Prime editing: therapeutic advances and mechanistic insights.

We are often confronted with a simple question, "which gene editing technique is the best?"; the simple answer is "there isn't one". In 2021, a year after prime editing first made its mark, we evaluated the landscape of this potentially transformative advance in genome engineering towards getting treatments to the clinic [1]. Nearly 20% of the papers we cited were still in pre-print at the time which serves to indicate how early-stage the knowledge base was at that time.

An African perspective on genetically diverse human induced pluripotent stem cell lines.

Human induced pluripotent stem cell-derived models are a well-established preclinical tool, with the ability to retain the genetics of the individual from which they are derived. Here we comment on the global representation and accessibility of such cellular tools from African population groups.

The generation of human induced pluripotent stem cell lines from individuals of Black African ancestry in South Africa.

The lack of equitable representation of African diversity in scientific resources, such as genome-wide association studies and human induced pluripotent stem cell (hiPSC) repositories, has perpetuated inequalities in the advancement of health research. HiPSCs could be transformative in regenerative and precision medicine, therefore, the generation of diverse lines is critical in the establishment of African-relevant preclinical cellular models. HiPSC lines were derived from two healthy donors of Black African ancestry using Sendai virus reprogramming of dermal fibroblasts, and characterised to confirm stemness markers, trilineage differentiation, and genetic integrity.

Impact of donor genotype on pharmacokinetics of tacrolimus in South African paediatric liver transplant patients.

Background: In the paediatric liver transplant programme in Johannesburg, South Africa (SA), tacrolimus is the calcineurin inhibitor of choice, comprising an essential component of the immunosuppression regimen. It is characterised by a narrow therapeutic index and wide interpatient variability, necessitating therapeutic drug monitoring of whole-blood concentrations. Pharmacogenetic research, although not representative of SA population groups, suggests that single-nucleotide polymorphisms within the cytochrome P450 3A5 (CYP3A5) gene contribute to the variability in tacrolimus dosing requirements.

The translational gap for gene therapies in low- and middle-income countries.

Gene therapies are designed to address the root cause of disease. As scientific understanding of disease prevention, diagnosis, and treatment improves in tandem with technological innovation, gene therapies have the potential to become safe and effective treatment options for a wide range of genetic and nongenetic diseases. However, as the medical scope of gene therapies expands, consideration must be given to those who will benefit and what proactive steps must be taken to widen development and access potential, particularly in regions carrying a high disease burden.

Assessing potential drug-drug interactions between clofazimine and other frequently used agents to treat drug-resistant tuberculosis.

Clofazimine is included in drug regimens to treat rifampicin/drug-resistant tuberculosis (DR-TB), but there is little information about its interaction with other drugs in DR-TB regimens. We evaluated the pharmacokinetic interaction between clofazimine and isoniazid, linezolid, levofloxacin, and cycloserine, dosed as terizidone. Newly diagnosed adults with DR-TB at Klerksdorp/Tshepong Hospital, South Africa, were started on the then-standard treatment with clofazimine temporarily excluded for the initial 2 weeks.

The Case for Pre-Emptive Pharmacogenetic Screening in South Africa.

Lack of equitable representation of global genetic diversity has hampered the implementation of genomic medicine in under-represented populations, including those on the African continent. Data from the multi-national Pre-emptive Pharmacogenomic Testing for Preventing Adverse Drug Reactions (PREPARE) study suggest that genotype guidance for prescriptions reduced the incidence of clinically relevant adverse drug reactions (ADRs) by 30%. In this study, hospital dispensary trends from a tertiary South African (SA) hospital (Steve Biko Academic Hospital; SBAH) were compared with the drugs monitored in the PREPARE study.

The African Liver Tissue Biorepository Consortium: Capacitating Population-Appropriate Drug Metabolism, Pharmacokinetics, and Pharmacogenetics Research in Drug Discovery and Development.

Pharmaceutical companies subject all new molecular entities to a series of in vitro metabolic characterizations that guide the selection and/or design of compounds predicted to have favorable pharmacokinetic properties in humans. Current drug metabolism research is based on liver tissue predominantly obtained from people of European origin, with limited access to tissue from people of African origin. Given the interindividual and interpopulation genomic variability in genes encoding drug-metabolizing enzymes, efficacy and safety of some drugs are poorly predicted for African populations.

Hepatic Models in Precision Medicine: An African Perspective on Pharmacovigilance.

Pharmaceuticals are indispensable to healthcare as the burgeoning global population is challenged by diseases. The African continent harbors unparalleled genetic diversity, yet remains largely underrepresented in pharmaceutical research and development, which has serious implications for pharmaceuticals approved for use within the African population. Adverse drug reactions (ADRs) are often underpinned by unique variations in genes encoding the enzymes responsible for their uptake, metabolism, and clearance.

Microbiomics: The Next Pillar of Precision Medicine and Its Role in African Healthcare.

Limited access to technologies that support early monitoring of disease risk and a poor understanding of the geographically unique biological and environmental factors underlying disease, represent significant barriers to improved health outcomes and precision medicine efforts in low to middle income countries. These challenges are further compounded by the rich genetic diversity harboured within Southern Africa thus necessitating alternative strategies for the prediction of disease risk and clinical outcomes in regions where accessibility to personalized healthcare remains limited. The human microbiome refers to the community of microorganisms (bacteria, archaea, fungi and viruses) that co-inhabit the human body.

