Targeting novel LSD1-dependent ACE2 demethylation domains inhibits SARS-CoV-2 replication

Treatment options for COVID-19 remain limited, especially during the early or asymptomatic phase. Here, we report a novel SARS-CoV-2 viral replication mechanism mediated by interactions between ACE2 and the epigenetic eraser enzyme LSD1, and its interplay with the nuclear shuttling importin pathway. Recent studies have shown a critical role for the importin pathway in SARS-CoV-2 infection, and many RNA viruses hijack this axis to re-direct host cell transcription. LSD1 colocalized with ACE2 at the cell surface to maintain demethylated SARS-CoV-2 spike receptor-binding domain lysine 31 to promote virus-ACE2 interactions. Two newly developed peptide inhibitors competitively inhibited virus-ACE2 interactions, and demethylase access to significantly inhibit viral replication. Similar to some other predominantly plasma membrane proteins, ACE2 had a novel nuclear function: its cytoplasmic domain harbors a nuclear shuttling domain, which when demethylated by LSD1 promoted importin-α-dependent nuclear ACE2 entry following infection to regulate active transcription. A novel, cell permeable ACE2 peptide inhibitor prevented ACE2 nuclear entry, significantly inhibiting viral replication in SARS-CoV-2-infected cell lines, outperforming other LSD1 inhibitors. These data raise the prospect of post-exposure prophylaxis for SARS-CoV-2, either through repurposed LSD1 inhibitors or new, nuclear-specific ACE2 inhibitors.

Simultaneous targeting of DNA replication and homologous recombination in glioblastoma with a polyether ionophore

BACKGROUND

Despite significant endeavor having been applied to identify effective therapies to treat glioblastoma (GBM), survival outcomes remain intractable. The greatest nonsurgical benefit arises from radiotherapy, though tumors typically recur due to robust DNA repair. Patients could therefore benefit from therapies with the potential to prevent DNA repair and synergize with radiotherapy. In this work, we investigated the potential of salinomycin to enhance radiotherapy and further uncover novel dual functions of this ionophore to induce DNA damage and prevent repair.

METHODS

In vitro primary GBM models and ex vivo GBM patient explants were used to determine the mechanism of action of salinomycin by immunoblot, flow cytometry, immunofluorescence, immunohistochemistry, and mass spectrometry. In vivo efficacy studies were performed using orthotopic GBM animal xenograft models. Salinomycin derivatives were synthesized to increase drug efficacy and explore structure-activity relationships.

RESULTS

Here we report novel dual functions of salinomycin. Salinomycin induces toxic DNA lesions and prevents subsequent recovery by targeting homologous recombination (HR) repair. Salinomycin appears to target the more radioresistant GBM stem cell-like population and synergizes with radiotherapy to significantly delay tumor formation in vivo. We further developed salinomycin derivatives which display greater efficacy in vivo while retaining the same beneficial mechanisms of action.

CONCLUSION

Our findings highlight the potential of salinomycin to induce DNA lesions and inhibit HR to greatly enhance the effect of radiotherapy. Importantly, first-generation salinomycin derivatives display greater efficacy and may pave the way for clinical testing of these agents.

Use and validation of a survey tool to measure the perceived effectiveness of insulin prescribing safety interventions in UK hospitals

AIMS

To describe the use and validation of a survey tool to elicit the opinion of hospital pharmacists and medicines safety officers in the UK regarding the perceived effectiveness of strategies to improve insulin prescribing safety in hospitals.

METHODS

One respondent from each participating organization completed the survey on behalf of the main acute hospital in their trust (n = 92). A five-point Likert scale was used to determine opinion on how effective 22 different interventions were at promoting insulin safety at the respondent's trust. The tool, the Perception of Effectiveness of Prescribing Safety Interventions for Insulin (PEPSII) questionnaire, underwent content validity testing. The reliability was estimated using Cronbach's alpha (α).

RESULTS

The PEPSII questionnaire demonstrated good reliability (α = 0.867). Outreach team review and mandatory insulin education were the highest-scoring interventions; the insulin passport was amongst the lowest scoring interventions. Most interventions were considered more effective by trusts using them compared to those who didn't, except for self-administration policies, electronic prescribing and the insulin passport.

