Extracellular Phospholipase Research Articles

Synergistic Effects and Mechanisms of Budesonide in Combination with Fluconazole against Resistant Candida albicans.

Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases in the clinic. The emergence of drug resistance in Candida albicans has become a noteworthy phenomenon due to the extensive use of antifungal agents and the development of biofilms. This study showed that budesonide potentiates the antifungal effect of fluconazole against fluconazole-resistant Candida albicans strains both in vitro and in vivo. In addition, our results demonstrated, for the first time, that the combination of fluconazole and budesonide can reverse the resistance of Candida albicans by inhibiting the function of drug transporters, reducing the formation of biofilms, promoting apoptosis and inhibiting the activity of extracellular phospholipases. This is the first study implicating the effects and mechanisms of budesonide against Candida albicans alone or in combination with fluconazole, which may ultimately lead to the identification of new potential antifungal targets.

The Synergistic Effect of Azoles and Fluoxetine against Resistant Candida albicans Strains Is Attributed to Attenuating Fungal Virulence.

This study evaluated the synergistic effects of the selective serotonin reuptake inhibitor, fluoxetine, in combination with azoles against Candida albicans both in vitro and in vivo and explored the underlying mechanism. MICs, sessile MICs, and time-kill curves were determined for resistant C. albicans Galleria mellonella was used as a nonvertebrate model for determining the efficacy of the drug combinations against C. albicans in vivo For the mechanism study, gene expression levels of the SAP gene family were determined by reverse transcription (RT)-PCR, and extracellular phospholipase activities were detected in vitro by the egg yolk agar method. The combinations resulted in synergistic activity against C. albicans strains, but the same effect was not found for the non-albicans Candida strains. For the biofilms formed over 4, 8, and 12 h, synergism was seen for the combination of fluconazole and fluoxetine. In addition, the time-kill curves confirmed the synergism dynamically. The results of the G. mellonella studies agreed with the in vitro analysis. In the mechanism study, we observed that fluconazole plus fluoxetine caused downregulation of the gene expression levels of SAP1 to SAP4 and weakened the extracellular phospholipase activities of resistant C. albicans The combinations of azoles and fluoxetine showed synergistic effects against resistant C. albicans may diminish the virulence properties of C. albicans.

Extracellular phospholipase production of oral Candida albicans isolates from smokers, diabetics, asthmatics, denture wearers and healthy individuals following brief exposure to polyene, echinocandin and azole antimycotics.

ObjectiveCandida albicans is the primary causative agent of oral candidosis, and one of its key virulent attributes is considered to be its ability to produce extracellular phospholipases that facilitate cellular invasion. Oral candidosis can be treated with polyenes, and azoles, and the more recently introduced echinocandins. However, once administered, the intraoral concentration of these drugs tend to be sub-therapeutic and rather transient due to factors such as the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, the pathogenic yeasts may undergo a brief exposure to antifungal drugs. We, therefore, evaluated the phospholipase production of oral C. albicans isolates following brief exposure to sub-therapeutic concentrations of the foregoing antifungals.Materials and methodsFifty C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sub-therapeutic concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for one hour. Thereafter the drugs were removed and the phospholipase production was determined by a plate assay using an egg yolk-agar medium.ResultsThe phospholipase production of these isolates was significantly suppressed with a percentage reduction of 10.65, 12.14, 11.45 and 6.40% following exposure to nystatin, amphotericin B, caspofungin and ketoconazole, respectively. This suppression was not significant following exposure to fluconazole.ConclusionsDespite the sub-therapeutic, intra oral, bioavailability of polyenes, echinocandins and ketoconazole, they are likely to produce a persistent antifungal effect by suppressing phospholipase production, which is a key virulent attribute of this common pathogenic yeast.

Effect of oral antiseptic agents on phospholipase and proteinase enzymes of Candida albicans

