Metaverse-powered basic sciences medical education: bridging the gaps for lower middle-income countries.

BACKGROUND: Traditional medical education often lacks contextual experience, hindering students' ability to effectively apply theoretical knowledge in real-world scenarios. The integration of the metaverse into medical education holds great enormous promise for addressing educational disparities, particularly in lower-middle-income countries (LMICs) accompanied by rapid technological advancements. This commentary paper aimed to address the potential of the metaverse in enhancing basic sciences education within the constraints faced by universities in LMICs. We also addressed learning design challenges by proposing fundamental design elements and a suggested conceptual framework for developing metaverse-based teaching methods.The goal is to assist educators and medical practitioners in comprehensivley understanding key factors in immersive teaching and learning. DISCUSSION: By immersing medical students in virtual scenarios mimicking real medical settings and patient interactions, the metaverse enables practice in clinical decision-making, interpersonal skills, and exposure to complex medical situations in a controlled environment. These simulations can be customized to reflect local healthcare challenges, preparing medical students to tackle specific community needs. Various disciplines, including anatomy, physiology, pharmacy, dentistry, and pathology, have begun leveraging the metaverse to offer immersive learning experiences, foster interdisciplinary collaborations, and facilitate authentic assessments. However, financial constraints pose a significant barrier to widespread adoption, particularly in resource-limited settings like LMICs. Addressing these challenges is crucial to realizing the full potential of metaverse technology in medical education. CONCLUSION: The metaverse offers a promising solution for enhancing medical education by providing immersive, context-rich learning experiences. This paper proposes a conceptual framework and fundamental design elements to aid faculty educators and medical practitioners in effectively incorporating metaverse technology into their teaching methods, thus improving educational outcomes in LMICs.

The metaverse offers a transformative pathway for basic sciences medical education in lower-middle-income countries (LMICs) through leveraging 3D human replicas, virtual dissection, laboratories, and simulations.A metaverse-based learning design may easily combine a variety of learning theories, instructional design models, and/or conceptual frameworks, including constructivism, the ADDIE model, universal design, and minimalism.Unlocking the full potential of VR and AR in basic sciences medical education for LMIC universities requires collaborative synergy among educators, policymakers, and technology developers, with a crucial emphasis on equitable access and resource allocation.Despite the immense promise held by metaverse-powered education, it is crucial to address issues surrounding technology accessibility, learning design challenges, and implementation barriers in LMICs as we provide guidance to educators and practitioners worldwide.

Noodles, the all-in-one system for on-target efficiency analysis of CRISPR guide RNAs.

The efficiency of clustered regularly interspaced short palindromic repeats (CRISPR) guide RNA (gRNA) targeting is critical for CRISPR associated protein 9 (Cas9)-dependent genomic modifications. Here, we developed Noodles, an all-in-one system to test the on-target activity of gRNAs easily and efficiently. Single-strand annealing repair mechanism of the split luciferase gene allows a positive selection of gRNAs efficiently driving nuclease activity of Cas9 from Streptococcus pyogenes (SpCas9). Our system can reliably validate in silico-predicted gRNAs before implementing them for in vitro and in vivo applications. Altogether, Noodles might be an asset for researchers and bioengineers, saving their time and efforts, while keeping the screening efficient and sensitive. •All-in-one dual-luciferase system to easily probe on-target activity of gRNAs based on homology-directed repair mechanism.•Easy-to-subclone spCas9-based 2-plasmid system comprising Renilla luciferase for transfection efficiency control.

From static web to metaverse: reinventing medical education in the post-pandemic era.

The World Wide Web and the advancement of computer technology in the 1960s and 1990s respectively set the ground for a substantial and simultaneous change in many facets of our life, including medicine, health care, and medical education. The traditional didactic approach has shifted towards more dynamic and interactive methods, leveraging technologies such as simulation tools, virtual reality, and online platforms. At the forefront is the remarkable evolution that has revolutionized how medical knowledge is accessed, disseminated, and integrated into pedagogical practices. The COVID-19 pandemic also led to rapid and large-scale adoption of e-learning and digital resources in medical education because of widespread lockdowns, social distancing measures, and the closure of medical schools and healthcare training programs. This review paper examines the evolution of medical education from the Flexnerian era to the modern digital age, closely examining the influence of the evolving WWW and its shift from Education 1.0 to Education 4.0. This evolution has been further accentuated by the transition from the static landscapes of Web 2D to the immersive realms of Web 3D, especially considering the growing notion of the metaverse. The application of the metaverse is an interconnected, virtual shared space that includes virtual reality (VR), augmented reality (AR), and mixed reality (MR) to create a fertile ground for simulation-based training, collaborative learning, and experiential skill acquisition for competency development. This review includes the multifaceted applications of the metaverse in medical education, outlining both its benefits and challenges. Through insightful case studies and examples, it highlights the innovative potential of the metaverse as a platform for immersive learning experiences. Moreover, the review addresses the role of emerging technologies in shaping the post-pandemic future of medical education, ultimately culminating in a series of recommendations tailored for medical institutions aiming to successfully capitalize on revolutionary changes.

