XB130 inhibits healing of diabetic skin ulcers through the PI3K/Akt signalling pathway.

BACKGROUND: Diabetic skin ulcers, a significant global healthcare burden, are mainly caused by the inhibition of cell proliferation and impaired angiogenesis. XB130 is an adaptor protein that regulates cell proliferation and migration. However, the role of XB130 in the development of diabetic skin ulcers remains unclear. AIM: To investigate whether XB130 can regulate the inhibition of proliferation and vascular damage induced by high glucose. Additionally, we aim to determine whether XB130 is involved in the healing process of diabetic skin ulcers, along with its molecular mechanisms. METHODS: We conducted RNA-sequencing analysis to identify the key genes involved in diabetic skin ulcers. We investigated the effects of XB130 on wound healing using histological analyses. In addition, we used reverse transcription-quantitative polymerase chain reaction, Western blot, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, immunofluorescence, wound healing, and tubule formation experiments to investigate their effects on cellular processes in human umbilical vein endothelial cells (HUVECs) stimulated with high glucose. Finally, we performed functional analysis to elucidate the molecular mechanisms underlying diabetic skin ulcers. RESULTS: RNA-sequencing analysis showed that the expression of XB130 was up-regulated in the tissues of diabetic skin ulcers. Knockdown of XB130 promoted the healing of skin wounds in mice, leading to an accelerated wound healing process and shortened wound healing time. At the cellular level, knockdown of XB130 alleviated high glucose-induced inhibition of cell proliferation and angiogenic impairment in HUVECs. Inhibition of the PI3K/Akt pathway removed the proliferative effects and endothelial protection mediated by XB130. CONCLUSION: The findings of this study indicated that the expression of XB130 is up-regulated in high glucose-stimulated diabetic skin ulcers and HUVECs. Knockdown of XB130 promotes cell proliferation and angiogenesis via the PI3K/Akt signalling pathway, which accelerates the healing of diabetic skin ulcers.

Morpho-molecular characterisation of Arecophila, with A.australis and A.clypeata sp. nov. and A.miscanthi comb. nov.

Three arecophila-like fungal samples were collected on dead culms of gramineous plants in China. Morphological studies of our new collections and the herbarium specimen of Arecophilagulubiicola (generic type) were conducted and the morphological affinity of our new collections with Arecophila was confirmed. Maximum likelihood and Bayesian analyses using combined ITS, LSU, rpb2 and ß-tubulin data from our collections revealed the phylogeny of Cainiaceae. The monospecific genus Alishanica (type species Al.miscanthi), which had been accepted in Cainiaceae, is revisited and synonymised under Arecophila. Based on morphology and phylogeny, Arecophilaaustralis sp. nov. and A.clypeata sp. nov. are introduced as new species, while A.miscanthi is a new record for China. All the new collections are illustrated and described.

Prediction of hospital discharge outcome from changes in cerebrospinal fluid/serum albumin quotient and cerebrospinal fluid lactate dehydrogenase in patients with cryptococcal meningitis.

Aim: This study aims to provide reliable prognostic factors for patients with cryptococcal meningitis (CM). Patients & methods: Clinical characteristics and laboratory findings of CM patients were retrospectively reviewed. Results: Sixty-three patients with CM were enrolled and 38/63 were confirmed to be HIV serology positive. Among clinical characteristics, headache, nausea and/or vomiting, and fever were the most common symptoms. Among cerebrospinal fluid (CSF) parameters, changes in leukocyte count, lactate dehydrogenase and chloride were significantly associated with the outcome. An increased CSF/serum albumin quotient (QAlb) was indicative of an unfavorable outcome in HIV-negative patients. Conclusion: CSF lactate dehydrogenase and QAlb may improve the prediction of outcomes in patients with CM.

In vitro Antifungal Susceptibility Profiles of Cryptococcus neoformans var. grubii and Cryptococcus gattii Clinical Isolates in Guangxi, Southern China.