ObjectiveCandida-associated denture stomatitis is the most prevalent form of oral candida infections among the denture wearers. Generally, antiseptic oral rinses used in the treatment of these infections are considered as an adjunct or alternative antifungal treatment. Studies have suggested that the intraoral concentrations of antiseptics decrease substantially to the sub-therapeutic levels on account of the dynamics of the oral cavity. This condition yields the question about the minimum antiseptic concentration that effect the character or pathogenesis of Candida during treatment. The extracellular phospholipase and proteinase enzymes of Candida albicans are regarded to have a crucial role in the pathogenesis of human fungal infections. Therefore, the aim of this study was to investigate the effect of different sub-therapeutic concentrations of chlorhexidine gluconate, hexetidine and triclosan on the production of these enzymes by C. albicans strains isolated from 20 patients with denture stomatitis. MethodsPhospholipase test was done by using Sabouraud dextrose agar with egg yolk, proteinase test was done by using bovine serum albumin agar. MethodsPhospholipase test was done by using Sabouraud dextrose agar with egg yolk, proteinase test was done by using bovine serum albumin agar. ResultsExoenzyme production of 20 strains which were brief exposured to sub-therapeutic concentrations of three antiseptic agents decreased significantly compared with the strains that were not exposured with antiseptic values (p<0.05). There was significant difference between the sub-therapeutic concentrations of each of three antiseptics (p<0.05). When the same concentrations of each antiseptic was compared, there were no significant differences between enzymatic activities (p>0.05). ConclusionsThe results of this study show that sub-therapeutic levels of each antiseptic may modulate candidal exoenzyme production, consequently suppressing pathogenicity of C. albicans.

Phospholipase and Aspartyl Proteinase Activities of Candida Species Causing Vulvovaginal Candidiasis in Patients with Type 2 Diabetes Mellitus.

Few research had investigated the secretion of phospholipase and aspartyl proteinase from Candida spp. causing infection in females with type 2 diabetes mellitus. This research aimed to investigate the prevalence of vulvovaginal candidiasis (VVC) in diabetic versus non-diabetic women and compare the ability of identified Candida isolates to secrete phospholipases and aspartyl proteinases with characterization of their genetic profile. The study included 80 females with type 2 diabetes mellitus and 100 non-diabetic females within the child-bearing period. Candida strains were isolated and identified by conventional microbiological methods and by API Candida. The isolates were screened for their extracellular phospholipase and proteinase activities by culturing them on egg yolk and bovine serum albumin media, respectively. Detection of aspartyl proteinase genes (SAP1 to SAP8) and phospholipase genes (PLB1, PLB2) were performed by multiplex polymerase chain reaction. Our results indicated that vaginal candidiasis was significantly higher among the diabetic group versus nondiabetic group (50% versus 20%, respectively) (p = 0.004). C. albicans was the most prevalent species followed by C. glabrata in both groups. No significant association between diabetes mellitus and phospholipase activities was detected (p = 0.262), whereas high significant proteinase activities exhibited by Candida isolated from diabetic females were found (82.5%) (p = 0.000). Non-significant associations between any of the tested proteinase or phospholipase genes and diabetes mellitus were detected (p > 0.05). In conclusion, it is noticed that the incidence of C. glabrata causing VVC is increased. The higher prevalence of vaginal candidiasis among diabetics could be related to the increased aspartyl proteinase production in this group of patients.

Mechanisms of Inhibition and Potentiation of α4β2 Nicotinic Acetylcholine Receptors by Members of the Ly6 Protein Family

α4β2 nicotinic acetylcholine receptors (nAChRs) are abundantly expressed throughout the central nervous system and are thought to be the primary target of nicotine, the main addictive substance in cigarette smoking. Understanding the mechanisms by which these receptors are regulated may assist in developing compounds to selectively interfere with nicotine addiction. Here we report previously unrecognized modulatory properties of members of the Ly6 protein family on α4β2 nAChRs. Using a FRET-based Ca(2+) flux assay, we found that the maximum response of α4β2 receptors to agonist was strongly inhibited by Ly6h and Lynx2 but potentiated by Ly6g6e. The mechanisms underlying these opposing effects appear to be fundamentally distinct. Receptor inhibition by Lynx2 was accompanied by suppression of α4β2 expression at the cell surface, even when assays were preceded by chronic exposure of cells to an established chaperone, nicotine. Receptor inhibition by Lynx2 also was resistant to pretreatment with extracellular phospholipase C, which cleaves lipid moieties like those that attach Ly6 proteins to the plasma membrane. In contrast, potentiation of α4β2 activity by Ly6g6e was readily reversible by pretreatment with phospholipase C. Potentiation was also accompanied by slowing of receptor desensitization and an increase in peak currents. Collectively our data support roles for Lynx2 and Ly6g6e in intracellular trafficking and allosteric potentiation of α4β2 nAChRs, respectively.

Genotyping and characterisation of the secretory lipolytic enzymes of Malassezia pachydermatis isolates collected dogs

IntroductionMalassezia species are commensals of normal skin microbial flora of humans and animals. These may become pathogenic under certain conditions such as those associated with atopic dermatitis or otitis externa...

