Co-production of the 'EPIC' multidimensional tool-kit to support neurodivergent children and young people at home and school: a feasibility and pilot study.

BACKGROUND: Interventions focused on cognitive function in neurodivergent children typically focus on single functions, e.g. working memory training. They are often focused on 'deficit' models and lack an emphasis on understanding areas of individual strengths and difficulties as a prerequisite to appropriate support. The multidimensional nature and phenotypic variability of cognitive profiles in these children indicate a need for a multicomponent-tailored intervention programme focused on understanding and supporting an individual child's cognitive functioning. AIMS: The 'EPIC' intervention (Edinburgh Psychoeducation Intervention for Children and Young People) is focused on improving cognition, learning and behaviour in neurodivergent children such as those with attention deficit hyperactivity disorder (ADHD) or who are autistic. Building on our previous co-production work, this study aimed to use a participatory methods approach to develop EPIC practices and materials in relation to our key principles which include psychoeducation, multicomponent, individualised approach, strengths and difficulties profiling and pairing of a child's individual strengths and difficulties with internal and external strategies. We also set out to assess the feasibility and acceptability of EPIC, and pilot this novel tool-kit intervention with neurodivergent children and their parents and teachers. METHODS: The intervention practices, materials and strategies of EPIC were co-produced with neurodivergent children, their parents, teachers and clinicians taking a strengths and difficulties approach. Identification of psychoeducation activities and strategy practices (e.g. mind-maps, chunking), testing of feasibility and collection of pilot data were conducted over a bi-weekly 8-week programme. Eleven neurodivergent children aged 7 to 12 completed the 16-session individualised programme. Acceptability and feasibility were ascertained via qualitative reports elicited within child and teacher interviews and child ratings of enjoyment. Pilot evaluation data was collected pre- and post-intervention participation, and across cognitive assessments (CANTAB, BRIEF), educational attainment (WIAT) and parent and teacher questionnaires measuring clinical symptoms and behaviour (Conners, AQ, SDQ, self-perception). Data was compared with a matched neurodivergent treatment-as-usual control group (N = 9). RESULTS: The co-produced EPIC intervention was both feasible to deliver and acceptable to children, parents and their teachers. Pilot data identified that the 8-week intervention improved cognition (short-term and working memory) and literacy (receptive vocabulary, oral word fluency, listening comprehension). Improvements in the intervention group were also found for parent-reported child behavioural difficulties and aggression, and teacher-reported scholastic competence. Effect sizes generated (Cohen's d) ranged from 0.65 to 2.83. Parents reported continuing to use EPIC strategies when interviewed over a year after participating in the programme. CONCLUSION: The current study met our objectives fully. 'EPIC' (Edinburgh Psychoeducation Intervention for Children and Young People) is feasible in home and school contexts and improves a range of aspects of cognition, learning and behaviour in neurodivergent children. Our findings show EPIC is suitable to be assessed within a full-scale trial.

Cognitive heterogeneity in Attention Deficit Hyperactivity Disorder: Implications for maths.

This study investigated whether cognitive function better predicted maths test performance than a clinical diagnosis of attention deficit hyperactivity disorder (ADHD). Forty-four drug naïve children (Mage = 101.34 months, SD = 19.39; 30% girls) were recruited from clinical ADHD referral waiting lists. Children underwent assessment of Executive Functions (EF), lower-level cognitive processes, and maths performance. Children were grouped using a categorical approach comprising (1) children with a clinical ADHD diagnosis and (2) children without a diagnosis (i.e., subthreshold ADHD). Secondly, hierarchical cluster analysis generated subgroups of children using EF scores. Children were compared on cognition, maths, and parent-rated symptoms of ADHD and co-occurring difficulties. Children's diagnostic outcomes did not differentiate maths performance. By contrast, EF subgroups generated meaningful cognitive clusters which differentiated maths test scores. This suggests that cognitive patterns of performance, rather than children's diagnostic outcomes, are more informative for identifying meaningful groups with variable maths performance which has implications for remedial support.

The Synergistic Benefit of Combination Strategies Targeting Tumor Cell Polyamine Homeostasis.

