Contemporary strategies and approaches for characterizing composition and enhancing biofilm penetration targeting bacterial extracellular polymeric substances

Extracellular polymeric substances(EPS)constitutes crucial elements within bacterial biofilms,facili-tating accelerated antimicrobial resistance and conferring defense against the host's immune cells.Developing precise and effective antibiofilm approaches and strategies,tailored to the specific charac-teristics of EPS composition,can offer valuable insights for the creation of novel antimicrobial drugs.This,in turn,holds the potential to mitigate the alarming issue of bacterial drug resistance.Current analysis of EPS compositions relies heavily on colorimetric approaches with a significant bias,which is likely due to the selection of a standard compound and the cross-interference of various EPS compounds.Considering the pivotal role of EPS in biofilm functionality,it is imperative for EPS research to delve deeper into the analysis of intricate compositions,moving beyond the current focus on polymeric materials.This ne-cessitates a shift from heavy reliance on colorimetric analytic methods to more comprehensive and nuanced analytical approaches.In this study,we have provided a comprehensive summary of existing analytical methods utilized in the characterization of EPS compositions.Additionally,novel strategies aimed at targeting EPS to enhance biofilm penetration were explored,with a specific focus on high-lighting the limitations associated with colorimetric methods.Furthermore,we have outlined the challenges faced in identifying additional components of EPS and propose a prospective research plan to address these challenges.This review has the potential to guide future researchers in the search for novel compounds capable of suppressing EPS,thereby inhibiting biofilm formation.This insight opens up a new avenue for exploration within this research domain.

Screening strategies for quorum sensing inhibitors in combating bacterial infections

Interference with quorum sensing(QS)represents an antivirulence strategy with a significant promise for the treatment of bacterial infections and a new approach to restoring antibiotic tolerance.Over the past two decades,a novel series of studies have reported that quorum quenching approaches and the discovery of quorum sensing inhibitors(QSIs)have a strong impact on the discovery of anti-infective drugs against various types of bacteria.The discovery of QSI was demonstrated to be an appropriate strategy to expand the anti-infective therapeutic approaches to complement classical antibiotics and antimicrobial agents.For the discovery of QSIs,diverse approaches exist and develop in-step with the scale of screening as well as specific QS systems.This review highlights the latest findings in strategies and methodologies for QSI screening,involving activity-based screening with bioassays,chemical methods to seek bacterial QS pathways for QSI discovery,virtual screening for QSI screening,and other potential tools for interpreting QS signaling,which are innovative routes for future efforts to discover additional QSIs to combat bacterial infections.

Rabdosia serra alleviates dextran sulfate sodium salt-induced colitis in mice through anti-inflammation,regulating Th17/Treg balance,maintaining intestinal barrier integrity,and modulating gut microbiota

Rabdosia serra(R.serra),an important component of Chinese herbal tea,has traditionally been used to treat hepatitis,jaundice,cholecystitis,and colitis.However,the chemical composition of R.serra and its effect against colitis remain unclear.In this study,the chemical composition of the water extract of R.serra was analyzed using ultra performance liquid chromatography coupled with a hybrid linear ion trap quadrupole-orbitrap mass spectrometer(UPLC-LTQ-Orbitrap-MS).A total of 46 compounds,comprising ent-kaurane diterpenoids,flavonoids,phenolic acids,and steroids,were identified in the water extract of R.serra,and the extract could significantly alleviate dextran sulfate sodium salt-induced colitis by improving colon length,upregulating anti-inflammatory factors,downregulating proinflammatory factors,and restoring the balance of T helper 17/T regulatory cells.R.serra also preserved intestinal barrier function by increasing the level of tight junction proteins(zonula occludens 1 and occludin)in mouse colonic tissue.In addition,R.serra modulated the gut microbiota composition by increasing bacterial richness and diversity,increasing the abundance of beneficial bacteria(Muribaculaceae,Bacteroides,Lactobacillus,and Prevotellaceae_UCG-001),and decreasing the abundance of pathogenic bacteria(Turicibacter,Eubacterium_fissicatena_group,and Eubacterium_xylanophilum_group).Gut microbiota depletion by antibiotics further confirmed that R.serra alleviated colitis in a microbiota-dependent manner.Overall,our findings provide chemical and biological evidence for the potential application of R.serra in the management of colitis.