The evolution of medical education from the Flexnerian era to the digital age provides valuable insight into how medical education has evolved and adapted to changing social needs, technological advancements, and educational paradigm shifts (Education 1.0, Education 2.0, Education 3.0, Education 4.0).The transition from static web to metaverse applications (Virtual Reality, Augmented Reality, and Mixed Reality) has brought about transformative changes in medical education merging physical and virtual reality, where users interact in real-time to have immersive and interactive learning experiences.Metaverse platforms enable external collaboration among medical learners, faculty educators, and other healthcare professionals from various parts of the world without the limitations of physical distance allowing them to exchange insights, discuss cases, and learn from diverse perspectives, including opportunities for collaborative research.Developing strategic implementation plans can help ensure that institutions and faculty educators can harness the benefits of emerging technologies while proactively addressing potential challenges, ensuring a well-rounded and effective learning experience for future medical professionals.

Relationship Between Genetic Variant Of OXTR (Rs53576) And MTNR1B (Rs1387153) And Symptoms Of Psychological Stress In Females With Gestational Diabetes Mellitus.

Objective: To assess the association of oxytocin receptor (rs53576) and melatonin hormone receptor 1B (rs1387153) gene single nucleotide polymorphisms with psychological symptoms in women with gestational diabetes mellitus. METHODS: The case-control study was conducted from May 1 to June 1, 2022, at the Department of Physiology, University of Karachi, in collaboration with the Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, and the Department of Obstetrics and Gynaecology, Jinnah Postgraduate Medical Centre, Karachi. Fifty gestational diabetic pregnant women and ninety healthy pregnant women were recruited. Sanger sequencing was performed to assess the genotypic frequency and polymorphic variation of all subjects. Perceived stress scale and diabetes-related distress scale were used to assess the stress levels. Data was analysed using SPSS 23. RESULTS: Of the 140 subjects, 90 (64.3%) were controls with mean age 24.96±4.35 years, and 50 (35.7%) were cases with mean age 28.78±5.25 (p<0.05). Mean body weight and mean gestational age were not significantly different between the groups (p>0.05). Melatonin hormone receptor 1B rs1387153 frequency was significantly different between the groups (p<0.05). Among the cases, a significant mean difference for regimen distress scores between AA and GG was observed for oxytocin receptor rs53576 (p=0.04). A significant mean difference in sum of PSS, diabetes-related stress, total diabetes- related stress and emotional distress was noted between CC and TT genotypes for melatonin hormone receptor 1B rs1387153 (p=0.001). Conclusion: MTNR1B rs1387153 genotypes were associated with perceived stress, diabetes-related stress, diabetic distress, and emotional burden, while OXTR rs53576 genotypes were associated with regimen distress in GDM women.

An in vivo and in silico evaluation of the hepatoprotective potential of Gynura procumbens: A promising agent for combating hepatotoxicity.

