Young Rats Research Articles

Changes in Histological Features, Apoptosis and Necroptosis, and Inflammatory Status in the Livers and Kidneys of Young and Adult Rats

Changes in Histological Features, Apoptosis and Necroptosis, and Inflammatory Status in the Livers and Kidneys of Young and Adult Rats

High-molecular-weight Hyaluronan Administration Inhibits Bone Resorption and Promotes Bone Formation in Young-age Osteoporosis Rats.

Osteoporosis poses a significant global health concern, affecting both the elderly and young individuals, including athletes. Despite the development of numerous antiosteoporotic drugs, addressing the unique needs of young osteoporosis patients remains challenging. This study focuses on young rats subjected to ovariectomy (OVX) to explore the impact of high-molecular-weight hyaluronan (HA) on preventing OVX-induced osteoporosis. Twenty-four rats underwent OVX, while 12 underwent sham procedures (sham control group). Among the OVX rats, half received subcutaneous injections of HA (MW: 2700 kDa) at 10 mg/kg/week into their backs (OVX-HA group), whereas the other half received saline injections (0.5 ml/week) at the same site (OVX-saline group). OVX-HA group exhibited significantly higher percentages of osteoclast surface (Oc. S/BS), osteoblast surface per bone surface (Ob. S/BS), and bone volume/tissue volume (BV/TV) compared with OVX-saline group at the same age. The proportions of Ob. S/BS and BV/TV in the OVX-HA group closely resembled those of the sham control group, whereas the proportion of Oc. S/BS in the OVX-HA group was notably higher than that in the sham control group. In summary, the administration of HA significantly mitigated bone resorption and enhanced bone formation, suggesting a crucial role for HA in the treatment of young adult osteoporosis.

Metformin treatment prevents experimental metabolic syndrome-induced femoral bone marrow adiposity in rats.

Motivation for the study. Most research supports a negative association between metabolic syndrome and bone health, although there is an overall lack of consensus. Therefore, there is a need for research in this area to develop a better understanding. Main findings. Metabolic syndrome induced by a fructose-rich diet increases the adipogenic predisposition of bone marrow progenitor cells and femoral medullary adiposity in rats. Furthermore, this can be partially prevented by co-treatment with metformin. Implications. Experimental metabolic syndrome has negative effects on bone tissue and can be prevented by oral treatment with metformin as a normoglycemic drug. To determine the effect of metformin (MET) treatment on adipogenic predisposition of bone marrow progenitor cells (BMPC), bone marrow adiposity and bone biomechanical properties. 20 young adult male Wistar rats were sorted into four groups. Each of the groups received the following in drinking water: 100% water (C); 20% fructose (F); metformin 100 mg/kg wt/day (M); or fructose plus metformin (FM). After five weeks the animals were sacrificed. Both humeri were dissected to obtain BMPC, and both femurs were dissected to evaluate medullary adiposity (histomorphometry) and biomechanical properties (3-point bending). BMPC were cultured in vitro in adipogenic medium to evaluate RUNX2, PPAR-γ and RAGE expression by RT-PCR, lipase activity and triglyceride accumulation. The fructose-rich diet (group F) caused an increase in both triglycerides in vitro, and medullary adiposity in vivo; being partially or totally prevented by co-treatment with metformin (group FM). No differences were found in femoral biomechanical tests in vivo, nor in lipase activity and RUNX2/PPAR-γ ratio in vitro. DRF increased RAGE expression in BMPC, being prevented by co-treatment with MET. Metabolic syndrome induced by a fructose-rich diet increases femoral medullary adiposity and, in part, the adipogenic predisposition of BMPC. In turn, this can be totally or partially prevented by oral co-treatment with MET.

Transplantation of Mesenchymal Stem Cells Derived from Old Rats Improves Healing and Biomechanical Properties of Vaginal Tissue Following Surgical Incision in Aged Rats

Pelvic floor dysfunction encompasses a group of disorders that negatively affect the quality of women’s lives. These include pelvic organ prolapse (POP), urinary incontinence, and sexual dysfunction. The greatest risk factors for prolapse are increased parity and older age, with the largest group requiring surgical intervention being post-menopausal women over 65. Prolapse recurrence rates following surgery were reported to be as high as 30%. This may be attributed to ineffective healing in the elderly. Autologous stem cell transplantation during surgery may improve surgical results. In our previous studies, we showed that the transplantation of bone marrow-derived mesenchymal stem cells (MSCs) from young donor rats improved the healing of full-thickness vaginal surgical incision in the vaginal wall of old rats, demonstrated by both histological and functional analysis. In order to translate these results into the clinical reality of autologous MSC transplantation in elderly women, we sought to study whether stem cells derived from old donor animals would provide the same effect. In this study, we demonstrate that MSC transplantation attenuated the inflammatory response, increased angiogenesis, and exhibited a time-dependent impact on MMP9 localization. Most importantly, transplantation improved the restoration of the biomechanical properties of the vagina, resulting in stronger healed vaginal tissue. These results may pave the way for further translational studies focusing on the potential clinical autologous adjuvant transplantation of MSCs for POP repair for the improvement of surgical outcomes.