Crocetin Prevents Amyloid <i>β</i>_1-42-Induced Cell Death in Murine Hippocampal Cells

Crocetin is an aglycon of carotenoid extracted by saffron stigmas (Crocus sativus L.) and known to have a potent anti-oxidative effect. Amyliod β (Aβ), hallmark of Alzheimer’s disease, is reported to have neurotoxicity partly via oxidative stress. In this study, we investigated the effect of crocetin on hippocampal HT22 cell death induced by Aβ1-42. Furthermore, to clarify the mechanism underlying the protective effects of crocetin against Aβ1-42- induced cell death, we measured reactive oxygen species (ROS) production by CM-H2DCFDA kit assay. Crocetin at 1 -10 μM protected HT22 cells against Aβ1-42-induced neuronal cell death and decreased ROS production increased by Aβ1-42. These results that crocetin has the potent neuroprotective effect against Aβ1-42-induced cytotoxicity in hippocampal cells by attenuating oxidative stress, suggest that crocetin may provide a useful therapeutic strategy against Aβ-related disorders.

Megastigmane Glycosides from Polygala hongkongensis Hemsl

Two new megastigmane glycosides,7Z-roseoside,and 7Z-trifostigmanoside Ⅰ,as well as,four known compounds,trifostigmanoside Ⅱ,epimedin C,3＇,7-dihydroxy-4＇-methoxyisoflavone-7-D-glucopyranoside,and formenonetin,were isolated from Polygala hongkongensis Hemsl.The structures of the isolated compounds were established on the basis of UV,IR,NMR,and MS spectral data.Megastigmane glycosides（1-3）were isolated from the family Polygalaceae for the first time.

Small molecule inhibitors of RORγt for Th17 regulation in inflammatory and autoimmune diseases

As a ligand-dependent transcription factor,retinoid-associated orphan receptor gt(RORγt)that controls T helper(Th)17 cell differentiation and interleukin(IL)-17 expression plays a critical role in the progression of several inflammatory and autoimmune conditions.An emerging novel approach to the therapy of these diseases thus involves controlling the transcriptional capacity of RORγt to decrease Th17 cell development and IL-17 production.Several RORγt inhibitors including both antagonists and inverse agonists have been discovered to regulate the transcriptional activity of RORγt by binding to orthosteric-or allosteric-binding sites in the ligand-binding domain.Some of small-molecule inhibitors have entered clinical evaluations.Therefore,in current review,the role of RORγt in Th17 regulation and Th17-related inflammatory and autoimmune diseases was highlighted.Notably,the recently developed RORγt inhibitors were summarized,with an emphasis on their optimization from lead compounds,efficacy,toxicity,mechanisms of action,and clinical trials.The limitations of current development in this area were also discussed to facilitate future research.

UnTTrapping the ends： A new player in overcoming protein linked DNA damage

DNA topoisomerases carry out their reactions by generating transient covalent phosphotyrosine intermediates with DNA [ 1 ]. This reaction mechanism allows these enzymes that need to break DNA to do so in a way that does not induce genome rearrangements or DNA damage responses. However, a variety of agents are able to trap topoisomerases while they are covalently bound to DNA.

The Effects of Blue LED Light on Behavior and Retinal Function in Maternal and Offspring Mice

In the present study, we investigated whether blue light emission diode (LED) light exposure affects the maternal behavior of mice. The brain function of the offspring mice, including short-term memory, locomotor activity, anxiety-like behavior, and depression-like behavior, was evaluated. Pregnant mice at day 11 were housed in the apparatus for exposure to blue LED light during the daytime. Nesting behavior and the survival of pups were observed until weaning. After weaning, the offspring mice were bred in normal light conditions until 12 weeks old, and then the Y-maze test, open field test, and tail suspension test were performed. Retinal functions were evaluated by electroretinogram and histological analysis. Blue LED light exposure during the daytime induced retinal damage, but did not affect behavior related to maternal care in maternal mice. In the offspring mice, blue LED light exposure during the daytime did not affect the retina or brain functions. These findings suggest that blue LED light during the daytime might not be a risk factor for disruption of the mother-infant relationship or offspring brain development in mice.