This study analyzed the in vitro drug sensitivity of Cryptococcus spp. from Guangxi, Southern China. One hundred three strains of Cryptococcus were recovered from 86 patients; 14 were HIV positive and 72 were HIV negative. Ninety-two strains were identified as Cryptococcus neoformans var. grubii, while 11 strains were identified as Cryptococcus gattii (5 C. gattii sensu stricto and 6 Cryptococcus deuterogattii). The recovered strains were tested against commonly used antifungal drugs (fluconazole, amphotericin B, 5-fluorocytosine, itraconazole, and voriconazole) and to novel antifungal drugs (posaconazole and isavuconazole) using CLSI M27-A4 method. The results showed that all isolates were susceptible to most antifungal drugs, of which the minimum inhibitory concentration (MIC) ranges were as follows: 0.05-4 µg/ml for fluconazole, 0.25-1 µg/ml for amphotericin B; 0.0625-2 µg/ml for 5-fluorocytosine, 0.0625-0.25 µg/ml for itraconazole, 0.0078-0.25 µg/ml for voriconazole, 0.0313-0.5 µg/ml for posaconazole, 0.0020-0.125 µg/ml for isavuconazole for C. neoformans var. grubii isolates, and 1-16 µg/ml for fluconazole, 0.125-1 µg/ml for 5-fluorocytosine, 0.25-1 µg/ml for amphotericin B, 0.0625-0.25 µg/ml for itraconazole, 0.0156-0.125 µg/ml for voriconazole, 0.0156-0.25 µg/ml for posaconazole, and 0.0078-0.125 µg/ml for isavuconazole for C. gattii isolates. Furthermore, some C. neoformans var. grubii isolates were found to be susceptible-dose dependent to 5-fluorocytosine and itraconazole. In addition, a reduction in the potency of fluconazole against C. gattii is possible. We observed no statistical differences in susceptibility of C. neoformans var. grubii and C. gattii in the tested strains. Continuous observation of antifungal susceptibility of Cryptococcus isolates is recommended to monitor the emergence of resistant strains.

Antifungal Susceptibility Profile of Candida Albicans Isolated from Vulvovaginal Candidiasis in Xinjiang Province of China.

We investigated the antifungal susceptibility profiles of 207 independent Candida albicans strains isolated from patients with vulvovaginal candidiasis (VVC) in Xinjiang Province of China. Using CLSI M27-A3 and M27-S4 guidelines, anidulafungin and micafungin were the most active drugs against C. albicans showing an MIC50/MIC90 corresponding to 0.016/0.0313 µg/mL, followed by caspofungin (0.25/0.25 µg/mL), posaconazole (0.125/0.5 µg/mL), ravuconazole (0.063/1 µg/mL), itraconazole (0.125/1 µg/mL), amphotericine B (0.5/1 µg/mL), isavuconazole (0.063/2 µg/mL), 5-flucytosine (1/2 µg/mL), voriconazole (0.125/4 µg/mL), and fluconazole (0.5/4 µg/mL). 96.1% (199)-100.0% (207) isolates were sensitive to the three echinocandins tested, amphotericine B and 5-flucytosine. The in vitro activity of triazoles against all isolates tested was variable; itraconazole and voriconazole had reduced the activity to almost half of the isolates (55.1% (114) and 51.2% (106) susceptible, respectively). Fluconazole was active against 76.3% (158) isolates tested. The new triazoles ravuconazole, isavuconazole and posaconazole showed good in vitro potency against 89.9% (186)-95.2% (197) of isolates with the geometric mean MIC (µg/mL) of 0.10, 0.12 and 0.14 µg/mL, respectively. In conclusion, our study indicates that for effective management of systemic candidiasis in Xinjiang Province of China, it is important to determine the susceptibility profiles of isolated C. albicans from patients with VVC.

Long noncoding RNA expression profile from cryptococcal meningitis patients identifies DPY19L1p1 as a new disease marker.

AIMS: LncRNAs play a vital role in the pathological and physiological process. This study aimed to explore the involvement of lncRNAs in cryptococcal meningitis. METHODS: Microarray was performed in cryptococcal meningitis patients, and then, GO and KEGG pathways were analyzed. Coexpression relationship between lncRNA and mRNA was explored. The expressions of the lncRNAs and mRNAs, and their changes after treatment were detected by PCR. RESULTS: A total of 325 mRNAs (201 upregulated and 124 downregulated) and 497 lncRNAs (263 upregulated and 234 downregulated) were identified. The top three enriched GO terms for the mRNAs were arachidonic acid binding, activin receptor binding, and replication fork protection complex. The top three pathways in KEGG were asthma, one carbon pool by folate, and allograft rejection. A total of 305 coexpression relationships were found between 108 lncRNAs and 87 mRNAs. LncRNA-DPY19L1p1 was significantly increased in patients and decreased after treatment. ROC analysis revealed DPY19L1p1 was a potential diagnostic marker (AUCROC  = 0.9389). Furthermore, the target genes of DPY19L1p1 in cis or trans regulation were mainly involved in immune-related pathways like the interleukin signaling pathway. CONCLUSIONS: This study analyzed the differential lncRNA profile in cryptococcal meningitis patients and revealed DPY19L1p1 could be used for treatment evaluation and disease diagnosis.