Effect of PASLoc Meals on the Zootechnical and Nutritional Parameters of Young Wistar Rats Suffering from Induced Moderate Acute Malnutrition

Aims: The objective of this study was to assess the efficacy of four food products manufactured from locally sourced ingredients in restoring Wistar rats afflicted with induced moderate acute malnutrition. Study Design: The rats used in this research were kept in separate metabolic cages with wire mesh flooring. Place and Duration of Study: The study was conducted at the vivarium of the Ecole Normale Supérieure in Abidjan, Côte d'Ivoire, over a period of 38 days. Methodology: 42 male rats, with an average age of 80 ±5 days and an average weight of 103.46 ±5.10 g, were randomly divided into six batches of seven rats each. Two control batches (MID and PCD) and four experimental batches (PASLoc1A, PASLoc1B, PASLoc2A, and PASLoc2B) were formed. The experiment consisted of an adaptation phase (5 days), a malnutrition induction phase (19 days), and a nutritional rehabilitation phase (14 days). Zootechnical and nutritional parameters were assessed at the end of the induction and nutritional rehabilitation phases. Results: Malnourished animals experienced a body weight loss rate of -22.36 ±6.47%, leading to a decline in all zootechnical parameters, including weight gain (1.39 ±0.28 g/day), body length (0.95 ±0.64 cm), and feed efficiency coefficient (-24.98 ±5.47). The nutritional rehabilitation phase resulted in the correction of the dysfunctions observed during induction, especially in terms of body weight gain, with rates comprised between 20.84 ±5.03% and 34.59 ±3.33%. The minimum weight gain for the rats fed PASLoc diet was 1.66 ±0.54 g/d for Pasloc1B, respectively. PASLoc diets have a significant impact on nutritional value, with a minimum biological value of 94.04 ±0.25%. Conclusion: The result of this study suggest that PASLoc2A and PASLoc2B possess a robust nutritional potential, and their consumption can effectively address issues of moderate acute malnutrition after weaning.

#1973 Factors conditioning cisplatin nephrotoxicity

Abstract Background and Aims Cisplatin is an antitumor drug whose use is significantly limited by its nephrotoxicity. Knowledge of the factors that determine or condition the pathogenesis of cisplatin-induced AKI will help to prevent or reduce nephrotoxic outcomes and improve safety during cisplatin treatment. Specifically, we aimed to study the impact of different factors (dehydration, hypertension, age and combinations of the former) on a pre-clinical model of AKI induced by a low dose of cisplatin. Method Young Wistar rats, young spontaneously hypertensive rats (SHR), and aged Wistar rats were divided into two experimental groups: Blood and 24-hour urine samples were collected, and renal function (plasma creatinine, plasma urea and urine protein levels) and dehydration parameters (weight loss, skin elasticity, haematocrit, plasma osmolality, urine flow and urine concentration) were monitored for each animal at three different timepoints: basal time (B), at the end of the dehydration period (D0), and 4 days after cisplatin administration (D4, day of maximum kidney damage). Results After 48 h water deprivation, dehydration was evinced by loss of weight, reduced skin elasticity, increases in plasma osmolality and haematocrit, urine flow reduction and highly concentrated urine (with elevated density and osmolality). A single, low dose of cisplatin induced minimal loss of renal function in young normohydrated Wistar rats that was not worsened by previous acute dehydration resulting from 48 h water deprivation. Interestingly, although renal function was fully preserved when cisplatin was administered to hypertensive rats under normohydrated conditions, a cisplatin-induced AKI (with significant increases in plasma creatinine, plasma urea and proteinuria) was developed in hypertensive rats when animals were previously forced to dehydration. Aged Wistar rats with free access to drinking water showed an important loss of renal function after cisplatin administration (as supported by increases in plasma creatinine and urea concentration). This effect was significantly amplified when aged animals were dehydrated at the time of cisplatin administration. Conclusion Our results suggest that age is an important factor conditioning cisplatin nephrotoxicity. Hypertension or dehydration in fully competent young rats are not in itself significant risk factors for AKI. However, when dehydration is combined with other comorbidity (age or hypertension) the risk of cisplatin-induced AKI is significantly increased. In perspective, our animal models reproducing conditions of increased vulnerability to cisplatin-induced AKI provide useful tools not only for the identification of predictive biomarkers pre-emptively detecting individuals at high risk, but also to assess preventive strategies potentially useful for vulnerable individuals. This study was supported by Project PI21/01226, funded by Instituto de Salud Carlos III (ISCIII) and co-funded by the European Union, and a grant from the Consejería de Educación, Junta de Castilla y León (IES160P20), Spain, co-funded by FEDER funds. Noelia Diaz-Morales is recipient of a Juan de la Cierva-Formación postdoctoral contract (FJC2020-043205-I) funded by MCIN/AEI/10.13039/501100011033 and European Union “NextGenerationEU/PRTR”.

