocycline-stimulated monocytes attenuated the growth of BTICs generated from human glioblastoma resections, as evaluated using neurosphere and alamarBlue assays, and cell counts. Demeclocycline also had direct effects in reducing BTIC growth. A global gene expression screen identified several genes, such as DNA damage inducible transcript 4, frizzled class receptor 5 and reactive oxygen species modulator 1, as potential regulators of demeclocycline-mediated BTIC growth reduction. Amongst several tetracycline derivatives, only demeclocycline directly reduced BTIC growth. In summary, we have identified demeclocycline as a novel inhibitor of the growth of BTICs, through direct effect and through indirect stimulation of monocytes. Demeclocycline is a candidate to reactivate compromised immune cells to improve the prognosis of patients with gliomas.
Topics: Antineoplastic Agents; Brain Neoplasms; Carcinogenesis; Cell Growth Processes; Cells, Cultured; Demeclocycline; Glioma; Humans; Monocytes; Neoplastic Stem Cells; Tumor-Associated Macrophages
PubMed: 32153581
DOI: 10.3389/fimmu.2020.00272 -
Cartilage Dec 2021The temporomandibular joint (TMJ) is a unique fibrocartilaginous joint that adapts to mechanical loading through cell signaling pathways such as the Wnt pathway....
OBJECTIVE
The temporomandibular joint (TMJ) is a unique fibrocartilaginous joint that adapts to mechanical loading through cell signaling pathways such as the Wnt pathway. Increased expression of low-density lipoprotein receptor-related protein 5 (Lrp5), a co-receptor of the Wnt pathway, is associated with a high bone mass (HBM) phenotype. The objective of this study was to analyze the effect of overexpression of Lrp5 on the subchondral bone and cartilage of the TMJ in mice exhibiting the HBM phenotype.
DESIGN
Sixteen-week-old Lrp5 knock-in transgenic mice carrying either the A214V (EXP-A) or G171V (EXP-G) missense mutations, and wildtype controls (CTRL) were included in this study. Fluorescent bone labels, calcein, alizarin complexone, and demeclocycline were injected at 3.5, 7.5, and 11.5 weeks of age, respectively. The left mandibular condyle was used to compare the subchondral bone micro-computed tomography parameters and the right TMJ was used for histological analyses. Cartilage thickness, matrix proteoglycan accumulation, and immunohistochemical localization of Lrp5 and sclerostin were compared between the groups.
RESULTS
Subchondral bone volume (BV) and percent bone volume (BV/TV) were significantly increased in both EXP-A and EXP-G compared with CTRL ( < 0.05) whereas trabecular spacing (Tb.Sp) was decreased. Cartilage thickness, extracellular matrix production, and expression of Lrp5 and Sost were all increased in the experimental groups. The separation between the fluorescent bone labels indicated increased endochondral maturation between 3.5 and 7.5 weeks.
CONCLUSIONS
These data demonstrate that Lrp5 overexpression leads to adaptation changes in the mandibular condylar cartilage of the TMJ to prevent cartilage degradation.
Topics: Animals; Bone and Bones; Cartilage; Low Density Lipoprotein Receptor-Related Protein-5; Mice; Temporomandibular Joint; X-Ray Microtomography
PubMed: 33124433
DOI: 10.1177/1947603520968875 -
Frontiers in Microbiology 2020Antibiotic resistance is a growing public health concern, though the constant development of new antibiotics. The combination of high-throughput screening and drug...
Antibiotic resistance is a growing public health concern, though the constant development of new antibiotics. The combination of high-throughput screening and drug repurposing is an effective way to develop new therapeutic uses of drugs. In this study, we screened a drug library consisting of 1,573 drugs already approved by the Food and Drug Administration and 903 drugs from the natural product library, to identify antimicrobials against . A high-throughput screening assay based on microtiter plate was used to screen 39 drugs that inhibit the planktonic or biofilm formation of while most of them are antibiotics. The antimicrobial activities of these drugs were evaluated by phenotypic analysis. Further studies showed the combined therapy of tetracycline antibiotics demeclocycline hydrochloride (DMCT) and the novel antimicrobial peptide SAAP-148 has an effective synergistic antibacterial effect on PAO1 and ATCC27853. Moreover, the time-kill curve assay and murine model of cutaneous abscesses further confirmed the synergistic effect. In addition, the combination of DMCT and SAAP-148 has the potential to combat clinically isolated multidrug-resistant (MDR) strains. Our results clearly indicate that DMCT and SAAP-148 combined therapy could be an effective method to combat MDR -related infections.
PubMed: 33362739
DOI: 10.3389/fmicb.2020.591426