Chinese family care partners of older adults in Canada have grit: A qualitative study

AIM

To explain the process taken by Chinese family care partners of older adults in the Greater Toronto Area, Canada, to access health and social services in their communities. The research question was: What mechanisms and structures impact the agency of Chinese family care partners of older adults, in the process of assisting them to access health and social services?

DESIGN

This qualitative study was informed by critical realism.

METHODS

Chinese family care partners of older adults in the Greater Toronto Area, Canada, were interviewed from August 2020 to June 2021. Transcripts underwent thematic analysis.

FINDINGS

Twenty-eight Chinese family care partners expressed a firm commitment to maintain caregiving conditions and to judiciously access health and social services. Their commitment was made up of three parts: (a) legislative and cultural norms of family, work, and society; (b) their perseverance to fill gaps with limited social and financial resources; (c) the quality of their relationship to, and illness trajectory of the older adults. The social structures created tension in how Chinese family care partners made decisions, negotiated resources, and ultimately monitored and coordinated timely access with older adults.

CONCLUSION

Participants' commitment and perseverance were conceptualized as "grit," central to their agency to conform to legislative and cultural norms. Moreover, findings support grit's power to motivate and sustain family caregiving, in order for older adults to age in place as long as possible with finite resources.

IMPLICATIONS FOR THE PROFESSION

This study highlights the importance of cultural awareness education for nurses, enabling continuity of care at a systems level and for a more resilient healthcare system.

IMPACT

Family care partners' grit may be crucial for nurses to harness when together, they face limited access to culturally appropriate health and social services in a system grounded in values of equity and inclusion, as in Canada.

REPORTING METHOD

When writing this manuscript, we adhered to relevant EQUATOR guidelines of the Consolidated Criteria for Reporting Qualitative Research (COREQ).

PATIENT OR PUBLIC INVOLVEMENT AND ENGAGEMENT

No patient or public involvement.

SUMOylation is enriched in the nuclear matrix and required for chromosome segregation

As an important posttranslational modification, SUMOylation plays critical roles in almost all biological processes. Although it has been well-documented that SUMOylated proteins are mainly localized in the nucleus and have roles in chromatin-related processes, we showed recently that the SUMOylation machinery is actually enriched in the nuclear matrix rather than chromatin. Here, we provide compelling biochemical, cellular imaging and proteomic evidence that SUMOylated proteins are highly enriched in the nuclear matrix. We demonstrated that inactivation of SUMOylation by inhibiting SUMO-activating E1 enzyme or KO of SUMO-conjugating E2 enzyme UBC9 have only mild effect on nuclear matrix composition, indicating that SUMOylation is neither required for nuclear matrix formation nor for targeting proteins to nuclear matrix. Further characterization of UBC9 KO cells revealed that loss of SUMOylation did not result in significant DNA damage, but led to mitotic arrest and chromosome missegregation. Altogether, our study demonstrates that SUMOylated proteins are selectively enriched in the nuclear matrix and suggests a role of nuclear matrix in mediating SUMOylation and its regulated biological processes.

Quantum gate algorithm for reference-guided DNA sequence alignment

Reference-guided DNA sequencing and alignment is an important process in computational molecular biology. The amount of DNA data grows very fast, and many new genomes are waiting to be sequenced while millions of private genomes need to be re-sequenced. Each human genome has 3.2B base pairs, and each one could be stored with 2 bits of information, so one human genome would take 6.4B bits or ∼760MB of storage (National Institute of General Medical Sciences, n.d.). Today's most powerful tensor processing units cannot handle the volume of DNA data necessitating a major leap in computing power. It is, therefore, important to investigate the usefulness of quantum computers in genomic data analysis, especially in DNA sequence alignment. Quantum computers are expected to be involved in DNA sequencing, initially as parts of classical systems, acting as quantum accelerators. The number of available qubits is increasing annually, and future quantum computers could conduct DNA sequencing, taking the place of classical computing systems. We present a novel quantum algorithm for reference-guided DNA sequence alignment modeled with gate-based quantum computing. The algorithm is scalable, can be integrated into existing classical DNA sequencing systems and is intentionally structured to limit computational errors. The quantum algorithm has been tested using the quantum processing units and simulators provided by IBM Quantum, and its correctness has been confirmed.