#1413 High performance of ACLARA calculator of rat creatinine clearance for the chronic follow up of renal function

Abstract Background and Aims A neural network-based calculator to estimate rat creatinine clearance (ClCr), as a measurement of the glomerular filtration rate (GFR), from paired plasma creatinine concentration and body weight data has been recently developed [1]. Like human GFR estimating formulae, ACLARA averts long experimental procedures and reduces animal stress (by obviating the use of individual isolation in metabolic cages). This tool is publicly available for free use among the scientific community (https://idal.uv.es/aclara/). When collated with experimentally measured ClCr, ACLARA performs very well at comparing experiments in the whole, showing almost identical behavior of all experimental groups and conditions. Yet, ACLARA was trained mostly with data from short experiments involving acute changes in renal function, and from young rats. Fewer data from older animals was included in the development of the calculator. Thus, its field performance on longer evolution of renal function in adult rats has not yet been sufficiently validated. Accordingly, the aim of this work was to deepen in the assessment of ACLARA in the long-term evolution of rat ClCr. Method The evolution of measured (mClCr) versus ACLARA-estimated ClCr (eClCr) was compared at different time points over a period of 3 months in 20 male Wistar rats with chronic renal damage and 8 age-matched controls. In total, 176 data pairs of mClCr and eClCr were obtained. On the one hand, mClCr was determined by the usual experimental procedure [2]. Briefly, rats were allocated in metabolic cages to obtain 24-hour urine samples and urine flow (UF). Creatinine concentration was measured in the urine (Cru) and plasma (Crp) by a colorimetric assay based on the Jaffe's reaction, and mCrCl was then calculated as Cru x UF / Crp. On the other hand, eClCr was estimated with the ACLARA calculator from the corresponding Crp and body weight data. A Pearson's correlation study between mClCr and eClCr was carried out. Results Our results reveal that the information provided by the 90-day evolution of mClCr and eClCr is virtually identical at the whole experiment level (see Fig. 1). Furthermore, ACLARA seems to provide slightly more coherent and homogeneous information, as the considerable experimental error introduced by urine collection is averted in eClCr but present in mClCr. At the individual data level, ACLARA-estimated values are slightly lower than the corresponding measurements. The correlation between mClCr and eClCr was highly significant (r Pearson= 0.83; p < 0.0001). Conclusion ACLARA shows high performance at estimating CrCl in rats of growing age. Our results support its use also in chronic studies in which renal function must be evaluated. Funding This research was funded by grants from Instituto de Salud Carlos III (ISCIII), Ministerio de Ciencia e Innovación (PI21/01226 and PI21/00548 co-funded by the European Union; and RICORS2040, RD21/0005/0004, co-funded by the European Union – NextGenerationEU, Mecanismo para la Recuperación y la Resiliencia (MRR)) and from Consejería de Educación, Junta de Castilla y León (IES160P20), co-funded by FEDER funds. Joana Mercado-Hernández is recipient of a predoctoral fellowship from the Junta de Castilla y Leon (Spain) and the European Social Fund from the European Commission.