Identification of the Stress Which Causes Optineurin Aggregation

Glaucoma is a common neurodegenerative disease that can cause blindness and occurs worldwide. Currently, lowering intraocular pressure is the only therapy available to protect retinal ganglion cells (RGCs). However, this therapy does not prevent RGC death in all patients. Therefore, new therapeutic approaches for glaucoma are urgently required, and neuroprotection of RGCs is a focus for many researchers. Optineurin (OPTN) is one of the normal tension glaucoma (NTG) relative genes, while mutant OPTN can form a characteristic aggregation, causing RGC death. Hence, elucidation of the mechanism of OPTN aggregation might provide a clue to help understand RGC death. To examine whether non-mutant OPTN could also aggregate, we pharmacologically induced some glaucoma-related stresses, such as endoplasmic reticulum (ER) stress, glutamate toxicity, activation of TNF-α signaling, mitochondrial dysfunction, and autophagic flux impairment. Our results showed that ER stress, TNF-α signaling, and autophagic flux are involved in OPTN aggregation. Furthermore, our data indicated that increased ER stress, activation of TNF-α signaling, and impaired autophagic flux induce OPTN aggregation, suggesting that OPTN aggregation might be an important therapeutic target not only for familial NTG with mutated OPTN but also for patients with glaucoma more generally.

The Effects of Rufinamide on <i>in Vitro</i>Spinal Muscular Atrophy Model

Spinal muscular atrophy (SMA) is devastating genetic disease characterized by progressive loss of motor neuron and skeletal muscle weakness. SMA is the most common lethal genetic disease in infancy. SMA is caused by deletion or mutation of SMN1 gene and subsequent lack of SMN protein. Our purpose in this study was to evaluate the therapeutic potential of rufinamide, an antiepileptic drug. In this study, SMA patient-derived fibroblasts and differentiated spinal motor neurons (MNs) using SMA patient-derived iPSCs were used as in vitro SMA model. SMN mRNA was significantly increased by addition of rufinamide in type III SMA patient-derived fibroblasts. Furthermore, rufinamide stimulated neurite elongation in type III SMA patient derived-iPSCs-MNs. In contrast of the result using type III SMA patient-derived fibroblasts, the expression level of SMN mRNA was not changed after rufinamide treatment in type I SMA patient-derived fibroblasts, and rufinamide did not affect neurite outgrowth in type I SMA patients derived-iPSCs-MNs. These findings indicate that rufinamide may be one of the potential candidate drugs for mild type of SMA.

The Novel cPLA2 Inhibitor AK106-001616 Has a Protective Effect on SOD1G93A-Induced Cell Death in NSC34 Murine Motor Neuron-Like Cell

The expression of cytosolic phospholipase A2 (cPLA2) expression is up-regulated in animal model of ALS and in patients with familial amyotrophic lateral sclerosis (fALS). Inhibition of cyclooxygenase 2 (COX2), which is a downstream enzyme of cPLA2, ameliorates the impairment of motor function in the ALS model mice. Therefore, the arachidonic acid cascade, including the cPLA2-COX2 pathway, is an important therapeutic target of ALS. The current study was designed to investigate the potential of AK106-001616, an inhibitor of cPLA2, in protection of motor neuron cell death induced by mutant superoxide dismutase (SOD1G93A). AK106-001616 (1 - 10 μM) protected NSC34 cells (mouse motor neuron like cells) against SOD1G93A-induced motor neuron cell death. Furthermore, aspirin, an inhibitor of COX1/2, reduced the SOD1G93A-induced motor neuron cell death at a concentration that inhibited COX2. Celecoxib, a selective COX2 inhibitor, also reduced the SOD1G93A-induced motor neuron cell death. These results suggest that the arachidonic acid cascade is important for SOD1G93A-induced motor neuron cell death and AK106-001616 has a potent neuroprotective effect against it. AK106-001616 may be a useful therapeutic agent against SOD1G93A-induced ALS.