Mammalian polyamines, including putrescine, spermidine, and spermine, are positively charged amines that are essential for all living cells including neoplastic cells. An increasing understanding of polyamine metabolism, its molecular functions, and its role in cancer has led to the interest in targeting polyamine metabolism as an anticancer strategy, as the metabolism of polyamines is frequently dysregulated in neoplastic disease. In addition, due to compensatory mechanisms, combination therapies are clinically more promising, as agents can work synergistically to achieve an effect beyond that of each strategy as a single agent. In this article, the nature of polyamines, their association with carcinogenesis, and the potential use of targeting polyamine metabolism in treating and preventing cancer as well as combination therapies are described. The goal is to review the latest strategies for targeting polyamine metabolism, highlighting new avenues for exploiting aberrant polyamine homeostasis for anticancer therapy and the mechanisms behind them.

Polyamine Depletion by D, L-alpha-difluoromethylornithine Inhibits Ewing Sarcoma Metastasis by Inducing Ferroptosis.

Polyamine metabolism and signaling play important roles in multiple cancers but have not previously been studied in Ewing sarcoma. Here, we show that blocking polyamine synthesis with D, L-alpha-difluoromethylornithine (DFMO) causes a G1 cell cycle arrest, dose-dependent decreases in sarcosphere formation from Ewing sarcoma cell lines growing in non-adherent conditions and a decrease in clonogenic growth in soft agar. Further, we utilized our orthotopic implantation/amputation model of Ewing sarcoma metastasis to demonstrate that DFMO slowed primary tumor growth in addition to limiting metastasis. RNA sequencing demonstrated gene expression patterns consistent with induction of ferroptosis caused by polyamine depletion. Induction of ferroptosis was validated in vitro by demonstrating that ferrostatin-1, an inhibitor of ferroptosis, allows sphere formation even in the presence of DFMO. Collectively, these results reveal a novel mechanism by which DFMO prevents metastasis - induction of ferroptosis due to polyamine depletion. Our results provide preclinical justification to test the ability of DFMO to prevent metastatic recurrence in Ewing sarcoma patients at high risk for relapse.

Cognitive Profiles are Better Predictors of Literacy Attainment Than Diagnostic Outcomes in Children with High ADHD Symptoms.

We examined whether cognitive profiles or diagnostic outcomes are better predictors of literacy performance for children being considered for an ADHD diagnosis. Fifty-five drug naïve children (Mage = 103.13 months, SD = 18.65; 29.09% girls) were recruited from an ADHD clinical referral waiting list. Children underwent assessment of IQ, Executive Functions (EF) and literacy attainment. Hierarchical cluster analysis was used to generate subgroups of children using EF scores. Data were then grouped based on presence of a clinical ADHD diagnosis and the results compared. Grouping participants by profiles of cognitive test scores led to groups which also differed on literacy scores. However, categorising by whether children had received an ADHD diagnosis or not did not differentiate either cognitive tests scores or literacy scores. Cognitive performance, rather than children's diagnostic outcomes, is more informative for identifying groups who differ in their literacy attainment which has important implications for remedial support.

The Polyamine Analogue Ivospemin Increases Chemotherapeutic Efficacy in Murine Ovarian Cancer.

Polyamines are small polycationic alkylamines that are absolutely required for the continual growth and proliferation of cancer cells. The polyamine analogue ivospemin, also known as SBP-101, has shown efficacy in slowing pancreatic and ovarian tumor progression in vitro and in vivo and has demonstrated encouraging results in early pancreatic cancer clinical trials. We sought to determine if ivospemin was a viable treatment option for the under-served platinum-resistant ovarian cancer patient population by testing its efficacy in combination with commonly used chemotherapeutics. We treated four ovarian adenocarcinoma cell lines in vitro and found that each was sensitive to ivospemin regardless of cisplatin sensitivity. Next, we treated patients with ivospemin in combination with four commonly used chemotherapeutics and found that ivospemin increased the toxicity of each; however, only gemcitabine and topotecan combination treatments were more effective than ivospemin alone. Using the VDID8+ murine ovarian cancer model, we found that the addition of ivospemin to either topotecan or gemcitabine increased median survival over untreated animals alone, delayed tumor progression, and decreased the overall tumor burden. Our results indicate that the combination of ivospemin and chemotherapy is a worthwhile treatment option to further explore clinically in ovarian cancer.

Reduction of spermine synthase enhances autophagy to suppress Tau accumulation.