#1962 Development of triple-whammy induced pre-renal AKI is highly dependent on the hydration status

Abstract Background and Aims The concomitant use of diuretics, non-steroidal anti-inflammatory drugs (NSAIDs), and angiotensin system inhibitors is known as Triple Whammy (TW) and significantly increases the risk of acute kidney injury (AKI) due to a reduction in the glomerular filtration rate. Maintenance of hydration contributes to correct kidney perfusion, and effective renal haemodynamic regulation allows the kidneys to cope with everyday stressors and challenges, such as TW therapy. Interference with these adaptive mechanisms frequently occurs due to extrinsic (environmental conditions, lifestyle, drugs) or intrinsic (comorbidities, ageing) factors and may lead to dehydration, a negative body liquid balance with a high impact on health. Identifying modifiable risk factors that pose individuals at high risk of AKI following TW therapy is key for the search and prescription of preventive strategies in a personalized manner. The aim of this work was to study the role of hydration status on the renal effect of TW. Method Two-month-old male Wistar rats were divided into 3 experimental groups: Blood and 24-hour urine samples were collected at basal state (B), two days after water deprivation (D0), and two days after TW therapy (D2). Body weight was monitored during the experiment. Haematocrit was assessed from blood samples, and osmolality, concentration of creatinine (Jaffe reaction), and urea (Jung method) were determined in plasma. Urinary flow was recorded, and specific gravity, osmolality and creatinine concentration were measured in urine samples. Results Dehydration was observed after 48 h water deprivation, evidenced by a 12% weight loss and significant increases in haematocrit and plasma osmolality. As expected, during this dehydrated state rats excreted a very reduced volume of a highly concentrated urine with elevated levels of specific gravity and osmolality. No changes in renal function were observed after 48 h water deprivation, nor after TW treatment in fully hydrated rats. Administration of TW triggered significant alterations of the renal function, indicative of AKI, only in rats previously deprived of water for 48 h. These alterations were markedly increased when dehydration was partially sustained during the TW treatment by a 60% water restriction. Conclusion TW-induced AKI in young Wistar rats is facilitated when the hydration status worsens. In this sense, assessing hydration and implementing (re)hydration strategies may help to reduce or prevent TW-induced AKI. This study was supported by Project PI21/01226, funded by Instituto de Salud Carlos III (ISCIII) and co-funded by the European Union, and a grant from the Conserjería de Educación, Junta de Castilla y León (IES160P20), Spain, co-funded by FEDER funds. Noelia Diaz-Morales is recipient of a Juan de la Cierva-Formación postdoctoral contract (FJC2020-043205-I) funded by MCIN/AEI/10.13039/501100011033 and European Union “NextGenerationEU/PRTR”.

Understanding the Liver’s Role in the Clearance of Aβ40

The clearance of peripheral beta amyloid (Aβ) is a potential target for the treatment of Alzheimer’s disease (AD). The liver has been implicated in the elimination of Aβ from the peripheral circulation. Here, the single-pass uptake of Aβ40 in perfused livers from young and old rats (6 to 10 rats per group) was investigated with the multiple indicator dilution technique. Aβ40 had volumes of distribution between those of the vascular marker Evans Blue and the extracellular marker sucrose. The hepatic extraction of Aβ40 was negligible, explained in part by the small permeability surface area products consistent with a high endothelial barrier to liver uptake. There were no substantial effects of age on any of these results. In vitro experiments with isolated hepatocytes and liver sinusoidal endothelial cells showed only very small amounts of Aβ uptake consistent with low intrinsic clearance. These results indicate that the hepatic clearance of Aβ is capacity-limited, explained by the low-permeability surface area products and hepatocyte uptake. However, this does not preclude an effect of aging in longer-term in vivo studies where age-related changes in liver blood flow and protein binding influence liver clearance.

Beneficial effects of gentiopicrin inhibiting experimental epilepsy in young rats through the P2X7R/NLRP3/Caspase-1 inflammatory pathway.

Beneficial effects of gentiopicrin inhibiting experimental epilepsy in young rats through the P2X7R/NLRP3/Caspase-1 inflammatory pathway.

Age- and Sex-Dependent Effects of Moderate Exercise on Endogenous Pain Inhibition in Rats.

Diffuse noxious inhibitory controls (DNICs), or the pain inhibits pain phenomenon, refer to reduced pain-like behaviors that are displayed following a noxious conditioning stimulus located far from the test stimulus and have also been referred to as "descending control of nociception" when measured in awake-behaving animals. In this study, we sought to determine the impact of moderate long-term exercise on the DCN response and determine if this effect differed across age and sex. After a six-week exercise program consisting of 30 min of moderate treadmill running 5 days a week, the animals' forepaws were injected with capsaicin, and DCN responses were assessed using thermal withdrawal latencies of the hind paw. Young, exercised male and female rats displayed prolonged DCN responses relative to their sedentary counterparts, with the young exercised male group displaying longer-lasting DCN facilitation than the young exercised females. Exercise did not impact DCN responses in either male or female aged rats. Additionally, the serum testosterone levels did not change following exercise in any group. Importantly, the levels of corticosterone did not change following the exercise program, indicating that changes in the DCN response are not due to stress-induced analgesia. Our findings suggest that moderate exercise can facilitate the DCN response in young animals, even when this exercise does not change the levels of serum testosterone.