Quantum algorithm for de novo DNA sequence assembly based on quantum walks on graphs

De novo DNA sequence assembly is based on finding paths in overlap graphs, which is a NP-hard problem. We developed a quantum algorithm for de novo assembly based on quantum walks in graphs. The overlap graph is partitioned repeatedly to smaller graphs that form a hierarchical structure. We use quantum walks to find paths in low rank graphs and a quantum algorithm that finds Hamiltonian paths in high hierarchical rank. We tested the partitioning quantum algorithm, as well as the quantum algorithm that finds Hamiltonian paths in high hierarchical rank and confirmed its correct operation using Qiskit. We developed a custom simulation for quantum walks to search for paths in low rank graphs. The approach described in this paper may serve as a basis for the development of efficient quantum algorithms that solve the de novo DNA assembly problem.

Initial Experience with the Commercial Electron FLASH Research Extension

PURPOSE/OBJECTIVE(S)

The purpose of this study was to introduce a new commercial electron FLASH system that has the potential to become widely available for FLASH researchers globally. In this study, we first present the initial acceptance and commissioning tests for the FLASH system, and second, we highlight preliminary FLASH effect results from our cell studies.

MATERIALS/METHODS

A linear accelerator was converted into a commercial research platform with the FLASH Research Extension, enabling the generation of a powerful 16 MeV electron FLASH beam. The dosimetric and stability tests were conducted using various dosimeters (i.e., radiochromic film, optically stimulated luminescent dosimeters (OSLDs), and a plane-parallel ionization chamber). To evaluate the FLASH effect, normal and cancer cell lines were FLASH irradiated using different pulse repetition frequencies (PRF) of 18 pulses/s and 180 pulses/s.

RESULTS

The electron FLASH mode was able to generate over 1 Gy per pulse at the isocenter and a dose rate of up to 690 Gy/s near the accessory mount of the Linac gantry head. The charge collected by the plane-parallel ionization chamber at the highest PRF (i.e., 180 pulses/s) showed a linear relationship with the delivered number of pulses (i.e., 1 to 99 pulses) with a coefficient of determination (R2) of 0.9996. The absorbed dose measured using radiochromic film and OSLDs agreed within 3%, on average, and followed an inverse square law as the source-to-axis distance (SAD) varied for which the R2 values were 0.9972 and 0.9955 for radiochromic film and OSLDs, respectively. The profile of the FLASH beam was symmetrical but was not as flat as the conventional 16 MeV electron beam due to the use of a thinner custom scattering foil to reduce the degradation of the ultra-high dose rate. The depth-dose curve beyond the build-up region for the FLASH beam was similar to the conventional 16 MeV electron beam for which the range at 50% the maximum dose (R50) agreed within 0.5 mm. The FLASH beam output remained consistent over a 4-month period with a variation of 2.5%, on average. The FLASH sparing effect was observed in vitro for healthy human pancreatic cells. Furthermore, we observed that the highest PRF beam (180 pulses/s) was more effective at destroying pancreatic cancerous cells while minimizing damage to healthy cells compared to the lowest PRF beam (18 pulses/s).

CONCLUSION

The novel commercial FLASH Research Extension system was dosimetrically characterized for pre-clinical FLASH research, and preliminary in vitro results demonstrated the FLASH effect. Given the prevalence of linear accelerators, this new commercial system has the potential to greatly increase the access to FLASH research.

MYC promotes global transcription in part by controlling P-TEFb complex formation via DNA-binding independent inhibition of CDK9 SUMOylation

MYC is an oncogenic transcription factor with a novel role in enhancing global transcription when overexpressed. However, how MYC promotes global transcription remains controversial. Here, we used a series of MYC mutants to dissect the molecular basis for MYC-driven global transcription. We found that MYC mutants deficient in DNA binding or known transcriptional activation activities can still promote global transcription and enhance serine 2 phosphorylation (Ser2P) of the RNA polymerase (Pol) II C-terminal domain (CTD), a hallmark of active elongating RNA Pol II. Two distinct regions within MYC can promote global transcription and Ser2P of Pol II CTD. The ability of various MYC mutants to promote global transcription and Ser2P correlates with their ability to suppress CDK9 SUMOylation and enhance positive transcription elongation factor b (P-TEFb) complex formation. We showed that MYC suppresses CDK9 SUMOylation by inhibiting the interaction between CDK9 and SUMO enzymes including UBC9 and PIAS1. Furthermore, MYC's activity in enhancing global transcription positively contributes to its activity in promoting cell proliferation and transformation. Together, our study demonstrates that MYC promotes global transcription, at least in part, by promoting the formation of the active P-TEFb complex via a sequence-specific DNA-binding activity-independent manner.