INTRODUCTION: The liver, the most important metabolic organ of the body, performs a wide variety of vital functions. Hepatic cell injury occurs by the activation of reactive oxygen species (ROS) that are generated by carbon tetrachloride (CCl4), xenobiotics, and other toxic substances through cytochrome P450-dependent steps resulting from the covalent bond formation with lipoproteins and nucleic acids. Observing the urgent state of hepatotoxic patients worldwide, different medicinal plants and their properties can be explored to combat such free radical damage to the liver. In vivo and in silico studies were designed and conducted to evaluate the antioxidant and hepatoprotective properties of Gynura procumbens in rats. MATERIALS AND METHODS: Gynura procumbens leaves were collected and extracted using 70% ethanol. The required chemicals CCl4, standard drug (silymarin), and blood serum analysis kits were stocked. The in vivo tests were performed in 140 healthy Wister albino rats of either sex under well-controlled parameters divided into 14 groups, strictly maintaining Institutional Animal Ethics Committee (IEAC) protocols. For the histopathology study, 10% buffered neutral formalin was used for organ preservation. Later the specimens were studied under a fluorescence microscope. In silico molecular docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies were performed, and the results were analyzed statistically. RESULTS AND DISCUSSION: Gynura procumbens partially negate the deleterious effect of carbon tetrachloride on normal weight gain in rats. The elevated level of serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), creatinine, LDH, total cholesterol (TC), low-density lipoprotein (LDL), triglycerides (TG), malondialdehyde (MDA), deoxyribonucleic acid (DNA) fragmentation ranges, gamma-glutamyl transferase (γ-GT) in CCl4 treated groups were decreased by both standard drug silymarin and G. procumbens leaf extract. We have found significant & highly significant changes statistically for different doses, here p<0.05 & p<0.01, respectively. On the other hand, G. procumbens and silymarin displayed Statistically significant (p<0.05) and high significant(p<0.01) increased levels of HDL, CAT SOD (here p<0.05 & p<0.01 for different doses) when the treatment groups were compared with the disease control group. Because the therapeutic activity imparted by plants and drugs accelerates the movement of the disturbed pathophysiological state toward the healthy state. In the molecular docking analysis, G. procumbens phytoconstituents performed poorly against transforming growth factor-beta 1 (TGF-ß1) compared to the control drug silymarin. In contrast, 26 phytoconstituents scored better than the control bezafibrate against peroxisome proliferator-activated receptor alpha (PPAR-α). The top scoring compounds for both macromolecules were observed to form stable complexes in the molecular dynamics simulations. Flavonoids and phenolic compounds performed better than other constituents in providing hepatoprotective activity. It can, thus, be inferred that the extract of G. procumbens showed good hepatoprotective properties in rats.

Cardiovascular disease risk stratification in the Pakistani population with and without metabolic syndrome: A single centre cross-sectional study.

Existing atherosclerotic cardiovascular disease (ASCVD) risk stratification algorithms are predominantly validated only for Western populations, and do not include parameters of metabolic syndrome (MetS) which may increase the relative risk for cardiovascular disease in South Asians. This study aimed to compare the differences between 10-year ASCVD risk by the Framingham Risk Score (FRS), Pooled Cohort Risk Equations (PCE), and QRISK3 calculators in a cohort of apparently healthy Pakistani adults and stratify the ASCVD risk by MetS status.A cross-sectional study recruited 179 subjects between the ages of 40 to 74 years from the outpatient department of the Aga Khan University Hospital between May 2019 to November 2022. Anthropometry, demography, and blood samples were collected from each subject after informed consent. The IDF criteria were used to categorize subjects as MetS positive (n = 122) and MetS negative (n = 57). The mean age of study participants was 51.07±7.38 years. The average 10-year ASCVD risk (%) for our cohort was calculated to be 15.34 ± 11.60, 9.66 ± 10.87, and 17.02 ± 14.66 using the FRS algorithm, PCE calculator, and QRISK3 calculator respectively. MetS status did not show a statistically significant association with the risk categories determined by any of the calculators, although numerical ASCVD risk estimates were significantly higher in the MetS positive group for all calculators.Although ASCVD risk is a useful way to reduce CVD burden by identifying asymptomatic individuals at the highest risk of developing ASCVD, a high proportion of individuals with MetS may still be identified as low risk by the current risk stratification algorithms in South Asians. Powered validation studies with larger sample sizes and longitudinal follow-up are needed in South Asians to modify existing calculators to make them more applicable to South Asian populations.

Exploring knowledge, attitudes and perceived myths towards foetal programming and factors affecting it among the public and health professionals in Pakistan: a needs assessment study.

