Exploration of neuron heterogeneity in human heart failure with dilated cardiomyopathy through single-cell RNA sequencing analysis.

OBJECTIVE: We aimed to explore the heterogeneity of neurons in heart failure with dilated cardiomyopathy (DCM). METHODS: Single-cell RNA sequencing (scRNA-seq) data of patients with DCM and chronic heart failure and healthy samples from GSE183852 dataset were downloaded from NCBI Gene Expression Omnibus, in which neuron data were extracted for investigation. Cell clustering analysis, differential expression analysis, trajectory analysis, and cell communication analysis were performed, and highly expressed genes in neurons from patients were used to construct a protein-protein interaction (PPI) network and validated by GSE120895 dataset. RESULTS: Neurons were divided into six subclusters involved in various biological processes and each subcluster owned its specific cell communication pathways. Neurons were differentiated into two branches along the pseudotime, one of which was differentiated into mature neurons, whereas another tended to be involved in the immune and inflammation response. Genes exhibited branch-specific differential expression patterns. FLNA, ITGA6, ITGA1, and MDK interacted more with other gene-product proteins in the PPI network. The differential expression of FLNA between DCM and control was validated. CONCLUSION: Neurons have significant heterogeneity in heart failure with DCM, and may be involved in the immune and inflammation response to heart failure.

Yeast Metabolic Engineering for Biosynthesis of Caffeic Acid-Derived Phenethyl Ester and Phenethyl Amide.

Caffeic acid (CA)-derived phenethyl ester (CAPE) and phenethyl amide (CAPA) are extensively investigated bioactive compounds with therapeutic applications such as antioxidant, anti-inflammatory, and anticarcinogenic properties. To construct microbial cell factories for production of CAPE or CAPA is a promising option given the limitation of natural sources for product extraction and the environmental toxicity of the agents used in chemical synthesis. We reported the successful biosynthesis of caffeic acid in yeast previously. Here in this work, we further constructed the downstream synthetic pathways in yeast for biosynthesis of CAPE and CAPA. After combinatorial engineering of yeast chassis based on the rational pathway engineering method and library-based SCRaMbLE method, we finally obtained the optimal strains that respectively produced 417 µg/L CAPE and 1081 µg/L CAPA. Two screened gene targets of ΔHAM1 and ΔYJL028W were discovered to help improve the product synthesis capacity. This is the first report of the de novo synthesis of CAPA from glucose in an engineered yeast chassis. Future work on enzyme and chassis engineering will further support improving the microbial cell factories for the production of CA derivatives.

Antibiotics De-Escalation in the Treatment of Ventilator-Associated Pneumonia in Trauma Patients: A Retrospective Study on Propensity Score Matching Method.

BACKGROUND: Antimicrobial de-escalation refers to starting the antimicrobial treatment with broad-spectrum antibiotics, followed by narrowing the drug spectrum according to culture results. The present study evaluated the effect of de-escalation on ventilator-associated pneumonia (VAP) in trauma patients. METHODS: This retrospective study was conducted on trauma patients with VAP, who received de-escalation therapy (de-escalation group) or non-de-escalation therapy (non-de-escalation group). Propensity score matching method was used to balance the baseline characteristics between both groups. The 28-day mortality, length of hospitalization and Intensive Care Unit stay, and expense of antibiotics and hospitalization between both groups were compared. Multivariable analysis explored the factors that influenced the 28-day mortality and implementation of de-escalation. RESULTS: Among the 156 patients, 62 patients received de-escalation therapy and 94 patients received non-de-escalation therapy. No significant difference was observed in 28-day mortality between both groups (28.6% vs. 23.8%, P = 0.620). The duration of antibiotics treatment in the de-escalation group was shorter than that in the non-de-escalation group (11 [8-13] vs. 14 [8-19] days, P = 0.045). The expenses of antibiotics and hospitalization in de-escalation group were significantly lower than that in the non-de-escalation group (6430 ± 2730 vs. 7618 ± 2568 RMB Yuan, P = 0.043 and 19,173 ± 16,861 vs. 24,184 ± 12,039 RMB Yuan, P = 0.024, respectively). Multivariate analysis showed that high Acute Physiology and Chronic Health Evaluation II (APACHE II) score, high injury severity score, multi-drug resistant (MDR) infection, and inappropriate initial antibiotics were associated with patients' 28-day mortality, while high APACHE II score, MDR infection and inappropriate initial antibiotics were independent factors that prevented the implementation of de-escalation. CONCLUSIONS: De-escalation strategy in the treatment of trauma patients with VAP could reduce the duration of antibiotics treatments and expense of hospitalization, without increasing the 28-day mortality and MDR infection.