CHINESE HERBAL DECOCTION AS A COMPLEMENTARY THERAPY FOR ATROPHIC GASTRITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS.

BACKGROUND: Chinese herbal decoction (CHD) has been extensively used in the treatment of atrophic gastritis (AG) in China and other Far Eastern countries. We conducted a systematic review and meta-analysis to estimate the efficacy and safety of CHD in AG. MATERIALS AND METHODS: Pubmed, Embase, Cochrane central register of controlled trials (central), VIP, China National Knowledge Infrastructure, Sinomed, Wanfang data were searched (up to December 2015). Randomized controlled trials recruiting patients with AG comparing CHD (alone or with western medicine (WM)) with WM were eligible. Dichotomous data were pooled to obtain relative risk (RR), with a 95% confidence interval (CI). RESULTS: Forty-two articles including 3,874 patients were identified. CHD, used alone or with WM, had beneficial effect over WM in the improvement of clinical manifestations (RR=1.28; 95% CI 1.22-1.34) and pathological change (RR=1.42; 95% CI 1.30-1.54) for AG patients. However, the H. pylori eradication effect of CHD was not supported by the existing clinical evidence, because of the significant study heterogeneity (I2>50%) and inconsistency between the primary results and sensitivity analysis. CONCLUSIONS: CHD, if prescribed as a complementary therapy to WM, may improve the clinical manifestations and pathological change for AG patients. But its monotherapy for H. pylori eradication is not supported by enough clinical evidence.

Receptor for advanced glycation end as drug targets in diabetes-induced skin lesion.

The involvement of the receptor for advanced glycation end (RAGE) in different diseases has been reviewed in great detail, previously, but the effects of diabetic drugs on RAGE-induced skin lesion during long course diabetes remains poorly understood. In the present study, we have shown that RAGE was overexpressed in both diabetic rats and human keratinocytes (HaCaT cells). Cell cycle arrest and apoptosis as well as alternations of relative protein levels were also found in diabetic rats and HaCaT cells with overexpression of RAGE that were rectified by metformin (Met) treatment. Moreover, overexpression of RAGE was also found to induce secretions of TNF-α, IL-1ß, IL-6, ICAM-1 and COX-2 in HaCaT cells, and Met treatment corrected these inflammatory factor secretions. In addition, treatment with Met markedly reduced RAGE overexpression-induced p38 and NF-κB activation. Taken together, the findings of the present study have demonstrated, for the first time that Met protects HaCaT cells against diabetes-induced injuries and inflammatory responses through inhibiting activated RAGE.

Complex Roles of Annexin A2 in Host Blood-Brain Barrier Invasion by Cryptococcus neoformans.

INTRODUCTION: Fungal transversal across the brain microvascular endothelial cells (BMECs) is the essential step for the development of cryptococcal meningoencephalitis. Annexin A2 (AnxA2) is an important signaling protein involved in several intracellular processes such as membrane trafficking, endocytosis, and exocytosis. AIM: To investigate the roles and mechanism of AnxA2 during cryptococcal transversal of BMECs. RESULTS: Cryptococcus neoformans infection initiated upregulation of AnxA2 in mouse BMECs. Blockade with anti-AnxA2 antibody led to a reduction in fungal transcytosis activity but no change in its adhesion efficiency. Intriguingly, AnxA2 depletion caused a significant increase in fungal association activity but had no effect on their transcytosis. AnxA2 suppression resulted in marked reduction in its partner protein S100A10, and S100A10 suppression in BMECs significantly reduced the cryptococcal transcytosis efficiency. Furthermore, AnxA2 dephosphorylation at Tyr23 and dephosphorylation of downstream cofilin were required for cryptococcal transversal of BMECs, both of which might be primarily involved in the association of C. neoformans with host cells. CONCLUSIONS: Our work indicated that AnxA2 played complex roles in traversal of C. neoformans across host BMECs, which might be dependent on downstream cofilin to inhibit fungal adhesion but rely on its partner S100A10 to promote cryptococcal transcytosis.

Pd@Ag Nanosheets in Combination with Amphotericin B Exert a Potent Anti-Cryptococcal Fungicidal Effect.