Acoustic tweezers for studying intracellular calcium signaling in SKBR-3 human breast cancer cells

Extracellular matrix proteins such as fibronectin (FNT) play crucial roles in cell proliferation, adhesion, and migration. For better understanding of these associated cellular activities, various microscopic manipulation tools have been used to study their intracellular signaling pathways. Recently, it has appeared that acoustic tweezers may possess similar capabilities in the study. Therefore, we here demonstrate that our newly developed acoustic tweezers with a high-frequency lithium niobate ultrasonic transducer have potentials to study intracellular calcium signaling by FNT-binding to human breast cancer cells (SKBR-3). It is found that intracellular calcium elevations in SKBR-3 cells, initially occurring on the microbead-contacted spot and then eventually spreading over the entire cell, are elicited by attaching an acoustically trapped FNT-coated microbead. Interestingly, they are suppressed by either extracellular calcium elimination or phospholipase C (PLC) inhibition. Hence, this suggests that our acoustic tweezers may serve as an alternative tool in the study of intracellular signaling by FNT-binding activities.

Inhibitory effects of oral Actinomyces on the proliferation, virulence and biofilm formation of Candida albicans

ObjectiveThe pathogenesis of Candida-associated stomatitis involves the dysfunction of flora antagonistic to Candida. Oral Actinomyces species play an important role in regulating the oral microecological balance. The objective of this study was to investigate the antagonism of three oral Actinomyces against Candida albicans. DesignSuspensions, culture supernatants and bacterial lysates of Actinomyces viscosus, Actinomyces naeslundii and Actinomyces odontolyticus were investigated for their actions upon C. albicans. In addition to a commercial strain, six clinical strains of C. albicans were also tested. The proliferation of C. albicans was assessed using a liquid co-cultivation assay. The adhesion, acid protease and extracellular phospholipase activity, hyphae growth, and biofilm formation of C. albicans were measured. ResultsThe results showed that the suspensions, culture supernatants and cell lysates of 108 colony forming units/ml oral Actinomyces significantly inhibited the proliferation of C. albicans (all P<0.001). The culture supernatants exhibited significant antagonistic interactions in terms of adhesion (A. viscosus P<0.001, A. naeslundii P=0.016 and A. odontolyticus P=0.009), acid protease (A. viscosus P=0.035, A. naeslundii P=0.022, A. odontolyticus P<0.001) and phospholipase activities (A. viscosus P=0.011, A. naeslundii P=0.042, A. odontolyticus P=0.021) of Candida, as well as its hyphae growth (A. viscosus P=0.002, A. naeslundii P=0.008, A. odontolyticus P=0.006). Inhibition of C. albicans biofilm formation was also observed. ConclusionsThis study provides preliminary evidence that oral Actinomyces have inhibitory effects on the proliferation, adhesion, metabolic enzyme activity, hyphae formation and biofilm development of C. albicans.

Cerebellar cryptococcoma due to Cryptococcus gattii VGI; a rare and first report from India

Introduction: Cryptococcus gattii is an emerging global pathogen. Recent reports suggest that C. gattii cryptococcosis is more common in immunocompetent as well as HIV-infected patients than earlier estimated. We report the first case of cerebellar cryptococcoma from India due to C. gattii in an immunocompetent individual. Case Presentation: A 73-year-old immunocompetent male, presented with a 3 month history of severe headache, neck stiffness, walking difficulty, bilateral papilloedema and slight cerebellar signs including gait imbalance and giddiness. Magnetic resonance imaging (MRI) revealed a well-defined enhancing lesion in the cerebellum, suggestive of abscess and mild hydrocephalus. Blood parameters and liver function tests were within normal limits. The patient underwent paramedian suboccipital craniotomy, and the aspirated purulent material grew Cryptococcus neoformans. Histologically, the lesion was a cryptococcoma. The isolate was further identified as C. gattii VGI, serotype C, mating type alpha, and produced extracellular phospholipase enzyme. It was sensitive to amphotericin B, 5-flucytosine and azoles. The patient was treated with intravenous amphotericin B (0.7 mg kg–1 day–1) for 15 days along with a maintenance dose of oral fluconazole (400 mg day–1) for 6 months. The patient's symptoms recovered while on treatment but he was lost to follow up. Conclusion: Cryptococcus gattii is an emerging pathogen in India that affects otherwise healthy, immunocompetent individuals and requires rapid identification and treatment in order to prevent severe neurological sequelae.