Precise polyamine metabolism regulation is vital for cells and organisms. Mutations in spermine synthase (SMS) cause Snyder-Robinson intellectual disability syndrome (SRS), characterized by significant spermidine accumulation and autophagy blockage in the nervous system. Emerging evidence connects polyamine metabolism with other autophagy-related diseases, such as Tauopathy, however, the functional intersection between polyamine metabolism and autophagy in the context of these diseases remains unclear. Here, we altered SMS expression level to investigate the regulation of autophagy by modulated polyamine metabolism in Tauopathy in Drosophila and human cellular models. Interestingly, while complete loss of Drosophila spermine synthase (dSms) impairs lysosomal function and blocks autophagic flux recapitulating SRS disease phenotype, partial loss of dSms enhanced autophagic flux, reduced Tau protein accumulation, and led to extended lifespan and improved climbing performance in Tauopathy flies. Measurement of polyamine levels detected a mild elevation of spermidine in flies with partial loss of dSms. Similarly, in human neuronal or glial cells, partial loss of SMS by siRNA-mediated knockdown upregulated autophagic flux and reduced Tau protein accumulation. Importantly, proteomics analysis of postmortem brain tissue from Alzheimer's disease (AD) patients showed a significant albeit modest elevation of SMS level. Taken together, our study uncovers a functional correlation between polyamine metabolism and autophagy in AD: SMS reduction upregulates autophagy, suppresses Tau accumulation, and ameliorates neurodegeneration and cell death. These findings provide a new potential therapeutic target for AD.

Polyamines: the pivotal amines in influencing the tumor microenvironment.

Cellular proliferation, function and survival is reliant upon maintaining appropriate intracellular polyamine levels. Due to increased metabolic needs, cancer cells elevate their polyamine pools through coordinated metabolism and uptake. High levels of polyamines have been linked to more immunosuppressive tumor microenvironments (TME) as polyamines support the growth and function of many immunosuppressive cell types such as MDSCs, macrophages and regulatory T-cells. As cancer cells and other pro-tumorigenic cell types are highly dependent on polyamines for survival, pharmacological modulation of polyamine metabolism is a promising cancer therapeutic strategy. This review covers the roles of polyamines in various cell types of the TME including both immune and stromal cells, as well as how competition for nutrients, namely polyamine precursors, influences the cellular landscape of the TME. It also details the use of polyamines as biomarkers and the ways in which polyamine depletion can increase the immunogenicity of the TME and reprogram tumors to become more responsive to immunotherapy.

Snyder-Robinson syndrome presenting with learning disability, epilepsy, and osteoporosis: a novel SMS gene variant.

Snyder-Robinson syndrome (SRS) is a rare X-linked recessive disorder characterized by a collection of clinical features including mild to severe intellectual disability, hypertonia, marfanoid habitus, facial asymmetry, osteoporosis, developmental delay and seizures. Whole genome sequencing (WGS) identified a mutation in the spermine synthase (SMS) gene (c.746 A>G, p.Tyr249Cys) in a male with kyphosis, seizures, and osteoporosis. His phenotype is unique in that he does not have intellectual disability (ID) but does have a mild learning disability. This case demonstrates a milder presentation of SRS and expands the phenotype beyond the reported literature.

Polyamine Catabolism and Its Role in Renal Injury and Fibrosis in Mice Subjected to Repeated Low-Dose Cisplatin Treatment.

Cisplatin, a chemotherapeutic agent, can cause nephrotoxic and ototoxic injuries. Using a mouse model of repeated low dose cisplatin (RLDC), we compared the kidneys of cisplatin- and vehicle-treated mice on days 3 (early injury phase) and 35 (late injury/recovery phase) after the final treatment. RNA-seq analyses revealed increases in the expression of markers of kidney injury (e.g., lipocalin 2 and kidney injury molecule 1) and fibrosis (e.g., collagen 1, fibronectin, and vimentin 1) in RLDC mice. In addition, we observed increased expression of polyamine catabolic enzymes (spermidine/spermine N1-acetyltransferase, Sat1, and spermine oxidase, Smox) and decreased expression of ornithine decarboxylase (Odc1), a rate-limiting enzyme in polyamine synthesis in mice subjected to RLDC. Upon confirmation of the RNA-seq results, we tested the hypothesis that enhanced polyamine catabolism contributes to the onset of renal injury and development of fibrosis. To test our hypothesis, we compared the severity of RLDC-induced renal injury and fibrosis in wildtype (WT), Sat1-KO, and Smox-KO mice. Our results suggest that the ablation of polyamine catabolic enzymes reduces the severity of renal injury and that modulation of the activity of these enzymes may protect against kidney damage and fibrosis caused by cisplatin treatment.