Silver nanoparticles have received considerable interest as new "nanoantibiotics" with the potential to kill drug-resistant microorganisms. Recently, a class of new core-shell nanostructures, Pd@Ag nanosheets (Pd@Ag NSs), were created using deposition techniques and demonstrated excellent inhibitory effects on various bacteria in vitro. In this study, we evaluated the antifungal activity of Pd@Ag NSs against common invasive fungal pathogens. Among these organisms, Cryptococcus neoformans complex species was most susceptible to Pd@Ag NSs, which exhibited potent antifungal activity against various molecular types or sources of cryptococcal strains including fluconazole-resistant isolates. The anticryptococcal activity of Pd@Ag NSs was significantly greater than fluconazole and similar to that of amphotericin B (AmB). At relatively high concentrations, Pd@Ag NSs exhibited fungicidal activity against Cryptococcus spp., which can likely be attributed to the disruption of cell integrity, intracellular protein synthesis, and energy metabolism. Intriguingly, Pd@Ag NSs also exhibited strong synergistic anti-cryptococcal fungicidal effects at low concentrations in combination with AmB but exhibited much better safety in erythrocytes than AmB, even at the minimal fungicidal concentration. Therefore, Pd@Ag NSs may be a promising adjunctive agent for treating cryptococcosis, and further investigation for clinical applications is required.

Deubiquitinase Ubp5 Is Required for the Growth and Pathogenicity of Cryptococcus gattii.

Cryptococcus gattii is a resurgent fungal pathogen that primarily infects immunocompetent hosts. Thus, it poses an increasingly significant impact on global public health; however, the mechanisms underlying its pathogenesis remain largely unknown. We conducted a detailed characterization of the deubiquitinase Ubp5 in the biology and virulence of C. gattii using the hypervirulent strain R265, and defined its properties as either distinctive or shared with C. neoformans. Deletion of the C. gattii Ubp5 protein by site-directed disruption resulted in a severe growth defect under both normal and stressful conditions (such as high temperature, high salt, cell wall damaging agents, and antifungal agents), similar to the effects observed in C. neoformans. However, unlike C. neoformans, the C. gattii ubp5Δ mutant displayed a slight enhancement of capsule and melanin production, indicating the evolutionary convergence and divergence of Ubp5 between these two sibling species. Attenuated virulence of the Cg-ubp5Δ mutant was not solely due to its reduced thermotolerance at 37°C, as shown in both worm and mouse survival assays. In addition, the assessment of fungal burden in mammalian organs further indicated that Ubp5 was required for C. gattii pulmonary survival and, consequently, extrapulmonary dissemination. Taken together, our work highlights the importance of deubiquitinase Ubp5 in the virulence composite of both pathogenic cryptococcal species, and it facilitates a better understanding of C. gattii virulence mechanisms.

Effect of non-steroidal anti-inflammatory drugs on the increasing the incidence of colonic anastomosis in rats.

BACKGROUND: Anastomotic leakage is one of serious complications of colorectal surgery. Research is inconsistent about whether non-steroidal anti-inflammatory drugs influence the healing of colorectal anastomoses and increase the incidence of anastomotic leakage. OBJECTIVE: To study the influence of NSAIDs on the healing of rat colonic anastomoses. DESIGN: This was an animal randomized-control trial. This study was approved by the ethical committee of Yangpu Hospital, Tongji University. INTERVENTION: 90 healthy Sprague-Dawley rats were randomly divided into 6 groups of 15 rats/group. Trail was performed in C (cotrol group) with no drugs, group M with morphine for analgesia, group F with flurbiprofen axeil, group L with lornoxicam, and group P with parecoxib sodium. MAIN OUTCOME MEASURES: The main outcomes measures were serological indexes including vascular endothelial growth factor, prostaglandin E2, hydroxyproline, and C reactive protein; histological specimens from the anastomotic stoma tissue including the collagen proportion, and hydroxyproline, cycloxygenase-2, and vascular endothelial growth factor content; physical indicators, including stoma fracture pressure, fracture strength and anastomotic leakage. RESULTS: No significant difference was observed among the indices of each group (P > 0.05). A significant difference occurred after operation (P < 0.05), with the data for groups K and M being dramatically higher than those for group F. LIMITATION: The study was nonblinded. CONCLUSION: The postoperative usages of non-steroidal anti-inflammatory drugs can decrease the strength of anastomotic tissue, and increase the incidence of anastomotic leakage.

Tryptase and protease-activated receptor-2 stimulate scratching behavior in a murine model of ovalbumin-induced atopic-like dermatitis.