OBJECTIVE: To explore knowledge, attitudes and practices of laypersons and health professionals towards foetal programming, and factors affecting it. METHODS: The mixed methods study was conducted at the Aga Khan University, Karachi, from January 20, 2021 to May 13, 2022, and comprised adults of either gender with access to social media platforms. Data was collected using an online survey questionnaire in English and Urdu developed to capture responses from a diverse pool of participants. The survey tool was circulated through WhatsApp, Facebook and Instagram. Two focus group discussions were conducted; one with laypersons in group A and the other with health and allied professionals in group B. Data was analysed using SPSS 21, while data related to focus group discussions was subjected to thematic analysis. RESULTS: Of the 358 participants, 173(48.3%) were in group A and 185(51.7%) were in group B. There were 34(18.4) subjects in group A and 27(15.6) in group B who had knowledge of foetal programming (p>0.05). Only factors related to father's health and dietary elements on the foetus were significantly different between the groups (p<0.05). Thematic analysis led to the formation of 3 overarching themes: parent's lifestyle, comorbidity and diet on foetal health; myths and cultural beliefs regarding foetal development; and the need for training / awareness for practitioners and community. CONCLUSIONS: Lack of knowledge and misinformation about foetal programming and development was common among health professionals and laypersons.

Chiral Lewis Base-Catalysed Asymmetric Syntheses of Benzo-fused ϵ-Lactones.

We herein report a two-step protocol for the asymmetric synthesis of novel chiral benzofused ϵ-lactones starting from O-protected hydroxymethyl-para-quinone methides and activated aryl esters. By using chiral isothiourea Lewis base catalysts a broad variety of differently substituted products could be obtained in yields of around 50 % over both steps with high levels of enantioselectivities, albeit low diastereoselectivities only.

Assessment during Covid-19: quality assurance of an online open book formative examination for undergraduate medical students.

BACKGROUND: The spread of COVID-19 pandemic in early 2020 compelled all the educational activities, including medical education to be shifted from face-to-face interaction to a virtual platform. This shift provided opportunities for exploring online assessment modalities. One such assessment method is an online open book exam which is a unique concept in medical education of Pakistan. Limited information is available in literature regarding open book exam for the basic science subjects. Hence, the objective of the study was to determine the quality of the open book exam administered as a pilot project to the first-year medical students. METHODS: It was a cross-sectional analytical study that included 99 students of first year MBBS. The students were administered an online unrestricted type of open book exam as a formative assessment. The exam consisted of 30 open-ended, short answer type questions. The scores of the exam were analyzed for psychometric quality. RESULTS: The mean score was 47.24 ± 15.30 SD %. The reliability of the exam was 0.79. The majority (66.6%) of items were found to be moderately difficult with their difficulty index ranging from 31 to 80%. The majority (86.6%) items were in the range of moderate to high discrimination. There were no questions with negative discrimination. CONCLUSIONS: The exam was found to be reliable and can be implemented with training of faculty and students. Online open book exam provides a good format for remote and formative assessment of students with minimum proctoring during times of constraints such as COVID-19 pandemic.

Update of pathophysiology and treatment options of seborrheic keratosis.

Seborrheic keratosis (SK) is a common, benign tumor that can occur on everybody site and can be conservatively managed. Cosmetic concerns, especially when a lesion involves the facial area, are the most common reason for excision. SK shows male gender preponderance and increasing age is an independent association with the condition. Even though more prevalent in the elderly, it has also been reported in younger age groups like adolescents and young adults. Precise pathogenesis is still obscure, but ultra-violet exposure represents a predisposing factor to SK by altering the biochemical concentration and expression of factors like Glutamine deaminases, endothelin, and stem cell factor. Moreover, the accumulation of amyloid-associated protein has also been postulated. Involvement of genitalia has been associated with human papillomavirus infection. Recently, Merkel cell polyomavirus nucleic acid was also detected in SK. Several oncogenic mutations involving FGFR-3 and FOXN1 have been identified. SKs are usually classified clinically and histologically. Dermatoscopy is a noninvasive alternative diagnostic technique widely used in differentiating SK from other benign and malignant tumors. In terms of treatment, topical agents, shave dissection, cryosurgery, electrodesiccation, laser application and curettage under local anesthesia are safe methods for eradication of SKs, mostly for cosmetic purposes. Though generally safe, the latter techniques may occasionally cause post-procedure depigmentation, scarring, and recurrence. Nanosecond-pulsed electric field technology is a promising new technique with fewer side-effects.

Availability and use of Automated External Defibrillators in Karachi, Pakistan: A cross-sectional study.