Effects of Spermine Synthase Deficiency in Mesenchymal Stromal Cells Are Rescued by Upstream Inhibition of Ornithine Decarboxylase.

Despite the well-known relevance of polyamines to many forms of life, little is known about how polyamines regulate osteogenesis and skeletal homeostasis. Here, we report a series of in vitro studies conducted with human-bone-marrow-derived pluripotent stromal cells (MSCs). First, we show that during osteogenic differentiation, mRNA levels of most polyamine-associated enzymes are relatively constant, except for the catabolic enzyme spermidine/spermine N1-acetyltransferase 1 (SAT1), which is strongly increased at both mRNA and protein levels. As a result, the intracellular spermidine to spermine ratio is significantly reduced during the early stages of osteoblastogenesis. Supplementation of cells with exogenous spermidine or spermine decreases matrix mineralization in a dose-dependent manner. Employing N-cyclohexyl-1,3-propanediamine (CDAP) to chemically inhibit spermine synthase (SMS), the enzyme catalyzing conversion of spermidine into spermine, also suppresses mineralization. Intriguingly, this reduced mineralization is rescued with DFMO, an inhibitor of the upstream polyamine enzyme ornithine decarboxylase (ODC1). Similarly, high concentrations of CDAP cause cytoplasmic vacuolization and alter mitochondrial function, which are also reversible with the addition of DFMO. Altogether, these studies suggest that excess polyamines, especially spermidine, negatively affect hydroxyapatite synthesis of primary MSCs, whereas inhibition of polyamine synthesis with DFMO rescues most, but not all of these defects. These findings are relevant for patients with Snyder-Robinson syndrome (SRS), as the presenting skeletal defects-associated with SMS deficiency-could potentially be ameliorated by treatment with DFMO.

Impaired polyamine metabolism causes behavioral and neuroanatomical defects in a mouse model of Snyder-Robinson syndrome.

Snyder-Robinson syndrome (SRS) is a rare X-linked recessive disorder caused by a mutation in the SMS gene, which encodes spermine synthase, and aberrant polyamine metabolism. SRS is characterized by intellectual disability, thin habitus, seizure, low muscle tone/hypotonia and osteoporosis. Progress towards understanding and treating SRS requires a model that recapitulates human gene variants and disease presentations. Here, we evaluated molecular and neurological presentations in the G56S mouse model, which carries a missense mutation in the Sms gene. The lack of SMS protein in the G56S mice resulted in increased spermidine/spermine ratio, failure to thrive, short stature and reduced bone density. They showed impaired learning capacity, increased anxiety, reduced mobility and heightened fear responses, accompanied by reduced total and regional brain volumes. Furthermore, impaired mitochondrial oxidative phosphorylation was evident in G56S cerebral cortex, G56S fibroblasts and Sms-null hippocampal cells, indicating that SMS may serve as a future therapeutic target. Collectively, our study establishes the suitability of the G56S mice as a preclinical model for SRS and provides a set of molecular and functional outcome measures that can be used to evaluate therapeutic interventions for SRS.

COVID-19 vaccine hesitancy among American Indian and Alaska native college students: the roles of discrimination, historical trauma, and healthcare system distrust.

For American Indians and Alaska Native (AIAN) and other communities of color, experiences with discrimination and historical trauma may contribute to healthcare system distrust and negatively affect health care decisions, including vaccination. A saturated path analysis was conducted to examine the direct and indirect associations of thoughts regarding historical losses (of culture, language, and traditional ways) and AIAN racial discrimination with historical loss associated distress, healthcare system distrust, and COVID-19 vaccine hesitancy among AIAN college students (N = 391). Historical loss thoughts and experiences with racial discrimination were strongly associated with each other, and both were uniquely associated with greater historical loss associated distress. In turn, historical loss associated distress was associated with greater healthcare system distrust, which in turn was associated with greater likelihood of being COVID-19 vaccine hesitant. While further research is needed, the findings suggest that to address health disparities for AIAN people it is necessary to consider how to best overcome healthcare system distrust and factors that contribute to it, including historical trauma and contemporary experiences with discrimination.

Illuminating the daily life experiences of adolescents with and without ADHD: protocol for an ecological momentary assessment study.