CONCLUSIONS

The perceived effectiveness of a variety of insulin prescribing safety strategies in UK hospitals was described by leveraging a purposely developed survey tool. The results describe current levels of support for recommended interventions, and may facilitate the direction of both local and national insulin prescribing safety improvement efforts.

Strategies to reduce insulin prescribing errors in UK hospitals: results from a national survey

AIM

To describe insulin prescribing practice in National Health Service hospitals in the UK and the current use of interventions and strategies to reduce insulin prescribing errors.

METHODS

We sent a cross-sectional questionnaire to chief pharmacists in all National Health Service hospital trusts in the UK in January 2019. Questions concerned the use and functionality of electronic and paper systems used to prescribe subcutaneous insulin, along with features and interventions designed to reduce insulin prescribing errors.

RESULTS

Ninety-five hospital trusts responded (54%). Electronic prescribing of insulin was reported in 40% of hospitals, most of which were teaching hospitals in England. We found a wide variation in the functionality of both electronic prescribing and paper-based systems to enable the safe prescribing of insulin for inpatients. The availability of specialist diabetes pharmacists to support the safe prescribing of insulin was low (29%), but was positively associated with the use of a greater number of insulin prescribing error reduction strategies (P=0.002). The use of specific interventions to improve insulin prescribing quality (e.g. self-administration policies) varied greatly between respondent hospitals.

CONCLUSIONS

There is potential to optimize the functionality of both electronic and paper-based prescribing systems to improve the safe prescribing of insulin in hospitals in the UK. The wide variation in the use of insulin error reduction strategies may be improved by the availability of specialist diabetes pharmacists who can support the implementation of insulin-prescribing interventions.

Interventions to improve insulin prescribing practice for people with diabetes in hospital: a systematic review

AIM

To conduct a systematic review of literature to identify interventions that are effective in improving insulin prescribing for people with diabetes in the hospital setting.

METHODS

Computerized bibliographic databases were searched for studies published in English that described the effectiveness of interventions to improve insulin prescribing within the hospital setting. Studies were eligible for inclusion if they reported data that compared insulin prescribing practice after an intervention or compared with a control group. Studies were not excluded on the basis of publication date, geographical location or risk of bias assessment.

RESULTS

We identified 35 studies for inclusion in the review, including two cluster randomized controlled trials, two cohort studies, and 31 uncontrolled before-after studies. Studies reported a variety of interventions that aimed to increase insulin prescribing accuracy or completeness or decrease the use of discouraged subcutaneous sliding scale insulin regimens. Differences in definition of insulin prescribing error, terminology and common practice based on geographical location was evident, and quality issues with respect to study design and reporting somewhat limited the interpretation of conclusions.

CONCLUSIONS

Implementing strategies that are sensitive to local context and designed to increase adherence to insulin prescribing guidelines are associated with a reduction in prescribing errors. Future implementation should build on effective approaches including multifaceted interventions involving multiple stakeholders at various institutional levels. Future studies in insulin prescribing errors would benefit from the use of standardized approaches, terminology and outcome measures to enable greater comparison.

Center for the Advancement of Pharmacy Education 2013 educational outcomes

An initiative of the Center for the Advancement of Pharmacy Education (formerly the Center for the Advancement of Pharmaceutical Education) (CAPE), the CAPE Educational Outcomes are intended to be the target toward which the evolving pharmacy curriculum should be aimed. Their development was guided by an advisory panel composed of educators and practitioners nominated for participation by practitioner organizations. CAPE 2013 represents the fourth iteration of the Educational Outcomes, preceded by CAPE 1992, CAPE 1998 and CAPE 2004 respectively. The CAPE 2013 Educational Outcomes were released at the AACP July 2013 Annual meeting and have been revised to include 4 broad domains, 15 subdomains, and example learning objectives.