Comparison of Efficacy and Safety Evaluation of Latanoprost Formulations with and without Benzalkonium Chloride

Background: This study investigated the safety (cytotoxicity in vitro) and pharmacological effects (ocular hypotensive effects and aqueous humor concentrations in normotensive monkeys in vivo) of latanoprost formulations with benzalkonium chloride (latanoprost with BAK) and without BAK (NP). Methods: A bioequivalence study of latanoprost with BAK and NP was also conducted on human healthy volunteers. Cytotoxicity and the protective effect against H2O2 stress in vitro were evaluated using human corneal epithelial cells. The ocular hypotensive effects in normotensive monkeys were measured by pneumatonometer and the aqueous humor concentrations of latanoprost free acid were determined by liquid chromatography/mass spectrum (LC/MS) methods. The bioequivalence study of latanoprost with BAK and NP was carried out as a single eye drop, two-sequence, crossover randomized study. Results: Cytotoxicity tests in vitro revealed that NP was less toxic than latanoprost with BAK and significantly inhibited H2O2 induced cell damage while latanoprost with BAK did not. The hypotensive efficacy and the latanoprost free acid concentrations in aqueous humor of each formulation were not significantly different in monkeys. In the bioequivalence study, NP was bioequivalent to latanoprost with BAK. NP was safer than latanoprost with BAK with respect the results obtained in the in vitro cytotoxicity test. There was no difference observed between latanoprost with BAK and NP in the IOP lowering effect in monkeys and healthy volunteers. Conclusion: Taken together, these results indicate that NP is as effective as latanoprost with BAK, and is more likely to maintain ocular surface health than latanoprost with BAK.

Establishment and Effects of Ginger and Kikyoto of a Haloperidol-Induced Dysphagia Model in Guinea Pigs

Dysphagia induces aspiration and causes aspiration pneumonia. There is no treatment for dysphagia fundamentally. Haloperidol reportedly induces dysphagia. In the present study, we established a haloperidol-induced dysphagia model in guinea pigs, and evaluated the effects of ginger, kikyoto, and a mixture of ginger and kikyoto on swallowing. Swallowing ability was evaluated using behavioral tests, computed tomography (CT), and videofluoroscopic examination of swallowing. To investigate the effect of ginger and kikyoto on swallowing, ginger, kikyoto, or a mixture of ginger and kikyoto was administered orally to guinea pigs with haloperidol-induced dysphagia. Effects of these compounds were evaluated with behavioral tests. Chronic administration of haloperidol reduced the number of swallows, as evaluated by the behavioral test and videofluoroscopic examination of swallowing. In our model, these compounds improved swallowing dysfunction. Our results suggest that this model might be useful in revealing the pathogenesis of dysphagia and evaluating compounds that might improve swallowing.

Repurposing vitamin D for treatment of human malignancies via targeting tumor microenvironment

Tumor cells along with a small proportion of cancer stem cells exist in a stromal microenvironment consisting of vasculature, cancer-associated fibroblasts, immune cells and extracellular components.Recent epidemiological and clinical studies strongly support that vitamin D supplementation is associated with reduced cancer risk and favorable prognosis. Experimental results suggest that vitamin D not only suppresses cancer cells, but also regulates tumor microenvironment to facilitate tumor repression. In this review, we have outlined the current knowledge on epidemiological studies and clinical trials of vitamin D. Notably, wesummarized and discussed the anticancer action of vitamin D in cancer cells, cancer stem cells and stroma cells in tumor microenvironment, providing a better understanding of the role of vitamin D in cancer. We presently re-propose vitamin D to be a novel and economical anticancer agent.

Receptor-mediated targeted drug delivery systems for treatment of inflammatory bowel disease: Opportunities and emerging strategies

Inflammatory bowel disease(IBD)is a chronic intestinal disease with painful clinical manifestations and high risks of cancerization.With no curative therapy for IBD at present,the development of effective therapeutics is highly advocated.Drug delivery systems have been extensively studied to transmit therapeutics to inflamed colon sites through the enhanced permeability and retention(EPR)effect caused by the inflammation.However,the drug still could not achieve effective concentration value that merely utilized on EPR effect and display better therapeutic efficacy in the inflamed region because of nontargeted drug release.Substantial researches have shown that some specific receptors and cell adhesion molecules highly expresses on the surface of colonic endothelial and/or immune cells when IBD occurs,ligandmodified drug delivery systems targeting such receptors and cell adhesion molecules can specifically deliver drug into inflamed sites and obtain great curative effects.This review introduces the overexpressed receptors and cell adhesion molecules in inflamed colon sites and retrospects the drug delivery systems functionalized by related ligands.Finally,challenges and future directions in this field are presented to advance the development of the receptor-mediated targeted drug delivery systems for the therapy of IBD.