The aim of the current study was to investigate the involvement of tryptase and protease-activated receptor-2 (PAR2) in the pathogenesis of itch using a recently developed murine model of atopic dermatitis (AD) elicited by epicutaneous sensitization with ovalbumin (OVA). We also examined whether tacrolimus exerts an antipruritic effect. Epicutaneous sensitization of BALB/c mice with OVA led to a significant increase in the number of scratches. Notably, PAR2 mRNA and protein levels as well as cutaneous levels of tryptase were significantly enhanced in epicutaneously sensitized mice. Pretreatment with the protease inhibitor, leupeptin, PAR2 antibody, and tacrolimus significantly reduced the number of degranulated mast cells and tryptase content, and consequently alleviated scratching behavior. Cetirizine (10mg/kg) exerted a significant inhibitory effect on the scratching behavior of mice, but did not affect the number of degranulated mast cells and induction of tryptase. Our results collectively suggest that tryptase and PAR2 are involved in OVA allergy-induced scratching behavior.

Cryptococcosis in kidney transplant recipients in a Chinese university hospital and a review of published cases.

BACKGROUND: Cryptococcosis is a severe fungal infection with a high mortality rate among solid-organ transplant recipients. Today, China is among the countries performing the most kidney transplants worldwide, however data on the association of cryptococcosis with kidney transplantation in mainland China remain scarce and fragmented. METHODS: We retrospectively analyzed cases of culture-confirmed cryptococcosis following kidney transplantation that have occurred at our hospital and reviewed the published cases in China over the last 30 years. RESULTS: Cryptococcosis in kidney transplant recipients was mainly caused by Cryptococcus neoformans var. grubii VNI strains and occurred most frequently in patients aged 41-50 years (37.9%, 11/29). The average time to infection after kidney transplantation was 5.16 ± 3.97 years. The clinical manifestations were found to be diverse, with slight to moderate headache and fever, meningeal irritation, and high cerebrospinal fluid pressure being relatively common. Physicians should be alert to these symptoms among kidney transplant recipients. CONCLUSIONS: Cryptococcosis is a serious infection among kidney transplant recipients in mainland China. It has unique characteristics, such as a relatively long time to onset after kidney transplantation, and diverse clinical manifestations. Treatment with intrathecal injection of amphotericin B is considered effective for central nervous system involvement. The findings of this study also highlight the urgent need for multicenter, prospective, and multidisciplinary clinical studies and education on cryptococcosis in kidney transplant recipients in China.

Comparison of clinical features in patients with persistent and nonpersistent cryptococcal meningitis: twelve years of clinical experience in four centers in China.

BACKGROUND AND AIMS: Cryptococcal meningitis (CM) has gradually increased in the recent 20 years in the whole world. Although the mortality decreased significantly in recent years, it was still high, especially in patients with persistent infection. Therefore, we compare differences of clinical features between persistent and nonpersistent CM patients. METHODS: We conducted a retrospective review of medical records of patients diagnosed with CM from January 2000 to December 2011 in four centers in China, including demographic features, underlying diseases, clinical presentations, laboratory data, and so on. RESULTS: Of 106 CM patients enrolled, 16 were identified as persistent cases. Among all variables, persistent CM patients were more like to be human immunodeficiency viruses (HIV) infection (P < 0.05), stiff neck (P < 0.01), a serum hemoglobin < 90 g/L (P < 0.01), a serum potassium concentration <2.7 mg/L (P < 0.01), an intracranial pressure (ICP) >400 mmH2 O (P < 0.01), and a latex agglutination cryptococcal antigen titer of cerebrospinal fluid (CSF LACT) >1:1024 (P < 0.01) than nonpersistent ones. A multivariate analysis showed that HIV infection (OR 7.49), stiff neck (OR 11.7), a serum potassium <2.7 mmol/L (OR 9.45), and an ICP >400 mmH2 O (OR 6.83) were closely correlated with persistent CM. CONCLUSIONS: Although it is difficult to deal with persistent CM nowadays, some cases could be predicted early enough in the future, so as to be treated appropriately and have relatively good outcomes.

Epidemiology of opportunistic invasive fungal infections in China: review of literature.