Enterogenous infection of Candida albicans in immunocompromised rats under severe acute pancreatitis.

BACKGROUND: Opportunistic infection of Candida albicans (C. albicans) has become a serious problem in immunocompromised patients. The study aimed to explore the mechanism of enterogenous infection of C. albicans in immunocompromised rats under severe acute pancreatitis (SAP). METHODS: Sprague Dawley (SD) rats (n=100) were randomly assigned into 5 groups as the following: blank group, cyclophosphamide+ceftriaxone+SAP group, cyclophosphamide+ceftriaxone group, cyclophosphamide+SAP group, and cyclophosphamide group. The rats were sacrificed at 5 and 10 days, and their jejunum, colon, mesenteric lymph nodes, pancreas, intestinal content, and blood were quickly collected to detect C. albicans. A region of the 25S rRNA gene was chosen and amplified by polymerase chain reaction (PCR) to differentiate C. albicans genotypes. The amplified products were further sequenced and compared to judge their homology. RESULTS: Compared with the Cyclophosphamide group, the combination of immunosuppressants and broad-spectrum antibiotics significantly increased the colonization of C. albicans in intestine in 5 and 10 days. Pure SAP stress did not increase the opportunistic infection of C. albicans. The PCR products of C. albicans isolates all belonged to the genotype A family, and sequence alignment showed that the amplified fragments were homologous. CONCLUSION: The damage of immune system and broad-spectrum antimicrobial agents are important risk factors for opportunistic fungal infection. Intestinal tract is an important source for genotype-A C. albicans to translocate and invade into bloodstream.

Structure-based design and confirmation of peptide ligands for neuronal polo-like kinase to promote neuroregeneration.

Neuronal polo-like kinase (nPLK) is an essential regular of cell cycle and differentiation in nervous system, and targeting nPLK has been established as a promising therapeutic strategy to treat neurological disorders and to promote neuroregeneration. The protein contains an N-terminal kinase domain (KD) and a C-terminal Polo-box domain (PBD) that are mutually inhibited by each other. Here, the intramolecular KD-PBD complex in nPLK was investigated at structural level via bioinformatics analysis, molecular dynamics (MD) simulation and binding affinity scoring. From the complex interface two regions representing separately two continuous peptide fragments in PBD domain were identified as the hot spots of KD-PBD interaction. Structural and energetic analysis suggested that one (PBD peptide 1) of the two peptides can bind tightly to a pocket nearby the active site of KD domain, which is thus potential as self-inhibitory peptide to target and suppress nPLK kinase activity. The knowledge harvesting from computational studies were then used to guide the structural optimization and mutation of PBD peptide 1. Consequently, two of three peptide mutants separately exhibited moderately and considerably increased affinity as compared to the native peptide. The computationally modeled complex structures of KD domain with these self-inhibitory peptides were also examined in detail to unravel the structural basis and energetic property of nPLK-peptide recognition and interaction.

Structure-based grafting and identification of kinase-inhibitors to target mTOR signaling pathway as potential therapeutics for glioblastoma.

Mammalian target of rapamycin (mTOR), a key mediator of PI3K/Akt/mTOR signaling pathway, has recently emerged as a compelling molecular target in glioblastoma. The mTOR is a member of serine/threonine protein kinase family that functions as a central controller of growth, proliferation, metabolism and angiogenesis, but its signaling is dysregulated in various human diseases especially in certain solid tumors including the glioblastoma. Here, considering that there are various kinase inhibitors being approved or under clinical or preclinical development, it is expected that some of them can be re-exploited as new potent agents to target mTOR for glioblastoma therapy. To achieve this, a synthetic pipeline that integrated molecular grafting, consensus scoring, virtual screening, kinase assay and structure analysis was described to systematically profile the binding potency of various small-molecule inhibitors deposited in the protein kinase-inhibitor database against the kinase domain of mTOR. Consequently, a number of structurally diverse compounds were successfully identified to exhibit satisfactory inhibition profile against mTOR with IC50 values at nanomolar level. In particular, few sophisticated kinase-inhibitors as well as a flavonoid myricetin showed high inhibitory activities, which could thus be considered as potential lead compounds to develop new potent, selective mTOR-inhibitors. Structural examination revealed diverse nonbonded interactions such as hydrogen bonds, hydrophobic forces and van der Waals contacts across the complex interface of mTOR with myricetin, conferring both stability and specificity for the mTOR-inhibitor binding.