Abstract 2127: SSB1 is essential for embryogenesis and maintenance of genomic stability in mice

Single-stranded DNA binding proteins (SSBs) are essential for multiple DNA transactions, including regulation of DNA damage checkpoints and repair of DNA damage. Previously, we reported the functional characterization of these proteins in human cells using specific siRNA and provided the initial evidence that both SSBs are essential for efficient repair of DNA double strand breaks by the homologous recombinational repair pathway, and for efficient initiation of the ATM/ATR dependent signaling pathway (Richard et al., 2008). However cellular model systems have inherent limitations. To decipher the role of these newly identified proteins at the organismal level, we have generated conditional SSB1 and SSB2 knockout (KO) mouse models. The constitutive SSB1 KO mice show late embryonic lethality and die perinatally. The conditional inactivation of SSB1 in adult mice is associated with testicular atrophy, reduced fertility and increased genomic instability. We also find compensatory up-regulation of SSB2 protein levels in multiple tissues of conditional SSB1 KO mice. In addition, we report increased radiosensitiity of SSB1-/- mice in response to ionizing radiation, and increased genomic instability, which manifests as a broad spectrum of tumours at approximately 1 year of age. T cells isolated from these animals exhibited mild G1/S and G2/M checkpoint defects, and a persistence of DNA damage as seen by increased gamma-H2AX and 53BP1 foci in response to α-irradiation. Collectively, these results demonstrate an essential role of SSB1 in the maintenance of genomic stability in-vivo. Reference Richard, DJ., Bolderson, E., —et al. Khanna KK (2008). Single-stranded DNA binding protein is critical for genomic stability. Nature 453: 677-681

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2127. doi:1538-7445.AM2012-2127

hSSB1 interacts directly with the MRN complex stimulating its recruitment to DNA double-strand breaks and its endo-nuclease activity

hSSB1 is a recently discovered single-stranded DNA binding protein that is essential for efficient repair of DNA double-strand breaks (DSBs) by the homologous recombination pathway. hSSB1 is required for the efficient recruitment of the MRN complex to sites of DSBs and for the efficient initiation of ATM dependent signalling. Here we explore the interplay between hSSB1 and MRN. We demonstrate that hSSB1 binds directly to NBS1, a component of the MRN complex, in a DNA damage independent manner. Consistent with the direct interaction, we observe that hSSB1 greatly stimulates the endo-nuclease activity of the MRN complex, a process that requires the C-terminal tail of hSSB1. Interestingly, analysis of two point mutations in NBS1, associated with Nijmegen breakage syndrome, revealed weaker binding to hSSB1, suggesting a possible disease mechanism.

Thermal and sodium dodecylsulfate induced transitions of streptavidin

The strong specific binding of streptavidin (SA) to biotin is utilized in numerous biotechnological applications. The SA tetramer is also known to exhibit significant stability, even in the presence of sodium dodecylsulfate (SDS). Despite its importance, relatively little is known about the nature of the thermal denaturation pathway for SA. This work uses a homogeneous SA preparation to expand on the data of previous literature reports, leading to the proposal of a model for temperature induced structural changes in SA. Temperature dependent data were obtained by SDS and native polyacrylamide gel electrophoresis (PAGE), differential scanning calorimetry (DSC), and fluorescence and ultraviolet (UV)-visible spectroscopy in the presence and absence of SDS. In addition to the development of this model, it is found that the major thermal transition of SA in 1% SDS is reversible. Finally, although SA exhibits significant precipitation at elevated temperatures in aqueous solution, inclusion of SDS acts to prevent SA aggregation.

Glutamine protects function and improves preservation of small bowel segments

BACKGROUND

Improved organ preservation is essential for the success of small bowel transplantation. Small bowel is usually preserved in UW (University of Wisconsin) solution which does not contain glutamine (Gln), the principal fuel for the enterocyte. We hypothesized that Gln-supplemented UW would improve mucosal function and structure of cold preserved small intestine.

MATERIALS AND METHODS

Jejunum (40 cm) was harvested from Lewis rats and preserved for 18 hr at 4 degrees C in saline; UW solution only; UW with 1, 2, or 4% Gln; and UW containing 1, 2, or 4% isonitrogenous balanced nonessential amino acids (NEAA). 14C glucose transport, mucosal protein, mucosal maltase and alkaline phosphatase, jejunal villous height, and histologic damage were measured.