Extracellular enzymes and susceptibility to fluconazole in Candida strains isolated from patients with vaginitis and healthy individuals.

Background:Extracellular phospholipase, proteinase, and coagulase are accounted as the major virulence factors in Candida albicans. Several reports showed that the incidence of resistance to fluconazole has risen during last two decades.Objectives:The present study has investigated the extracellular enzymes of C. albicans and non-albicans species isolated from both patients with vaginitis and healthy women. In addition, susceptibility of the isolates was evaluated against fluconazole.Patients and Methods:Vaginal samples were collected using sterile cotton swabs and inoculated on CHROMagar Candida. Routine morphological tests and ID 32C and API 20C AUX Kits were used to identify species. Phospholipase, proteinase, and coagulase activity were determined by standard methods. Susceptibility to fluconazole was also evaluated using ATB Fungus 3 Kits.Results:The phospholipase activity was detected in 66.7% of the tested isolates recovered from patients with vaginitis. In the present study, phospholipase activity with higher Pz values (< 0.70) was more common in patients with vaginitis (28 of 66 isolates) whereas this rate in the normal individual was 13 of 42. Proteinase activity was detected in 74.2% and 61.9% of tested isolates recovered from patients and normal individuals, respectively. All tested isolates were negative for coagulase activity. In the present study, resistance to fluconazole was found in 34.8% of isolates. C. dubliniensis was the most common isolate (6 out of 11 isolates) that showed resistance to fluconazole.Conclusions:Our results showed that C. albicans was the most frequently isolated from both patients with vaginitis and normal individual. In the present study, we could not find any correlation between extracellular activities and sources of isolates (patients and normal flora) and sensitivity or resistance to fluconazole.

A new aurone glycoside with antifungal activity from marine- derived fungus Penicillium sp. FJ-1

Endophytic fungi which reside in the tissue of mangrove plants seem to play an important role in the discovery of new biologically active substances. During the course of screening for the antimicrobial metabolites from the endophytic fugus Penicillium sp. FJ-1 of mangrove plant Avicennia marina, a new aurone glycoside (1) was isolated by repeated column chromatography on silica gel and recrystallization methods. The structure of 1 was elucidated as (Z)-7,4'-dimethoxy-6-hydroxy-aurone-4-O-β-glucopyranoside, on the basis of spectroscopic analysis. Compound 1 exhibited antifungal activity against Candida sp., with the potency comparable to amphotericin B and much better than fluconazole. Compound 1 can also inhibit extracellular phospholipase secretion in a concentration-dependent manner.

Betamethasone augments the antifungal effect of menadione--towards a novel anti-Candida albicans combination therapy.

The fluorinated glucocorticoid betamethasone stimulated both the extracellular phospholipase production and hypha formation of the opportunistic human pathogen Candida albicans and also decreased the efficiency of the polyene antimycotics amphotericin B and nystatin against C. albicans in a dose-dependent manner. Importantly, betamethasone increased synergistically the anti-Candida activity of the oxidative stress generating agent menadione, which may be exploited in future combination therapies to prevent or cure C. albicans infections, in the field of dermatology.

Detection of phospholipase activity of Candida albicans and non albicans isolated from women of reproductive age with vulvovaginal candidiasis in rural area.

Vulvovaginal candidiasis (VVC) is most common accounting for 17 to 39% of symptomatic women. Both Candida albicans and non albicans Candida species are involved in VVC. Amongst various virulence factors proposed for Candida, extracellular phospholipases is one of the virulence factor implicated in its pathogenicity. With this background the present study was carried out to find the prevalence of different Candida species and to detect phospholipase producing strains isolated from symptomatic women with VVC. At least two vaginal swabs from 156 women of reproductive age with abnormal vaginal discharge were collected. Direct microscopy and Gram's stained smear examined for presence of budding yeast and pseudo mycelia followed by isolation and identification of Candida species. Extracellular phospholipase activity was studied by inoculating all isolates on Sabouraud's dextrose egg yolk agar (SDA) medium. Of the 156 women with curdy white discharge alone or in combination with other signs, 59 (37.82%) women showed laboratory evidence of VVC. A total of 31 (52.54%) women had curdy white discharge followed by 12 (20.33%) with other signs and symptoms. C. albicans (62.59%) and non albicans Candida (37.28%) in a ratio of 1.68:1 were isolated. Of the 37 strains of C. albians 30 (81.08%) showed the enzyme activity. Seventeen (56.66%) strains showed higher Pz value of < 0.70 (++++). Although there may be typical clinical presentation of Candidiasis. all the patients did not show laboratory evidence of infection. Pregnancy was found to be major risk factor for development of VVC. C. albicans was prevalent species but non albicans species were also frequently isolated. Extracellular phospholipase activity was seen in C. albicans and not in non albicans Candida isolates.