OBJECTIVE: To assess the availability and use of automated external defibrillators in various public and private establishments, and to assess knowledge, attitude and practices related to its use. METHODS: The telephone-based survey was conducted from March to August 2019 in Karachi after approval from the ethics review committee of the Aga Khan University, Karachi, and comprised public and private establishments identified through purposive sampling based on the standard requirements for automated external defibrillators installation. Data was collected using a predesigned questionnaire which was pilot-tested for reliability and validity. Data was analysed using SPSS 23. RESULTS: Of the 53 establishments, 32(60.4%) were private and 21(39.6%) were public. Overall, 9(17%) establishments were aware of automated external defibrillators and 1(1.9%) had an automated external defibrillator on the premises. Also, 25(47.2%) establishments believed that having an automated external defibrillator on the premises would be useful, while 25(47.2%) were undecided. Besides, 22(41.5%) establishments said they would consider installing an automated external defibrillator on the premises, while 24(45.3%) were undecided. Finally, 37(69.8%) establishments expressed a positive desire to get trained in giving basic life support. Conclusion: There was a need for a city-wide automated external defibrillator placement project for a reduction in mortality due to out-of-hospital cardiac arrest.

Midlife suicide: A systematic review and meta-analysis of socioeconomic, psychiatric and physical health risk factors.

Suicide is an increasing contributing cause of mortality in middle-aged adults; however, knowledge to guide prevention is limited. This first systematic review and meta-analysis of studies on midlife suicide has provided an overview of published research on this issue and synthesized the evidence on socioeconomic and physical and mental health factors associated with this mortality. Using PRISMA guidelines MEDLINE, Embase, PsycINFO, Scopus and Web of Science were searched for English-language publications that involved persons aged 35 to 65, used individual-level data, and reported prevalence of exposure(s) or relative risks. The search identified 62 studies on midlife suicides and associated factors (28 for SES, 22 for psychiatric disorder and 23 for physical illness). All studies were from high income countries, and most (80.6%) used data from population registries. Meta-analyses showed that the pooled prevalence of exposure in suicide decedents was 57.8% for psychiatric disorder, 56.3% for low income, 43.2% for unemployment, and 27.3% for physical illness. The associated pooled risk ratio was 11.68 (95% confidence intervals: 5.82-23.47) for psychiatric illness of any type, 12.59 (8.29-19.12) for mood disorders, 3.91 (2.72-5.59) for unemployment, 3.18 (2.72-3.72) for being separated or divorced, 2.64 (2.26-3.10) for cancer, 2.50 (0.96-6.38) for central nervous system illness, and 2.26 (1.16-4.41) for low income. In conclusion, midlife suicide is strongly associated with socioeconomic difficulties and physical and psychiatric illnesses that are common in this age population. Future investigations should consider the interactions between risk factors, the intersectionality of sex and ethnicity, and include data from low- and middle-income countries.

The Potential Utility of Lead Compound, E18, in Inhibiting Docking of SARS-CoV-2 by inhibiting ACE2-B0AT1 Complex.

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In Vivo Reductionist Approach Identifies miR-15a Protecting Mice From Obesity.

Obesity is a growing medical and social problem worldwide. The control of energy homeostasis in the brain is achieved by various regions including the arcuate hypothalamic nucleus (ARH). The latter comprises a number of neuronal populations including the first order metabolic neurons, appetite-stimulating agouti-related peptide (AgRP) neurons and appetite-suppressing proopiomelanocortin (POMC) neurons. Using an in vivo reductionist approach and POMCCre-dependent CRISPR-Cas9, we demonstrate that miR-15a-5p protects from obesity. Moreover, we have identified Bace1, a gene previously linked to energy metabolism imbalance, as a direct target of miR-15a-5p. This work warrants further investigations of non-coding RNA-mediated regulation of energy homeostasis and might contribute to the development of novel therapeutic approaches to treat metabolic diseases.

Obesity-associated metabolites in relation to type 2 diabetes risk: A prospective nested case-control study of the CARRS cohort.