IPSC-derived models in Africa: An HIV perspective.

Cellular manipulation techniques, which create in vitro disease-in-a-dish models, provide opportunities for high-throughput screening in physiologically relevant conditions against the backdrop of a species accurate genetic background. However, with the advancement of technologies such as induced pluripotent stem cells (iPSCs) the list of desired characteristics has expanded to include the ability to generate infinite amounts of multiple cell types derived from a single genetic source without repeated and ethically contentious biopsies. This technology has been applied extensively to many diseases, both inherited and communicable, and increasingly within the context of HIV, is being leveraged to uncover mechanisms of pathogenesis, target latent reservoirs, and screen for optimal drug dosages which limit adverse drug reactions.

Molecular and electrophysiological features of spinocerebellar ataxia type seven in induced pluripotent stem cells.

Spinocerebellar ataxia type 7 (SCA7) is an inherited neurodegenerative disease caused by a polyglutamine repeat expansion in the ATXN7 gene. Patients with this disease suffer from a degeneration of their cerebellar Purkinje neurons and retinal photoreceptors that result in a progressive ataxia and loss of vision. As with many neurodegenerative diseases, studies of pathogenesis have been hindered by a lack of disease-relevant models.

A Multicenter Randomized Controlled Trial Comparing Safety, Efficacy, and Cost-effectiveness of the Surgisis Anal Fistula Plug Versus Surgeon's Preference for Transsphincteric Fistula-in-Ano: The FIAT Trial.

Objective: To undertake a randomized comparison of the Biodesign Surgisis anal fistula plug against surgeon's preference in treating cryptoglandular transsphincteric fistula-in-ano.

Summary Background Data: The efficacy of the Biodesign Surgisis anal fistula plug in healing anal fistulae is uncertain.

Methods: Participants were randomized to the fistula plug with surgeon's preference (advancement flap, cutting seton, fistulotomy, Ligation of the Intersphincteric Fistula Tract procedure).

Therapeutic genome engineering: Implications for South Africa.

South Africa encompasses extraordinary genetic diversity, frequently revealing unique mutations and variations associated with disease. Despite the advances of traditional gene therapy, our understanding of causative mutations in the South African population has, for the most part, contributed to diagnostic rather than therapeutic interventions. Recent developments in genome engineering and its ease of use have released a powerful tool with which to intervene in otherwise untreatable disease.

The impact of baculovirus challenge on immunity: The effect of dose and time after infection.

Understanding how hosts respond to pathogen attack is crucial to disease management. The response of a host can be particularly important if hosts have to defend against multiple pathogens which could either benefit from or be suppressed by prior pathogen exposure. Insect defence against viruses is less well understood than responses to other entomopathogens and much of the information available relates to in vitro studies and model systems.

Anal fistula plug versus surgeon's preference for surgery for trans-sphincteric anal fistula: the FIAT RCT.

Background: The aim of fistula surgery is to eradicate the disease while preserving anal sphincter function. The efficacy of the Surgisis anal fistula plug (Cook Medical, Bloomington, IN, USA) in the treatment of trans-sphincteric fistula-in-ano has been variably reported.

Objectives: To undertake a randomised comparison of the safety and efficacy of the Surgisis anal fistula plug in comparison with surgeon's preference for the treatment of trans-sphincteric anal fistulas.

Viral Apoptosis Evasion via the MAPK Pathway by Use of a Host Long Noncoding RNA.

An emerging realization of infectious disease is that pathogens can cause a high incidence of genetic instability within the host as a result of infection-induced DNA lesions. These often lead to classical hallmarks of cancer, one of which is the ability to evade apoptosis despite the presence of numerous genetic mutations that should be otherwise lethal. The Human Immunodeficiency Virus type 1 (HIV-1) is one such pathogen as it induces apoptosis in CD4+ T cells but is largely non-cytopathic in macrophages.

Regional Distribution of Nitric Oxide Synthase in Human Anorectal Tissue: A Pilot Study on the Potential Role for Nitric Oxide in Haemorrhoids.

Objective: To study the distribution of nitric oxide synthase (NOS) isoforms and protein levels in human haemorrhoids and rectal tissue.

Methods: Protein expression of NOS1, NOS2 and NOS3 was compared between haemorrhoids (n=14) and normal rectal submucosa (n=6) using Western blot analysis. The localisation of all NOS isoforms to specific structures was determined by immunohistochemistry.

The emerging molecular biology toolbox for the study of long noncoding RNA biology.

Long noncoding RNAs (lncRNAs) have been implicated in many biological processes. However, due to the unique nature of lncRNAs and the consequential difficulties associated with their characterization, there is a growing disparity between the rate at which lncRNAs are being discovered and the assignment of biological function to these transcripts. Here we present a molecular biology toolbox equipped to help dissect aspects of lncRNA biology and reveal functionality.

Endothelin-1 and its receptors on haemorrhoidal tissue: a potential site for therapeutic intervention.

Background And Purpose: Haemorrhoids is a common anorectal condition affecting millions worldwide. We have studied the effect of endothelin-1 (ET-1) and the role of endothelin ET and ET receptors in haemorrhoid tissue.

Experimental Approach: Protein expression of ET-1, ET and ET receptors were compared between haemorrhoids and normal rectal submucosa using Western blot analysis, with the localization of proteins determined by autoradiography and immunohistochemistry.