From dandruff to deep-sea vents: Malassezia-like fungi are ecologically hyper-diverse.

As the dominant component of the mycobiota on human skin [1] —both healthy and diseased [2] —the genus Malassezia has received a fair amount of attention. Since the middle of the 19th century, researchers have linked these fungi with skin maladies such as dandruff and eczema [3], but their difficulty to culture axenically long hampered studies of their systematics and diversity [4]. Malassezia is the sole genus within the fungal order Malasseziales, contained within the proposed subphylum Malasseziomycetes (anonymous reviewer; personal communication). Although Malassezia is sister to the so-called “smut” plant pathogens, they are markedly divergent in ecological terms. A hallmark of Malassezia species is their incomplete fatty acids synthesis metabolic pathway, and reliance, instead, on a suite of extracellular lipases, phospholipases, and acid sphingomyelinases [5]. In fact, only a single species, M. pachydermatis, is able to survive in axenic culture lacking lipid amendment [6]. Until recently, it was assumed that Malassezia evolved into a specialized and narrow niche associated with the skin of mammalian hosts. However, culture-independent studies of fungi from environmental samples show that Malassezia are exceedingly widespread and ecologically diverse [3]. Recent studies in little-characterized marine environments point to extensive diversification of Malassezia-like organisms, providing exciting opportunities to explore the ecology, evolution and diversity of this enigmatic group.

Aliphatic fatty acids and esters: Inhibition of growth and exoenzyme production of Candida, and their cytotoxicity in vitro: Anti-Candida effect and cytotoxicity of fatty acids and esters

The secretion of extracellular phospholipases and proteinases of Candida has been described as a relevant virulence factor in human infections. Aliphatic fatty acids have antimicrobial properties, but the mechanism by which they affect the virulence factors of microorganisms, such as Candida, is still unclear, and there are a few reports about their toxicity. The current study investigated the in vitro antifungal activity, exoenzyme production and cytotoxicity of some aliphatic fatty acids and their ester derivatives against the Candida species. The minimum inhibitory concentration and minimum fungicidal concentrations of aliphatic medium-chain fatty acids, methyl and ethyl esters were performed using the CLSI M27-A3 method and the cytotoxicity assay was performed according to ISO 10993-5. The influence of these compounds in the inhibition of the production of hydrolytic enzymes, phospholipases and proteinases by Candida was also investigated. Data analysis was performed using the one-way ANOVA method (p≤0.05). In relation to the MIC against Candida species, the fatty acid with the best result was Lauric acid, although its ester derivatives showed no activity. The inhibition of phospholipase production was more significant than the inhibition of proteinase production by Candida. Tested fatty acids revealed more than 80% cell viability in their MIC concentrations. Additionally, a cell viability of 100% was reported at concentrations of anti-enzymatic effect. Therefore, the potential use of these fatty acids could be the basis for more antimicrobial tests.

The postantifungal effect and phospholipase production of oral Candida albicans from smokers, diabetics, asthmatics, denture wearers and healthy individuals following brief exposure to subtherapeutic concentrations of chlorhexidine gluconate

Candida albicans is the major aetiological agent of oral candidosis and one of its important virulent factors is the production of extracellular phospholipases, which can be modulated by subtherapeutic concentrations of antifungal agents thus decreasing their pathogenicity. Hence, considering that chlorhexidine gluconate (CG) is a common antimicrobial mouthwash used in dentistry and that its concentration in the mouth reaches subtherapeutic levels during dosage intervals due to the diluent effect of saliva and cleansing effect of the oral musculature, the postantifungal effect (PAFE) and the phospholipase production of oral C. albicans following brief exposure to subtherapeutic concentrations of CG was studied. Fifty C. albicans planktonic oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to three subtherapeutic concentrations of CG (0.005%, 0.0025% and 0.00125%) for 1 h. Isolates unexposed to CG was the control group. Thereafter the antiseptic was removed and the PAFE and phospholipase production was determined by a turbidometric method and a plate assay using an egg yolk agar medium respectively. Mean PAFE (hours) of 50 oral isolates of C. albicans following 1-h exposure to 0.005%, 0.0025% and 0.00125% CG was 6.97, 1.85 and 0.62 respectively. The phospholipase production of these isolates was significantly suppressed with a percentage reduction of 21.68, 18.20 and 14.04% following exposure to 0.005%, 0.0025% and 0.00125% CG respectively. Brief exposure of C. albicans isolates to subtherapeutic concentrations of CG would wield an antifungal effect by suppressing growth and phospholipase production, thereby quelling its pathogenicity.