AIMS: To determine whether obesity-associated metabolites are associated with type 2 diabetes (T2DM) risk among South Asians. MATERIALS AND METHODS: Serum-based nuclear magnetic resonance imaging metabolomics data were generated from two South Asian population-based prospective cohorts from Karachi, Pakistan: CARRS1 (N = 4017) and CARRS2 (N = 4802). Participants in both cohorts were followed up for 5 years and incident T2DM was ascertained. A nested case-control study approach was developed to select participants from CARRS1 (Ncases  = 197 and Ncontrols  = 195) and CARRS2 (Ncases  = 194 and Ncontrols  = 200), respectively. First, we investigated the association of 224 metabolites with general obesity based on body mass index and with central obesity based on waist-hip ratio, and then the top obesity-associated metabolites were studied in relation to incident T2DM. RESULTS: In a combined sample of the CARRS1 and CARRS2 cohorts, out of 224 metabolites, 12 were associated with general obesity and, of these, one was associated with incident T2DM. Fifteen out of 224 metabolites were associated with central obesity and, of these, 10 were associated with incident T2DM. The higher level of total cholesterol in high-density lipoprotein (HDL) was associated with reduced T2DM risk (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.53, 0.86; P = 1.2 × 10-3 ), while higher cholesterol esters in large very-low-density lipoprotein (VLDL) particles were associated with increased T2DM risk (OR 1.90, 95% CI 1.40, 2.58; P = 3.5 × 10-5 ). CONCLUSION: Total cholesterol in HDL and cholesterol esters in large VLDL particles may be an important biomarker in the identification of early development of obesity-associated T2DM risk among South Asian adults.

Ischemia modified albumin as a useful marker for diagnoses and management of diabetic retinopathy.

Objectives: Ischemia modified albumin (IMA) may aid in the early detection and management of diabetic retinopathy (DR). In this study, we examined the relationship between IMA and DR, and the effect of intravitreal anti-vascular endothelial growth factor (anti-VEGF) on IMA levels in patients with DR. Methods: This Quasi-experimental study was conducted from March-December 2018 at a Al-Ibrahim Eye Hospital in Karachi, Pakistan. Adult patients (age ≥ 18 year) with Type-2 diabetes mellitus (T2DM) presenting to the Diabetic Clinic were categorized as control (Group-A n=30: DM without DR) or case (Group-B n=59: DM with DR). Patients in Group-B received an intravitreal injection of bevacizumab (anti-VEGF). Visual acuity, retinoscopy and serum IMA were recorded at baseline and at a 30-day follow-up for both groups. Results: A significant drop in IMA levels was seen one month after bevacizumab (IMA baseline: 1590.82±121.22 and follow up: 940.8±91.26; p<0.01) in Group-B subjects. Visual acuity (VA) of patient in Group-B also improved one month after bevacizumab injection in both eyes (p<0.001). Whereas, the IMA levels in Group-A showed an upward rising trend after one month (baseline 448.80±22.4ng/ml and follow up 522.21±33.15 ng/ml; p>0.05) indicating disease progression. Conclusion: Ischemia modified albumin may be used as an effective and novel screening biomarker for assessing oxidative stress associated with DR, and to quantify response to and prognosis after intravitreal bevacizumab injection for DR.

Neuronal miR-29a protects from obesity in adult mice.

OBJECTIVE: Obesity, a growing threat to the modern society, represents an imbalance of metabolic queues that normally signal to the arcuate hypothalamic nucleus, a critical brain region sensing and regulating energy homeostasis. This is achieved by various neurons many of which developmentally originate from the proopiomelanocortin (POMC)-expressing lineage. Within the mature neurons originating from this lineage, we aimed to identify non-coding genes in control of metabolic function in the adulthood. METHODS: In this work, we used microRNA mimic delivery and POMCCre-dependent CRISPR-Cas9 knock-out strategies in young or aged mice. Importantly, we also used CRISPR guides directing suicide cleavage of Cas9 to limit the off-target effects. RESULTS: Here we found that mature neurons originating from the POMC lineage employ miR-29a to protect against insulin resistance obesity, hyperphagia, decreased energy expenditure and obesity. Moreover, we validated the miR-29 family as a prominent regulator of the PI3K-Akt-mTOR pathway. Within the latter, we identified a direct target of miR-29a-3p, Nras, which was up-regulated in those and only those mature POMCCreCas9 neurons that were effectively transduced by anti-miR-29 CRISPR-equipped construct. Moreover, POMCCre-dependent co-deletion of Nras in mature neurons attenuated miR-29 depletion-induced obesity. CONCLUSIONS: Thus, the first to our knowledge case of in situ Cre-dependent CRISPR-Cas9-mediated knock-out of microRNAs in a specific hypothalamic neuronal population helped us to decipher a critical metabolic circuit in adult mice. This work significantly extends our understanding about the involvement of neuronal microRNAs in homeostatic regulation.