INTRODUCTION: Adolescents with attention-deficit/hyperactivity disorder (ADHD) are at elevated risk of a range of difficulties, among which emotion regulation, peer and co-occurring mental health problems are prominent challenges. To better support adolescents with ADHD, ecologically valid interventions that can be embedded in daily life to target the most proximal antecedents of these challenges are needed. Ecological momentary assessment (EMA) designs are ideally suited to meeting this need. METHODS AND ANALYSES: In the mental health in the moment ADHD study, we will use an EMA design to capture the daily life experiences of approximately 120 adolescents aged 11-14 years with a clinical diagnosis of ADHD and the same number of age-matched and gender-matched peers without a diagnosis of ADHD. We will combine this with comprehensive information gathered from online surveys. Analysing the data using techniques such as dynamic structural equation modelling, we will examine, among other research questions, the role of emotion regulation and peer problems in mediating the links between characteristics of ADHD and commonly co-occurring outcomes such as anxiety, depression and conduct problems. The results can help inform interventions to support improved peer functioning and emotion regulation for adolescents with ADHD. ETHICS AND DISSEMINATION: This study received a favourable ethical opinion through the National Health Service ethical review board and the University of Edinburgh PPLS Research Ethics panel. The results will be disseminated through journal publications, conferences and seminar presentations and to relevant stakeholders, such as those with ADHD, their families and clinicians.

Difluoromethylornithine rebalances aberrant polyamine ratios in Snyder-Robinson syndrome.

Snyder-Robinson syndrome (SRS) results from mutations in spermine synthase (SMS), which converts the polyamine spermidine into spermine. Affecting primarily males, common manifestations of SRS include intellectual disability, osteoporosis, hypotonia, and seizures. Symptom management is the only treatment. Reduced SMS activity causes spermidine accumulation while spermine levels are reduced. The resulting exaggerated spermidine:spermine ratio is a biochemical hallmark of SRS that tends to correlate with symptom severity. Our studies aim to pharmacologically manipulate polyamine metabolism to correct this imbalance as a therapeutic strategy for SRS. Here we report the repurposing of 2-difluoromethylornithine (DFMO), an FDA-approved inhibitor of polyamine biosynthesis, in rebalancing spermidine:spermine ratios in SRS patient cells. Mechanistic in vitro studies demonstrate that, while reducing spermidine biosynthesis, DFMO also stimulates the conversion of spermidine into spermine in hypomorphic SMS cells and induces uptake of exogenous spermine, altogether reducing the aberrant ratios. In a Drosophila SRS model characterized by reduced lifespan, DFMO improves longevity. As nearly all SRS patient mutations are hypomorphic, these studies form a strong foundation for translational studies with significant therapeutic potential.

Editorial to the Special Issue on "Polyamine Metabolism in Health and Disease: Potential for Polyamine-Targeted Therapies and Prevention".

To introduce this Special Issue, I refer the reader to the timely review by Zahedi and colleagues [...].

Polyamine transport inhibition and cisplatin synergistically enhance tumor control through oxidative stress in murine head and neck cancer models.

Background: Surgery and/or platinum-based chemoradiation remain standard of care for patients with head and neck squamous cell carcinoma (HNSCC). While these therapies are effective in a subset of patients, a substantial proportion experience recurrence or treatment resistance. As cisplatin mediates cytotoxicity through oxidative stress while polyamines play a role in redox regulation, we posited that combining cisplatin with polyamine transport inhibitor, AMXT-1501, would increase oxidative stress and tumor cell death in HNSCC cells. Methods: Cell proliferation was measured in syngeneic mouse HNSCC cell lines treated with cisplatin ± AMXT-1501. Synergy was determined by administering cisplatin and AMXT-1501 at a ratio of 1:10 to cancer cells in vitro . Cancer cells were transferred onto mouse flanks to test the efficacy of treatments in vivo . Reactive oxygen species (ROS) were measured. Cellular apoptosis was measured with flow cytometry using Annexin V/PI staining. High-performance liquid chromatography (HPLC) was used to quantify polyamines in cell lines. Cell viability and ROS were measured in the presence of exogenous cationic amino acids. Results: The combination of cisplatin and AMXT-1501 synergize in vitro on HNSCC cell lines. In vivo combination treatment resulted in tumor growth inhibition greater than either treatment individually. The combination treatment increased ROS production and induced apoptotic cell death. HPLC revealed the synergistic mechanism was independent of intracellular polyamine levels. Supplementation of cationic amino acids partially rescued cancer cell viability and reduced ROS. Conclusion: AMXT-1501 enhances the cytotoxic effects of cisplatin in vitro and in vivo in aggressive HNSCC cell lines through a polyamine-independent mechanism.