The relation of diet with PAF and its metabolic enzymes in healthy volunteers

Platelet-activating factor (PAF), a potent inflammatory mediator, is implicated in atherosclerosis. Its key biosynthetic enzymes are lyso-PAF acetyltransferases (lyso-PAF-AT), responsible for PAF synthesis through the remodeling route and a specific CDP-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT), responsible for its de novo biosynthesis. PAF acetylhydrolase (PAF-AH) and its extracellular isoform lipoprotein-associated phospholipase A₂ catabolize PAF. The impact of diet on PAF metabolism is ill-defined. The aim was to investigate associations between PAF, its enzymes and dietary factors. One-hundred and six (n = 106) healthy volunteers were recruited. Food-frequency questionnaires, dietary recalls, lifestyle and biochemical variables were collected. Food groups, macronutrient intake, a priori (MedDietScore) and a posteriori defined food patterns with PCA analysis, dietary antioxidant capacity (DAC), glycemic index (GI) and glycemic load were assessed. PAF was inversely correlated with antioxidant-rich foods (herbal drinks and coffee), the DAC as well as a dietary pattern characterized by legumes, vegetables, poultry and fish (all Ps < 0.05). PAF was positively correlated to % fat intake. Lyso-PAF-AT was also negatively associated with healthy patterns (fruits, nuts and herbal drinks, and a pattern rich in olive oil and whole-wheat products), as well as the DAC and % monounsaturated fatty acids. PAF-CPT was negatively associated with GI and coffee intake and positively with dietary cholesterol. PAF-AH was negatively associated with coffee and positively associated with alcohol consumption (all Ps < 0.05). In conclusion, the DAC and healthy dietary patterns were inversely associated with PAF or its biosynthetic enzymes, suggesting potential new mechanisms of the diet-disease associations.

Dendrimer Conjugate of [4-(Tetradecanoylamino)benzyl]phosphonic Acid (S32826) as an Autotaxin Inhibitor.

Autotaxin is an extracellular phospholipase D that catalyzes the hydrolysis of lysophosphatidyl choline (LPC) to bioactive lipid lysophosphatidic acid (LPA). LPA has been implicated in many pathological processes relevant to cancer, including cell migration and invasion, proliferation, and survival. The most potent autotaxin inhibitor described to date is the LPA analogue S32826 (IC50 5.6 nM). S32826 and many other autotaxin inhibitors are notably lipophilic, creating a need to improve their physical properties. Polymers are becoming an increasingly useful tool in the delivery of drugs and have the potential to improve the properties of small molecules. Herein we report the synthesis of a S32826 dendrimer conjugate and its biological evaluation. The conjugate was found to inhibit autotaxin activity using two different substrates and to decrease the migration of an ovarian cancer cell line modified to overexpress autotaxin. Furthermore, the conjugate potentiated activation of caspase 3/7 induced by carboplatin.

Lipolytic Enzymes Involved in the Virulence of Human Pathogenic Fungi

Pathogenic microbes secrete various enzymes with lipolytic activities to facilitate their survival within the host. Lipolytic enzymes include extracellular lipases and phospholipases, and several lines of evidence have suggested that these enzymes contribute to the virulence of pathogenic fungi. Candida albicans and Cryptococcus neoformans are the most commonly isolated human fungal pathogens, and several biochemical and molecular approaches have identified their extracellular lipolytic enzymes. The role of lipases and phospholipases in the virulence of C. albicans has been extensively studied, and these enzymes have been shown to contribute to C. albicans morphological transition, colonization, cytotoxicity, and penetration to the host. While not much is known about the lipases in C. neoformans, the roles of phospholipases in the dissemination of fungal cells in the host and in signaling pathways have been described. Lipolytic enzymes may also influence the survival of the lipophilic cutaneous pathogenic yeast Malassezia species within the host, and an unusually high number of lipase-coding genes may complement the lipid dependency of this fungus. This review briefly describes the current understanding of the lipolytic enzymes in major human fungal pathogens, namely C. albicans, C. neoformans, and Malassezia spp.