HDAC1/2/3 are major histone desuccinylases critical for promoter desuccinylation

Lysine succinylation is one of the major post-translational modifications occurring on histones and is believed to have significant roles in regulating chromatin structure and function. Currently, histone desuccinylation is widely believed to be catalyzed by members of the SIRT family deacetylases. Here, we report that histone desuccinylation is in fact primarily catalyzed by the class I HDAC1/2/3. Inhibition or depletion of HDAC1/2/3 resulted in a marked increase of global histone succinylation, whereas ectopic expression of HDAC1/2/3 but not their deacetylase inactive mutants downregulated global histone succinylation. We demonstrated that the class I HDAC1/2/3 complexes have robust histone desuccinylase activity in vitro. Genomic landscape analysis revealed that histone succinylation is highly enriched at gene promoters and inhibition of HDAC activity results in marked elevation of promoter histone succinylation. Furthermore, our integrated analysis revealed that promoter histone succinylation positively correlates with gene transcriptional activity. Collectively, we demonstrate that the class I HDAC1/2/3 but not the SIRT family proteins are the major histone desuccinylases particularly important for promoter histone desuccinylation. Our study thus sheds new light on the role of histone succinylation in transcriptional regulation.

Loss of PHF8 induces a viral mimicry response by activating endogenous retrotransposons

Immunotherapy has become established as major treatment modality for multiple types of solid tumors, including colorectal cancer. Identifying novel immunotherapeutic targets to enhance anti-tumor immunity and sensitize current immune checkpoint blockade (ICB) in colorectal cancer is needed. Here we report the histone demethylase PHD finger protein 8 (PHF8, KDM7B), a Jumonji C domain-containing protein that erases repressive histone methyl marks, as an essential mediator of immune escape. Ablation the function of PHF8 abrogates tumor growth, activates anti-tumor immune memory, and augments sensitivity to ICB therapy in mouse models of colorectal cancer. Strikingly, tumor PHF8 deletion stimulates a viral mimicry response in colorectal cancer cells, where the depletion of key components of endogenous nucleic acid sensing diminishes PHF8 loss-meditated antiviral immune responses and anti-tumor effects in vivo. Mechanistically, PHF8 inhibition elicits H3K9me3-dependent retrotransposon activation by promoting proteasomal degradation of the H3K9 methyltransferase SETDB1 in a demethylase-independent manner. Moreover, PHF8 expression is anti-correlated with canonical immune signatures and antiviral immune responses in human colorectal adenocarcinoma. Overall, our study establishes PHF8 as an epigenetic checkpoint, and targeting PHF8 is a promising viral mimicry-inducing approach to enhance intrinsic anti-tumor immunity or to conquer immune resistance.

GSK3β-driven SOX2 overexpression is a targetable vulnerability in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest forms of human malignancy that currently lacks approved targeted therapeutics. Accumulating evidence suggests that SOX2 overexpression is a key driving factor for ESCC and various squamous cell carcinoma. Here, through screening a small-molecule kinase inhibitor library, we identified GSK3β as a kinase that is critically required for robust SOX2 expression in ESCC cells. GSK3β did not promote SOX2 transcriptionally but was required for SOX2 protein stability. We demonstrated that GSK3β interacts with and phosphorylates SOX2 at residue S251, which blocks SOX2 from ubiquitination and proteasome-dependent degradation instigated by ubiquitin E3 ligase CUL4ADET1-COP1. Pharmacological inhibition or knockdown of GSK3β by RNA interference selectively impaired SOX2-positive ESCC cell proliferation, cancer stemness, and tumor growth in mouse xenograft model, suggesting that GSK3β promotes ESCC tumorigenesis primarily by driving SOX2 overexpression. GSK3β was found to be frequently overexpressed in clinical esophageal tumors, and there was a positive correlation between GSK3β and SOX2 protein levels. Notably, we found that SOX2 enhanced GSK3β expression transcriptionally, suggesting the existence of a vicious cycle that drives a coordinated GSK3β and SOX2 overexpression in ESCC cells. Finally, we demonstrated in tumor xenograft model that GSK3β inhibitor AR-A014418 was effective in suppressing SOX2-positive ESCC tumor progression and inhibited tumor progression cooperatively with chemotherapeutic agent carboplatin. In conclusion, we uncovered a novel role for GSK3β in driving SOX2 overexpression and tumorigenesis and provided evidence that targeting GSK3β may hold promise for the treatment of recalcitrant ESCCs.