Chinese herbal medicines for treating ulcerative colitis via regulating gut microbiota-intestinal immunity axis

Ulcerative colitis(UC)is one of types of inflammatory bowel disease with high recurrence.Recent studies have highlighted that microbial dysbiosis as well as abnormal gut immunity are crucial factors that initiate a series of inflammatory responses in the UC.Modulating the gut microbiota-intestinal immunity loop has been suggested as one of key strategies for relieving UC.Many Chinese herbal medicines including some of single herb,herbal formulas and the derived constituents have been reported with protective effect against UC through modulating gut microbiome and intestinal immunity.Some clinical trials have shown promising results.This review thus focused on the current knowledge on using Chinese herbal medicines for treating UC from the mechanism aspects of regulating intestinal homeostasis involving microbiota and gut immunity.The existing clinical trials are also summarized.

Effects of fibroblast transplantation into the internal pallidum on levodopa-induced dyskinesias in parkinsonian non-human primates

Recent studies have shown that fibroblast transplantation can modify the activity of basal ganglia networks in models of Parkinson＇s disease. To determine its effects on parkinsonian motor symptoms, we performed autologous dermal fibroblast transplantation into the internal pallidum （GPi） in two parkinsonian rhesus monkeys with stable levodopa- induced dyskinesias （LIDs）. Levodopa responses were assessed every week after transplantation for three months. A reduction of between 58% and 64% in total LIDs on the contralateral side was observed in both animals. No clear LID changes were observed on the ipsilateral side. These effects lasted the entire 3-month period in one monkey, but declined after 6-8 weeks in the other. The antiparkinsonian effects of levodopa did not diminish, The results of this pilot study indicate that fibroblast transplantation into the GPi may have beneficial effects on LIDs and warrant further investigation for potential therapeutic use.

Polyoxypregnanes as safe, potent, and specific ABCB1-inhibitory pro-drugs to overcome multidrug resistance in cancer chemotherapy in vitro and in vivo

Multidrug resistance(MDR)mediated by ATP binding cassette subfamily B member 1(ABCB1)is significantly hindering effective cancer chemotherapy.However,currently,no ABCB1-inhibitory drugs have been approved to treat MDR cancer clinically,mainly due to the inhibitor specificity,toxicity,and drug interactions.Here,we reported that three polyoxypregnanes(POPs)as the most abundant constituents of Marsdenia tenacissima(M.tenacissima)were novel ABCB1-modulatory pro-drugs,which underwent intestinal microbiota-mediated biotransformation in vivo to generate active metabolites.The metabolites at non-toxic concentrations restored chemosensitivity in ABCB1-overexpressing cancer cells via inhibiting ABCB1 efflux activity without changing ABCB1 protein expression,which were further identified as specific non-competitive inhibitors of ABCB1 showing multiple binding sites within ABCB1 drug cavity.These POPs did not exhibit ABCB1/drug metabolizing enzymes interplay,and their repeated administration generated predictable pharmacokinetic interaction with paclitaxel without obvious toxicity in vivo.We further showed that these POPs enhanced the accumulation of paclitaxel in tumors and overcame ABCB1-mediated chemoresistance.The results suggested that these POPs had the potential to be developed as safe,potent,and specific pro-drugs to reverse ABCB1-mediated MDR.Our work also provided scientific evidence for the use of M.tenacissima in combinational chemotherapy.

Conditional reprogramming:next generation cell culture

Long-term primary culture of mammalian cells has been always difficult due to unavoidable senescence. Conventional methods for generating immortalized cell lines usually require manipulation of genome which leads to change of important biological and genetic characteristics. Recently, conditional reprogramming(CR) emerges as a novel next generation tool for long-term culture of primary epithelium cells derived from almost all origins without alteration of genetic background of primary cells. CR cocultures primary cells with inactivated mouse 3T3-J2 fibroblasts in the presence of RHO-related protein kinase(ROCK) inhibitor Y-27632, enabling primary cells to acquire stem-like characteristics while retain their ability to fully differentiate. With only a few years’ development, CR shows broad prospects in applications in varied areas including disease modeling, regenerative medicine, drug evaluation, drug discovery as well as precision medicine. This review is thus to comprehensively summarize and assess current progress in understanding mechanism of CR and its wide applications, highlighting the value of CR in both basic and translational researches and discussing the challenges faced with CR.