Deoxyhypusine synthase mutations alter the post-translational modification of eukaryotic initiation factor 5A resulting in impaired human and mouse neural homeostasis.

DHPS deficiency is a rare genetic disease caused by biallelic hypomorphic variants in the Deoxyhypusine synthase (DHPS) gene. The DHPS enzyme functions in mRNA translation by catalyzing the post-translational modification, and therefore activation, of eukaryotic initiation factor 5A (eIF5A). The observed clinical outcomes associated with human mutations in DHPS include developmental delay, intellectual disability, and seizures. Therefore, to increase our understanding of this rare disease, it is critical to determine the mechanisms by which mutations in DHPS alter neurodevelopment. In this study, we have generated patient-derived lymphoblast cell lines and demonstrated that human DHPS variants alter DHPS protein abundance and impair enzyme function. Moreover, we observe a shift in the abundance of the post-translationally modified forms of eIF5A; specifically, an increase in the nuclear localized acetylated form (eIF5AAcK47) and concomitant decrease in the cytoplasmic localized hypusinated form (eIF5AHYP). Generation and characterization of a mouse model with a genetic deletion of Dhps in the brain at birth shows that loss of hypusine biosynthesis impacts neuronal function due to impaired eIF5AHYP-dependent mRNA translation; this translation defect results in altered expression of proteins required for proper neuronal development and function. This study reveals new insight into the biological consequences and molecular impact of human DHPS deficiency and provides valuable information toward the goal of developing treatment strategies for this rare disease.

Lived experiences of depression in autistic children and adolescents: A qualitative study on child and parent perspectives.

BACKGROUND: Depression is highly prevalent in autistic children and adolescents. Despite this, little is known about the nature of the autistic child's subjective experience of depression and the impact of depression on their lives. METHODS: We therefore conducted a qualitative study using thematic analysis with 7 autistic children and adolescents and their parents to identify common themes and individual differences. All children had previously experienced at least one depressive episode. RESULTS: Six main themes were identified: (1) Autism related experiences; (2) Difficulties with peer relationships; (3) Co-occurring relationships between anxiety and depression; (4) Impactful pessimism and anhedonia; (5) Impactful difficulties with focus and concentration and (6) Feelings of irritability, including aggressive behaviours. Parent's accounts of their children's experience of depression mirrored the child's perspective. Novel findings included reports of depression related restriction of diet variety and masking of mental health difficulties. Children and parents linked being autistic and developing depression, referring to the difficulties of being autistic in a complex, neurotypical world. CONCLUSIONS: These results highlight key challenges that autistic children and their families experience, calling for increased awareness of the impact of depression on autistic young people.

Difluoromethylornithine rebalances aberrant polyamine ratios in Snyder-Robinson syndrome: mechanism of action and therapeutic potential.

Snyder-Robinson Syndrome (SRS) is caused by mutations in the spermine synthase (SMS) gene, the enzyme product of which converts the polyamine spermidine into spermine. Affecting primarily males, common manifestations of SRS include intellectual disability, osteoporosis, hypotonic musculature, and seizures, along with other more variable symptoms. Currently, medical management focuses on treating these symptoms without addressing the underlying molecular cause of the disease. Reduced SMS catalytic activity in cells of SRS patients causes the accumulation of spermidine, while spermine levels are reduced. The resulting exaggeration in spermidine-to-spermine ratio is a biochemical hallmark of SRS that tends to correlate with symptom severity in the patient. Our studies aim to pharmacologically manipulate polyamine metabolism to correct this polyamine imbalance and investigate the potential of this approach as a therapeutic strategy for affected individuals. Here we report the use of difluoromethylornithine (DFMO; eflornithine), an FDA-approved inhibitor of polyamine biosynthesis, in re-establishing normal spermidine-to-spermine ratios in SRS patient cells. Through mechanistic studies, we demonstrate that, while reducing spermidine biosynthesis, DFMO also stimulates the conversion of existing spermidine into spermine in cell lines with hypomorphic variants of SMS. Further, DFMO treatment induces a compensatory uptake of exogenous polyamines, including spermine and spermine mimetics, cooperatively reducing spermidine and increasing spermine levels. In a Drosophila SRS model characterized by reduced lifespan, adding DFMO to the feed extended lifespan. As nearly all known SRS patient mutations are hypomorphic, these studies form a foundation for future translational studies with significant therapeutic potential.