Control of SOX2 protein stability and tumorigenic activity by E3 ligase CHIP in esophageal cancer cells

SOX2 is highly expressed and controls tumor initiation and cancer stem cell function in various squamous cell carcinomas including esophageal squamous cancer. However, the molecular mechanism leading to SOX2 overexpression in cancer is incompletely understood. Here, we identified CHIP, a chaperone-associated ubiquitin E3 ligase, as a novel negative regulator of SOX2 protein stability and tumorigenic activity in esophageal squamous carcinoma cells. We showed that CHIP interacted with SOX2 primarily via chaperone HSP70, together they catalyzed SOX2 ubiquitination and degradation via proteasome. In contrast, HSP90 promoted SOX2 stability and inhibition of HSP90 activity induced SOX2 ubiquitination and degradation. Notably, unlike the case in normal esophageal tissues where CHIP was detected in both the cytoplasm and nucleus, CHIP in clinical esophageal tumor specimens was predominantly localized in the cytoplasm. Consistent with this observation, we observed increased expression of exportin-1/CRM-1 in clinical esophageal tumor specimens. We further demonstrated that CHIP catalyzed SOX2 ubiquitination and degradation primarily in the nuclear compartment. Taken together, our study has identified CHIP as a key suppressor of SOX2 protein stability and tumorigenic activity and revealed CHIP nuclear exclusion as a potential mechanism for aberrant SOX2 overexpression in esophageal cancer. Our study also suggests HSP90 inhibitors as potential therapeutic agents for SOX2-positive cancers.

Interdisciplinary management of an adult patient with significant tooth wear

Adult patients may present with compromised dentitions which require extensive oral rehabilitation. This case report shows the fulfilment of both functional and aesthetic treatment objectives for a patient with significant tooth wear through carefully planned interdisciplinary management. © 2022 Australian Dental Association.

1301 OUTCOMES FROM A PILOT PROJECT OFFERING FRAIL OLDER ADULTS LIVING WITH HIV A VIRTUAL MDT COMPREHENSIVE GERIATRIC ASSESSMENT

Introduction

Advancements in HIV treatment has resulted in an ageing population in people living with HIV (PLWH). Increasing prevalence of frailty in older PLWH has been demonstrated, giving rise to multi-morbidities, polypharmacy and consequently, complex medical and social needs. Approximately 5650 people are living with HIV across Greater Manchester. With increasing patient complexity, a pathway was developed to help provide holistic care and improve quality of life for older adults living with HIV.

Methods

A pilot involving multi-disciplinary professionals from the hospital frailty, HIV and community teams was established. Patients were screened using the Clinical Frailty Scale and patients with a CFS ≥ 4 were referred for completion of a comprehensive geriatric assessment (CGA). Patients would then be discussed at the Frailty MDT meeting, where action plans were devised.

Results

47 patients were assessed between October 2020 to December 2021, with 30 eligible for review in the frailty clinic. Commonly reported issues were mobility n=26 (86.6%), pain n=23 (76.6%), low mood n= 14 (46.6%), memory issues n=3 (43.3%) and falls n=12 (40%). Following MDT recommendations, 8 (26.6%) referrals were completed for social care, 1 (3%) referral for safeguarding and 9 (30%) referrals for active case management community teams for co-ordination of care in the community. Deprescribing recommendations were suggested for 16 (53.3%) patients and new medicine recommendations made for 24 (80%) patients.

Conclusion

A collaborative MDT approach to managing older PLWH can facilitate formulation of action plans to address patients physical, psychological and social needs.

Short-term risk prediction after major lower limb amputation: PERCEIVE study

BACKGROUND

The accuracy with which healthcare professionals (HCPs) and risk prediction tools predict outcomes after major lower limb amputation (MLLA) is uncertain. The aim of this study was to evaluate the accuracy of predicting short-term (30 days after MLLA) mortality, morbidity, and revisional surgery.

METHODS

The PERCEIVE (PrEdiction of Risk and Communication of outcomE following major lower limb amputation: a collaboratIVE) study was launched on 1 October 2020. It was an international multicentre study, including adults undergoing MLLA for complications of peripheral arterial disease and/or diabetes. Preoperative predictions of 30-day mortality, morbidity, and MLLA revision by surgeons and anaesthetists were recorded. Probabilities from relevant risk prediction tools were calculated. Evaluation of accuracy included measures of discrimination, calibration, and overall performance.