Serine racemase expression profile in the prefrontal cortex and hippocampal subregions during aging in male and female rats.

Aging is associated with a decrease in N-methyl-D-aspartate (NMDA) receptor function, which is critical for maintaining synaptic plasticity, learning, and memory. Activation of the NMDA receptor requires binding of the neurotransmitter glutamate and also the presence of co-agonist D-serine at the glycine site. The enzymatic conversion of L-serine to D-serine is facilitated by the enzyme serine racemase (SR). Subsequently, SR plays a pivotal role in regulating NMDA receptor activity, thereby impacting synaptic plasticity and memory processes in the central nervous system. As such, age-related changes in the expression of SR could contribute to decreased NMDA receptor function. However, age-associated changes in SR expression levels in the medial and lateral prefrontal cortex (mPFC, lPFC), and in the dorsal hippocampal subfields, CA1, CA3, and dentate gyrus (DG), have not been thoroughly elucidated. Therefore, the current studies were designed to determine the SR expression profile, including protein levels and mRNA, for these regions in aged and young male and female Fischer-344 rats. Our results demonstrate a significant reduction in SR expression levels in the mPFC and all hippocampal subfields of aged rats compared to young rats. No sex differences were observed in the expression of SR. These findings suggest that the decrease in SR levels may play a role in the age-associated reduction of NMDA receptor function in brain regions crucial for cognitive function and synaptic plasticity.

Morphological aspects of the heart of young rats subjected to high and medium intensity progressive resistance physical exercise protocols

The present study investigated the effects of medium and high intensity physical exercise on the morphology of the heart of young rats, after carrying out two physical exercise protocols on the stairs, medium and high intensity. We used 24 young male Wistar rats, 21 days old, divided into three groups: sedentary control group (CG, n=8), group trained with medium intensity physical exercises (GM, n=8) and group trained with physical exercises high intensity (GA, n=8). For 4 weeks, the animals in the GM and GA groups were subjected to a medium and high intensity physical exercise protocol. The physical exercise protocol was applied over a period of 4 weeks, 5 days a week. After training, the animals were euthanized and the heart was removed for weighing, analysis of macroscopic morphology (left ventricular thickness, weight, analysis of diameter and ventricular area); The 5um sections were then processed and stained with Hematoxylin and Eosin (HE) for subsequent histomorphometric analysis of the cardiomyocytes. The results did not demonstrate significant differences in the macroscopic parameters of the heart (weight, left ventricular thickness, ventricular area, total area, ventricular diameter). A significant difference was observed in the area of cardiomyocytes in the left ventricle of rats that exercised with high intensity. It is concluded that rats exercising at high intensity showed an increase in the area of cardiomyocytes compared to rats that exercised at medium intensity and sedentary ones. Thus, it is concluded that progressive resistance physical exercise on the vertical ladder when performed at high intensity promotes cardiomyocyte hypertrophy in young rats.

Skeletal effects of a prolonged oral metformin treatment in adult Wistar rats.

We previously showed that a 3-week oral Metformin (MET) treatment enhances the osteogenic potential of bone marrow stromal cells (BMSCs) and improves several bone histomorphometric parameters in Wistar rats with metabolic syndrome (MetS). However, the skeletal effects of extended periods of MET are still not completely elucidated. Hence, we investigated the impact of a prolonged (3-month) MET treatment on bone architecture, histomorphometric and biomechanics variables and osteogenic potential of BMSCs in Wistar rats with or without MetS. 36 young male Wistar rats were randomized into four groups (n=9) that received either 20% fructose (F); MET (MET); F plus MET treatments (FMET); or drinking water alone (Veh). Rats were euthanized, blood was collected, and bones were dissected and processed for pQCT analysis, static and dynamic histomorphometry and bone biomechanics. In addition, BMSCs were isolated to determine their osteogenic potential. MET affected trabecular and cortical bone, altering bone architecture and biomechanics. Furthermore, MET increased the pro-resorptive profile of BMSCs. In addition, fructose-induced MetS practically did not affect the skeleton's structural or mechanical variables. A 3-month treatment with MET (with or without MetS) affects bone architecture and biomechanical variables in Wistar rats.