RESULTS

UW with 2% Gln significantly increased glucose transport and mucosal protein when compared to the 2% NEAA and UW-only groups. Two percent Gln significantly decreased histologic damage of jejunum following cold preservation. Increasing Gln to 4% did not significantly increase its efficacy when compared to the UW with 2% Gln group. There were no significant differences in the activities of mucosal maltase and alkaline phosphatase among the various treatment groups.

CONCLUSIONS

The addition of Gln, optimally provided at a concentration of 2%, to UW solution may protect the preserved small bowel segments from cold ischemic injury and improve mucosal function.

Resection-induced colonic adaptation is augmented by IGF-I and associated with upregulation of colonic IGF-I mRNA

The effects of exogenous insulin-like growth factor-I (IGF-I) on colonic adaptation were examined in male Sprague-Dawley rats (n = 60, 225-275 mg) after either a 60% small bowel and cecal resection (RX) or mid-small bowel transection with reanastomosis (TX). Animals received a 7-day treatment with either IGF-I (2.4 mg.kg-1.day-1) or vehicle (V; 0.1 mol/l acetic acid). Body weight decreased significantly after resection (-25.6 +/- 4.0 g; P < 0.05 vs. TX/V). IGF-I treatment significantly reduced weight loss after resection (-12.4 +/- 3.8 g; P < 0.01 vs. RX/V) and induced significant weight gain after transection (15.6 +/- 4.0 g; P < 0.05 vs. TX/V). Plasma IGF-I decreased with resection (526 +/- 41 TX/V vs. 344 +/- 17 ng/ml RX/V; P < 0.01). IGF-I treatment significantly increased plasma IGF-I levels (805 +/- 100 ng/ml TX/IGF, 677 +/- 56 ng/ml RX/IGF). After resection, IGF-I treatment significantly increased colonic mucosal weight, DNA, protein content, and crypt depth when compared with resection alone (P < 0.05). Colonic water absorption, measured by an in vivo [3H]polyethylene glycol assay, was significantly increased by IGF-I treatment in resected animals (399 +/- 23 RX/IGF vs. 306 +/- 32 microliter.cm-1.h-1 RX/V; P < 0.05). Resection resulted in increased steady-state colonic IGF-I mRNA (182% of TX/V; P < 0.01) without significantly affecting IGF-I receptor mRNA expression. Regulation of IGF binding protein (BP)-3 and -4 was discoordinate, with IGFBP-3 mRNA tending to decrease with resection (67% of TX/V; P is not significant) and IGFBP-4 increasing significantly (191% of TX/V; P < 0.05). An important role for IGF-I in colonic adaptation after massive intestinal resection is indicated by 1) significantly enhanced colonic mucosal growth and water absorption with IGF-I treatment and 2) postresection upregulation of colonic IGF-I mRNA and alteration of IGFBP-3 and IGFBP-4 mRNA expression.

Insulin-like growth factor-I (IGF-I) and glutamine improve structure and function in the small bowel allograft

IGF-I, a mitogenic polypeptide hormone, and glutamine (GLN), the preferred enterocyte fuel, singularly improve growth and structure of the small bowel isograft; however, their combined effects on intestinal allografts are unknown. This study examined the effects of IGF-I and GLN, singularly and in combination, on the structure and function of the intestinal allograft. Fifty-nine adult rats underwent resection of the distal 60% of small bowel and received either a 40-cm isograft or an allograft. Either IGF-I (2.4 mg/kg/day) or its vehicle was infused continuously by subcutaneous minipumps. An isocaloric polymeric diet with either 2% GLN or isonitrogenously balanced 2% nonessential amino acids was given continuously by gastrostomy for 10 days. Five groups were studied: isograft (ISO) alone, allograft (ALLO) alone, ALLO and GLN, ALLO and IGF-I, and ALLO and IGF-I with GLN. All recipients received Cyclosporine A (15 mg/kg, im) daily. Mucosal villus height, surface area, crypt depth, IgA, IgG, IgM, and intercellular adhesion molecule-1 (ICAM-1) plasma cells in intestinal tissue, glucose and water absorption of intestinal graft, bacterial translocation (BT) to mesenteric lymph nodes, and body weight were determined. IGF-I increased villus height, surface area (P < 0.001), crypt depth (P < 0.01), and glucose absorption (P < 0.05) compared to the ISO and ALLO groups. GLN increased only crypt depth when compared to the ALLO group (P < 0.01). Both IGF-I and GLN independently decreased BT to MLN (P < 0.05) and, in combination, enhanced water absorption (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-like growth factor-I improves mucosal structure and function in transplanted rat small intestine