RESULTS

Some 537 patients were included. HCPs had acceptable discrimination in predicting mortality (931 predictions; C-statistic 0.758) and MLLA revision (565 predictions; C-statistic 0.756), but were poor at predicting morbidity (980 predictions; C-statistic 0.616). They overpredicted the risk of all outcomes. All except three risk prediction tools had worse discrimination than HCPs for predicting mortality (C-statistics 0.789, 0.774, and 0.773); two of these significantly overestimated the risk compared with HCPs. SORT version 2 (the only tool incorporating HCP predictions) demonstrated better calibration and overall performance (Brier score 0.082) than HCPs. Tools predicting morbidity and MLLA revision had poor discrimination (C-statistics 0.520 and 0.679).

CONCLUSION

Clinicians predicted mortality and MLLA revision well, but predicted morbidity poorly. They overestimated the risk of mortality, morbidity, and MLLA revision. Most short-term risk prediction tools had poorer discrimination or calibration than HCPs. The best method of predicting mortality was a statistical tool that incorporated HCP estimation.

Maternal secretin ameliorates obesity by promoting white adipose tissue browning in offspring

Our knowledge of the coordination of intergenerational inheritance and offspring metabolic reprogramming by gastrointestinal endocrine factors is largely unknown. Here, we showed that secretin (SCT), a brain-gut peptide, is downregulated by overnutrition in pregnant mice and women. More importantly, genetic loss of SCT in the maternal gut results in undesirable phenotypes developed in offspring including enhanced high-fat diet (HFD)-induced obesity and attenuated browning of inguinal white adipose tissue (iWAT). Mechanistically, loss of maternal SCT represses iWAT browning in offspring by a global change in genome methylation pattern through upregulation of DNMT1. SCT functions to facilitate ubiquitination and degradation of DNMT1 by activating AMPKα, which contributes to the observed alteration of DNMT1 in progeny. Lastly, we showed that SCT treatment during pregnancy can reduce the development of obesity and improve glucose tolerance and insulin resistance in offspring of HFD-fed females, suggesting that SCT may serve as a novel biomarker or a strategy for preventing metabolic diseases.

AB0979 Recommendations for weight management in osteoarthritis: a systematic review of clinical practice guidelines

Background

Weight loss interventions are often recommended to target overweight and obesity in the clinical practice guidelines (CPGs) for the management of osteoarthritis. This is despite evidence from meta-analyses of clinical trials that significant weight loss results in modest improvements in symptoms and minimal effects on disease progression1,2. There is evidence that weight gain is associated with increase in knee pain3,4. In countries such as USA, adults gain on average 0.5 to 1 kilogram per year from early to middle adulthood Preventing weight gain is easier to achieve and sustain than losing weight.

Objectives

Given that weight loss is accepted as fundamental to osteoarthritis management, we systematically reviewed the recommendations and approaches for weight management in all current osteoarthritis CPGs.

Methods

Nine databases were searched (1st January 2010 to 30th September 2021) to identify guidelines informing the non-pharmacological management of osteoarthritis. Three reviewers appraised guidelines according to the AGREE II instrument, and independently extracted data on their characteristics. One author extracted and summarised guideline recommendations on weight management. This systematic review is registered on PROSPERO (CRD42021274195).

Results

Fifteen CPGs from developed and developing countries were included. Weight loss was recommended for knee (12 of 13 guidelines) and hip (10 of 11 guidelines) but not hand osteoarthritis (0 of 4 guidelines). Combination approaches of diet and/or exercise were recommended for overweight or obese individuals (knee: 8 of 12; hip: 4 of 10), with 2 guidelines specifying ≥5% weight loss for knee and hip osteoarthritis. One of 15 guidelines specified strategies for weight loss and maintenance of lost weight. Two of 15 guidelines recommended controlling body weight for osteoarthritis, regardless of obesity status.

Conclusion

Most CPGs for knee and hip osteoarthritis include recommendations for weight loss in those with overweight or obesity as key to managing osteoarthritis, despite evidence of modest at best effect of weight loss on symptoms and no effect on joint structure1,2. Given obesity is a major risk factors for osteoarthritis, the prevention of weight gain may be more effective and practical in improving clinical outcomes for osteoarthritis, and hence should be considered as part of the key management in osteoarthritis.