Risk factors for posttraumatic cerebral infarction in patients with moderate or severe head trauma.

We examined the incidence and timing of posttraumatic cerebral infarction (PTCI) and provide predictive factors for the development of PTCI in patients with moderate or severe traumatic brain injury. Three hundred and fifty-three consecutive patients with moderate or severe head trauma were retrospectively reviewed to determine the incidence and timing of PTCI and to evaluate the effects of age, gender, admission Glasgow Coma Scores (GCS), decompressive craniectomy, brain herniation, and low systolic blood pressure (BP) on the development of cerebral infarction. Risk factors for posttraumatic cerebral infarction were evaluated using logistic regression analysis. PTCI was observed in 36 (11.96%) of the 353 patients, and in a majority of cases, cerebral infarction developed within 2 weeks after injury. Poor admission GCS (P<0.01), low systolic BP (P<0.01), brain herniation (P<0.05), and decompression craniotomy (P<0.05) were significantly associated with the development of PTCI. No relationship was found between PTCI and gender or increased age. Posttraumatic cerebral infarction is a relatively common complication in patients with head trauma that develops early in the clinical course. Low GCS, low systolic BP, brain herniation, and decompression craniotomy may be risk factors for PTCI in patients with moderate or severe traumatic brain injury.

Risk factors related to hydrocephalus after traumatic subarachnoid hemorrhage.

BACKGROUND: Posttraumatic hydrocephalus is a common complication of head injury. However, hydrocephalus after tSAH has seldom been addressed. We present this clinical study to determine the incidence of hydrocephalus and analyze the risk factors for developing hydrocephalus in patients with tSAH. METHODS: A consecutive series of 301 patients with tSAH were retrospectively reviewed to determine the effects of the admission GCS score, age, sex, decompressive craniectomy, intraventricular hemorrhage, and features of tSAH (according to the initial computerized tomography scans) on the development of hydrocephalus. Risk factors for hydrocephalus were evaluated by using logistic regression analysis. RESULTS: Of the 301 patients, hydrocephalus was observed in 36 (11.96%). Increasing age (P< .05), intraventricular hemorrhage (P< .05), and thickness (P< .01) or distribution (P< .05) of tSAH were significantly associated with the development of hydrocephalus. No relationship was found between hydrocephalus and sex, admission GCS score, location of tSAH, or decompressive craniectomy. CONCLUSION: Hydrocephalus frequently occurs in patients with tSAH. Increasing age, low GCS score on admission, intraventricular hemorrhage, and severe SAH could be risk factors for facilitating the development of hydrocephalus.

Increased protein and mRNA expression of endostatin in the ischemic brain tissue of rabbits after middle cerebral artery occlusion.

OBJECTIVE: To explore the changes of endostatin (a strong anti-angiogenesis factor) and vascular endothelial growth factor (VEGF) in the brain tissues of rabbits following cerebral ischemia induced by middle cerebral artery occlusion (MCAO). METHODS: Twenty-four New Zealand white rabbits were randomly divided into 5 groups: control (n = 5), sham-operation (n = 4), 2-hour ischemia (n = 5), 24-hour ischemia (n = 5), and 48-hour ischemia (n = 5). The expression of VEGF and endostatin were measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, respectively. In situ hybridization was used to characterize the expression of mRNA for the endostatin. RESULTS: Both the protein (at least 50%, P < 0.01) and mRNA (at least 70%, P < 0.05) of endostatin increased significantly in the ischemic brain tissues after MCAO compared with the control group. VEGF increased at least 270% in the brain after cerebral ischemia (P < 0.05). CONCLUSION: Cerebral ischemia leads to an up-regulation of endostatin in the brain, which is not associated with the increase of VEGF in the brain. The increase of endostatin may serve as a deleterious mechanism for ischemic injury through blocking angiogenesis.