OBJECTIVE: To summarize the recent findings on the epidemiology of medically important, opportunistic invasive fungal infections (IFIs) in China and discuss the relevant social, economical reasons and medical factors. DATA SOURCES: We performed a comprehensive search of both English and Chinese literatures of opportunistic IFIs from China up to April 2012. STUDY SELECTION: Relevant literatures involving researches and cases/case series were identified, retrieved and reviewed. RESULTS: The incidence of opportunistic IFIs in China was steadily increasing. The incidence and mortality of IFIs were different in patients with various underlying conditions/diseases, from 4.12% to 41.18% and 9.8% to 60.0%, respectively. Candida species, Aspergillus species and Cryptococcus neoformans species complex were the most frequent isolated pathogens. Other uncommon opportunistic IFIs were also been reported, including trichosporonosis, mucormycosis, hyalohyphomycosis (hyaline hyphomycetes) and phaeohyphomycosis (dematiaceous hyphomycetes). Reports of Chinese patients differed from those of many other countries as there were a higher number of patients without identifiable underlying diseases/conditions. CONCLUSIONS: Because of the rapid economic development, changing population structure and a growing number of immunocompromised hosts with risk factors, today opportunistic IFIs in China have a significant impact on public health, associated with high morbidity/mortality and higher care costs. Now information related to the epidemiology of opportunistic IFIs in China is still sparse, so we need more organized groups of clinical scientists performing related researches to help the clinicians to obtain more accurate epidemiological characteristics.

Disseminated cryptococcal lymphadenitis with negative latex agglutination test.

We reported an unusual case of disseminated cryptococcal lymphadenitis in an immunocompetent host who presented with fever and lymphadenopathy, which were the only two symptoms and signs. Latex agglutination test of serum and cerebrospinal fluid (CSF) were negative, while lymph node biopsy showed Cryptococcus neoformans. A diagnosis of disseminated cryptococcal lymphadenitis was made. Then the patient was treated with amphotericin B for 15 days as initial therapy and itraconazole for 6 months as maintenance therapy respectively. The patient received re-examination per 6 months and was followed up for 2 years. Swollen lymph nodes diminished gradually, and no fever or other symptoms were found. Latex agglutination test of serum and CSF were negative throughout the follow-up period, and anti-HIV, syphilis and tuberculosis antibody were all negative.

Fungal infection after a tragedy: a report of three cases of candidosis in a fire accident.

Patients who suffer severe burns are at increased risk for local and systemic infections. The incidence of fungal infections has increased in recent years, and these infections represent a major issue in burn intensive care units. Herein, we report three cases of fungal infection due to Candida species occurring in patients undergoing supportive therapy and antibiotic treatment during their hospitalization. Two of these patients were infected with Candida parapsilosis, and one was infected with Candida albicans. The risk factors for these patients' Candida infections were multiple and prolonged courses of antimicrobial treatment, steroid treatment, tracheal intubation and smoke inhalation. Susceptibility testing of nine antifungal compounds was performed, and the minimum inhibitory concentration (MIC) values of all isolated strains were lower than the breakpoint MIC value for resistance of the relevant drug. All three patients were cured by treatment with antifungal agents. Candida infection may occur 1 - 3 weeks after thermal injury, and the prompt recognition and treatment of such infections with antifungal therapies may result in decreased morbidity and mortality associated with these infections in burn patients.

Pleiotropic effects of deubiquitinating enzyme Ubp5 on growth and pathogenesis of Cryptococcus neoformans.

Ubiquitination is a reversible protein modification that influences various cellular processes in eukaryotic cells. Deubiquitinating enzymes remove ubiquitin, maintain ubiquitin homeostasis and regulate protein degradation via the ubiquitination pathway. Cryptococcus neoformans is an important basidiomycete pathogen that causes life-threatening meningoencephalitis primarily in the immunocompromised population. In order to understand the possible influence deubiquitinases have on growth and virulence of the model pathogenic yeast Cryptococcus neoformans, we generated deletion mutants of seven putative deubiquitinase genes. Compared to other deubiquitinating enzyme mutants, a ubp5Δ mutant exhibited severely attenuated virulence and many distinct phenotypes, including decreased capsule formation, hypomelanization, defective sporulation, and elevated sensitivity to several external stressors (such as high temperature, oxidative and nitrosative stresses, high salts, and antifungal agents). Ubp5 is likely the major deubiquitinating enzyme for stress responses in C. neoformans, which further delineates the evolutionary divergence of Cryptococcus from the model yeast S. cerevisiae, and provides an important paradigm for understanding the potential role of deubiquitination in virulence by other pathogenic fungi. Other putative deubiquitinase mutants (doa4Δ and ubp13Δ) share some phenotypes with the ubp5Δ mutant, illustrating functional overlap among deubiquitinating enzymes in C. neoformans. Therefore, deubiquitinating enzymes (especially Ubp5) are essential for the virulence composite of C. neoformans and provide an additional yeast survival and propagation advantage in the host.