References

[1]Chu IJH, Lim AYT, Ng CLW. Effects of meaningful weight loss beyond symptomatic relief in adults with knee osteoarthritis and obesity: a systematic review and meta-analysis. Obes Rev. 2018;19(11):1597-1607.

[2]Daugaard CL, Hangaard S, Bartels EM, Gudbergsen H, Christensen R, Bliddal H, et al. The effects of weight loss on imaging outcomes in osteoarthritis of the hip or knee in people who are overweight or obese: a systematic review. Osteoarthritis Cartilage. 2020;28(1):10-21.

[3]Tanamas SK, Wluka AE, Davies-Tuck M, Wang Y, Strauss BJ, Proietto J, et al. Association of weight gain with incident knee pain, stiffness, and functional difficulties: a longitudinal study. Arthritis Care Res (Hoboken). 2013;65(1):34-43.

[4]Teichtahl AJ, Wluka AE, Tanamas SK, Wang Y, Strauss BJ, Proietto J, et al. Weight change and change in tibial cartilage volume and symptoms in obese adults. Annals of the rheumatic diseases. 2015;74(6):1024-1029.

[5]Zheng Y, Manson JE, Yuan C, Liang MH, Grodstein F, Stampfer MJ, et al. Associations of Weight Gain From Early to Middle Adulthood With Major Health Outcomes Later in Life. JAMA. 2017;318(3):255-269.

Disclosure of Interests

None declared

Long term non-invasive endothelial function assessment in patients with paediatric inflammatory multisystem syndrome temporarily associated with Covid 19 (PIMS TS)

Funding Acknowledgements

Type of funding sources: None.

Introduction

Patients with PIMS-TS present with features of vasculitis (bright coronary arteries and diffuse coronary ectasia on transthoracic echocardiography) and prothrombotic features (e.g. elevated D Dimers) indicating involvement of the endothelial layer in the inflammatory process. Impairment in endothelial function may contribute to the acute but also to possible long-term consequences in patients with PIMS-TS. The aim of this pilot study is to assess non-invasively the endothelial (dys)function using reactive hyperemic peripheral arterial tonometry (RH-PAT) 6 months after the acute inflammatory phase. 

Methods

Ten patients with previous diagnosis of PIMS-TS were compared to  age-matched controls. The endothelial function was assessed using the EndoPAT device which provides the reactive hyperemic index (RHI) of endothelial function in a 15-min test. Cardiac function indices by means of LV fractional shortening (FS) was also assessed.

Results

There were no significant differences regarding age (11.2 ± 3.0 vs 13.6 ± 2.4, p = 0.063), height, weight and body surface area, (BSA: 1.49 ± 0.36 vs 1.52 ± 0.25, p = 0.856) in patients with previous diagnosis of PIMS-TS and controls respectively. The two groups also had similar LV systolic function assessed by FS (36.3 ± 9.1% vs 36.7 ± 7.1%, p = 0.922). The RHI in the PIMS TS group was similar to the control group (1.65 ± 0.43 vs 1.81 ± 0.60, p = 0.533 respectively).

Conclusions.  Patients with PIMS-TS who may present with features of vasculitis during the acute phase, do not show evidence of endothelial dysfunction during the long term follow-up, suggesting resolution. Further studies are required to accurately determine the endothelial (dys)function during the acute phase of the inflammatory syndrome and course.

Class I histone deacetylases (HDAC1-3) are histone lysine delactylases

Lysine L-lactylation [K(L-la)] is a newly discovered histone mark stimulated under conditions of high glycolysis, such as the Warburg effect. K(L-la) is associated with functions that are different from the widely studied histone acetylation. While K(L-la) can be introduced by the acetyltransferase p300, histone delactylases enzymes remained unknown. Here, we report the systematic evaluation of zinc- and nicotinamide adenine dinucleotide–dependent histone deacetylases (HDACs) for their ability to cleave ε-N-L-lactyllysine marks. Our screens identified HDAC1–3 and SIRT1–3 as delactylases in vitro. HDAC1–3 show robust activity toward not only K(L-la) but also K(D-la) and diverse short-chain acyl modifications. We further confirmed the de-L-lactylase activity of HDACs 1 and 3 in cells. Together, these data suggest that histone lactylation is installed and removed by regulatory enzymes as opposed to spontaneous chemical reactivity. Our results therefore represent an important step toward full characterization of this pathway’s regulatory elements.