Intake of oligoelements with cytarabine or etoposide alters dopamine levels and oxidative damage in rat brain

Research on the relationships between oligoelements (OE) and the development of cancer or its prevention is a field that is gaining increasing relevance. The aim was to evaluate OE and their interactions with oncology treatments (cytarabine or etoposide) to determine the effects of this combination on biogenic amines and oxidative stress biomarkers in the brain regions of young Wistar rats. Dopamine (DA), 5-Hydroxyindoleacetic acid (5-Hiaa), Glutathione (Gsh), Tiobarbituric acid reactive substances (TBARS) and Ca+2, Mg+2 ATPase enzyme activity were measured in brain regions tissues using spectrophometric and fluorometric methods previously validated. The combination of oligoelements and cytarabine increased dopamine in the striatum but decreased it in cerebellum/medulla-oblongata, whereas the combination of oligoelements and etoposide reduced lipid peroxidation. These results suggest that supplementation with oligoelements modifies the effects of cytarabine and etoposide by redox pathways, and may become promising therapeutic targets in patients with cancer.

The effect of magnesium sulfate on memory and anxiety-like behavior in a rat model: an investigation of its neuronal molecular mechanisms

ABSTRACT Background Anxiety is an adaptive response to potentially threatening conditions. Excessive and uncontrolled anxiety responses become nonadaptive and cause anxiety disorders. To better understand the anxiety-modulating effects of Mg sulfate, behavioral test batteries in the assessment of anxiety and learning and memory functions were performed simultaneously over a time period. This study also examines the effects of Mg sulfate compared to diazepam, an anxiolytic drug with amnestic effects on anxiety-like behavior, as well as possible oxidative-nitrosative stress and hippocampal changes in male rats exposed to predator odor. Methods Young adult Sprague-Dawley male rats were used. The rats were assessed using a comprehensive neurobehavioral test battery consisting of novel object recognition, open field, and successive alleys tasks. Anxiety was induced by cat odor, and diazepam and Mg were used as study drugs. Of the frontal cortex and hippocampus, the state of total oxidant and antioxidant and NO levels and histological examination of hippocampal CA1, CA2, CA3, and DG regions were performed. Results Diazepam- and Mg-treated rats showed an improvement in anxiety-related behavior to predator odors. Furthermore, Mg treatment alleviated some of the increasing oxidative stress in the frontal cortex and hippocampus of rats, while diazepam treatment in particular enhanced hippocampal oxidant and antioxidant activity. In addition, brain NO increase induced by animal odor exposure or diazepam treatment was ameliorated by Mg administration. Conclusions Overall, our work suggests that Mg had a partial anxiolytic effect on anxiety-like behaviors, although not as much as diazepam, and this effect varied depending on the dose. Mg treatment might counteract increased oxidative stress and elevated NO levels in the brain.

Xiaoer-Feire-Qing granules alleviate pyretic pulmonary syndrome induced by Streptococcus pneumoniae in young rats by affecting the lungs and intestines: An in vivo study based on network pharmacology

Ethnopharmacological relevanceThe traditional Chinese medicine (TCM) Xiaoer-Feire-Qing granules (XEFRQ) has been used to treat pyretic pulmonary syndrome (PPS) in children for many years. The function of the lungs is considered to be closely related to the large intestine in TCM. Purpose: We aimed to investigate the effects of XEFRQ on PPS and the underlying mechanisms via network pharmacology and animal experiments. MethodsThe TCMSP platform was used to identify the ingredients and potential targets of XEFRQ. The GeneCards, OMIM, and TTD databases were used to predict PPS-associated targets. Cytoscape 3.9.1 was employed to construct the protein–protein interaction network, and target prediction was performed by GO and KEGG analyses. For the animal experiment, a PPS model was constructed by three cycles of nasal drip of Streptococcus pneumoniae (STP; 0.5 mL/kg). The animals were randomly divided into the following four groups according to their weight (n = 10 rats per group): the blank group, the model group, the XEFRQ-L (16.3 g/kg) group, and the XEFRQ-H (56.6 g/kg) group. Rats in the blank group and the model group were given 0.5% CMC-Na by gavage. The general conditions of the rats were observed, and their food-intake, body weight, and body temperature were recorded for 14 days. After the intervention of 14 days, serum was collected to detect inflammatory cytokines (TNF-α, IL-1β, and PGE2) and neurotransmitters (5-HT, SP, and VIP). H&E staining was used to observe the pathological morphology of lung and colon tissue. AQP3 expression was detected by Western blot. In addition, the gut microbiota in cecal content samples were analyzed by 16S rDNA high-throughput sequencing. ResultsOur network analysis revealed that XEFRQ may alleviate PPS injury by affecting the levels of inflammatory cytokines and neurotransmitters and mitigating STP-induced PPS.In vivo validation experiments revealed that XEFRQ improved STP-induced PPS and reduced the expression of inflammatory cytokines and neurotransmitters. Notably, XEFRQ significantly decreased the protein expression levels of AQP3, which was associated with dry stool. Our gut microbiota analysis revealed that the relative abundance of [Eubacterium]_ruminantium_group, Colidextribacter, Romboutsia, and Oscillibacter was decreased, which means XEFRQ exerts therapeutic effects against PPS associated with these bacteria. ConclusionOur results demonstrate that XEFRQ alleviates PPS by affecting the lungs and intestines, further guiding its clinical application.