The transplanted small intestine develops significant mucosal atrophy, impaired nutrient and water absorption, and increased bacterial translocation to mesenteric lymph nodes in rats maintained on elemental diets or total parenteral nutrition. This study determined the effects of administration of an peptide growth factor (insulin-like growth factor-I[IGF-I]) on the mucosal structure and barrier function of rat small bowel isografts. Thirty-six adult Lewis rats underwent either resection of the distal 60% of the small bowel and proximal colon followed by a 40-cm orthotopic jejunal isograft or proximal small bowel transection and distal small bowel resection to leave an analogous length of small intestine in control animals. All rats received an isocaloric, isonitrogenous, polymeric diet (200 kcal/kg/day, 2 gN/kg/day) by gastrostomy and were infused with either IGF-I (2.4 mg/kg/day) or vehicle by osmotic pumps subcutaneously. After 10 days of treatment, jejunal crypt cell production, mucosal morphometric indices, glucose and water absorption, body weight, and bacterial translocation to mesenteric lymph nodes (MLN) were measured. Jejunal mRNA content for IGF-I, IGF-I receptor, and IGF-binding proteins 3 and 4 (IGFBP-3,4) were determined by Northern blotting. Crypt cell production, villus height, crypt depth, and villus surface area were significantly increased in control and transplanted jejunum of rats infused with IGF-I when compared to animals given vehicle alone. Additionally, jejunal glucose absorption and water absorption were significantly improved in both IGF-I groups when compared with their respective vehicle controls. IGF-I infusion increased body weight in transplanted and control animals and markedly reduced bacterial translocation to MLN after small bowel transplantation. Jejunal levels of IGF-I mRNA were significantly increased in transplanted animals when compared to transected controls. IGF-I treatment significantly increased IGFBP-3 tissue mRNA levels in both transected and transplanted animals. These results demonstrate that IGF-I administration, after small bowel transplantation, improves mucosal structure and absorptive function and reduces bacterial translocation to MLN. IGF-I may have important effects in transplanted small bowel both as an endogenous and administered growth factor.

Glutamine reduces bacterial translocation after small bowel transplantation in cyclosporine-treated rats

Bacterial translocation (BT) of enteric organisms is a major cause of sepsis in patients undergoing small bowel transplantation (SBT). Cyclosporine (CsA) may be toxic to intestinal epithelium and increase the risk of BT. Glutamine (Gln) is the preferred enterocyte fuel and maintains graft epithelial integrity in experimental SBT. This study determined the effects of CsA on mucosal structure and function of transplanted intestinal isograft and examined whether Gln-enriched diet reversed CsA-induced intestinal toxicity. Thirty-three adult Lewis rats underwent resection of the distal 60% of small bowel and received an orthotopic jejunal isograft. Rats received either elemental diet with 2% Gln or the same diet with balanced nonessential amino acids (non-Gln) by gastrostomy for 10 days. CsA (15 mg/kg, im) or olive oil was injected daily. Rats were assigned to four groups: non-Gln with vehicle, non-Gln with CsA, Gln with vehicle, and Gln with CsA. Mucosal villous height, surface area, crypt depth, 14C glucose absorption, BT to mesenteric lymph nodes (MLN), and body weight change were evaluated. The non-Gln with CsA group had the highest incidence of BT (P < 0.001). Gln groups had significantly decreased BT (P < 0.01) and increased crypt depth and villous surface area (P < 0.01) when compared to non-Gln groups. Body weight significantly decreased in CsA groups when compared to non-CsA groups (P < 0.01). These results indicate at CsA significantly decreased body weight and increased BT without decreasing mucosal structure and glucose absorption of intestinal isografts.(ABSTRACT TRUNCATED AT 250 WORDS)