An acetylation-enhanced interaction between transcription factor Sox2 and the steroid receptor coactivators facilitates Sox2 transcriptional activity and function

SRY-box 2 (Sox2) is a transcription factor with critical roles in maintaining embryonic stem (ES) cell and adult stem cell functions and in tumorigenesis. However, how Sox2 exerts its transcriptional function remains unclear. Here, we used an in vitro protein–protein interaction assay to discover transcriptional regulators for ES cell core transcription factors (Oct4, Sox2, Klf4, and c-Myc) and identified members of the steroid receptor coactivators (SRCs) as Sox2-specific interacting proteins. The SRC family coactivators have broad roles in transcriptional regulation, but it is unknown whether they also serve as Sox2 coactivators. We demonstrated that these proteins facilitate Sox2 transcriptional activity and act synergistically with p300. Furthermore, we uncovered an acetylation-enhanced interaction between Sox2 and SRC-2/3, but not SRC-1, demonstrating it is Sox2 acetylation that promotes the interaction. We identified putative Sox2 acetylation sites required for acetylation-enhanced interaction between Sox2 and SRC-3 and demonstrated that acetylation on these sites contributes to Sox2 transcriptional activity and recruitment of SRC-3. We showed that activation domains 1 and 2 of SRC-3 both display a preferential binding to acetylated Sox2. Finally, functional analyses in mouse ES cells demonstrated that knockdown of SRC-2/3 but not SRC-1 in mouse ES cells significantly downregulates the transcriptional activities of various Sox2 target genes and impairs ES cell stemness. Taken together, we identify specific SRC family proteins as novel Sox2 coactivators and uncover the role of Sox2 acetylation in promoting coactivator recruitment and Sox2 transcriptional function.

Does an empowerment-based self-care supportive intervention save cost for improving self-care and health service utilization among heart failure patients

Background

Heart failure (HF) evolves as a global pandemic and strains the over-stretched hospital service. Ineffective self-care remains the key factor to explain the avoidable hospital admission. Patient empowerment is as a theory-based strategy to optimize the patients' self-care changes for disease management [1]. Its cost-effectiveness to enhance self-care and health service utilization has yet to be determined.

Purpose

This was a double-blind randomized controlled trial to compare the effects and cost-effectiveness of a 12-week empowerment self-care program with a didactic education program on self-care maintenance and management as well as health service utilization among the community-dwelling HF patients.

Methods

A total of 236 HF patients were recruited from the specialist clinics of the Department of Cardiology in two regional hospitals. They were randomized to receive either the 12-week empowerment self-care program (Figure 1) or the 12-week didactic education. Outcome evaluation using the Self-care Heart Failure Index (SCHFI) at baseline, post-intervention (T1) and three months thereafter (T2), with record on the number of emergency room (ER) attendance and hospital admission. Cost effectiveness analyses were performed on total cost (medical, intervention and societal costs) incurred in both interventions as well as incremental cost-effectiveness ratios (ICER) expressed as incremental cost per 1) a reflected clinically meaningful improvement in self-care (i.e. a half standard deviation increase in SCHFI), 2) an ER attendance reduced, 3) a day of hospital stay reduced.

Results

As compared with the education group, the empowerment group reported significantly greater improvement in self-care management at T1 [B=13.77 (95% CI=6.07, 21.46), p<0.001] and T2 [B=10.98 (95% CI=3.21, 18.75), p=0.006]. For cost-effective analysis, The ICER (empowerment-education) was −USD220/0.5 SD increase in SCHFI, indicating the mean cost saved per patient for making a clinically significant improvement in self-care was USD 220. The cost-effectiveness acceptability curve showed patients were willing to pay at USD 207- 441 for a 80–90% chance of improved self-care, indicating that the empowerment approach was a cost saving strategy. Although the empowerment approach was associated with a lower risk of ER attendance [IRR=0.55, 95% CI=0.31–0.95)] and hospital admission [IRR=0.38 (95% CI=0.31–0.95)], it is not cost saving for reducing hospital service utilization.

Conclusions

The empowerment-based self-care program is a cost-saving strategy to produce a clinical significant change in HF-related self-care. Although it is associated with lower risk for hospital service utilization, its effect is not significant enough to be cost-saving. Future care model may explore the need to integrate dyadic science [2] and e-health [3] to strengthen the care continuity and effects of self-care intervention.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health and Medical Research Fund, Food and Health Bureau, Hong Kong Special Administrative Region Figure 1

565 Predictors of Single Versus Multi-Level Lumbar Spinal Fusion: A Retrospective Cohort Study

Aim

Degenerative spine disease (DSD) of the lumbar spine is a common disorder among the aging population in the world, with a substantial humanistic and economic burden. Although lumbar spinal fusion is currently the mainstay surgical management of DSD, surgery is also associated with adjacent segment disease due to the modification of spinal biomechanics. Therefore, it is important to identify potential risk factors of DSD in order to prevent progressive deterioration and provide early intervention before the surgical option is absolutely necessary.