Hydroalcoholic Extract of Centella asiatica and Madecassic Acid Reverse Depressive-Like Behaviors, Inflammation and Oxidative Stress in Adult Rats Submitted to Stress in Early Life.

Major depressive disorder (MDD) is a severe disorder that causes enormous loss of quality of life, and among the factors underlying MDD is stress in maternal deprivation (MD). In addition, classic pharmacotherapy has presented severe adverse effects. Centella asiatica (C. asiatica) demonstrates a potential neuroprotective effect but has not yet been evaluated in MD models. This study aimed to evaluate the effect of C. asiatica extract and the active compound madecassic acid on possible depressive-like behavior, inflammation, and oxidative stress in the hippocampus and serum of young rats submitted to MD in the first days of life. Rats (after the first day of birth) were separated from the mother for 3h a day for 10days. When adults, these animals were divided into groups and submitted to treatment for 14days. After subjecting the animals to protocols of locomotor activity in the open field and behavioral despair in the forced swimming test, researchers then euthanized the animals. The hippocampus and serum were collected and analyzed for the inflammatory cytokines and oxidative markers. The C. asiatica extract and active compound reversed or reduced depressive-like behaviors, inflammation in the hippocampus, and oxidative stress in serum and hippocampus. These results suggest that C. asiatica and madecassic acid have potential antidepressant action, at least partially, through anti-inflammatory and antioxidant profiles.

Abstract PO1-14-09: Age-related remodeling of the systemic and breast microenvironment promotes a tumor-permissive locale for ER+ breast cancer in older women

Abstract Introduction: The peak incidence of ER+ breast cancer occurs in women around the age of 70. Compared to younger cohorts, we and others have shown that older patients with ER+ breast cancer have an enrichment of luminal disease and experience fewer recurrences, suggesting overtreatment. Differences in the biological phenotypes of tumors in older women remain poorly understood and treatment remains challenging as older patients are underrepresented in clinical trials. In this study, we hypothesized that aging alters both local and systemic hormones and inflammatory cytokines, creating a permissive environment for tumor formation and growth. To address this hypothesis, we employed a systems biology approach across multiple model systems and tissue samples. Methods: Our study included specimens from two cohorts of patients: (1) n = 90 women without breast cancer obtained from the Komen Tissue Bank, from whom we obtained matched plasma and non-cancerous breast tissue (n = 30 across age groups comprising of young donors (35-45yo), middle-aged donors (55-69yo), and older donors (≥ 70yo); and (2) n = 115 women with ER+ breast cancer (n = 25 young patients, n = 57 middle-aged patients, and n = 33 older patients) obtained from our institutional biobank, including matched plasma, tumor tissue, and tumor-adjacent tissue. From each of these sets of specimens, we measured estrogen disposition using mass spectrometry, a 22-plex panel of inflammatory markers, and transcriptomic changes using RNA-seq. Using scRNA-seq and multiplexed IHC, we further characterized the immune changes that occur with age. Lastly, we used an aged, carcinogen-induced ER+ tumor model in F344 rats (obtained from the NIA) to model tumor development and growth. Results: In the plasma, estradiol (E2) drastically decreased in post-menopausal women, leaving estrone (E1) as the predominant circulating estrogen in older women. However, the breast tumor microenvironment (TME) showed comparable levels of E1 and E2 across age groups. Multi-class concordance analysis of breast cancer tissue from RNA revealed significant increases in gene expression of the HSD17B7 enzyme and decreases in HSD17B2 enzyme across age, likely elevating local E1-to-E2 conversion and yielding high local E2 levels despite low circulating levels specifically in older women. In older patients with ER+ breast cancer, there was a significant increase in a chemokine network characterized by CCL2 and CXCL9 within the TME. scRNA-seq revealed enrichment of inflammatory M2-like macrophages in the aged TME. Immune dysfunction and decreased immunosurveillance in older patients manifested with widespread decreases in the presence of cytotoxic lymphocytes and decreased pathway enrichment of key immune pathways, such as JAK/STAT and IFNy signaling. mIHC analysis revealed decreases in CD4 and CD8 T cells and increases in M2-like macrophages in older patients in both tumor and stromal regions. Lastly, in the carcinogen-induced F344 rat model, aged rats (~ 24mo, human equivalent 60-70yo) had a shorter tumor-free interval than the younger rats (~ 4-6mo, human equivalent 20-30yo), likely due to increases in tumor-promoting inflammation and decreased immune surveillance. Ongoing mechanistic work is focused on macrophage-patient derived organoid co-cultures evaluating the functional relevance of E2, CCL2, and CXCL9 in shaping the aged TME. Conclusions: Our study of systemic and local breast hormones and cytokines in both healthy individuals and breast cancer patients showed that older women with ER+ breast cancer harbor different systemic and local environments compared to younger women. The aged TME is characterized by high E2, cytotoxic lymphocyte depletion, and immune dysfunction, creating a permissive environment for tumor formation. Future translational work should be aimed at chemo-preventative strategies to reduce the age-related chronic inflammation and immune dysfunction. Citation Format: Neil Carleton, Jian Zou, Sanghoon Lee, Dixcy Jaba Sheeba John Mary, Ruxuan Li, Jennifer Atkinson, Ziyu Huang, Hatice Osmanbeyoglu, Peter Lucas, Emilia Diego, Michael Lotze, George Tseng, Jagmohan Hooda, Ioannis Zervantonakis, Priscilla McAuliffe, Steffi Oesterreich, ADRIAN LEE. Age-related remodeling of the systemic and breast microenvironment promotes a tumor-permissive locale for ER+ breast cancer in older women [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-14-09.