Fiber: effect on bacterial translocation and intestinal mucin content

Total parenteral nutrition (TPN) and elemental diet (ED) produce intestinal atrophy and increase bacterial translocation (BT) to mesenteric lymph nodes. The increased rate of BT may be due to alterations in mucosal structure, enzyme activity, or mucin content. Fiber improves intestinal structure and function in rats and may reduce the rate of BT. This study determined whether the addition of fiber to TPN or ED would maintain intestinal integrity and decrease BT to the mesenteric lymph nodes. Fifty-six adult male Sprague-Dawley rats underwent placement of jugular catheters and were assigned to one of five dietary groups: TPN, TPN+oral oat fiber (TPNF) 2 g/day, ED, ED+oral oat fiber (EDF) 2 g/day, or AIN-76 (control); they were pair-fed for 7 days. On day 8 the mesenteric lymph nodes were removed for bacterial cultures; and jejunal mucosal weight, DNA, protein, alkaline phosphatase, maltase, and jejunal mucin content were measured. Enteral nutrition significantly decreased BT when compared to parenteral feeding, and fiber significantly decreased BT when administered to rats receiving TPN or ED. Improvements in intestinal mucosal structure were not consistently associated with decreased rates of BT. Additionally, BT occurred independently of jejunal mucin concentration. Mechanisms other than maintenance of mucosal structure or mucin content are important in the mediation of fiber-induced decreased BT in rats receiving TPN or ED.

Butyrate increases colonocyte protein synthesis in ulcerative colitis

Butyrate promotes epithelial cell healing and improves symptoms when administered rectally in patients with distal ulcerative colitis (UC). It was hypothesized that butyrate may enhance healing in patients with UC by stimulating colonocyte proliferation and/or protein production. Mucosa from the descending colon was obtained from patients with UC (n = 5), Crohn's disease (n = 8), diverticulitis (n = 6), and cancer (normal tissue 10 cm from tumor; n = 10). Epithelial cells were isolated using dispase/collagenase and differential sedimentation and incubated for 4 hr at 37 degrees C with either Na butyrate (10 mM) or NaCl (10 mM). Protein synthesis was assessed by [14C]leucine incorporation and proliferation was determined with [3H]thymidine. Mean viability and purity were >88%. Spontaneous proliferation was significantly increased in UC when compared to diverticulitis and normal controls. Butyrate significantly increased protein synthesis in UC epithelial cells when compared to saline control. The therapeutic effects of butyrate in patients with UC may be due to its use by epithelial cells as a metabolic fuel to increase protein production and promote healing.

Validity of a perceived exertion scale for children: a pilot study

The purpose of this study was to examine the validity of a recently developed rating scale of perceived exertion, the Children's Effort Rating Table (CERT), for controlling exercise intensity in young children. 16 children (M age = 9.9 yr., SD = 1.2) performed three separate exercise tests on a mechanically braked cycle ergometer. Stage I (response protocol) consisted of a graded test with heart rate and perceived effort rating recorded in response to specified steady-state work outputs. Stage II (production protocol) examined subjects' ability to produce work outputs corresponding to levels 5, 7, and 9 of the CERT. This protocol was repeated on a further occasion (Stage III) to assess the reliability of the findings. Pearson correlations between ratings and heart rate (0.76) and ratings and work output (0.75) highlight the potential of the scale as a valid measure of exercise intensity. Also, the work rates produced by subjects in Stage II correlated 0.89 with those predicted from Stage I; however, analysis of variance showed that work output was significantly lower in Stage II than predicted. Finally, an intraclass correlation of 0.91 between Stages II and III suggests that the scale gave a reliable estimate of exercise intensity of children. The findings from this pilot study suggest that children's perceptions of effort might be used to guide intensity of exercise during structured activity classes.

Infectious drug resistance during an outbreak of samonellosis

The sudden acquisition of aminoglycoside resistance among Salmonella group C1 isolates causing summer diarrhoea raised the possibility oif plasmid-mediated reistance. The demonstration of circular DNA species in the resistant, but not in the sensitive salmonellae and the transfer by conjugation of antibiotic resistance to a sensitive strain of Escherichic coli, was consistent with plasmid-mediated resistance.