Method

Adult patients who underwent posterior lumbar spinal fusion from 2006-2016 were identified via OPCS-4codes. Smoking status, weight, age of operation, gender, diagnosis of ischaemic heart disease (IHD) were obtained via TrakCare®. The degree of deprivation was extrapolated using the Scottish Index of Multiple Deprivation (SIMD) 2020 quintile score. Data were analysed using logistic regression.

Results

In total, 313 met inclusion criteria and had data available, of which 205 and 108 patients underwent single and multi-level lumbar fusion respectively. Within the study population, 66.8% (206) and 33.2% (104) were female and male. Adjusted for all outcome measures, age of operation achieved statistical significance (p = 0.040). There was a 1.021-fold increase in risk of multi-level spinal fusion with each additional year of age. Weight was approaching statistical significance (p = 0.068).

Conclusions

Lumbar spinal health declines over time, but some patients experience more progressive deterioration. While some components of the spine are irreparable, early prescription of regimented exercise programs may strengthen spinal musculature to maintain a healthy sagittal balance, particularly in older, overweight, female patients.

Acute kidney injury following hepatectomy and its impact on long-term survival for patients with hepatocellular carcinoma

Background

Acute kidney injury (AKI) is increasingly being recognized after hepatectomy. This study aimed to identify factors predicting its occurrence and its impact on long-term outcome among patients with hepatocellular carcinoma (HCC).

Methods

This was a retrospective analysis of the incidence of AKI, factors predicting its occurrence, and its impact on patients undergoing hepatectomy between September 2007 and December 2018. A subgroup analysis included patients with histologically proven HCC.

Results

The incidence of AKI was 9.2 per cent in 930 patients. AKI was associated with increased mortality, morbidity, posthepatectomy liver failure (PHLF), and a longer hospital stay. On multivariable analysis, study period December 2013 to December 2018, diabetes mellitus, mean intraoperative BP below 72.1 mmHg, operative blood loss exceeding 377ml, high Model for End-Stage Liver Disease (MELD) score, and PHLF were predictive factors for AKI. Among 560 patients with HCC, hypertension, BP below 76.9 mmHg, blood loss greater than 378ml, MELD score, and PHLF were predictive factors. The 1-, 3-, and 5-year overall survival rates were 74.1, 59.2, and 51.6 per cent respectively for patients with AKI, and 91.8, 77.9, and 67.3 per cent for those without AKI. Corresponding 1-, 3-, and 5-year disease-free survival rates were 56.9, 42.3, and 35.4 per cent respectively in the AKI group, and 71.7, 54.5, and 46.2 per cent in the no-AKI group. AKI was an independent predictor of survival in multivariable analysis.

Conclusion

AKI is associated with longer hospital stay, and higher morbidity and mortality rates. It is also associated with shorter long-term survival among patients with HCC. To avoid AKI, control of blood loss and maintaining a reasonable BP (72–77 mmHg) during hepatectomy is important.

Mutation-induced DNMT1 cleavage drives neurodegenerative disease

Specific mutations within the replication foci targeting sequence (RFTS) domain of human DNMT1 are causative of two types of adult-onset neurodegenerative diseases, HSAN1E and ADCA-DN, but the underlying mechanisms are largely unknown. We generated Dnmt1-M1 and Dnmt1-M2 knock-in mouse models that are equivalent to Y495C and D490E-P491Y mutation in patients with HSAN1E, respectively. We found that both mutant heterozygous mice are viable, have reduced DNMT1 proteins, and exhibit neurodegenerative phenotypes including impaired learning and memory. The homozygous mutants die around embryonic day 10.5 and are apparently devoid of DNMT1 proteins. We present the evidence that the mutant DNMT1 proteins are unstable, most likely because of cleavage within RFTS domain by an unidentified proteinase. Moreover, we provide evidence that the RFTS mutation–induced cleavage of DNMT1, but not mutation itself, is responsible for functional defect of mutant DNMT1. Our study shed light on the mechanism of DNMT1 RFTS mutation causing neurodegenerative diseases.