Age-related blunting of serial sarcomerogenesis and mechanical adaptations following 4 weeks of maximal eccentric resistance training

During natural aging, muscles atrophy, which is partly accounted for by a loss of sarcomeres in series. Serial sarcomere number (SSN) is associated with aspects of muscle mechanical function including the force-length and force-velocity-power relationships; hence, the age-related loss of SSN contributes to declining performance. Training emphasizing muscle lengthening (eccentric) contractions increases SSN in young healthy rodents. However, the ability for eccentric training to increase SSN and improve mechanical function in old age is unknown. Older individuals often exhibit a blunted ability for training-induced hypertrophic adaptations. Therefore, the purpose of this study was to investigate the sarcomerogenic response to eccentric training in old rats. We hypothesized that old rats would experience a smaller magnitude of serial sarcomerogenesis than young rats, which would correspond to smaller beneficial adaptations in mechanical function as compared with young. Ten young (9 months) and 11 old (33 months) Fisher344/BN F1 rats completed 4 weeks of unilateral isokinetic eccentric plantar flexion training 3 days/week. Pre- and post-training, the plantar flexors were assessed for maximum tetanic torque (ankle angles of 70° and 90°), the torque-frequency relationship (stimulation frequencies of 1-100 Hz), the passive torque-angle relationship (ankle angles of 110-70°), and the torque-angular velocity-power relationship (isotonic loads of 10%-80% maximum). Following post-training testing, rats were sacrificed, and the soleus, lateral gastrocnemius (LG), and medial gastrocnemius (MG) were harvested for SSN assessment by measuring sarcomere lengths with laser diffraction, with the untrained leg used as a control. In the untrained leg/pre-training, old rats had lower SSN in the soleus (−9%), LG (−7%), and MG (−14%), lower maximum torque (−27 to −42%), power (−63%), and shortening velocity (−35%), and greater passive torque (+62 to +191%) than young. Young rats showed 6% increased SSN from the untrained to the trained soleus and MG. In contrast, old rats had no change in soleus SSN, only a 2% increase in MG SSN, and 4% SSN loss in the LG. Young rats saw modest improvements in isometric mechanical function, including a 13% increase in maximum torque at 90° and 4-11% increases in 10-60 Hz torque. Old rats, however, had reductions in maximum torque (−35%), shortening velocity (−46%), and power (−63%), and increased passive torque (+24 to +51%). Altogether, eccentric training induced serial sarcomerogenesis and improved mechanical function in young rats, while old rats exhibited dysfunctional remodelling that led to impaired muscle mechanical performance. Supported by NSERC. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.